Introduction: Calvarial bone grafts are widely used in craniofacial reconstruction. In order to evaluate the split calvarial donor site in cadavers, a study was designed to measure the thickness of calvarial layers using conventional caliper method versus computer imaging software (CANFIELD Imaging Systems).

Methods: The study population consisted of 75 cadavers, all of who were at least 54 years of age at the time of death. All cadavers were free from any suspicion of head trauma. Coronal sections were made at 2 cm and 6 cm posteriorly from the coronal suture line. Measurements of the total thickness, inner table, outer table, and diploe space were obtained with calipers. All measurements were made by the same individual. Photographs were taken of both the anterior and posterior views using a 5.0 mega pixel digital camera. The layers were comparatively measured using the software program by calibrating the measurements with a centimeter ruler that was photographed along with the calvarial section.

Results: The average age of the study group was 81.3 +/- 11.4 years with a range of 54 to 101 years of age. The mean total thickness of the calavarium varied from 6.82 mm +/- 1.54 mm at 2 cm to 8.43 mm +/- 1.73 mm at 6 cm using the caliper method. This was compared to computer measurement of 8.05 mm +/- 1.63 mm at 2 cm and 8.83 mm +/- 2.13 mm at 6 cm. There was no significant correlation between age and thickness of all layers for either the caliper method or the computer imaging method. There was a significant difference between the thickness of the outer table, inner table, and diploe space between the two methods (p<.001).

Conclusions: We determined that there was no correlation between age and calvarial thickness using both caliper and computer imaging methods. The difference in the analysis of the outer table, inner table and diploe space between the two methods could be due to the software's ability to enhance image size and clarity. Current investigations are under way to determine the source of the difference and the variability of the two approaches. Computer imaging may facilitate future planning for craniofacial reconstruction using the calvarium.