Methods of X-ray examination and X-ray diagnostics in dentistry. X-ray research methods
Information is presented on the basic and special methods of radiation examination used in the diagnosis of diseases of the maxillofacial region. The diagnostic capabilities of the methods are reviewed and indications for their use are determined. The capabilities of modern methods - computed tomography, ultrasound - are also covered.
I.I. Sergeeva, T.F. Tikhomirov, V.V. Rozhkovskaya, N.A. Savrasova, Belarusian State Medical University
Presented are the data on the basic and special methods of beam research used in diagnostics of diseases of maxillofacial area. Diagnostic opportunities of methods are considered and indications to their application are determined. Opportunities of modern methods - a computer tomography, ultrasonic research are covered also.
Key words: roentgenography, intraoral roentgenography, a linear, panoramic and computer tomography, ultrasonic diagnostics.
X-ray research methods are leading in the diagnosis of diseases of the maxillofacial region, due to their reliability and information content. X-ray diagnostic methods have found wide application in the practice of therapeutic dentistry (for identifying peri- and periodontal diseases); in orthopedic dentistry (to assess the condition of remaining teeth, periapical tissues, periodontal tissue, which determines the choice of orthopedic measures). X-ray methods are also in demand in maxillofacial surgery in the diagnosis of traumatic injuries, inflammatory diseases, cysts, tumors and other pathological conditions. The method and technique of x-ray examination of teeth and jaws has its own characteristics. The most commonly used in dental practice are:
· plain radiography;
· extraoral radiography of teeth and jaws;
· intraoral radiography.
SURVEY RADIOGRAMS can be performed in three projections - direct, lateral and anterior semi-axial - and allow you to obtain an image of the entire facial and cerebral skull. The direct projection can be performed with naso-frontal or naso-mental adherence to the cassette. Indications for images in the nasofrontal projection are: injuries and diseases of the brain and facial skull. This installation is also used for sialography and fistulography. Images in the nasomental projection are used: to study the bones of the middle and upper floors of the facial skull, paranasal sinuses. The condition of teeth on radiographs in direct projection is not analyzed.
Lateral photographs of the skull are taken as a mandatory addition to direct ones. However, it is quite difficult to study the condition of the bones of the facial skeleton from these photographs due to the summative effect of the right and left halves of the skull. Usually only gross, extensive bone changes are visible. Lateral photographs are often performed to examine the condition of the skull, its base, sella turcica, sphenoid and frontal sinuses, as well as to determine the location of foreign bodies.
Axial and anterior semi-axial photographs are performed if it is necessary to examine all structures of the base of the skull, bones of the midface, including the orbits, maxillary sinuses, and zygomatic bones.
EXTRAORAL (extraoral) photographs of the jaws are performed using both dental and other x-ray machines. X-ray film measuring 13x18 or 18x24 cm and corresponding cassettes with intensifying screens are used. Extraoral radiographs are performed to study the lower jaw, zygomatic bones, temporomandibular joint (TMJ), as well as for sialography and fistulography. Indications for such images may be inflammatory, tumor, traumatic injuries of the jaws, extensive cysts, periodontal lesions of the lower jaw when it is impossible to perform intraoral radiographs. To study the condition of the TMJ, special installations according to Schüller and Parma can be used. Pictures must be taken on both sides to compare the joints.
INTRAORAL radiography continues to be the basis of radiographic examination for most dental and periodontal diseases. Currently, there are four methods of intraoral radiography used to study the condition of teeth, para- and periodontal tissue:
1. Contact radiography according to the isometric rule.
2. Interproximal radiography.
3. Bitewing radiography (occlusal).
4. Radiography with increasing focal length by a parallel beam of rays (long-focus radiography).
For many years, in the X-ray diagnosis of dental and periodontal diseases, the technique of contact radiography according to the bisector rule or isometric projection, developed by Cieszinski (1907), was mainly used. The main objective of research using this technique is to obtain a clear image of the periapical tissues, therefore the beam is centered on the facial skin at a point corresponding to the projection of the apex of the root of the tooth being studied.
One of the objectives of this technique is to obtain an image of teeth identical to their true size. To reduce projection distortions in practical work, the isometric rule is used - the central beam is directed to the apex of the root of the tooth under study perpendicular to the bisector of the angle formed by the tooth axis and the plane of the film. Any other direction of the central ray leads to lengthening or shortening of the tooth image. It must be remembered that the permissible shortening of the tooth image should not exceed 0.2, and the elongation should not exceed 0.1 of its true dimensions.
However, exact adherence to the isometric rule, unfortunately, is impossible, because It is difficult for each patient to accurately determine the bisector of the angle formed by the axis of the tooth and the plane of the film. Therefore, they use angles of inclination of the tube, calculated empirically for certain groups of teeth. So, for images of molars, the angle of inclination of the X-ray tube to the horizontal plane is 25-30°, for premolars - 35°, canines - 45°, incisors - 55°. When photographing the same groups of teeth using the bite technique, the angle increases by 20°.
Equally important is compliance with the orthoradial rule, when using which the central beam at the time of the image is directed perpendicular to the tangent drawn to the dental arch of the upper or lower jaw in the area of the tooth being examined. If this rule is observed, the image of the tooth being examined does not overlap the image of neighboring teeth.
For contact photographs, the film size is 2x3 cm, 3x4 cm (the latter format is available in the form of standard packages), for bite-size photographs the film size is slightly larger - 5x6 cm, 6x8 cm. In the absence of factory packaging, use a special film for radiography of teeth RM. The corners of the film are cut off so that they do not injure the oral mucosa, and placed in a small envelope made of opaque paper, and then in wax paper. A bag of film is inserted into the oral cavity, and the patient presses it firmly against the hard palate and alveolar process of the area under study with the first finger of the opposite hand. Dental X-rays are usually performed with the patient sitting. The head is fixed on the headrest in the desired position.
When examining the teeth of the upper jaw, the patient's head is placed in a position in which the wings of the nose and the external auditory canal are in a plane parallel to the plane of the floor. The film is inserted into the oral cavity so that its edge is parallel to the occlusal plane and protrudes 0.5 cm from the edge of the teeth, while the tooth to be removed should be in the center of the film. In this position, the film is pressed with the second or first fingers of the patient’s hand to the mucous membrane of the hard palate. The apexes of the roots of the teeth of the upper jaw are usually projected onto the skin of the face along a line connecting the wing of the nose and the tragus of the ear: when examining the central incisors, the beam is directed to the tip of the nose, the lateral incisors to the wing of the nose, and the canines to the upper part of the nasolabial fold.
When radiography of the lower jaw, the patient's head is fixed on the headrest so that the line connecting the angle of the open mouth and the tragus of the ear is in a plane parallel to the floor. To do this, the patient tilts his head back a little. The projection of the apexes of the roots of the teeth of the lower jaw onto the skin of the face corresponds to a line running 1 cm above the lower edge of the jaw. The central beam is directed from bottom to top and medially to the apex of the tooth being examined, while maintaining the angles for the corresponding groups of teeth. When taking photographs using the bite-to-bite technique, the angle increases by 20°.
In some cases, it is necessary to deliberately change the projection of the beam to obtain a separate image of the roots of multi-rooted teeth or to clarify the relationship of the roots with pathological formations. In such cases, oblique intraoral projections are used: mesodistal (the central ray is directed obliquely from the front to the medial and back) and distomedial (the ray is directed from the back to the medial and forward).
Thus, contact radiography according to the isometric rule can be used to obtain images of teeth identical to their true sizes, to obtain a clear image of periapical tissues and to determine the spatial relationships of objects localized in the zone of roots and periapical tissues.
At the same time, the isometric imaging technique has a significant drawback; it does not allow assessing the condition of the marginal sections of the interalveolar ridges, since the latter are filmed with an oblique beam, which leads to a shortening of their image.
That is why it should be abandoned when diagnosing periodontal diseases.
Interproximal radiography is used to obtain a clear, undistorted image of the marginal parts of the alveolar processes of the jaws. The method allows you to objectively assess the degree of bone tissue resorption over time and is the best way to identify proximal and cervical caries.
Using special film holders, X-ray film is placed in the oral cavity parallel to the crowns of the teeth at some distance from them, which makes it possible to obtain an image of symmetrical areas of both jaws. To secure the film, you can use a piece of thick paper attached to the film wrapper and pressed between closed teeth. The central beam is directed perpendicular to the crowns and film. Radiographs simultaneously display the crowns of the teeth and the marginal sections of the alveolar processes of the upper and lower jaws. To study the entire bite, 3-4 photographs are taken.
Bitewing (occlusal) radiography technique. A simple and common technique for intraoral imaging. Bitewing photographs are performed when it is necessary to study large areas of the alveolar process - 4 or more teeth, when looking for impacted and dystopic teeth. Bitewing radiography is used when examining children, as well as in cases where intraoral contact photographs are not possible (in case of jaw damage, TMJ stiffness, increased gag reflex). The technique is indicated for obtaining an image of the floor of the mouth in case of suspected stones of the submandibular and sublingual salivary glands, as well as for studying the condition of the hard palate. Bite X-ray allows you to assess the condition of the outer and inner cortical plates of the jaws in case of cysts and neoplasms, and to identify the reaction of the periosteum.
When conducting occlusal radiography, the rules of bisector and tangent are observed. A film measuring 5x6 or 6x8 cm is inserted between the rows of teeth and is held in place by their closure.
When x-raying the upper jaw, the film is inserted as deep into the oral cavity as possible and clamped between the teeth. The patient sits in a dental chair, the midsagittal plane of the skull is perpendicular to the floor, and the line connecting the tragus of the ear and the wing of the nose should be parallel to the floor of the office. The central beam at an angle of +80° is directed to the root of the nose. The image shows a significant part of the alveolar process of the upper jaw and the floor of the nasal cavity.
When taking pictures of the lower jaw, the patient's head is tilted back so that the line from the corner of the mouth to the tragus of the ear is parallel to the floor of the office. The central beam is directed perpendicular to the film 3-4 cm posterior to the chin. The radiograph clearly shows the area of the floor of the mouth, the buccal and lingual cortical plates of the lower jaw, and the entire dentition in the axial projection.
Long focal radiography (parallel beam imaging) was introduced by Hilscher in 1960 and is increasingly used in many countries instead of contact intraoral radiography. Long-focus radiography allows you to avoid the disadvantages of contact photography and preserve its positive aspects: coverage of a significant part of the alveolar process vertically, a complete image of the tooth, a clear structure of the bone tissue. One of the important advantages of shooting with parallel beams is that the image of the marginal parts of the alveolar processes is not distorted, and therefore the technique can be recommended for wide use in periodontology.
The X-ray film is placed in the mouth parallel to the long axis of the tooth, for which special film holders or hemostatic clamps are used (cotton or gauze rolls can also be used).
For long-focus radiography, devices with a more powerful X-ray tube and a long localizer tube (36-40 cm minimum) are used. The object-film distance ranges from 1.5 to 3 cm, and the central beam hits the film perpendicularly or at an angle of no more than 15°. The image and the object are almost equal in size to each other.
When performing any methods of radiography of the dentofacial apparatus, in order to eliminate dynamic blurriness of the image obtained in the image, an indispensable and most important condition is complete immobility of the patient. For this purpose, it is necessary to ensure the stabilization of the patient using a comfortable chair with a fixing headrest and armrests. Usually the picture is taken 3-4 seconds after the command: “do not breathe.”
In recent years, a new branch of radiation diagnostics has emerged - DIGITAL RADIOGRAPHY, which is not so much an independent method of X-ray diagnostics as a progressive modification of the transformation of the energy of the X-ray beam. If in classical radiography the radiation receiver was x-ray film, then in digital radiography these are highly sensitive sensors that directly form a digital image (direct digital radiography), or electro-optical converters that create an analog video signal, which is later converted into a digital signal using an analog-to-digital converter signal. The digital code is then processed by a computer and transformed again into a visible (analog) image on the monitor screen. Computer information processing allows you to improve image quality by manipulating contrast, brightness, clarity, size, eliminating technical errors, and highlighting areas of interest. The advantages of digital radiography are also a significant reduction in radiation exposure (tens of times), economic costs (since expensive X-ray film is not used), and the possibility of archiving information. The principle of digital information processing is also used in computer, magnetic resonance imaging and in some modes of ultrasound diagnostics. Currently, digital radiography has become the leading method of radiological diagnostics.
Similar systems are widely used in dental practice: these are X-ray machines from Siemens, Finnish-made Digora devices, etc. With their help, you can obtain intraoral radiographs and panoramic tomograms.
X-ray protection
The widespread use of X-ray examinations in dentistry requires careful monitoring of doses, given that a significant number of patients are children and young people. The biological effect of small doses of ionizing radiation associated with X-ray examinations does not cause immediate radiation reactions, but can cause so-called stochastic long-term consequences in the form of induced malignant diseases, genetic consequences, shortened life span, etc.
