Occlusal force after mandibular advancement in adult rhesus monkeys.
Maxillofacial surgery not only alters facial appearance and occlusion but also affects the morphology, physiology, and biomechanics of the craniofacial skeleton and the muscles of mastication. This study was performed to evaluate one aspect of craniofacial function--maximum stimulated bite force (BF)--after mandibular advancement. BF in the molar region was measured with a transducer during muscle stimulation in 63 rhesus monkeys that had been divided into two groups: a control group of various ages and sexes (n = 50); and an experimental sample of 13 monkeys that had undergone mandibular advancement via C-osteotomy at least one year prior to BF measurement. Biomechanical analysis of lateral cephalograms was performed to estimate the amount of the change in BF in the experimental group that could be attributed to alteration of craniofacial form. Regression analysis demonstrated a significant relation between molar bite force and weight in control animals (r = 0.94). In the monkeys that underwent surgery, BF values were an average of 16.7% less than those found for the control animals relative to body weight. However, the biomechanical analyses suggested a smaller and less variable BF loss in the operated monkeys (11.6%). These results indicate a greater and more variable change in BF following mandibular advancement than would be predicted on the basis of biomechanical considerations.
Dechow
P C
PC
Carlson
D S
DS
D000818:Animals; D001696:Biomechanical Phenomena; D001732:Bite Force; D002508:Cephalometry; D003766:Dental Occlusion; D004558:Electric Stimulation; D005260:Female; D005544:Forecasting; D008253:Macaca mulatta; D008297:Male; D008334:Mandible / Q000502:physiology / Q000601:surgery*; D008410:Masticatory Muscles / Q000502:physiology; D008954:Models, Biological; D008963:Molar / Q000502:physiology; D010027:Osteotomy / Q000379:methods