The anatomic relationship of the insertion of the superior lateral pterygoid muscle to the articular disc in the temporomandibular joint of human cadavers.

Confusion has existed as to whether the major insertion of the superior lateral pterygoid muscle is into the articular disc or the condyle. Five human cadaver joints were studied under the dissecting microscope. This allowed superior lateral pterygoid fibres to be selectively placed under tension to determine their point of insertion and to examine the integrity of the anterior joint capsule. All superior lateral pterygoid fibres gained either direct or indirect insertion to the condyle. A classification for the variation in insertion is suggested. The fibres of the anterior joint capsule extended from the anterior rim of the condyle to the roof of the infratemporal fossa but under the foot of the disc they blended with and became indistinguishable from disc fibres.