Radiation exposure to patients is assessed using an effective equivalent dose (EDD), which is measured in microsieverts (µSv) and is determined by measuring the exposure of vital organs that are most sensitive to the effects of ionizing radiation (lens of the eye, brain, thyroid gland, etc.).
As can be seen from the table above, the dose loads are especially high when examining the entire dentition, performed on a device of type 5D-1 and 5D-2m without additional protection. Examination using an orthopantomograph sharply reduces the radiation dose to the patient. Additional shielding, including the thyroid gland, makes the study even safer.
Thus. Radiation safety of patients can be ensured in the following ways:
· the dentist’s knowledge of optimal algorithms for examining patients with various types of pathology,
· the dentist’s knowledge of radiation load values using various methods of x-ray examination,
shielding the patient’s vital and highly sensitive organs,
· diaphragm of the irradiation field,
· reducing research time to a minimum, which is ensured by the quality of the film and intensifying screens.
Special research methods
PANORAMIC RADIOGRAPHY (Fig. 1) is a technique that allows you to obtain a detailed (slightly enlarged) image of one of the jaws on one film.
Fig.1. Panoramic radiograph of the upper jaw
An X-ray machine with a special high-focus X-ray tube is used to obtain the image. The anode of the X-ray tube is inserted into the patient's mouth during imaging. When photographing the upper dentition, the focus of the tube is placed above the tongue at the level of the fifth teeth; for photographing the lower row, in the area of the frenulum under the tongue. X-ray film with a format of 18x24 cm is placed in a flexible polyethylene cassette with high-resolution intensifying screens. During filming, the patient presses the cassette with his hands to the skin around the area of the face being examined. If the cassette is not firmly fixed, the image of the bone structure will be unclear.
Since the focus of the X-ray tube is as close as possible to the object of study, and the film is located at a certain distance from the teeth, due to the thickness of the soft tissues, the image is almost doubled in size. Thanks to this circumstance, small details that are poorly visible on conventional x-rays are visible in panoramic photographs.
Panoramic photographs of the upper jaw also provide images of the maxillary sinuses, nasal cavity, cusps of the upper jaw and zygomatic bones. The inferior panoramic radiograph clearly shows the mandibular canal and the base of the mandibular bone. The lateral panoramic image simultaneously displays the teeth of the upper and lower rows of each half of the jaw.
Based on panoramic images, caries and its complications, inflammatory processes, cysts, neoplasms and traumatic injuries of the jaws are diagnosed. However, this method is not suitable for assessing the degree of resorption of interalveolar ridges.
Another disadvantage of panoramic radiography is the inability to control the position of the X-ray tube applicator in the mouth.
This research method exposes the oral mucosa to significant radiation, so panoramic radiography is recommended to be used only when indicated and no more than 1-2 times a year for each patient. Additional protection with this type of radiography is ineffective, because Oral organs located outside the protective zone are exposed to irradiation.
It should be borne in mind that this technique, due to the emergence in recent years of more modern research methods, is rarely used.
LINEAR TOMOGRAPHY or layer-by-layer radiography is a method that allows you to eliminate the summative nature of the image and most clearly highlight a certain flat layer of the organ or area being studied. The essence of the method is the synchronous movement of the tube and film relative to the patient. A clear image of the layer located at the level of the geometric axis of rotation of the lever is obtained. The remaining elements of the object are blurred as a result of the dynamic blur effect. The swing angle of the X-ray tube during tomography is 30-60 є, the slice thickness is 0.2-0.5 cm. Typically, tomography is performed after survey X-rays have been taken, which make it possible to determine the required slice depth.
In dentistry, tomography is used to study the TMJ, for complex fractures of the midface, post-traumatic deformities, neoplasms, inflammatory processes and can be performed in direct and lateral projections. In the last 10-15 years, LINEAR ZONOGRAPHY has been widely used in practice - layer-by-layer research with a small swing angle of the X-ray tube (usually 8º). The advantage of zonography is that it produces thicker slices, which reduces the number of images, makes the procedure more economical and safe in terms of radiation exposure, and obtains the same information as a series of tomograms.
ORTHOPANTOMOGRAPHY (panoramic tomography) (Fig. 2) is a method that allows you to obtain an image of a curved layer on a flat X-ray film. During shooting, the tube and film cassette describe an incomplete circle around the patient’s head (270º). At the same time, the cassette rotates around its own vertical axis, as if “rolling” the patient’s jaws from the front. The X-ray beam passes through a 2 mm wide slit-shaped diaphragm, then through the anatomical structures of the head and facial part of the skull and enters new unexposed areas of the film. As with linear tomography, anatomical structures distant from the film are projectedly enlarged and their image is blurred. Modern orthopantomographs provide programs for studying the dentition, the bone structure of the upper, middle and lower zones of the facial skull, the TMJ, as well as the craniovertebral junction, the inner and middle ear, and the optic nerve canal. It is possible to change the thickness and depth of the layer being studied.
Fig.2. Panoramic tomogram of the lower face area
The simplicity of the method, high information content and relatively low radiation exposure allow the technique to be widely used for diagnosing almost the entire range of diseases of the maxillofacial area.
The disadvantages of the method include the unequal degree of magnification of the resulting image, as well as the deformation of anatomical structures in some types of devices.
The PANORAMIC ZONOGRAPHY method (Fig. 3) is a type of orthopantomography that allows you to obtain an image of a thicker layer of the object (up to 3 cm), which increases the information content of the method.
Fig.3. Panoramic zonogram of the midface
TELERENTGRAPHY is a technique that allows you to obtain images of anatomical structures with minimal projection magnification. During teleradiography, the object of study and the film cassette are moved away from the X-ray tube to a distance of 2-2.5 m or more. The image magnification is 2-4% and can practically be neglected. Teleradiograms of the skull are performed on films measuring 24x30 cm. The photographs should show not only bone structures, but also soft tissues of the maxillofacial area, soft palate, tongue, and posterior wall of the pharynx. If necessary, soft tissues are marked with a viscous contrast agent (iodolipol, bariodol, etc.), and radiopaque marks are also applied to the soft palate. Subsequently, craniometric calculations are performed according to a certain scheme. Despite the errors that arise when analyzing teleroentgenograms, the technique is widely used in orthodontics for diagnosing and planning the treatment of malocclusions, as well as for planning surgical treatment for congenital and acquired deformities of the maxillofacial region.
COMPUTED TOMOGRAPHY allows you to obtain a transverse layer-by-layer image of any area of the human body, including the skull. It is based on recording the energy of a beam of X-ray radiation passing through the human body at different angles when the tube is rotated by highly sensitive sensors that convert the received information into electrical signals. The latter are “digitized” and sent for analysis to a computer, where the program allows you to calculate the density of each voxel (volume unit of the layer) and present it on the display screen in the form of a pixel of the corresponding brightness. Contrast enhancement techniques are used to enhance tissue contrast. A series of cross sections can be transformed into a planar or volumetric image in any longitudinal plane.
The examination is not burdensome for the patient; when examining the maxillofacial area, it does not require special preparation.
CT is used in the diagnosis of diseases of the facial skull and dental system: fractures, tumors, cysts, systemic diseases, pathology of the salivary glands and TMJ. CT examination is especially indicated for processes in hard-to-reach locations (ethmoidal labyrinth, sphenoid bone, pterygopalatine fossa, etc.). Spiral CT scanners have a new “dental” program for studying the dentition.
However, the use of this method is associated with significant radiation exposure to the patient. Thus, with CT of the facial skull, the surface dose is 2-10, and the dose to the lens of the eye is 100 times higher than that with radiography and linear tomography.
MAGNETIC RESONANCE IMAGRAPHY (MRI) is a method of radiation diagnostics based on recording the energy emitted by protons of hydrogen nuclei in the internal environments of the human body when they return from an excited state to their original state (so-called relaxation). Resonant excitation of nuclei and the spin effect occur under the influence of radio frequency pulses generated by the interaction of a magnet creating a static magnetic field and an additional high-frequency coil. The latter also serves to record the relaxation signal. A powerful computer analyzes the information received.
MRI allows you to obtain images of the layers of the human body in any plane - frontal, sagittal, axial, etc., which can then be reconstructed into three-dimensional images. To enhance the contrast of the tissues being studied, chemical substances containing nuclei with an odd number of protons and neutrons (fluorine compounds, paramagnetic substances) are used, which change the relaxation time of water. This method has advantages in visualizing soft tissues, such as muscle, fat, cartilage, etc., which makes its use especially necessary when studying the TMJ, mucous membranes of the paranasal sinuses and oral cavity, salivary glands and other soft tissue structures of the head and neck . The method is not burdensome for the patient and does not have any harmful effects on his body. A contraindication for MRI examination is the presence of metal foreign bodies in the patient (including some types of crowns).
Artificial contrast techniques
Artificial contrast is widely used in practical work in the study of: ducts of the salivary glands (sialography), fistulous tracts (fistulography), maxillary sinuses (maxillary sinusography), etc.
SIALOGRAPHY. On plain radiographs, the salivary glands are usually not visible; only shadows of radiopaque salivary stones can be detected. To examine the ducts of the salivary glands, 1.5-3 ml of contrast agent is injected at the mouth of the duct using a blunt-tipped needle or through a thin catheter until a feeling of tension appears in the gland area. As contrast agents, water-soluble contrast agents of high viscosity or sharply diluted and emulsified oil preparations (dianosyl, ultra-liquid lipiodol, ethiodol, mayodil, etc.) are used. Pictures are taken in frontal and lateral projections. To obtain a contrast image of all major salivary glands simultaneously, orthopantomography is also indicated. Sialography is used to diagnose salivary stone disease, inflammatory and tumor processes.
DOUBLE CONTRAST - the technique consists of simultaneous injection of lipoiodol into the ducts of the salivary glands, and oxygen into the tissues surrounding the gland. This technique is the most informative in the diagnosis of tumor processes of the salivary glands.
FISTULOGRAPHY – filling the fistula tracts with a contrast agent in order to study their extent, direction, and connection with the pathological process in the image. Warmed iodolipol is used as a contrast agent. Immediately after the administration of the contrast agent, photographs are taken in two mutually perpendicular projections.
ARTHROGRAPHY is used to study the condition of the TMJ and, first of all, to clarify the condition of the intra-articular meniscus. Under the control of a television screen, 0.8-1.5 ml of a viscous water-soluble contrast agent is injected into the joint cavity and tomograms or zonograms of the joint are performed with the mouth open and closed.
ANGIOGRAPHY is a technique for studying the vessels of the maxillofacial area using water-soluble and non-ionic contrast agents (cardiotrast, verografin, hypaque, omnipaque, ultravist, etc.). The technique is performed in a cath lab environment.
Angiography is used to diagnose diseases and anomalies of the vascular system (hemangiomas, juvenile angiofibromas of the skull base). In the practice of maxillofacial surgery, this technique is used quite rarely.
MAXILLARY - X-ray examination of the maxillary sinuses after the introduction of a contrast agent into them by puncturing its wall, through the socket of an extracted tooth (if there is communication with the sinus) or through a fistulous tract. After aspiration of the sinus contents, 3-7 ml of slightly warmed contrast (iodolipol, iodipine, lipiodol, etc.) is injected. Pictures are taken in the nasomental and lateral projections. The technique is indicated for the diagnosis of cysts, sinus polyps, productive forms of sinusitis, and tumor diseases.
ULTRASONOGRAPHY. The method is based on the effect of registering reflected ultrasonic radiation within the range of 1.0-2.0 MHz and forming a linear (static) or multidimensional (dynamic) image. The method is harmless and informative when studying soft tissues. It is quite widely used in the diagnosis of diseases of the salivary glands, pathology of the soft tissues of the neck, and lymph nodes.
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X-RAY EXAMINATION
In modern dentistry, various X-ray diagnostic methods are widely used. The main method of X-ray examination in surgical dentistry is radiography. Recently, new methods of X-ray examination of teeth and jaws have been developed and put into practice - panoramic tomography, teleradiography, X-ray cinematography, which make it possible to give a more complete X-ray characterization of most dental diseases.
There are two methods of dental radiography - intraoral (intraoral) and extraoral (extraoral). Intraoral photographs, in turn, are divided into contact and bite-based.
When taking contact photographs, a film wrapped in black or wax paper is pressed against the mucous membrane of the inner surface of the alveolar process of the jaw. Bite photographs - the film is clamped between the teeth of the upper and lower jaws. Extraoral x-rays are often used to view the mandible, facial bones, temporomandibular joint, paranasal sinuses, zygomatic and cranial bones, and salivary glands.
On survey radiographs of the facial bones in direct, lateral and axial projections, both (upper and lower) jaws and palatine bones, forming the bony walls of the oral cavity, are identified. For a detailed analysis of a number of anatomical formations, special targeted images are used. Sight radiography is performed intra- and extraorally. Intraoral photographs taken in the bite are used to study the bony palate, alveolar processes of the upper and lower jaws, and the floor of the mouth. Contact intraoral photographs with a film pressed against the alveolar process make it possible to study the structure of the corresponding limited areas of the upper and lower jaws, periodontium and teeth. Extraoral x-rays are taken to study the structure of the bones of the maxillofacial area.
