A mathematical model for hypothetical force distribution between opposing jaws

Area of Science:

• Biomechanics
• Anthropology
• Dental Anatomy

Background:

• The traditional view of the lower jaw (mandible) as a simple Class III lever may oversimplify its complex biomechanical function.
• Understanding the forces acting on the mandible is crucial for fields ranging from anthropology to dental implantology.

Purpose of the Study:

• To investigate the hypothesis that mandibular bite force is not solely determined by jaw length and lever class.
• To analyze the distribution of forces along the dental arch using a biomechanical model.

Main Methods:

• Measurements of relevant dimensions were taken from 58 dry human skulls (29 male) from the Dart Collection.
• A mathematical model was employed, incorporating force analyses in both sagittal and frontal planes.
• Calculated forces were mapped along a schematic dental arch.

Main Results:

• Calculated bite forces increased linearly along the dental arch model up to a point of maximum force (Fmax).
• Beyond Fmax, forces gradually decreased towards the posterior limit of the dental arch.
• The location of Fmax differed between sexes, occurring at 56.54 mm in males and 53.31 mm in females from the glenoid fossa baseline.

Conclusions:

• The lower jaw's force distribution is more complex than a simple lever model suggests.
• A specific point of maximum force (Fmax) exists along the dental arch, with variations between males and females.
• These findings have implications for understanding mandibular function and potentially for dental and orthodontic applications.