Examination of the Heads of the Lateral Pterygoid Muscle on the Temporomandibular Joint

The lateral pterygoid muscles (LPMs) function as a unit during precise mandibular positioning movements that occur during such activities as speech, singing, or playing musical instruments. The LPM has been the focus of an attempt to explain problems associated with the temporomandibular joint and anterior displacement of the meniscus of the joint. The aim of the study was to define the general morphology, describing the position and shape of the heads of the LPMs. In the course of dissection, the heads of the LPMs were noted, as well as the pattern, position of the origin and insertion, and course under 2.5x loupe magnification in 25 adult male human cadavers. The LPM has the general form of an irregular pyramid that narrows progressively toward the front. As a result of the macroscopic examination, the LPM was found to originate, with 3 heads as the Superior LPM (SLIM), the inferior LPM (ILPM), and inner LPM. It was realized that the ILPM width was 3 times more than that of the SLPM. The SLPM ending fibers of LPM had a more tendinous structure compared with the ILPM ending fibers. The SLPM and ILPM were observed as being adhered mostly to the pterygoid fovea. The study has shown that the muscle has atypical penniform structure made up of 8 tendinous layers that were particularly well developed. It is an indisputable fact that the success in surgical strategy and planning mainly relies on the surgeon's knowledge of the variable origins and insertions of the LPM.