The upper jaw in a direct anterior projection can be traced from the infraorbital margin to the alveolar process. It is projectively shortened. In the lateral sections, the body of the upper jaw is limited by a clear concave contour, smoothly passing outward and upward into the zygomatic bone. The nasal cavity is located medially above the bony palate, and the sinuses of the same name are located laterally in the bodies of the maxillary bones. In the nasomental projection, the distortion of the body of the upper jaw is less than in the anterior view. In the lateral projection, the right and left upper jaws are projectively summed up. The bony palate is represented by an intense linear shadow extending to the anterior part of the alveolar process of the upper jaw. At this level it bifurcates. One of the lines, continuing horizontally anteriorly, is the bottom of the nasal cavity, and the second, arcuately deviating downwards, is formed by the vault of the oral cavity. The alveoli and teeth are not clearly differentiated due to summation.
Intraoral radiography of the bony palate is performed in the axial chin position. The central x-ray beam is directed from top to bottom at the tip of the nose in relation to the film at an angle of 75°, open anteriorly. The bony palate on intraoral radiographs is defined as irregular rectangles with an anterior rounded contour. The posterior contour cannot be reproduced, since it is impossible to introduce the film into the oral cavity to the required depth. The anterior and lateral contours of the bony palate are bordered by the alveolar arch with teeth located on it. The structure of the bony palate is finely looped, oval or round in shape with alveolar lacunae measuring 3-5 mm, located near the incisors in the thickness of the spongy substance.
The median palatine suture can be traced in the sagittal plane. The incisive foramen has the appearance of an oval lucency, turning into a narrow slit-like incisive canal, located parallel or at an angle to the median palatal suture. When the projection coincidence of the incisive foramen with the apex of the incisor root, it resembles a granuloma. Unlike granuloma, the incisive opening, projected onto the root of the tooth, and on repeated radiographs taken with a change in the centering of the beam of rays, projectionally moves relative to its root. In this case, the tooth and periodontal gap are not changed.
The lower jaw is also examined on survey and targeted radiographs. On survey x-rays of the facial bones in the anterior and nasomental projections, the body of the jaw is projected in the form of an irregular quadrangle with a convex lower contour, passing into the area of the angle in its branches. The base of the lower jaw is represented by a clear wide (up to 2-4 mm) strip of the cortical layer. The formation of the upper contour is due to the alveolar arch of the lower jaw and the alveoli with the teeth located in them. On a radiograph in the nasomental projection, the sockets and heads of the temporomandibular joints with the articular spaces located between them, as well as the neck of the lower jaw, are clearly visible, which makes it possible to evaluate them in comparison. The coronoid and condylar processes coincide in projection.
On a radiograph taken in an axial projection, the lower jaw is projected onto the middle cranial fossa and gives a convex horseshoe-shaped shadow caused by the body and projectionally shortened branches of the lower jaw. The condylar processes end in transversely oriented ovals of the head of the mandible. The coronoid processes are revealed in the form of triangular pointed formations located medially from the condylar ones. On a targeted lateral radiograph of the lower jaw, the same details are determined as on a survey one, but without significant projection layering. The examined half of the body of the lower jaw and its branch with the coronoid and condylar processes and the notch located between them are clearly visible. The anterior section of the jaw body, oriented orthogradely along the central ray, forms an oval-shaped clearing with clear, intense contours. The cortical layer of the base of the lower jaw reaches 3-4 mm in an adult.
The alveolar arch of the lower jaw does not have projection layers to the level of the premolars; it is covered medially by the opposite side of its body. The structure of the spongy substance is wide-lobed. In the body and lower part of the jaw branch, the mandibular canal can be traced - a linear clearing with dense walls. At the point of transition of the body into the branch there is an arched or obtuse angle of the lower jaw. The coronoid process is clearly contoured, its apex can projectively coincide with the angle of the opposite side of the lower jaw, less often with the tubercle of the upper jaw. The condylar process coincides with the image of the cervical vertebrae.
On a targeted radiograph of the temporomandibular joint, taken in a lateral projection, the bottom of the glenoid cavity is clearly defined. Anterior to it is the articular tubercle of the temporal bone, which continues at the base of the zygomatic arch. The head of the lower jaw has the shape of a compacted semi-oval and smoothly passes into the condylar process of the jaw. The head is covered with a thin cortical layer, which thickens significantly in the neck area. The joint space is widened in the central section, corresponding to the deepening of the bottom of the articular cavity.
Application of the X-ray method of research in the diagnosis of odontogenic inflammatory diseases. Periodontitis is inflammation of periodontal tissue. Granulating periodontitis is an active form of inflammation, characterized by frequent exacerbations. With granulating periodontitis, on radiographs performed using the intraoral method of examination (regardless of the degree of exacerbation), in the bone at the apex of the tooth root one can discern an area of bone tissue resorption with uneven and unclear contours. Bone destruction can spread to the alveoli of adjacent teeth. Sometimes partial resorption of the root of the causative tooth is detected. Periodontitis of multi-rooted teeth leads to resorption of the interradicular bone septum. At the same time, on radiographs, the roots of the teeth are visible against the background of an area of osteolysis of bone tissue that does not have clear boundaries. Chronic periodontitis of the central incisors of the lower jaw, especially traumatic, is accompanied by bone loss around their roots and resembles a perihilar cyst in size and shape. The final diagnosis is established after pathohistological examination of the removed tissues.
Granulomatous periodontitis (granuloma) is asymptomatic for a long time. On x-rays taken using the intraoral method of examination, a center of destruction of a round shape with clear contours is detected at the apex of the tooth root. The apices of the roots of the teeth included in the granuloma are often resorbed. In children, during the formation of the apex of the roots of the teeth, on radiographs these places resemble a granuloma, especially if a carious cavity is found in the coronal part of the tooth. It should be remembered that with granulomas the end plate of the alveoli is partially destroyed, but in growing teeth at the stage of an unclosed apex it is preserved. At the stage of the Unformed apex, the root is thin, with a wide canal, expanding in the form of a center of clearing, clearly surrounded by a closing plate.
Fibrous periodontitis is essentially the outcome of an acute inflammatory process. On the radiograph, the periodontal fissure of the affected tooth is widened over a large area and narrows in places. If the periodontium has undergone ossification as a result of inflammation, the periodontal fissure is absent on the radiograph.
Periostitis. Exacerbation of chronic periodontitis leads to acute periostitis of the jaws. According to radiological signs, acute periostitis is indistinguishable from periodontitis, while chronic periostitis is characterized by radiological changes. A muff-like compaction with smooth and indistinct boundaries appears on the lower jaw. Bite radiographs reveal a soft tissue shadow of infiltrated periosteum. Chronic ossifying periostitis is detected on the outer surface of the lower jaw in the form of a linear shadow or hemispherical bone formation, inferior in intensity to the structure of the cortical substance of the jaw. Referential periostitis most often has a post-traumatic origin and is localized in the lower jaw in the area of the anterior teeth. X-ray shows a focus of osteoporosis of bone tissue with fairly clear boundaries, which resembles a radicular cyst, but unlike it, the periodontal gap of the teeth located in the affected area is not changed.
Odontogenic osteomyelitis. It is impossible to differentiate acute odontogenic osteomyelitis of the jaw from periostitis radiographically, since the phenomena of destruction are not yet clearly expressed. Bone necrosis occurs on the 3rd-4th day, but the first signs of bone tissue damage can be detected on radiographs only by the end of the 2nd-3rd week from the onset of the disease. Changes in the jaw are manifested by the unclearness of their structure, and subsequently foci of osteolysis or necrosis appear. In the subacute phase, a zone of sclerotic demarcation gradually appears around them, more clearly expressed in the lower jaw. In the upper jaw after 5-6 weeks, and in the lower jaw after 6-7 weeks, cavities containing bone sequestra, denser than the surrounding bone tissue, are clearly visible on X-ray. The edges of the sequestra are uneven, jagged. Between them and the viable bone tissue, a clearing zone is visible; its appearance is due to the formation of pus and granulations. In the chronic phase, as sclerosis develops, sequestral cavities form. Around them in the lower jaw, as a result of subperiosteal bone formation, a sequestral capsule is formed, clearly visible on the radiograph. A sequestral capsule does not form on the upper jaw. Bone regeneration in the upper jaw is much less pronounced than in the lower jaw. Chronic odontogenic osteomyelitis after removal of rejected bone sequestra is completed by reparative processes. After sequestrectomy, X-ray control is performed. Its implementation is necessary to determine the effectiveness of surgical treatment and detect bone regeneration.
Pericoronitis. An X-ray of the lower jaw taken in a lateral view shows the wisdom tooth in an incorrect position in relation to the lower jaw and other teeth. It can be tilted (at different angles) with the crown forward or backward. In the first case, it rests on the tooth in front, in the second - on the anterior edge of the lower jaw branch. In a strictly vertical position, the tooth is in inclusion. With repeated exacerbations, an x-ray taken in a lateral projection can reveal bone resorption between the second and third molars or behind the crown of the wisdom tooth, in the anterior edge of the mandibular ramus. The presence of these changes and corresponding clinical symptoms allows us to establish a diagnosis with maximum confidence. The tactics of medical manipulations depend on the nature of the changes detected radiographically in the hard tissues of the tooth in front and in the bone tissue surrounding the crown of the wisdom tooth on the distal side. According to Harniseh, expansion of up to 2 mm of the pericoronal space on the distal side of the wisdom tooth crown is a physiological norm.
Odontogenic sinusitis. To study diseases of the maxillary sinus and identify their causal relationship with the teeth of the upper jaw, both intraoral and extraoral x-rays are used. In our opinion, of all the positions used for radiography of the maxillary sinuses, the most appropriate is the anterior nasofrontal one. Inflammatory processes in the maxillary sinus create an x-ray picture ranging from slight veiling to complete disappearance of radiation permeability. If during a tooth extraction operation the root is pushed into the maxillary sinus, it is not always possible to detect it on extraoral x-rays. To locate the tooth, an intraoral contact photograph is taken.
Contrast radiography of the salivary glands - sialography - is a reliable diagnostic method and is included in the examination plan for patients with inflammatory diseases of the corresponding anatomical areas.
For sialography, we use aqueous solutions of triiodinated organic compounds: Visotrast 76%, Urotrast 75%, Verotrast 76%, Urografin 76%, etc. They are low-toxic, quite radiopaque, have a high resorption capacity, due to which they do not remain in the gland even with significant impairment its functions. However, it is difficult to administer water-soluble radiopaque contrast agents with a conventional syringe. A. M. Solntsev and co-authors developed a special technique for sialography using water-soluble X-ray contrast agents.
N.A. Rabukhina A.P. Arzhantsev
X-RAY DIAGNOSIS IN DENTISTRY
MEDICAL
INFORMATIONAL
AGENCY
Moscow 1999
UDC 616.314+616.761.8]-073.75 BBK 56.3
Rabukhina N.A., Arzhantsev A.P.
p12 X-ray diagnostics in dentistry.-M.: 000 "Medical Information Agency", 1999.-452 p., ill.
ISBN 5-89481-036-1
The monograph covers issues of X-ray examination of diseases of the maxillofacial region in adults. Various x-ray examination techniques are presented. Much attention is paid to the rules for performing radiographs, ensuring their good quality, and to the issues of radiation safety of X-ray studies. The X-ray semiotics of dental diseases, para- and periodontal diseases, as well as X-ray manifestations of fractures of the lower jaw, bones of the middle and upper zones of the facial skull, osteomyelitis of the jaw bones, benign and malignant tumors, cysts of various origins, congenital and acquired deformities are presented. Radiological signs of diseases of the salivary glands, temporomandibular joints, systemic and tumor-like lesions of the jaw bones are given.
For radiologists, x-ray technicians, practicing dentists and their assistants
UDC 61b.314+616.761.8]-073.75 BBK 56.3
© Rabukhina N A, Arzhantsev A P, 1999 © 000 "Medical information
agency", 1999
All rights reserved. No part of this books cannot be reproduced in any form without writing ISBN 5-89481-036-1 No permission from the copyright holders
PREFACE
X-ray examination is the leading diagnostic method and is constantly used in recognizing most diseases of the dental system in people of different age groups, both in the practice of therapeutic and surgical dentistry, and in orthodontic treatment and orthopedic measures. In recent years, attention to various problems of dentistry has been steadily increasing, all types of dental care to the population are being improved, and the boundaries of maxillofacial surgery for traumatological, oncological, systemic diseases, deformities, and diseases of the salivary glands are expanding. This naturally caused an increase in the level of use and expansion of the range of x-ray techniques for studying the dental system, and the emergence of new types of x-ray examination.
Achievements dentistry, which marked last two decades, rapid development of X-ray technology, emergence of new techniques research led to revise ideas about nature and methods of treating many diseases maxillofacial areas in adults and children - diseases periodontal, congenital and acquired deformities, tumors, inflammatory and traumatic defeats. This contributed significant changes in the semiotics of pathological states, methodology X-ray examination and organization of diagnostic process. Generalization these materials are not important only for everyday practice, but also for scientific developments And teaching.
