The potential role of stereolithography in the study of facial aging.

The potential role of high-resolution stereolithography for the study of facial aging was evaluated. Stereolithography has been used extensively in the engineering sciences to create model replicas prior to full production. More recently, stereolithography has found a role in the preoperative planning of complex dentofacial anomalies. Previous work has suggested that continued differential growth of the maxilla may occur throughout life. To further evaluate this finding, computed tomography scans were collected from younger (mean, 20.2 years) and older (mean, 58.8 years) individuals (N = 20). Both men and women were included. An exact replica of the facial skeleton was made for each subject by the process of laser polymerization. The angles of the maxillary wall and piriform aperture, defined by specific points, were measured relative to sella-nasion. Height, width, and depth changes were also evaluated. Findings show that angular changes occurred with age. The mean angle of the maxilla relative to sella-nasion decreased from 69 degrees to 56.8 degrees with age (P =.015). The mean angle of the piriform likewise decreased from 65.1 degrees to 55.7 degrees (P =.019). This angular change with age suggests that differential growth may continue throughout life. This work highlights the potential role of 3-dimensional modeling for future research in the field of facial aging. Curve and contour analysis are 2 additional areas in which stereolithography may yield valuable insights into the mechanisms of facial growth.