Meeting Abstract

P3.93  Sunday, Jan. 6  3D Kinematics and Muscle Activity Pattern During Mastication in Ferrets (Mustela putorius furo) DAVIS, JS*; SIDOTE, J; MONTUELLE, SJ; WOOD, R; WILLIAMS, SH; Ohio University; Ohio University; Ohio University; Ohio University; Ohio University jd330008@ohio.edu

Jaw movements and adductor muscle activity were simultaneously recorded during mastication in adult ferrets (Mustela putorius furo) using biplanar fluoroscopy and electromyography. Reconstruction of masticatory movements using XROMM facilitated the observation of movements of the mandibular symphysis and condyles. An average ferret chewing cycle lasts approximately 300 ms, of which roughly 60% is opening and 40% is closing. Initial puncture crushing cycles are characterized by a distinct slow-opening phase (approximately 60% of total jaw opening) in which the jaw is steadied by the balancing side posterior temporalis while the tongue is used to position the food. During opening, the dentaries rotate around their long axes causing the eversion of the alveolar margins and separation of the mandibular symphysis. Maximum separation of the symphysis occurs during fast-opening. During closing, the alveolar margins invert, and occlusion at the carnassial teeth drives the working-side dentary to invert further, supporting the hypothesis that tooth occlusion drives masticatory movements during the power stroke. As the pellet is further reduced, both closing and fast opening become relatively shorter components of the chewing cycle. Despite a relatively constrained TMJ due to a tight glenoid fossa, mediolateral translation of the condyle occurs. However, there is very little anteroposteror translation, consistent with the restrictions imposed by the well-developed pre- and postglenoid processes.