The importance of the issues of X-ray diagnostics of diseases of the maxillofacial region was determined by the fact that in different periods of the development of domestic clinical radiology this problem attracted the attention of leading specialists - S. L. Kopelman, V. G. Ginzburg, I. A. Shekhter, G. A Zedgenidze, E. A. Lichtenstein, Yu. I. Vorobyov, A. N. Kishkovsky, S. A. Vaindrukh, etc. Nevertheless, the number of domestic manuals and monographs devoted to maxillofacial radiology
PREFACE
gia is small. Issues of X-ray diagnostics of diseases of the teeth and jaws are covered mainly in journals
articles.
The proposed guide covers the issues of X-ray examination in dentistry. It contains data on the technical features of modern specialized X-ray equipment designed for various types of radiography, layer-by-layer and contrast studies of the dental system and other parts of the facial skull. Methodological techniques and the basis for standardizing the X-ray diagnostic process for diseases of the maxillofacial area, as well as new techniques, are described. The general x-ray semiotics of lesions in the bones of the facial skull is presented. A detailed description of the radiological manifestations of diseases of the teeth, jaws and other parts of the facial skull, diseases of the salivary glands and temporomandibular joints, and lesions of the maxillary sinuses of odontogenic origin is given. These data are constantly used in clinical dentistry for primary diagnosis, determining the dynamics of the process, monitoring the effectiveness of treatment measures, and for timely recognition of complications. Due to the increasing frequency of X-ray examinations in dentistry, the manual includes special sections on radiation exposure and ensuring the safety of examinations, as well as the organization of specialized dental X-ray rooms. Thus, the manual is addressed to a wide range of specialists related to the pathology of the maxillofacial region, primarily radiologists and dentists, as well as ophthalmologists, otolaryngologists and, to some extent, pediatricians and internists.
The manual reflects many years of experience in the radiology department of the Central Dental Research Institute.
The authors hope that the guide will assist clinicians in their daily work and will contribute to the improvement of radiographic diagnostics in dentistry. All critical comments will be accepted with gratitude.
CHAPTER 1
ORGANIZATIONAL PRINCIPLES OF USE
X-RAY METHOD IN DENTISTRY. BASIC RESEARCH METHODS
Role X-ray research in modern dentistry and maxillofacial surgery is growing steadily. Towards the traditional problem of identifying and clarification of the nature of diseases of the dental system are increasingly being added indications for use X-ray methods for determining results conservative and surgical treatment, assessing the dynamics the course of pathological processes and completeness convalescence.
However, parallel to the trend towards expanding the scope of radiation diagnostics, the frequency of exposure of the population to ionizing radiation is increasing. This puts on the agenda the need to streamline the conduct of x-ray procedures, strictly define the indications for them, assess the informativeness of the techniques and develop the most radiation-safe methods for obtaining x-ray images.
Knowledge of technical aspects of radiography and laws Skiology is not mandatory only for correct diagnosis, but also to carry it out in the most radiation-safe manner possible conditions, especially when examining children, adolescents, women childbearing age. In dentistry these issues should give special importance, given proximity sources radiation to the body when used majority special X-ray machines. Therefore it is necessary optimal standardized schemes research various parts of the dental system.
Given that this manual is intended for use by a wide range of dentists and radiologists, we will Not only Pay attention to the current state organizational and methodological problems in dentistry, but also decrees-
to find the most correct, from our point of view, ways to solve them in the near future.
When determining indications for x-ray examination in dentistry, one should proceed from a number of factors. First of all, it is necessary to take into account that more than 50% of the area of the teeth is not visible during an external examination and can only be studied radiographically. Consequently, X-ray examination turns out to be the most important "in the diagnosis of the most common dental disease - caries. It is necessary to identify approximal and subgingival carious lesions, secondary caries under fillings and crowns, provides valuable information about the relationship between the carious defect and the tooth cavity, the depth of the cavities, which is very important not only for fissure caries, but also for other localizations of the process. X-ray data facilitate the implementation of all types of treatment procedures, identifying the condition of the root canals, the presence of replacement dentin. They are also important for monitoring the correctness of endodontic measures. The capabilities of the X-ray method in the diagnosis of caries are used not yet in full, which makes it necessary to recommend not only the expansion of its use in the treatment of carious disease, but also the inclusion of orthopantomography as the safest technique in terms of radiation in some programs of epidemiological studies and clinical observations.
For complications of caries, pulpitis and periodontitis, X-ray examination is indicated to determine the presence of the nature and extent of lesions of the perialical bone tissue. It should be taken into account that periodontitis can develop with a partially vital pulp, in the absence of a clinical picture of pulpitis. Therefore, the indications for X-ray examination of periodontitis need to be expanded, as this helps to select the correct method of treatment for complicated carious lesions.
It is obvious that without X-ray examination, an accurate diagnosis of periodontal diseases cannot be made. The indication for it is not only a detailed primary diagnosis, but also an assessment of the results of treatment.
_____7
study and further course of the process in dynamics, which require periodic x-ray monitoring.
X-ray examination should be widely used in orthopedic procedures, which require detailed data on the condition of the remaining teeth and surrounding periapical tissues, periodontium, and temporomandibular joints. Based on X-ray data, the possibility of performing dental implantation with complete or partial edentia is determined and the condition of the jaw bone tissue in the implant area is monitored.
During orthodontic treatment, only on the basis of X-ray data can one obtain a complete picture of the condition of temporary teeth, the position and degree of eruption of permanent teeth, evaluate the possibilities of their installation in the dentition, and determine the features of the formation and harmonious development of the jaws and the entire facial skull, which determine and planning of orthodontic interventions and their combination with surgical treatment of skeletal disorders.
The scope of clinical dentistry and maxillofacial surgery includes diseases of the facial skull:
traumatic injuries, inflammatory lesions, tumors, tumor-like diseases, cysts, deformations and systemic lesions of the skull bones. For all of the listed pathological conditions, X-ray examination is the leading method of refined primary diagnosis, the most important aid in assessing the effectiveness of treatment measures, the completeness of the reverse development of the process and its dynamics, and the timely detection of complications. All of these diseases are a direct indication for a thorough and, in some cases, repeated x-ray examination. It is the most important way to actively identify hidden foci of odontogenic infection, causing allergization and immunological changes in the body.
Indications for the use of radiation diagnostics in children and adolescents are most strictly assessed. They are considered from the perspective of the volume of expected
information and the dangers of exposure to ionizing radiation on a developing organism and future offspring. At the same time, it is impossible to refuse X-ray examination of the maxillofacial area in this age group. Indications for it include disorders of teeth eruption and formation, identification of hidden caries and its complications, neoplasms, cysts and deformations.
When justifying the need for X-ray examination of people in younger age groups, it is necessary to especially clearly plan its tactics, choosing the safest and most effective methods. Thus, even a short list of indications indicates that without radiological data, a clinical study cannot be considered complete in any section of dentistry.
When referring a patient for an x-ray examination, the dentist must indicate the purpose of the diagnosis and provide the radiologist with a medical history containing the necessary information about the clinical status, anamnesis data, the state of the bite and facial skull, and the oral mucosa. The choice of the x-ray method is the prerogative of the radiologist, so there is no need to indicate in the direction which x-ray should be taken. Having given the radiographer the appropriate instructions, the radiologist is obliged to check the correctness and sufficiency of the study performed and, after final processing of the images, give a conclusion. Only after this the image, together with the x-ray report, is made available to the clinician. Direct contact between the dentist and the x-ray technician is permissible only when taking emergency photographs of patients with endodontic instruments in the root canals. In other cases, excluding a radiologist from the research process not only worsens the methodological aspects and quality of diagnosis, but also risks violating the rules of radiation safety of procedures.
It must be emphasized that the radiologist retains the right to refuse to conduct a study that he considers insufficiently substantiated, inappropriate or unsafe. In this case, he should inform the clinician of his decision and discuss it with him. A radiograph is a document that can provide...
X-RAY METHOD IN DENTISTRY _____9
This is necessary not only in a specific clinical situation, but also in the future. This obliges the preservation of photographs in an archive in accordance with established rules, as well as taking into account the provisions on the storage and collection of silver-containing materials.
The opening of each X-ray room located in a state or non-state dental institution, as well as the use of X-ray equipment in a dental office, requires permission from the SES with the issuance of technical and sanitary passports. The only regulatory document in these cases is the “Rules for the Design and Operation of X-ray Rooms”, the latest edition of which should be published in 1998. Currently, the following sanitary standards exist: the area of the X-ray room in the presence of one dental apparatus or an apparatus for panoramic radiography of the jaws should be at least 10 m2; installation of one orthopantomograph or together with a dental apparatus requires an area of 20 m2. The control room or compartment must be at least 5 m2. In general X-ray diagnostic rooms, additional space for the dental apparatus is not required, and the installation of an orthopantomograph is acceptable if the room area is at least 55 m 2. When installing several tripods in one room, the distance between them should not be less than 2 m. For a darkroom, the minimum area is 6 m2. If there is no special control room, the X-ray room personnel during the images should be behind a large protective screen, which is installed no closer than 2-3 m from the X-ray stand.
The organization of an X-ray room equipped with dental devices or orthopantomographs in a residential building is permitted only in exceptional cases. In this case, there should be a vertical gap of one floor between the living quarters and the office. Protection of the treatment room walls is calculated depending on the power of the device and may not be required for low-power dental stands, orthopantomographs and panoramic devices. Ordinary wooden doors should be protected with 0.5 mm of lead. Window protection with shutters is carried out
10
CHAPTER 1
This applies only when the orthopantomograph is located on the first floor at the rate of 0.25 mm of lead.
The X-ray room and darkroom are equipped with a repeated grounding circuit, supply and exhaust ventilation with triple air exchange, a wooden floor in the treatment room and a tiled floor in the darkroom. The latter must have good light protection, hot and cold water supply, special heated tanks for developing and fixing images, non-actinic flashlights and X-ray cameras, a dry laboratory table for recharging cassettes, light-protective storage for unexposed film, a drying cabinet, and a laboratory clock.
The X-ray room should have lead aprons and skirts to protect children and adults during the examination, enclosed in plastic covers to prevent air pollution from lead dust. The walls of the office should be wet cleaned monthly to eliminate lead dust.
In table 1.1 presents a table of technical equipment for X-ray rooms in various types of dental institutions.
Table 1.1
Table of equipment for X-ray diagnostic rooms in dental clinics
| Item of equipment | |
|||
| | Office for orthopantomography and dental research | Office for orthopanto-msgraphy | |
|
| Devices |
||||
| Dental X-ray device type 5D2, 6D4, Stomaks-100, “Minray”, “Minident” or radiovisiographic complex | 1 | - | 1 |
|
| Stationary x-ray diagnostic complex (for images and tomography for 2 workstations) | 1 | - |
||
| Orthopantomograph type “Phoenix”, “Kranes”, PM 2002 SS with or without craniostat | 1 | - |
||
11
X-RAY METHOD IN DENTISTRY
End of table. 1.1
| Item of equipment | Number of equipment items by type of X-ray diagnostic rooms |
|||
| Cabinet for a comprehensive study of the facial skeleton (basic dental floor) | Office for ortholanto-mophia and dental research | Orthopanto-mography room | Dental radiography room |
|
| Devices and accessories |
||||
| Developing machine or tanks for photo processing of X-ray images (BR) | 1 |
|||
| Lead-lined protective collar | 1 |
|||
| Clamp for dental x-ray films (for 6-10 films) | 5 | - | 5 |
|
| Cassette for X-ray films (13x18, 15x40, 18x24, 24x30) with intensifying screens EU-L4 and EU-I4 | 5 each | - | 5 each |
|
| Bracket for hanging X-ray frames | 1 |
|||
| General purpose X-ray viewer | 3 | 1 |
||
| Dental X-ray viewer | 1 | - | 1 |
|
| Frames for developing X-ray films (13x18, 18x24, 24x30, 15x40) | 15 of each size | 15 15x40 | 15 each 13x18 18x24 |
|
| X-ray film cutter | 1 |
|||
| Universal fluoroscope | 1 | 1 |
||
| Protective apron made of leaded rubber | 2 |
|||
| Non-actinic lantern with red, green and milky glass for the darkroom | 2 |
|||
| Darkroom clock | 1 |
|||
| Large protective X-ray screen (type B-40) in the absence of a control room | 1 |
|||
| X-ray film storage cabinet | 1 |
|||
| Electric cabinet for drying x-rays | 1 |
|||
| Protective skirt made of leaded rubber | 2 | 1 |
||
12
CHAPTER 1
Expansion of the tasks facing craniofacial radiology is impossible without a significant modification of the range of radiological techniques used in wide practice. In contrast to other clinical disciplines, where numerous new methods of radiological and non-radiological diagnostics have been developed, practical dentistry is still traditionally based on the use of a very small number of methods of intra- and extraoral radiography.
