An algorithm of facial aging: verification of Lambros's theory by three-dimensional stereolithography, with reference to the pathogenesis of midfacial aging, scleral show, and the lateral suborbital trough deformity.

An algorithm of facial aging is presented that serves as the conceptual basis for understanding aesthetic surgical principles and techniques. This model begins with the verification of Lambros's theory of skeletal remodeling. It was suggested that bony changes of the midface may be summarized as a clockwise rotation of the midface relative to the cranial base. Three-dimensional stereolithography/rapid prototyping was used to test this hypothesis. A precisely duplicated facial skeleton was created for young and old men (n = 12) by laser polymerization. Angular measurements confirmed that the angle of the pyriform and maxilla decreased with age (p = 0.004 and 0.005, respectively); there was a trend for the angle of the glabella (frontonasal angle) and orbits to do the same. These results validate Lambros's theory, which serves as a basis to further comprehend the pathogenesis of midfacial aging and the formation of ectropion and scleral show. The algorithm of facial aging is extrapolated from these data, from previous research, and from clinical observation. This model encompasses three main concepts or tenets, and it may serve as a clinical tool for the diagnosis and treatment of facial aging.