The Role of Ultrasound in Diagnosis of Temporomandibular Joint Disc Displacement: A Case-Control Study

Ultrasound is extensively being used for imaging of temporomandibular joint as it is non-invasive and relatively inexpensive. The purpose of this study was to evaluate the use of ultrasound in identifying TMJ with internal derangement and to access its usefulness as a diagnostic tool in patients with TMJ clicking.

A case-control study was done: 25 patients with a complaint of clicking sound while opening the jaw were randomly selected as the study group and 25 patients who were asymptomatic on TMJ examination were selected as the control group. Both the groups were subjected to bilateral ultrasound scanning of the TMJ. The lateral part of capsule to condyle distance (LCCD) and the anterior part of capsule to condyle distance (ACCD) were measured.

The mean LCCD of all the 50 joints in the control group was 1.3630 mm, and the mean ACCD of the 50 joints was 1.4850 mm. These values were compared with each of the 50 symptomatic joints scanned in the study group. It was noted that 56% of the subjects showed deviation towards right side and 44% showed deviation towards right side. Clicking was heard in all the subjects while opening the mouth on auscultation. The frequency and percentage distribution of negative and non-negative deviations of LCCD from that of control group were noted. In total, 40% showed negative deviation and 60% showed non-negative deviation. In total, 24% of the subjects showed negative deviation and 76% showed non-negative 190 deviation of ACCD when compared with the control group. T test shows that with respect to LCCD measurement there is no significant difference between symptomatic and asymptomatic subjects, whereas ACCD measurements are significantly different between the symptomatic and asymptomatic subjects.

Hence, it can be concluded that auscultation is mandatory in the examination of temporomandibular joint for clicking sound. Ultrasonography, which has shown high specificity, can supplement clinical evaluation in patients with TMJ disorders and can be used as a potential diagnostic tool for identifying internal derangement of the temporomandibular joint with reduction.