The basis of radiological examination for most dental and periodontal diseases is still intraoral radiography. Currently, there are four of its techniques used in photographing teeth, para- and periodontal tissues: radiography of periapical tissues according to the rule of isometric projection, interproximal (bitewings-radiography), Bite shooting (occlusal) and radiography from an increased focal length with a parallel beam of rays.
For 60 years, in the X-ray diagnosis of dental disease, the technique of shooting according to the bisector rule or isometric projection, developed by Cieszinski (1907), was mainly used. The main objective of research using this technique is to obtain a clear image of the periapical tissues, therefore the beam is centered on the projection onto the facial skin of the apexes of the roots of various teeth of the upper and lower jaws. On the upper jaw they are projected along a line connecting the wing of the nose and the tragus of the ear, and on the lower jaw - along a line running parallel to the edge of the lower jaw 1 cm above it. The method is a method of close-focus contact radiography and is carried out using various types of dental devices. For this purpose, the domestic device 5D2, produced since 1982, is used, which has a tube-trator 15 cm long (Fig. 1.1). Power supply with a current of 7 mA is carried out at a stable voltage of 50 kV. Photographing of teeth of different groups varies only by exposure with eight settings: from 1 to 25 mAs.
To save time, settings are selected using a push-button switch on the wall-mounted control panel. On the latter there is also a power switch, signal lamps for turning on the power
X-RAY METHOD IN DENTISTRY
Rice. 1.1. Domestic dental device 5D2
voltage and remote control button. Repeated the picture can be taken intermittently at least 3 minutes(for cooling x-ray tubes).
Purpose of the cone x-ray tubes - save permanent cutaneous focal distance and unify X-ray conditions for check collimation x-ray beam. For the cone itself serves this purpose, made from plastics, and aluminum diaphragm at its base, filtering X-rays and limiting dimensions fields. Without beam collimation x-rays Dental devices when shooting with distance 15 cm give a round field with a diameter of up to 12 cm, which is necessary reduce to 4-6 cm. The most effective radiation at 50 kV is produced by an aluminum filter thickness 2 and 2.5 mm, if the radiation is harder.
The device is powered from the mains voltage 220 V(permissible variation limits ±22 V), frequency 50 Hz(±1 Hz);
Network resistance is no more than 1.6 Ohm. Greatest consumed power does not exceed 1.3 kVA. Apparatus must
14
CHAPTER 1
be grounded. Power supply and grounding are carried out through a two-pole plug with a grounding contact. Replaceable diaphragms are installed inside the tube, creating a round field with a diameter of 45 mm or a rectangular field with a cross-section of 40x45 mm in the plane of the top of the tube. Without replaceable diaphragms, the working radiation beam in this plane has a circular cross-section with a diameter of 60 mm. The device's tripod is mounted at a height of 150 cm above the floor. The headrest is fixed separately on the wall in the most convenient place, approximately at a height of 107 cm above the floor. The device complex includes an X-ray protective apron for patients. The weight of the device does not exceed 25 kg.
Since 1993, a new domestic dental apparatus, 6D4, has been produced, which has a more powerful X-ray tube, which made it possible to increase the recording voltage to 60 kV and use a tube 20 cm long.
Foreign dental devices of the latest generation, such as the Finnish device "Minrey" from the company "Sore-dex" (Fig. 1.2), have a high-frequency current rectification circuit, which reduces the radiation dose to patients, are equipped with organo-automation, accelerating the research process, and built-in microprocessors, indicating the value of radiation doses. The voltage on the X-ray tube is from 60 to 70 kV, the nominal current is 7 mA, the exposure time is selected in the range from 0.01 to 1.75 s at a skin-focal distance of 40 cm. After determining the optimal conditions for photographing each group of teeth, the data are entered into the RAM of the microprocessor, and subsequently the laboratory assistant only needs to select the button indicating the tooth to be removed. The device can be operated using the remote control.
Considering the absence for a long time of any other method of intraoral radiography of teeth, this type of imaging was used for various purposes. One of his tasks was to obtain an image of teeth identical to their true size. Due to the anatomical structure of the jaw bones, it is almost impossible to position the X-ray film in the mouth parallel to the crown and root of the tooth. With this technique, radiography is carried out with a beam perpendicular to
15
X-RAY METHOD B DENTISTRY
Rice. 1.2. Dental X-ray machine "Mirey" from Soredex with a cylindrical tube 30 cm long. The device can be removed from the stand and mounted on the wall
bisector of the angle formed between removable tooth and x-ray film, and centered on the line which is a projection onto the skin of the roots teeth.
To facilitate the daily work of x-ray technicians, a scale of tube inclination angles has been developed for each group of teeth: top jaws for incisors +55 °, fangs+45°, premolars +35°, molars +25°, on the lower jaw for incisors -20°, canines -15°, premolars -10°, molars -5°. The given indicators serve only landmarks, since the reference data matches and individual features random.
The patient is seated in such a way that midsagitum- the tal plane of the skull was located perpendicular, and the occlusal one is strictly horizontal. For shooting teeth lower jaw of the patient's head slightly move back to the headrest of the chair so that the line connecting the corner of the nose with the earlobe is horizontal ear. Increase
16
CHAPTER 1
Rice. 1.3. Scheme of the relationships between the central beam, tooth and X-ray film when shooting using the following methods: o - periapical radiography; b - occlusal radiography; c - shooting with a parallel beam of rays from a long focal length
An angle greater than necessary leads to distortion in the size of the teeth. Since any movement during an image creates so-called dynamic blur, it is necessary that the patient's head is positioned on the headrest.
To take intraoral radiographs, films with dimensions of 3.1x4.1 cm (standard radiographs), 2.7x5.4 cm (interproximal), 5.7x7.6 cm (occlusal) and 2.2x3.5 cm (children's) are used. The quality of the film significantly affects the information content of the image. Optimal performance is achieved by special packaged domestic X-ray film RZ-1 and films from Kodak (USA) Ultra-speed DF-58 and Ektaspeed Plus EP 21 (see insert to p. 24, fig. A And B). The use of intensifying screens makes it possible to reduce the radiation dose by 8-10 times. In these cases, an image is also formed due to the luminescent glow of the screen. X-ray conditions on the 5D2 apparatus without screens: 50 kV, 7 mA, 0.3-1.5 s (2-10.5 mA-s).
Intraoral photographs using the isometric projection method (Fig. 1.3, a-c) can be successfully used to determine the spatial relationships of objects localized in the zone of roots and periapical tissues. In such cases, in addition to the main image, an additional radiograph is taken with a beam bevel to the medial or distal side. A buccally located object is displaced in the direction of the beam, and a lingually located object is shifted in the opposite direction. The same happens with cranial or caudal displacement of the beam. In this case, objects lying buccally also shift along the direction of the beam’s inclination.
X-RAY METHOD IN DENTISTRY 17
The isometric imaging technique has been developed to obtain images of periapical tissues. With this type of radiography, the marginal sections of the interalveolar ridges are removed with an oblique beam. Due to the proximity of the X-ray tube and the volume of the alveolar edge, especially in the area of premolars and molars, images of the vestibular and lingual edges of the interalveolar ridges are projected onto different sections of the film and shortened compared to their true height. The discrepancy between them is directly proportional to the magnitude of the beam inclination and the thickness of the alveolar edge. In the area of the lower molars, it can reach, as shown by E.I. Zhibitskaya (1967), N. Joung (1965) and others, 0.7 cm. Consequently, the isometric shooting technique cannot be considered an adequate type of radiography in periodontology and is often source of over- and under-diagnosis. That is why when diagnosing periodontal diseases it should be abandoned (Fig. 1.4, a-c).
The most clear and correct image of the marginal sections of the alveolar processes is obtained on interprox.
Rice. 1.4.
X-ray images of a jaw phantom made using the following methods: A - occlusal radiography; b- periapical radiography; c - shooting with a parallel beam of rays from a long focal length. The position of the metal marks applied to the vestibular and lingual closing cortical plates of the interalveolar septa changes depending on the shooting technique
18
CHAPTER 1
Rice. 1.5
Interproximal radiographs. d - production method, b - Interproximal images of the premolar and molar areas 
small radiographs proposed by Raper (1920) (bite shsh^-radiography). For this type of X-ray images, films of the same name from Kodak (USA) Bite-wing (Ultra-speed DF-42 and Ektaspeed Plus EB 31P) measuring 2.7x5.4 cm are ideal (see insert to p. 25, fig. IN). For these photographs, special film holders are used, which allow the X-ray film to be positioned parallel to the crowns of the teeth at a certain distance from them and in such a way that symmetrical areas of both jaws are recorded in the picture (Fig. 1.5, a and b). Radiographs simultaneously display the crowns and marginal areas of the alveolar processes of the teeth of the upper and lower jaws. To study the entire bite, 3-4 photographs are needed. Using standard film shooting and photographic processing techniques, it is possible to objectively assess the degree of bone tissue resorption over time. The technique is also the best way to identify approximal and cervical caries. A common method of intraoral photography is
19
X-RAY METHOD IN DENTISTRY
Bitewing radiography (occlusal radiography) is available, with which you can obtain an image of a large area of the alveolar process - over 4 teeth or more. This type of radiography is usually used as an additional one, making it possible to clarify the spatial features of the pathological focus - an impacted tooth, a large cystic cavity, etc. Bitewing photography is carried out when examining children and adolescents, patients with impaired mouth opening, as well as people with sensitive mucous membranes oral cavity, in which the touch of the film causes a gag reflex. Bitewing radiography is also used to obtain an image of the floor of the mouth in case of suspected stones of the submandibular and sublingual salivary glands, to obtain an image of the jaws in an axial projection (Fig. 1.6, A And b). It allows you to clarify the course of the fracture line within the dentition, the location of bone fragments, the state of the outer and inner cortical plates in cysts and neoplasms, and identify the reaction of the periosteum.
The conditions for bite radiography depend on the purpose of the survey. The X-ray film must be of a larger format than for contact radiography. The Kodak company (USA) produces special films Ultra-speed DF-50 and Ektaspeed Plus EO 4 IP measuring 5.7 x 7.6 cm (see insert on p. 25, Fig. D). To obtain an occlusal image of the upper jaw, the film is inserted as deep as possible into the subject’s mouth and positioned perpendicular to the sagittal plane of the skull. The patient's head should be in such a position that the line connecting the tragus of the ear and the wing of the nose is horizontal. The beam is directed downwards to the center of the film through the root of the nose and at an angle of +80°. With this technique, a significant part of the alveolar process of the upper jaw and the floor of the nasal cavity is imaged. If it is necessary to capture only the most anterior parts of the jaw, then the beam is centered on the tip of the nose at an angle of +70° to the plane of the film. Occlusion conditions: 60-70 kV, 10 mA, 0.6-0.8 s.
To obtain an image of the lateral parts of the upper jaw, the film is shifted as far as possible into the area being removed. side, and the beam is directed at an angle of +65° through the point, located on 1
cm below the center of the infraorbital the edges. Similar
The X-ray research method, due to its effectiveness and reliability, has found wide application in the diagnosis of diseases of the maxillofacial region. The main X-ray diagnostic technique in maxillofacial surgery is radiography.
There are extraoral and intraoral radiography.
Extraoral radiography
The initial examination of the patient, as a rule, begins with survey radiographs, which are performed in the main projections (direct anterior and posterior, lateral, axial) and additional views (nasofrontal, nasomental, anterior semi-axial, etc.). Survey X-rays are performed using stationary and mobile X-ray machines.
Direct anterior projection gives general information about the bones of the cranial vault and facial skeleton.
Positioning: the patient lies on his stomach, the head is positioned strictly symmetrically so that the sagittal plane and the physiological horizontal are perpendicular to the plane of the table (film). Centering the beam on the occipital protuberance.
Side shots skulls are produced as a mandatory addition to straight ones. However, it is quite difficult to study the condition of the bones of the facial skeleton from these photographs due to the summation effect of the right and left halves of the skull. Usually only gross, extensive bone changes are visible. Lateral photographs are often performed to examine the condition of the skull, its base, the sella turcica, the main and frontal sinuses, as well as the anterior walls of the maxillary sinuses.
Laying: the head is placed with the lateral (sick) side to the cassette so that the sagittal plane of the skull is parallel to the plane of the cassette. The central beam is directed vertically to the cassette to the area of the sella turcica.
Axial images are performed, if necessary, to examine the base of the skull, pyramids of the temporal bones, to assess the condition of the anterior and posterior walls of the maxillary sinuses, and zygomatic bones.
Layout: the patient lies on his stomach, the chin is extended anteriorly as much as possible and touches the cassette, the front surface of the neck is adjacent to the cassette. The central ray is directed perpendicularly to the crown area. If you have a short neck and it is impossible to perform the specified styling, another method can be used.
Indications for the image in nasofrontal projection are. inflammatory, tumor processes of horizontal segments of the body and branches of the lower jaw; traumatic injuries to the bones of the facial and cerebral skull, etc. This installation is also used for sialography and fistulography.
