An assessment of impact strength of the mandible

Abstract

In this study, an animal biomechanical study was performed to investigate the absorbed energy and impact strength of the mandible in relation to specimen position. Four regions of mandibles were loaded as complete pieces and gripped by the jaw of an Izod impact tester. All tests were carried out wet using the Izod impact test under two different impact loading directions, lateral and ventral. Absorbed energy and impact strength in kilojoules per square meter of specimen area were determined for each specimen. Under lateral impact loading, the absorbed energy was lowest for the anterior section due to the mental foramen's notch effect. The premolar region demonstrated more absorbed energy per unit area, or impact strength, than any other region. However, due to its small cross-sectional area, the premolar region also absorbs less impact energy. Under ventral impact loading conditions, anterior region absorbed twice as much impact energy than under lateral loading conditions. Premolar region absorbed the same impact energy under both lateral and ventral loading. Interestingly, mandibular angle under ventral loading absorbed five times more impact energy than under lateral loading. This behaviour is considered to be a mechanical adaptation to the actual loading of the mandible in vivo. © 2008 Elsevier Ltd. All rights reserved.