Development and function of the mandibular symphysis in mammals [abstract]

Abstract

The mandibular symphysis is the midsagittal articulation between left and right dentaries that is the third jaw joint of the mammalian feeding complex. There is remarkable evolutionary diversity in symphyseal anatomy that characterizes postnatal growth. It varies from the primitive mammalian condition of smooth joint surfaces loosely connected by a fibrocartilage pad and ligaments to a more tightly bound joint with greater sutural complexity and numerous variably calcified ligaments to an ossified joint. Unfortunately, load-induced responses of jaw-joint connective tissues are incompletely documented in growing mammals. To address this gap we investigated the proportions and composition of symphyseal tissues in growing rabbits subjected to diet-induced variation in masticatory stresses.