Variations of the attachment of the superior head of human lateral pterygoid muscle

IntroductionThe superior head of the lateral pterygoid muscle (LPM), is closely related to the temporomandibular joint (TMJ) and plays a role in the aetiology of temporomandibular disorders. Increased activity of this muscle has been implicated in the anterior displacement of the TMJ disc. However, there is uncertainty about the manner of the LPM attachment to the disc–condyle complex.AimThe aim of this study was to investigate the exact anatomy of the attachment of the superior head of the LPM (SLPM) to the disc–condyle complex of the TMJ.Material and methodsThirty-six TMJs were examined – both sides of 18 Greek cadavers (eight males and 10 females, mean age 79.6 years). Examination of the attachment of the SLPM was undertaken viewed under the dissecting microscope.ResultsVariation in the attachment of the SLPM was categorized into three types: in type I, the SLPM inserted into the condyle and the disc–capsule complex (55.5%). In type II, the SLPM only inserted into the condyle (27.8%). In type III, the SLPM inserted purely into the disc–capsule complex (16.7%).ConclusionsThis study demonstrates that there are three different attachment types of the SLPM to the disc–condyle complex. The type III variation could be involved in the TMJ pathology. The knowledge of the variations of the SLPM attachment could be useful for precise surgical and pharmaceutical approaches.