Joint play movements of the temporomandibular joint: clinical considerations

During the voluntary mandibular movements produced by various combinations of medial and lateral pterygoid muscle activity, the mandibular condyle is confined to a line roughly parallel to the articular surface of the temporal bone. Techniques using involuntary joint-play movements of the temporomandibular joint (TMJ) can move the condyles downward or mediolaterally. Condylar distraction is accomplished by application of a downward force to the patient's posterior molar and a simultaneous upward force to the patient's chin. Variations, such as addition of a forward component to the distraction, or bilateral distraction (requiring an assistant to stabilize the patient's head), are often used. Lateral condylar movement requires application of a gentle lateral force to the lingual surface of the patient's posterior molar, as an opposite force is applied to the anterior part of the patient's mandible. These joint-play procedures are indicated initially, in TMJ evaluation, or during treatment of TMJ hypomobility. However, these techniques must be used cautiously if the joint is inflamed, as indicated by tenderness to palpation. TMJ evaluation requires gentle downward and lateral movements, while treatment of TMJ hypomobility may require alternation of forceful distraction and gentle lateral movements. Hypomobility due to an anteriorly displaced disc requires a strong distraction to reduce the disc and a removable dental prosthesis to maintain it in its correct position as the posterior ligament retracts. These joint play techniques are valuable in restoring function to the TMJ.