Fracture properties of the human mandible.

A total of seven human mandibles were struck to breaking point under standardised conditions using a pendulum. The cortical deformation for two impact directions was measured with strain gauge strips located at eight defined sites. Fronto-median impacts led to mostly bilateral and always multiple fractures in the posterior area of the bone, especially in the collum and the condyle. The fracture threshold was between 2.5 and 3.1 kN. Lateral impact caused fractures near the impact area as direct fractures of the ipsilateral corpus. Mainly single and double fractures were observed. For lateral impact the fracture threshold was between 0.6 and 0.8 kN.