Instrumental assessment of tooth mobility
Determining the degree of tooth fixation in the socket is a crucial stage in diagnosing periodontal disease and traumatic injuries. This manipulation is performed exclusively through instrumental methods. To do this, the clinician uses dental tweezers to gently rock the crown of the tooth being examined.
Depending on the amplitude and direction of pathological displacement, three degrees of mobility are distinguished:
- Grade I: the tooth is displaced in only one direction — vestibulo-oral (forward and backward relative to the oral vestibule).
- Grade II: pathological mobility in lateral directions is added to the vestibulo-oral displacement.
- Grade III: the crown is displaced not only in horizontal planes, but also along its vertical axis (up-and-down movement is observed).
Probing of fistulous tracts
Upon detecting a fistula opening on the mucosa (typically in the area of the transitional fold) with purulent exudate discharge and protruding granulations, the clinician must perform probing. A special dental probe is carefully inserted into the lumen of the tract.
Goals of instrumental examination of a fistula:
- To determine whether the tract has a direct connection to the jawbone.
- To determine the relationship of the inflammatory focus to a specific tooth or group of teeth.
- To identify the presence of a bone erosion (pathological defect).
Such a clinical picture, often supplemented by the detection of a dense cord upon palpation from the oral vestibule, is typical for chronic granulating periodontitis.
Measurement of maxillofacial parameters
Assessment of functional status requires clinical measurements. First, the mouth-opening amplitude is checked. Normally, this process should be unhindered and painless. The physiological norm for mouth opening is approximately 5 centimeters. In practice, this distance is equivalent to the width of three fingers (index, middle, and ring fingers) placed between the central incisors of the upper and lower jaws.
Restricted mouth opening indicates a contracture, which can be:
- Inflammatory: muscles are involved in an acute purulent or infectious process.
- Cicatricial: occurs due to past infections, trauma, surgeries, or systemic pathologies (rheumatoid arthritis, Sjögren's syndrome).
- Neoplastic: a consequence of malignant neoplasms invading the masticatory muscles.
Additionally, the depth of the oral vestibule is evaluated. The distance from the dental necks to the fornix of the vestibule is measured, after which the vestibule is classified as normal, shallow, or deep. The tension degree of mucosal frenula and strands is also checked (indicated by tissue ischemia when pulled).
Specific tests and auscultation
In addition to using basic dental instruments, the examination includes methods that require precise application of physical force or a medical stethoscope.
- Auscultation (listening): a mandatory step when examining neoplasms that exhibit pulsation. This method allows the clinician to differentiate vascular tumors from blood vessel aneurysms.
- Indirect load sign: a diagnostic technique used when facial skeleton trauma is suspected. The clinician presses on a known uninjured part of the jaw, yet pain occurs remotely — strictly at the fracture site. For the maxilla (maxilla), the sign is tested by applying pressure from the oral cavity.
- Instrumental sensitivity testing: performed by comparing sensations (e.g., from a needle prick) on symmetrical areas of the skin or mucosa. Special attention is paid to the exit points of the trigeminal nerve branches (n. trigeminus). Loss of sensitivity in the innervation zone of the inferior alveolar nerve (Vincent's sign) is an important marker of jaw osteomyelitis or a malignant process.
Briefly: answers to topical questions
What electric pulp testing (EPT) values are characteristic of a healthy pulp and the development of periodontitis?
Healthy pulp of intact teeth is characterized by threshold excitation values in the range of 2–6 µA. With the development of periodontitis, electric pulp testing values indicate pulp death (necrosis), with readings exceeding 100 µA.
Additional indicators of periodontal response:
- Normal periodontium — sensitive to currents of 100–200 µA.
- Pronounced morphological changes — the tooth responds to currents exceeding 200 µA.
Through which anatomical walls and landmarks is palpation of the TMJ condylar heads performed from the external acoustic meatus?
Palpation of the temporomandibular joint condylar heads through the external acoustic meatus is carried out via its anterior wall. To perform the examination, the clinician inserts index fingers into the patient's external acoustic meatus on both sides and presses them against the anterior wall. Palpation of the condylar heads is performed directly during mandibular movements, which allows for the assessment of their configuration, excursion pattern, synchronicity, and range of motion.
What is the methodology for vertical and horizontal tooth percussion, and what does pain during each of them indicate?
Tooth percussion is performed by gently tapping with the handle of a dental probe or tweezers, starting with a healthy tooth.
- Vertical percussion — performed strictly along the longitudinal axis of the tooth (along the incisal edge or occlusal surface). Pain during this test determines the state of the apical periodontium.
- Horizontal percussion — performed in a horizontal direction in the area of the tooth neck. Pain during this test determines the state of the marginal periodontium.
In general, painful percussion indicates the presence of a pathological process in the tissues surrounding the tooth.
The degrees of tooth mobility are easy to remember via coordinate axes: Grade I — one axis (forward-backward), Grade II — two axes (left-right added), Grade III — three axes (vertical movement added).
Class and exam questions
How can temporomandibular joint disorders be distinguished from cicatricial contracture of the masticatory muscles?
For precise differential diagnosis, the physician palpates the temporomandibular joint through the external auditory meatus. This assesses the mobility of the condylar heads, as well as the range of their rotational and lateral excursions.
What is the indirect load sign?
This is a clinical sign used to detect hidden fractures. When physical pressure is applied to the healthy part of the bone, acute pain occurs not at the site of pressure, but directly in the area of bone integrity disruption.
For what purpose is auscultation used in dentistry?
Auscultation (listening) is mandatory when pulsating neoplasms are present in the maxillofacial region. This method helps differentiate true vascular tumors from vascular aneurysms.
What else to study on this topic
- Strict algorithm for examining the oral mucosa (clockwise).
- Differential diagnosis of inflammatory and tumor lesions of the lymph nodes.
- Clinical manifestations and stages of jaw osteomyelitis.
- Assessment of neurological status and examination of Valle's points.
- Red flag symptoms (markers) of maxillofacial malignancies.
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