The role of closed-packed positions in the pathogenesis of temporomandibular joint internal derangements.

A hypothesis is presented as to how certain occlusal relationships and habitual patterns of jaw use may predispose an individual to TMJ internal derangements. Knowledge of diarthrodial joint biomechanics, in general, and the appreciation of close-packed positions of the TMJ, in particular, would not only provide the clinician with a greater discriminatory sense when diagnosing intracapsular problems but also help him to make better decisions and judgement about therapy. Popular treatment regimens, in particular those based upon the age-old Centric Relation concept, will be re-appraised.