CROSS-SECTIONAL AREA OF THE MANDIBLE

Purpose: The anatomy of the mandible was examined by measuring the cro ss-sectional area (CSA) of multiple regions of 10 fully dentulous hemi mandibles to provide a better understanding of regional structural dif ferences that may have implications regarding biomechanical strength, surgical reconstruction, and fracture site frequency. Materials and Me thods: Fifteen cuts from the condyle to the symphysis were made of eac h hemimandible (n = 150 cuts). A Zeiss Videoplan digitizer was used to determine the CSA. Results: The total CSA through the condyle was gre ater than the CSA through the condylar neck, The GSA through the ramus exceeded that of the condylar neck, The total CSA of the midramus was significantly greater than that of the upper ramus. The total CSA at the body, parasymphysis, and symphysis was significantly greater than at the mid-angle. The total CSA of the cortex increased anteriorly; th ese differences become significant between the condylar neck and the b ody, parasymphysis, and symphysis, The total CSA, and the CSA of the c ortex and spongiosa, remained relatively constant from the inferior an gle anteriorly. Conclusions: Significant differences exist in the CSA at different points, with an increase in the total, cortical, and spon giosal CSA anteriorly from the condylar neck to the angle. The total C SA and the CSA of the cortex and spongiosa remain relatively constant anterior to the inferior angle, These data suggest that bony CSA alone is not the sole factor in determining fracture site frequency.