Correlations between the loss of acoustic TMJ symptoms and alterations in mandibular mobility after surgical mandibular advancement.

A longitudinal clinical-axiographic study including 10 patients who had undergone surgical mandibular advancement to correct a dental and skeletal Class II anomaly, produced evidence of correlations between alterations of acoustic symptoms and of mandibular mobility. In 7 of 11 movements, where TMJ-sounds disappeared, post-operative mandibular mobility was reduced to such a degree that the point at which the acoustic symptom originated pre-operatively could no longer be attained. On the other hand, in all cases, where TMJ sounds remained uninfluenced by the surgical intervention, reductions in mobility occurred only beyond this point. Even the persistence of losses of TMJ sounds during the further post-operative follow-up period could, in the majority of cases (4 of 7) be well explained by the persistence of mobility restriction. Accordingly, in the future a differentiation between mobility- and non-mobility-dependent alterations of TMJ symptoms should be made.