The disc is thick all around its rim, and thin in the centre. From anterior to posterior it shows – anterior extension, thick anterior band (2.0mm thick), intermediate thin zone (1.0 mm thick), thick posterior band (3.0 mm thick) and posterior most bilaminar region (Dubrul, 1996; Williams et al, 1999). The disc is attached all around the joint capsule except the strong straps those fix the disc directly to the medial and lateral condylar poles which ensures that the disc and condyle move together in protraction and retraction (Choukas and Sicher, 1960; Williams et al, 1999). The anterior extension of the disc is attached to fibrous capsule superiorly and inferiorly and through that to temporal bone and the mandibular neck respectively. In between it gives insertion to lateral pterygoid muscle where the fibrous capsule is lacking and synovial membrane is supported only by loose areolar tissue. In the opinion of Kreutziger and Mahan (1975), this deficiency anteriorly is the weak point since there is no fibrous resistance to hypertranslation. Apart from lateral pterygoid, anteromedially, there are attached some fibres of masseter and temporalis laterally. Although more than one muscle is inserted into the disc, majority of the interest has been focussed on lateral pterygoid, whose deep position, unfortunately makes it difficult to investigate under natural conditions (Moore). Continue reading →