THE CHIN - SKELETAL AND SOFT-TISSUE COMPONENTS

The quantity of soft tissue overlying the symphysis menti affords an i mportant attribute that can aid in determination of the correct surgic al approach for optimal facial harmony. Xerograms of the facial profil e of 100 patients with normal occlusion were analyzed by accepted radi ographic cephalometric techniques. The relative contribution of skelet al structures and soft tissue of the chin was evaluated. All linear me asurements were noted to be larger in males than in females, but in bo th groups, facial features were in proportion. In both males and femal es, the average thickness of the soft tissue overlying the symphysis m enti progressively increased from the B point to midway between the B point and the pogonion. The soft tissue at the pogonion was thinner th an at the B point. The soft tissue over the chin in males was signific antly thicker than in females in all areas measured. When compared wit h patients over 60 years of age, the soft tissue at the B point was si gnificantly thinner in patients 50 years of age and younger (p = 0.005 ), while the soft tissue at the pogonion was significantly thinner in patients 40 years of age and younger (p = 0.04). Pseudomacrogenia was noted in 6 percent of the patients, a diagnosis only possible with cep halometric analysis. An understanding of the relative contribution of the soft tissue to the chin can aid in the diagnosis and appropriate s urgical management of chin incongruity. Furthermore, there is signific ant variation in skin thickness, which will influence the soft-tissue response to skeletal alteration. This has to be considered in planning a predictable surgical result.