Anatomy of the mouth and related structures: Part II. Musculature of expression

Abstract The complex interplay of bone and musculature becomes apparent in even a limited analysis of facial expression. The complexity continues in any attempt to analyze further functions of speech, respiration, mastication, and deglutition, all of which are processes occurring in the arena of the pyramid previously delineated. Analyses of functions of facial expression and speech and the study of dissections of the muscles of facial expression indicate that certain of these muscles, acting as combined units and attached to fixed and movable bone, may play a role in mandibular movements associated with the functions of speech and facial expression. These functions and their interassociations will be considered in the next article of this series.