The role of radiography in the diagnostic process
According to the classification of examination methods for a dental patient, all procedures are divided into basic (interview, visual inspection, palpation, percussion, probing) and additional. Radiography is an instrumental additional method.
Its performance is strictly justified by a preliminary diagnosis formulated by the physician based on patient complaints, anamnesis (Anamnesis morbi and Anamnesis vitae), and objective examination data. The results of the X-ray examination must be recorded in the dental patient's medical record (accounting form No. 043/U), which is a legal document. The attending physician is responsible for the accuracy and timeliness of entering dated records.
Intraoral radiography
Intraoral techniques provide a detailed image of specific teeth and their surrounding tissues. These include:
- Close-focus contact radiography;
- Occlusal radiography.
Structures evaluated during an intraoral examination:
- Condition of the hard tissues of the tooth crown and root canals.
- Periodontal tissues (the space between the tooth root and the alveolar wall).
- Cortical plate.
- Surrounding bone tissue of the tooth socket.
This method is frequently used to detect pathological changes in periapical tissues, for example, in caries complications or trauma, as well as to monitor the quality of endodontic treatment.
Extraoral radiography and new technologies
Extraoral radiographs capture more extensive areas of the maxillofacial region and are used for a comprehensive assessment of the dentognathic system. Extraoral methods include:
- Panoramic radiography;
- Orthopantomography;
- Tomography;
- Contrast radiography.
Indications for extraoral examinations:
- Large-scale assessment of periodontal tissue condition across all dental arches.
- Traumatic injuries of the jaw bones.
- Suspected neoplasms (tumors).
- Inflammatory processes in the maxillary sinus.
- Examination of the temporomandibular joint (TMJ).
- General assessment of the alveolar process and jaw bodies.
A separate category is radiovisiography. This is modern digital radiography that allows instant image acquisition on a computer monitor while reducing radiation exposure for the patient.
The role of radiographs in periodontal pathology
X-ray examination plays a key role in the differential diagnosis of periodontal diseases. While gingival inflammation (catarrhal or hypertrophic gingivitis) is characterized by the absence of bone changes, the development of periodontitis is always accompanied by bone tissue destruction.
The radiograph in periodontitis reveals:
- Primary resorption of the cortical plate of the interdental septum (the tip of the plate may be absent).
- Subsequent loss (resorption) of the bone septum itself.
- Depending on the severity of the disease, resorption is recorded at 1/3, 2/3, or 1/2 of the root length.
These data are correlated with the clinical picture: the presence of periodontal pockets with disrupted epithelial attachment, bleeding, exudate discharge, and the degree of tooth mobility (grade I, II, or III).
Example of a radiograph description in the medical record
When documenting the local status (Status localis) of a tooth, the physician enters the radiograph data into the corresponding section of the medical history.
For example, in medium caries of a tooth (diagnosis: Caries media, Black class II cavity), the record may look as follows: "On the radiograph in the area of the examined tooth, pathological changes in periapical tissues are absent. The apex of the compact plate of the interdental septum between adjacent teeth is missing. Resorption of the interdental septum of grade I is projected." These data confirm the absence of pulp and periodontal complications, allowing preparation and filling to proceed.
Briefly: answers to topical questions
What intraoral radiography techniques are used in dental practice?
Four main intraoral radiography techniques are used in dental practice.
- Periapical radiography — performed according to the isometric projection rule, introduces size distortions.
- Interproximal radiography — displays teeth and marginal parts of the jaws without distortion, detecting caries on proximal surfaces.
- Occlusal radiography (bite-wing/occlusal) — shows the state of the cortical plate and periosteal thickness, used when contact radiographs are not feasible.
- Long-cone radiography — eliminates distortion of the marginal parts of the teeth due to a large focal distance; the film is held strictly parallel to the long axis of the tooth.
Close-focus contact radiography is also distinguished.
What radiographic features are characteristic of chronic granulomatous periodontitis?
Chronic granulomatous periodontitis is characterized by the presence of a well-defined focus of bone tissue destruction at the root apex. Key radiographic features:
- Focus of destruction — has a rounded shape.
- Periodontal ligament space — may not be widened.
- Bone sclerosis — bone tissue at the edges of the granuloma absorbs X-rays more intensively.
- Inner border — facing the granuloma, has clear and smooth margins.
- Outer border — the boundary of sclerotic bone areas, has uneven and indistinct margins.
Repeat examinations years later reveal no significant changes in the size and shape of the radiolucent areas.
Class and exam questions
What is the main difference between gingivitis and periodontitis on a radiograph?
In gingivitis (catarrhal or hypertrophic), the radiograph shows no bone tissue changes. In periodontitis, the radiograph invariably shows resorption of the cortical plate and the interdental bone septum itself.
Which structures are evaluated using intraoral radiography?
This method allows a detailed assessment of the hard tissues of the crowns, root canals, periodontium, cortical plate, and surrounding bone tissue of a specific tooth's socket.
In what cases is extraoral radiography indicated?
Extraoral radiographs (e.g., orthopantomography) are ordered for a comprehensive assessment of the periodontium, jaw trauma, suspected tumors, and evaluation of the temporomandibular joint (TMJ) and maxillary sinuses.
What else to study on this topic
- Electric pulp testing (EPT) and thermal tests
- Technique of dental probing and percussion
- Assessment of tooth mobility grade (grade I, II, III)
- Clinical presentation and differential diagnosis of periodontal diseases
- Guidelines for maintaining the dental patient's medical record (form No. 043/u)
Master the entire topic in the «Propaedeutics of Dentistry» course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Radiological Examination Methods in Dentistry" and 868 more pages on the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 65 video lessons on the subject
Other topics of section "Chapter 16. Methodology of dental patient examination"
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.