The ontogeny of maximum bite force in humans

• Published in: Journal of anatomy Vol. 237; no. 3; pp. 529 - 542
• Main Authors: Edmonds, Hallie M., Glowacka, Halszka
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.09.2020; John Wiley and Sons Inc
• Subjects: Adductor muscle; bite force; Biting; Chewing; constrained lever model; Dentition; humans; jaw adductors; Juveniles; Mastication; Minors; Ontogeny; Original Paper; Original Papers; Teeth; bite force; constrained lever model; jaw adductors; humans; ontogeny
• DOI: 10.1111/joa.13218
• ISSN: 0021-8782; 1469-7580

Ontogenetic changes in the human masticatory complex suggest that bite force, a key measure of chewing performance, increases throughout growth and development. Current published bite force values for humans exist for molar and incisal biting, but few studies measure bite forces across all tooth types, or measure bite force potentials in subjects of different ages. In the absence of live data, models of bite force such as the Constrained Lever Model (CLM), are employed to predict bite force at different bite points for adults, but it is unclear whether such a model can accurately predict bite force potentials for juveniles or subadults. This study compares theoretically derived bite forces and live bite force data, and places these within an ontogenetic context in humans. Specifically, we test whether (1) patterns of maximum bite force increase along the tooth row throughout ontogeny, (2) bite force patterns estimated using the CLM match patterns observed from live bite force data, and (3) changes in bite forces along the tooth row and throughout ontogeny are associated with concomitant changes in adductor muscle leverage. Our findings show that maximum bite forces increase throughout ontogeny and change along the tooth row, with the highest forces occurring at the posterior dentition. These findings adhere to the expectations under the CLM and validate the model’s utility in predicting bite force values throughout development. Furthermore, adductor muscle leverage values reflect this pattern, with the greatest leverage values occurring at the posterior dentition throughout ontogeny. The CLM informs our study of mammalian chewing mechanics by providing a model of how morphological changes of the masticatory apparatus during ontogeny affect bite force distribution along the tooth row. Furthermore, the decreased bite force magnitudes observed in juveniles and subadults compared with adults suggest that differences in juvenile and subadult diets may partially be due to differences in bite force production potentials. Using humans as a model, we measured how maximum bite forces changed across the tooth row throughout ontogeny. We found that the highest forces are produced by the posterior dentition, which supports the predictions under the Constrained Lever Model. By comparing live bite force data to predicted values from this model, we validated its utility to predict bite forces throughout growth and further contribute to our understanding of how the growing masticatory system produces increased bite force.