Pathological changes in the mental part of the body of the lower jaw with such placement are difficult to analyze due to the interposition of the cervical spine.
Positioning: the patient lies face down on the table of a stationary X-ray machine, with his forehead and tip of his nose touching the cassette. The central ray is directed through the occipital protuberance vertically to the cassette passing through the apertura piriformis.
Indications for pictures in nasomental projections are diseases of the paranasal sinuses, damage and diseases of the upper jaw. zygomatic bones, orbits.
Laying: the patient lies face down, touching the cassette with his chin and the tip of his nose, his mouth is open. The central beam is directed vertically (perpendicular to the plane of the cassette) just below the edge of the upper incisors. Direct photographs of the skull do not analyze the condition of the teeth. In order to identify the level of fluid in the maxillary sinuses, the picture should be taken in a vertical position.
Information content anterior semiaxial radiograph similar to the previous study, however, here the lower parts of the maxillary sinuses and the roofs of the orbits and zygomatic arches are better identified.
Placement: the patient touches the cassette with his chin, the tip of the nose is 2-3cm away from it. The sagittal plane of the head is perpendicular to the plane of the table, the physiological horizontal makes an angle of 45 degrees with the plane of the table.
In addition to the main and additional projections, special layouts have been developed for visualizing individual bones and even their individual elements. These include, for example, X-ray of the temporal bone according to Schüller which allows you to study its cavity system, developmental anomalies, as well as the temporomandibular joint. This study is carried out, as a rule, on both sides, which makes it possible to compare the elements of the joints.
Extraoral radiography of teeth and jaws used to display teeth only in cases where obtaining their image using the intraoral method becomes impossible (increased gag reflex, jaw contracture, etc.), since the display of teeth and surrounding formations is less structural.
A method has been developed to obtain extraoral contact radiographs on a dental apparatus. It allows you to assess the condition of the teeth, the marginal parts of the alveolar process, the relationship of the roots of premolars and molars with the maxillary sinus and the mandibular canal.
For radiography of the frontal parts of the jaws, the first oblique contact projection is used. A cassette with a film and an intensifying screen is pressed against the brow ridge of the side being examined, flattening the tip of the nose and displacing it. The head is turned to the side being examined by approximately 60°. The central beam of X-rays is directed perpendicular to the film through the sternocleidomastoid muscle at the level of the angle of the mandible.
When radiography the area of molars and premolars, a second oblique contact projection is used. The cassette is pressed against the zygomatic bone of the area being examined. The central beam is directed perpendicular to the cassette below the lower edge of the lower jaw to the area of the second premolar.
When examining the angle and ramus of the mandible (third oblique contact projection), the sagittal plane is parallel to the plane of the cassette pressed against the zygomatic bone of the side being examined. The central beam is directed perpendicular to the film on the upper jaw.
Radiography in oblique tangential projections is used to assess the condition of the vestibular parts and primarily the upper jaw. The patient sits in a dental chair with his head resting on the headrest. The central beam of rays is directed tangentially to the area under study, perpendicular to the cassette with film and intensifying screens.
The examination of the temporomandibular joint using an apparatus for intraoral radiography is carried out according to the Pordes-Parma method.
Positioning: the patient presses the film cassette to the joint being examined parallel to the sagittal plane of the head. The central bundle is directed through the semilunar notch of the healthy side to the zygomatic arch (3-4 cm anterior to the external auditory canal). The tube is as close to the patient's head as possible. You can take pictures with your mouth open and closed.
Intraoral radiography
Intraoral radiography of teeth and jaws can be performed in the following ways: contact, bite (occlusal), interproximal, long-focus.
For contact photographs, the film size is 2.5 × 3 cm and 3 × 4 cm (the latter format is available in standard packaging), for bite-size photographs, the film size is slightly larger – 5 × 6, 6 × 6 cm. The corners of the film are cut so that they do not if the mucous membrane is injured, the film is placed in a small envelope made of light-proof paper, then in wax paper. A bag of film is inserted into the oral cavity and the patient presses it against the hard palate and alveolar process of the area under study with the first finger of the hand.
It should be borne in mind that the anatomical structure of the jaws does not allow the film to be positioned strictly parallel to the tooth. It can only be installed obliquely to the long axis of the tooth, while the crown of the tooth is tightly adjacent to the film. and the root is at some distance. Such unequal arrangement of the end sections of the tooth to the plane of the film usually leads to projection distortions of the image - more often to an enlargement of the roots of the teeth and, accordingly, pathological formations in the peri-root tissues.
To reduce projection distortions in practical work, the isometric rule developed in the twenties by Cieszynski is used - when taking an image, the central ray is directed to the apex of the tooth root perpendicular to the bisector of the angle formed by the tooth axis and the plane of the film. Any other direction of the central beam will lead to lengthening or shortening of the tooth image. It must be remembered that the permissible shortening of the tooth image should not exceed 0.2, and with elongation 0.1 of its true dimensions. To facilitate the daily work of radiologists, a scale of inclination of tube angles has been developed for each group of teeth: on the upper jaw for cusps 50-55°, canines 45°, premolars 35°, molars 25-30°; on the lower jaw for incisors 20°, canines 10-15°, premolars 5-10°, molars 1-5°.
The isometric imaging technique has been developed to obtain images of periapical tissues. It should be taken into account that in the area of premolars and molars the image of the interalveolar ridges is shortened compared to their true height, which is often a source of over- and under-diagnosis in periodontology. That is why it should be abandoned when diagnosing periodontal diseases.
The image on contact radiographs is usually more clear and with less distortion; in connection with CSM, contact images are used to study the bone structure of the periodontium and teeth.
During bite radiography, a film is inserted into the oral cavity and fixed with closed teeth. Bitewing photographs are performed when the pathological process is widespread, when searching for impacted and dystopic teeth, to study the condition of the hard palate and floor of the oral cavity, as well as in cases where contact radiography is impossible (damaged jaws, stiffness of the mandibular joints, increased sensitivity of the mucous membrane).
INTERPROXIMAL Radiography allows you to obtain the most correct and clear image of the marginal parts of the alveolar processes. For these photographs, special film holders are used, which allow the X-ray film to be positioned parallel to the crowns of the teeth at a certain distance from them and in such a way that the crowns and marginal sections of the alveolar processes of the upper and lower jaws are simultaneously recorded in the image. To study the entire bite, 3-4 photographs are needed. The technique allows you to objectively assess the degree of bone tissue resorption over time and is the best way to identify proximal and cervical caries.
LONG FOCUS radiography or shooting with parallel rays was proposed by E. Hilcher (1960). This method of intraoral radiography uses a beam of parallel rays from a long distance. In these cases, the film is located in the mouth parallel to the long axis of the tooth. To perform such images, a device with a powerful X-ray tube and a long localizer cone (36-40 cm minimum) is used. The image and the object are almost equal in size to each other. The parallel beam imaging technique has many advantages over isometric radiography in displaying the marginal parts of the alveolar processes, which are not distorted. In this regard, it can be used in periodontology and maxillofacial surgery.
In the absence of panoramic radiography or tomography equipment, the study of the dentition can be done using intraoral filming, either by a combination of periapical and interproximal radiographs, or using parallel beam photography.
Indications for occlusion examination in adults are the patient’s initial visit to a dentist, multiple caries, periodontal disease, and surgical diseases of the maxillofacial area.
Simultaneous X-ray examination of the entire bite using intraoral photographs is contraindicated for children and pregnant women.
Special techniques for studying teeth and jaws
LINEAR TOMOGRAPHY or layer-by-layer radiography is a method that allows you to eliminate the summative nature of the image and most clearly highlight a certain layer of the organ or area being studied. The essence of the method is that the X-ray tube and film cassette, attached to opposite ends of the lever, move synchronously relative to the patient during the shooting process. In this case, the photograph produces a clearer image of that layer in the thickness of the object, which is located in a plane lying at the level of the geometric axis of rotation of the mentioned lever. The image of the above and underlying bone structures is unclear and blurred. The most widely used is linear longitudinal tomography with swing angles of 30°, 45°, 60°. The study can be carried out in any projection, depending on the specific purpose of the study.
Indications for tomography arise in the diagnosis and determination of the prevalence of tumors of the maxillofacial region, fractures of the midface, diseases of the maxillary sinus, trigeminal neuralgia, systemic diseases, diseases of the temporomandibular joint.
LINEAR ZONOGRAPHY–– layer-by-layer study with a tube swing angle of 8°. The slice thickness is 1.5-2.5 cm, which allows you to reduce the number of images and significantly reduce the radiation dose without loss of information content.
PANORAMIC TOMOGRAPHY(orthopantomography) is a method that allows you to obtain an image of a curved layer of an object, unfolded on a flat film. The thickness of the extracted layer is different when using different types of devices and can range from 5 to 26 mm (panoramic zonography). Orthopantomographs, as a rule, have several programs for visualizing various parts of the facial skeleton and some structures of the base of the skull. In particular, the Zonark system provides the possibility of research according to the following programs:
- upper and lower jaw
- temporomandibular joint
- middle third of facial bones
- optic nerve foramen
- middle and inner ear
- lateral projections
- cranio-vertebral junction
An orthopantomogram shows the entire dental system as a single complex and with virtually no angular distortion. The image on the film is unequally magnified in the central and lateral parts of the jaws. In addition, the image of the frontal sections of the jaws is sometimes unclear and the cervical spine can be projected onto this area.
When performing panoramic tomography, the patient sits in a chair, the head is fixed with special supports. The cassette holder of a regular shape or in the form of a half-cylinder is located on one side of the patient. An X-ray tube is placed on a common axis with it on the other side of the head. While the image is being taken, the tube and cassette holder describe an eccentric, partial circle around the patient's motionless head. In this case, the cassette holder also rotates around its vertical axis. The X-ray beam passes through a 2 mm wide slit-shaped diaphragm. All this ensures that the rays pass perpendicularly (orthoradially) to each part of the jaw.
Pantomography allows you to assess the condition of the lower jaw, elements of the pterygopalatine fossa (posterior wall of the maxillary sinus, pterygoid processes of the main bone), alveolar bay and medial wall of the maxillary sinus, etc.
PANORAMIC RADIOGRAPHY–– a method that allows you to obtain images of fairly large areas of the jaws, including both the alveolar process and the body of the jaw, as well as the alveolar bays of the maxillary sinuses and zygomatic bones. In this case, the anode of the X-ray tube is inserted into the patient’s oral cavity, and the X-ray film in a light-proof case is pressed by the patient to the facial skin in the corresponding area. The method is highly informative, especially when studying the frontal parts of the jaws.
TELERENTGRAPHY It is performed on a cassette with intensifying screens measuring 24×30 cm, the focus film distance is at least 150 cm. During teleradiography, it is necessary to fix the patient’s head with special devices. The complexity of the structure of the skull requires performing radiographs in two mutually perpendicular projections – direct and lateral. However, in practical work, in most cases only lateral projection is used.
For ease of calculations and to avoid damage to the image, anatomical landmarks from radiographs are transferred to tracing paper or transparent film. Measurements on a teleroentgenogram make it possible to mathematically characterize the characteristics of the growth and development of various parts of the skull and their relationships in a particular patient.
Craniometric analysis is used in orthodontics and maxillofacial surgery to diagnose and evaluate the effectiveness of treatment in patients with facial deformities and various malocclusions.
ELECTRO-RADIOGRAPHY. In this technique, instead of X-ray film, a sensitive selenium plate pre-charged with a static electric potential is used as an X-ray receiver. A visible image appears on the plate, and the latter is transferred by contact to plain paper.
Electroradiograms of the lower jaw in nasofrontal and lateral projections are quite informative for diagnosing fractures. The edge effect allows you to identify small fragments and small foreign bodies. With osteomyelitis, foci of bone tissue destruction are clearly visible. The resolution of the method in identifying small spongy sequesters is higher than that of conventional radiography.
The photographic breadth of electroradiography during sialography allows one to obtain not only an image of the salivary ducts, but also the soft tissues of the gland.
An electroradiogram of the lower jaw clearly shows periapical changes in periodontitis.
The technique is quite informative for diagnosing complications encountered during dental treatment (root fracture, unfinished tooth extraction, instrument fragment in the root canal).
Due to the large format of selenium plates, only extraoral electroradiograms can be performed with this method.
Modern methods of X-ray examination
CT SCAN allows you to obtain an image of the structures of the maxillofacial region and soft tissues, including skin, subcutaneous tissue, muscles, large nerves, vessels and lymph nodes, in a series of axial sections.
Computed tomography expands diagnostic capabilities in recognizing traumatic injuries, inflammatory and tumor diseases of various nature, primarily the midface and in particular the upper jaw. The method allows one to resolve diagnostic difficulties, especially when the process spreads to the pterygopalatine, infratemporal fossa, into the orbit, and into the cells of the ethmoidal labyrinth. Using computed tomography, intracranial complications of acute sinusitis (epidural and subdural abscesses), involvement of orbital tissue in the inflammatory process, and intracranial hematomas in injuries of the maxillofacial area are well recognized.
