Determining primates bite force from histological tooth sections.

Area of Science:

• Paleontology
• Biological Anthropology
• Biomechanics

Background:

• Estimating primate bite force (BF) is crucial for biological anthropology.
• Traditional methods require complex analyses and complete cranial morphology.
• A simpler method using fossil teeth is needed.

Purpose of the Study:

• Propose a simple method to determine primate bite force (BF).
• Utilize data from histological sections of fossil teeth.
• Link BF to evolutionary trends in primates.

Main Methods:

• Examined molar teeth sections from 27 extinct and extant primate species.
• Measured enamel thickness (d_c) and dentin horn angle (φ) in cusp regions.
• Used finite element analysis to determine cusp fracture force (P_F) and linked it to BF.

Main Results:

• Established a conclusive link between d_c and φ, yielding a constant P_F and BF.
• Derived an explicit formula relating BF to d_c and φ.
• Found strong correlations between BF, molar crown area, and body mass in nonhominins; hominin BF is gender-averaged.

Conclusions:

• Fracture mechanics applied to tooth histology provides a novel way to determine primate BF.
• This method offers quantitative insights into evolutionary trends related to crown area, body mass, and BF.
• The approach can be extended to other mammals with asymmetric cusp structures.