Meeting Abstract

90.11  Thursday, Jan. 7  Tooth Root Surface Area as an Indicator of Bite Force SELF, CJ; University of Washington, Seattle cjself@u.washington.edu

The tooth root provides attachment area for the periodontal ligament and an increase in root area may be advantageous for subsisting on harder food or having a larger bite force. The goal of this study was to determine if root surface area can act as a potential surrogate for bite force. Frugivory that does not involve seed processing is thought to be less challenging than insect crushing. If insects require more force to process, the relative tooth root surface area should be larger in insectivorous species when compared to fruigivores. Two frugivorous (Carollia perspicillata and Chiroderma vollosum) and two insectivorous bat species (Phyllostomus discolor and Macrotus californicus) were chosen for their potential force disparity during food processing. This study utilized 9 micron CT scans to allow accurate 3D measurement of tooth root surface areas. Surface areas from the mandibular cheek tooth row were measured for five specimens of each species. Mandible length was used to control for body size. The combined tooth root surface area of all teeth studied was not significantly different between the dietary groups, however the distribution varied. Insectivorous species had a larger relative tooth root surface area at the first molar (M1). Frugivores had larger root surface areas for the first and second premolars (P1 and P2). Root surface area varied along the tooth row, peaking at the M1 for insectivores and at P1 for Frugivores. Insectivorous species did exhibit the overall largest root surface area for the M1, but not at any other location. It is possible that the M1 is the primary processing location for these insectivores, while the frugivores produce the highest bite force near P1 and P2. Overall, these results indicate that tooth root surface area may be a reliable indicator of bite force, and could represent a record of habitually encountered oral forces.