Sonographic Measurement of Condylar Translation, Joint space and Mouth Opening in Healthy and Subjects with Temporomandibular Joint Disorders

Objectives: A sonographic approach can be used to quantify joint movement, muscle thickness, and available joint space. This study aimed to compare the amount of mouth opening, joint articular distance, and both anterior and inferior translation of the mandibular condyle between healthy participants and individuals with temporomandibular joint (TMJ) disorders. Methods: A cross-sectional study design was used with 52 participants (control: 26 healthy and TMJ: 26 symptomatic individuals) recruited using convenience sampling. The joint space distance and the anterior and inferior condylar translation on both sides were evaluated using sonography during maximum mouth opening and closing. Mouth opening was measured with a graduated ruler. Reliability was performed on a subgroup (n=10) with an interval of 3-7 days. Results: The reliability was good to excellent (ICC=0.57-0.94). The highest reliability was related to the joint space distance. The mean values for mouth opening were 43.1 and 35.3mm, respectively for healthy and TMJ patients. The anterior condylar translation was 7.14-7.57mm, inferior condylar translation was 2.35-2.66mm, and the joint space distance was 49.4-0.44mm. No significant differences were found between the left and right sides in either group. The mouth opening and joint space values were significantly higher in the healthy group while the rate of anterior transition movement was higher but not significant. Furthermore, there was a significant negative relationship between pain, mouth opening, and joint distance. Discussion: Sonography can be considered an accurate tool for the assessment of joint space and condylar translation in individuals with symptomatic TMJ disorders.