Along with the bone elements of the temporomandibular joint, the intra-articular disc is also visualized, especially when it is displaced anteriorly.
DIGITAL (DIGITAL) RADIOGRAPHY– This is a digital (digital) method of obtaining an image. In all digital devices, the image is constructed in basically the same way. Each digital image consists of many individual dots. Each point is assigned a number that corresponds to the intensity of its glow (its grayness). The degree of brightness of a point is determined in a special device – an analog-to-digital converter (ADC). To turn digital information into an image on a television screen or film, a digital-to-analog converter (DAC) is needed. Its functions are the opposite of an ADC. The DAC transforms the digital image, “hidden” in the computer, into an analog, visible image (carries out decoding).
Digital radiography has a bright future. There is reason to believe that it will gradually replace conventional radiography. It does not require expensive X-ray film or photo processing and is fast. It allows, after the end of the study, to carry out further (posterior) processing of the image and transmit it over a distance. It is very convenient to store information on magnetic media (disks, tapes).
Fluorescent digital radiography, based on the use of a storage image of a luminescent screen, is of great interest. During an x-ray exposure, an image is recorded on such a plate, and then read from it using a helium-neon laser and recorded digitally. Radiation exposure is reduced by 10 times or more compared to conventional radiography.
X-RAY TELEVISION TRANSMISSION–– a modern method of fluoroscopy, performed using an X-ray image intensifier (IIA), which includes an X-ray electron-optical converter (X-ray electron-optical converter) and a closed-circuit television system.
The image is transmitted through a system of mirrors and lenses to the transmitting tube-vidicon. The electrical signals arising in it are sent for processing to the television channel unit, and then to the TV screen. If necessary, the image can be recorded using a video recorder.
X-ray television scanning does not require dark adaptation of the doctor. Radiation exposure to staff and patients is significantly reduced. The screen reveals details that are not captured by fluoroscopy. The image can be transmitted to other monitors (classroom, consultant's office, etc.). The image can be input into a movie camera and sent to a still camera. Another advantage is the possibility of high-speed shooting – up to 6 frames/sec.
MAGNETIC RESONANCE TOMOGRAPHY (MRI)–– along with computed tomography, it is also becoming widespread in the diagnosis of diseases of the maxillofacial area.
MRI allows for accurate topical diagnosis of tumors of the maxillofacial region, especially tumors of the paranasal sinuses. Thanks to visualization of the image of the neoplasm itself, the spread to adjacent areas is clearly determined (into the pterygopalatine and infratemporal fossa, into the orbit, nasal cavity, into the cells of the ethmoidal labyrinth, into the main sinus and into the parapharyngeal space).
With the help of MRI, it is possible to distinguish tumor tissue from edematous and inflamed mucous membranes, and determine the inflammatory nature of the changes.
MRI visualizes the intra-articular disc of the temporomandibular joint, which significantly expands the possibilities for diagnosing joint diseases.
Methods of X-ray examinations using contrast agents
SIALOGRAPHY–– a method for studying the ducts of large salivary glands by filling them with iodine-containing preparations. The technique was proposed by Barsony in 1925. Contrast agents are injected into the ducts of the salivary glands using a regular syringe through a blunt needle slightly curved to fit the shape of the duct, a cannula or a catheter. Using a needle has a number of disadvantages: it is not always possible to insert it into the duct, it is not fixed in the duct and can come out of it at the time of administration of the contrast agent. instillation is often a labor-intensive procedure for the doctor and a painful procedure for the patient.
Initially, iodolipol was widely used in sialography, which was also considered as a disinfectant that gave a therapeutic effect in inflammatory processes of the salivary glands. It was later discovered that viscous iodized oils have a number of disadvantages. They often linger in the ducts for a long time, disrupting the function of the salivary glands and increasing sclerotic changes in them. Their high viscosity forces them to administer the drug under pressure much higher than the physiological resistance of the salivary ducts. As a result, they become overstretched, extravasated, and the integrity of the terminal branches is disrupted. Damage to the walls of the salivary ducts can lead to iodolipol entering the soft tissues of the maxillofacial area, where painful oleomas are formed that require surgical treatment. Sometimes shadow symptoms, considered characteristic of restorative or tumor diseases of the salivary glands, appear as a result of non-physiological contrast.
In recent years, water-soluble contrast agents of increased viscosity or sharply diluted and emulsified oil preparations (diazinol, ultra-liquid lipol, ethiodine, mayodil, etc.), the viscosity of which is 0.2-0.25 Poise, have begun to be used. These drugs should be administered through thin catheters under visual x-ray control and using manometry to ensure that the injection pressure corresponds to physiological pressure (30-40 cmH2O). Less viscous water-soluble contrasts do not allow obtaining a clear picture of the ducts, since they are hypertonic, have low surface tension and are quickly removed from the ducts, not giving a clear x-ray picture. In addition, these substances irritate the internal lining of the ducts and cause discomfort in patients.
Before introducing a contrast agent, the drug is heated to 37-40°C to avoid spasm of the ducts. The amount of the administered drug depends on the type of gland, gender and age of the patient (1-6 ml). For the parotid gland it is most often 2-2.5 ml, and for the submandibular gland it is about 1-1.5 ml. Before contrasting, the ducts are washed with isotonic sodium chloride solution and bougie with a thin eye bougie. The catheter should have an outer diameter of no more than 0.6 mm. It is introduced into the duct with a mandrel, which is removed only before the introduction of a contrast substance, or it is filled with a contrast suspension before injection to avoid the ingress of saliva or air. The catheter is advanced into the duct to a depth of 2-3 cm and fixed with an adhesive tape on the skin of the neck.
Television fluoroscopy allows you to dose the filling of the ducts and avoid excessive administration of contrast agents, as well as select the optimal projections for radiography. Typically, survey direct, lateral, axial, tangential photographs, orthopantomograms and panoramic radiographs are performed. In addition to tight filling, in the images taken after 15 minutes, the speed and completeness of emptying of the ducts is recorded, which makes it possible to judge the function of the glands. To stimulate salivation, pharmacological drugs, such as citric acid, are often used.
Often the ducts are filled in small portions of 0.5-0.6 ml in three doses at intervals of 10 minutes. Between the second and third administration of the contrast agent, the patient is given citric acid extract. Radiography is carried out in three phases: filling the ducts, the contrasting phase of the parenchyma and the post-evacuation phase. It is possible to fill the duct of the sublingual salivary gland only if it flows into the submandibular gland.
Orthopantomography significantly simplifies the sialography technique and allows you to simultaneously obtain images of various glands without layering the bone tissue of the lower jaw. Panoramic radiography can also be used to study the parotid salivary gland in a lateral projection, and the submandibular gland in a direct projection. If salivary stone disease is suspected, the study should always begin with survey photographs (straight, lateral, occlusal or panoramic).
PNEUMOSUBMANDIBULOGRAPHY. The shadow of the submandibular glands is visible against the background of oxygen or carbon dioxide introduced into the tissue of the submandibular space using a pneumothorax apparatus. The injection site is the floor of the mouth or submandibular space. The results of the study are most often recorded on straight and lateral tomograms. Often pneumosubmandibulography is combined with sialography.
The widespread use of radionuclide studies, thermo- and echography in everyday practice leads to a reduction in the number of contrast studies of the salivary glands, especially with the use of gas media.
SINUSOGRAPHY(maxillary sinusography). Its essence consists in the preliminary introduction of a contrast substance into the maxillary sinus, followed by radiography. A contrast agent is introduced through the nasal cavity by puncture, through a postoperative anastomosis, fistula or socket of an extracted tooth. Before contrasting, it is advisable to rinse the sinus with saline solution. For contrasting, water-soluble contrast agents of high viscosity and diluted ones are used (diazinol, lipoiodol, ethiodol, mayodil, etc.). After the administration of a contrast agent in the presence of a fistula, you should use a tampon to prevent its spillage until radiography is performed. It is better to conduct the study in an X-ray room. Pictures are taken in the nasomental and lateral projections. After sinusography is performed, the sinus is washed again to remove the contrast agent.
With the help of contrast radiography, you can determine the shape and size of the sinus, the condition of the mucous membrane (swelling, the presence of polyps), bone walls, and most importantly, exclude or confirm the presence of a filling defect; its shape, size and location. In other words, contrast radiography allows you to detect a tumor, cyst, polyps and swelling of the mucous membrane in the sinus.
FISTULOGRAPHY– filling the fistula tracts with a contrast substance in order to study their extent, direction, and connection with the pathological process in the image. Immediately after the administration of contrast, photographs are taken in two mutually perpendicular projections.
ARTHROGRAPHY–– the purpose of this research method is to detail the diagnosis of joint lesions by clarifying the condition of the intra-articular meniscus. The technique was introduced into radiology practice in 1947 by T. Norgaard. In practice, it has been used since the late 60s, since the widespread introduction into practice of layer-by-layer studies, which facilitated the interpretation of arthrograms. As a rule, it is enough to contrast the lower floor of the articulation. The manipulation is carried out after skin anesthesia under X-ray television control. The joint is punctured in the posterior sections with a needle, through which 0.8 to 1.5 ml of a viscous water-soluble contrast agent is injected. Tomograms or zonograms of the joint are produced during various movements of the lower jaw. The procedure requires caution and experience. Some authors (Husted E., 1967) performed air arthrography of the joint, but its results are more difficult to decipher.
ANGIOGRAPHY–– contrasting of arterial and venous vessels of the maxillofacial region is most widely carried out for neoplasms of various types, especially hemangiomas. The contrast agent can be administered in three ways. The simplest of them is puncture of the hemangioma with the introduction of a contrast agent into the thickness of the tumor and registration of the image on separate images. To get an idea of the extent of the tumor in direct and lateral projections, the puncture is performed 2 times. The technique allows us to identify the nature of venous changes, but does not always allow us to see the details of the blood flow, the vessels approaching the hemangioma, and is not suitable for contrasting the arterial network.
For cavernous hemangiomas and arteriovenous shunts, it is practiced to inject contrast agents into the afferent vessel, which are removed surgically. For pulsating arterial and arteriovenous formations, serial angiography is performed after the administration of contrast agents into the common carotid artery by puncture. In recent years, contrasting of the external carotid artery is more often carried out through catheters, passed either in the usual way for angiography (through the femoral or subclavian vein) or through the external carotid artery.
Angiography is a complex procedure that should be performed in a specially equipped X-ray operating room under aseptic and antiseptic conditions under local anesthesia. Its implementation requires special equipment that ensures automatic recording of a series of angiograms at high speed and in accordance with a given program. Most modern angiographic units are equipped with an automatic syringe, including a tube and a serial cassette according to a given program, two X-ray tubes and a two-projection cassette, which records the state of the vessels in the frontal and lateral projections simultaneously with a single injection of a contrast agent. The passage of catheters and the correctness of their location in the vessels are controlled using the X-ray television channel of the X-ray image intensifier. For angiography, the following are most often used: verografin, urografin, hypaque, cardiografin, cardiotrust.
Currently, angiography is combined with a special type of subtraction (digital subtraction angiography), which makes it possible to register the smallest branching of vessels and determine changes in the arterial, capillary and venous vascular network when contrasting with small amounts of drugs by puncture or catheterization of peripheral veins. There is every reason for the expanded implementation of this technique both in the diagnosis and treatment of a number of diseases.
DIRECT LYMPHOGRAPHY–– used for visualization of lymphatic vessels. First, a dye is injected into the thickness of the skin, which makes thin lymphatic vessels visible. After a small incision, which for cosmetic reasons is often made in the area behind the ear, the stained vessel is ligated and ultra-liquid lipoiodol is slowly injected into it, after which photographs are taken. Currently, such research is increasingly being replaced by indirect isotope lymphography.
STANDARDIZATION OF X-RAY EXAMINATION
Diagnostic methods of X-ray examination can provide a variety of information about the morphology and function of various parts of the maxillofacial region and are necessary for recognizing pathological processes and their dynamic assessment. At the same time, rational research schemes are used extremely limitedly, mainly in large research centers. In the majority of outpatient dental institutions, intraoral isometric radiography is used exclusively, unsystematically and often in a much smaller volume than necessary. This deprives the clinician of valuable information and negatively affects the quality of clinical work.
In surgical hospitals, the range of techniques used is usually larger, but their use is also not regulated and in most cases is based on outdated and insufficiently informative radiography methods.
In order to optimize the X-ray process in maxillofacial surgery, increase its information content and radiation safety, it is necessary:
- Simplify the research design based on modern, more informative methods and introduce standardized rational programs for each disease.
- Conduct X-ray examination of the maxillofacial area only by radiologists and, accordingly, solve the problems of training qualified personnel.
- Provide a system for storing x-ray documentation and continuity between specialists in its use.
The introduction of standardized programs can be carried out even regardless of the technical base of institutions. This refers to the optimization of technical conditions and radiography schemes, the revision of the timing and order of dynamic control studies for a number of diseases, the widespread introduction of zonography instead of tomography and even survey radiography, advanced training of X-ray room personnel, as well as a more complete familiarization of clinicians with current problems of X-ray diagnostics.
STANDARDIZED SCHEME FOR X-RAY STUDY OF THE MAXILLOFACIAL AREA
- Caries and its complications:
Optimal data can be obtained by orthopantomography with additional separate intraoral photographs, if some areas of the dentition are not clearly displayed on the orthopantomogram, or by using two enlarged panoramic radiographs. The choice of additional radiography technique is dictated by orthopantomography data and clinical indicators. During a dynamic study during the treatment process, single “periapical” radiographs are sufficient, which can be replaced by panoramic ones if it is necessary to monitor the condition of several teeth. The lack of specialized equipment complicates and lengthens the process of X-ray examination, as it requires several (at least seven) dental images taken with parallel beams from a large skin-focal distance, or a combination of isometric “periapical” and interproximal radiography (12-14 images). The total dose measured on the patient's skin in these cases is several tens of times higher than the dose during orthopantomography.
- 3 periodontal diseases:
Diagnosis is best carried out using orthopantomograms combined with lateral panoramic photographs, and in the absence of special equipment, using oblique extraoral photographs. During control studies over time, the study design is reduced according to clinical indicators and depending on the data of the primary study. In children, when diagnosing, only orthopantomography data should be taken into account as the most radiation-friendly technique.
- Lesions of the lower third of the facial skull (inflammatory, traumatic, tumor):
X-ray diagnostics is carried out mainly on the basis of orthopantomograms, which, in case of fractures of the lower jaw, are supplemented with direct survey photographs of the skull and panoramic or linear zonograms of the temporomandibular joints, and in osteomyelitis - with survey photographs of the body or branch of the mandible, panoramic radiographs or occlusal intraoral radiographs. In these cases, if orthopantomography is not performed, the number of extraoral plain radiographs has to be increased.
- Midface lesions:
They are most easily identified on panoramic zonograms. The latter are supplemented only by a lateral view of the skull for spatial orientation in the displacement of fragments and identification of fractures of the base of the skull or the growth of neoplasms. Damage to the zygomatic arch may not be detected when using this scheme and requires an additional image in the anterior semi-axial or axial projection. The panoramic zonogram is only partially replaced by two survey photographs, a direct eccentric photograph of the orbital area and a radiograph in the anterior semi-axial projection, as well as an additional linear zonogram of the maxillary sinuses. Maxillary cysts are most clearly visible on direct panoramic photographs.
- Congenital deformities:
The study design is complex; a combination of survey images (tele-radiographs) in two or three projections, panoramic zonograms of the lower and middle third of the facial skull, joints, and often pharyngograms is necessarily used.
- Neoplasms of the maxillofacial region:
In addition to the above schemes, computed tomography of the skull, stereoradiography, and contrast studies are performed.
- Screening and epidemiological studies:
It is advisable to use panoramic tomography. Hidden processes are revealed in 35-67% of those examined.
RADIATION SAFETY OF PATIENTS DURING X-RAY DIAGNOSTICS
Currently, in 70-80% of cases, a clinical diagnosis is made on the basis of X-ray data, which simultaneously creates more than 90% of the population's above-background radiation. On average, every resident of the country undergoes about 1.1 x-ray examinations per year. Ensuring radiation safety of patients is important to reduce the degree of exposure of the population, especially since this section of x-ray diagnostics is developing at an accelerated pace.
The biological effect of small doses of ionizing radiation can cause the so-called long-term consequences in the form of induced malignant neoplasms, genetic consequences of shortened life span, etc. There is a so-called latent period of tumor formation, which depends on the type of tissue, age and gender of the irradiated dose and ranges from several up to tens of years.
It is generally accepted that the average latent period is 20-25 years. According to UNSCEAR and the International Commission on Radiological Protection (1978), the risk of myeloid leukemia, for example, is 2 cases per 1 million irradiated at a dose of 1 mSv, the risk of breast cancer is 1.5 cases, lung cancer is 2 cases, thyroid gland – 0.5 cases, bones – 0.5 cases, brain, salivary glands, mucous membranes – 0.2-0.5 cases, genetic disorders in the first two generations – 4 cases.
Principles of protecting the patient from excess radiation during radiography of the maxillofacial area:
- shielding of the body with a protective apron made of leaded rubber, sewing up the area of the thyroid gland and the lens of the eye with special devices of various designs;
- diaphragm of the irradiation field;
- conducting radiation examinations strictly according to indications, taking into account the individual characteristics and total dose of a particular patient;
In children, repeated radiography is allowed after 3 weeks, and if many images were taken, then no earlier than after 5 weeks.
Petrenko K.A. Promising methods of X-ray examination in dentistry // International Journal of Social Sciences and Humanities. – 2016. – T. 4. No. 1. – pp. 32-35.
Promising methodsX-ray
research in dentistry
K.A. Petrenko, oh dinator
Penza State University
(Russia, Penza)
Annotation . The article is devoted to innovative methods of examination in st. O matology. Are considered ascurrently in use in practice in medical medicine, X-ray machines (in particular, 3 D computer tomography A Physics), as well as promising diagnostic methods (X-ray laser). The main advantages of these methods over each other and compared to others x-ray methods dmental diagnostics, as well as description on their significance for orthodontics, maxillofacial surgery, therapeutic, surgical and orthopedic dentistry.
Keywords: diagnostics, dentistry, radiography, computed tomography, x-ray laser.
X-ray research methods e advancements in dentistry have been and remain T being a priority compared to other existing at the moment oh cop clinical and laboratorydiagnostic methods due to its information content, ease of use, relative strong cheapness and fast obtaining high quality results. This research method is widely used in absolutely all areas. With in dentistry and maxillofacial surgery, especially for the diagnosis of periodontal tissue diseases, peri a pecal tissues, traumatic O lesions, cysts and tumor processes in the bone tissue of the maxillofacial b lusty.
One of the main problems stomatology to date an acute odontogenic infection remains. About the problem lies in the need for timely and error-free diagnosis of the inflammatory process, what is it about? indicates high percentage of none during the examination errors. Of all those currently existing Almost all diagnostic tests only reflect the presence of inflammation , and judge from them the depth and x and character I can't imagine defeat seems possible. Therefore, most rational choice in this matter with lurks complex use of l from the Chevys diagnostic methods based onwhich lie modern technologies.
For each area of dentistry, as well as for maxillofacial surgery, the preferred X-ray methods e but the diagnostics are different O wild research. So, for example, All currently known radiological methods used in periodontology can be identify 5 main groups, arrange them in descending order significance for the dentist and quality quality of the resulting image in in the following order: computer volume o graphy; orthopantomography; panora m radiography; sighting ren t genography.
Innovative x-ray diagnostic method in the last decade has becomethree-dimensional dental computer thorn tomography (3 D CT). Now and from are used by the following apparatus: 3 DX Accuitomo (Morita, Japan); GALILEOS (Sirona, Germany); Picasso Pro (Vatech, E - WOO, South Korea), Scanora 3 D, (Soredex ", Finland). All of them is it ours? widely used in identifying numerous dental diseases e maxillary system, maxillofacial area, maxillary sinuses and TMJ [5].
The above CT scanners represent universal diagnostic devices, powerful and generation tools XXI century, open defining an era in the diagnosis of pathologies of the maxillofacial area, dental diseases, havinghuge potential and from use. 3D CT has clear advantages for the patient , and for doctors of various specialties, including dentists and maxillofacial surgeons. Available about attempts to use 3 D tomographs speaks about high precision obtained from O discussions and, accordingly, about the quality of this research, which is important for practical applications in all areas of tomatology and maxillofacial surgery, as well as to increase level of aftercare of the patient's next treatment based on the images obtained. 3D tomographs have huge practical e skoy significance in different areas m e dicines, but for the dentist V The following clinical situations are of interest: detection of non-cutting in a wide (impacted and dystopic) tooth ov in pediatric dentistry; endodontic treatment; traumatic dental damage and CHLO; research bone grafting before implantation a tion; detection of pathology in tissues A rhodontium and foci of chronic inflammation and leniya in periapecal tissues; arthr and you, and r trosis and other pathology of the TMJ; tumors and tumor-like processes detected inoncodentistry; di f diagnostics pathological processes in Gamer's sinus of various etiol O gical nature .
In orthodontics in the last decade e tie promising and X-ray methods nological diagnosticsThere are two main CT examination techniques, such as cone beam computer tomography (CBCT) and multisp and ral computed tomography (MSCT). CBCT is a higher priority fororthodontists due to gender of higher quality O fermentation in combination with a low dose of radiation, which is of particular importance due to the fact that the main patients at the appointment orthodontists are children. CBCT increases dia efficiency G nostics and treatment of patients with dentofacial anomalies.
Innovative in the field of X-ray O logic was the appearance of devices, slave O melting not only from X-ray tube, but also based on the following phenomena: optical, electrical, laser. For example, the combination of computer Yuter and positron emission tomography, which provided increased e improving the quality of the resulting image of the object under study is not only about b dentistry, but also neurology, cardiology and oncology, including in a multidisciplinary clinic and ki. Another such “combiner” O The bathtub machine is an x-ray enovsky laser. In 2009, physicists at Stanford developed the most powerful X-ray laser currently available: Linear and With coherent light source" ( Linac Coherent Light Source or LCLS). Currently, active work is underway to improve it in order to be able to study the substance at the molecular level. His ideological idea difference from X-ray machines A The second generation consists of a wavelength of up to 0.15 nanometers. To date, the daytime device is the shortest wavelength. Previously with the task and With tracing the substance at the molecular level was only accomplished by synchronization O throne devices, but unlike the X-ray laser, they required a perfect crystal to operate, whereas LCLS can work with single molecules. His beam is so highly accurate , which does not deviate by more than five micrometers at a distance of five meters.The operating principle of this device T swarm is to disperse to O herent X-ray beam at And visualization of atoms and molecules at the time of research. Examination for p O The power of the X-ray laser differs from traditional X-ray examination, more closely resembling To roscopy, because For a more detailed examination, a mat fence is required e rial. U scientists say that in R in the future, the operating principle of such devices A product will form the basis for other more sch tomographs and will allow you to examine the body in the clinic as a whole, and not just tons of efficient organs and tissues to the laboratory about riya.
Quality improvement is now a reality t different techniques X-raysurveys, as well as the development of O new diagnostic methods in the future And ve, will allow dentists, maxillofacial surgeons and doctors of related specialties to improve the quality of A called diagnostic and treatment With meadow in the hospital and outpatient clinic, will reduce the time spent on treatment And diagnostics of each patient. For floor To achieve more accurate survey results, an integrated approach is requiredin the diagnosis of patient pathology and ent, involving all available in the room And nick resources and based on the results of clinical, laboratory and X-ray e nological studies, especially those obtained onradiovisiographsand computer 3 D tomographs, for the purpose of evaluation results obtained, diagnostics and diagnostics of disease diseases of various etiologies between themselves , drawing up a more accurate treatment planand subsequent assessment of quality e quality of its implementation. So usingmodern high A high-quality devices and rent methods genological examination, such as 3D computed tomographs in outpatient and hospital settings increases the effectiveness of treatment of diseases of hard tissues of teeth, periodontium, people Yu bones and other tissues of the jaw T but-facial area, which means, reduces the likelihood of relapses and possible complications in patients.As a result, the time spent on b following each patient, abbreviated A decreases and the total radiation exposure is reduced, which makes it possible to use b call these techniques not only in p a rodontology , therapeutic and ort O pediatric dentistry, but also in other areas such as orthodontics and pediatric dentistry.– Volume 3. Issue 9. – P. 1100.
2. Medical equipment and medical products: CT scan, issue No. 3, “Pharos”, - 2012, - pp. 18-22.
3. Mikhailov M.K. The role and place of radiation diagnostics in modern conditions. – Practical medicine.–2010. – No. 2. – P. 19.
4. Tikhonov E.P. The state and prospects of theoretical and experimental research O understanding the morphology of hard dental tissues. Medical computers yuter technologies. – 2009. – No. 1. – P. 32.
5. Chibisova M.A. The possibilities of traditional X-ray methods and dental volumetric tomography in improving the quality of treatment and diagnosis in therapeutic dentistry, endodontics and periodontology. – Medical a l favet. Dentistry II. – 2010 – S. 12-23.
6. http://www.membrana.ru/
t he innovative Methods of the day tal X-ray diagnostics
TO . A . Petrenko, resident
Penza state university
(Russia, Penza)
Abstract. The article is devoted to innovative methods of diagnostics in dentistry. It is considered the modern X-ray machines, which are used in practicalmedicine (3D CT scan, for example) and perspective diagnostic methods (X-ray laser). There are the main advantages of these methods to each other and to other radiological methods of the dental diagnostics. It’s described their significance for the Orthodontics, Maxillofacial and De n tal Surgery, Therapy and Orthopedic Dentistry.
Keywords: diagnostics, dentistry, X-ray, CT scan, X-ray laser.
