A novel chin-reductive drawer-genioplasty using subapical and mandibular contouring ostectomy

Abstract

Summary: As the most prominent feature of the lower face, the chin is crucial to human facial morphology and it plays a large role in contributing to facial attractiveness and harmony. Although an increasing number of genioplasty procedures are being introduced for chin augmentation, chin reduction procedures are rarely performed. Due to the inevitable cervicomental angle (CA) widening and relaxation of the floor-of-mouth muscles caused by chin shortening and the elevation of the lower edge of the mandible, chin reduction remains a challenging procedure. Our novel drawer-genioplasty approach involves a flexible chin-reducing procedure using subapical and mandibular contouring ostectomy. This technique can effectively shorten various long chins for improved facial proportions and maximize the floor-of-mouth muscle protection during surgery, thereby avoiding postoperative submental sagging. Several parameters, including the ratio between the lower (the subnasale to menton distance) and middle facial heights (the glabella to subnasale distance) (R1), the ratio between the anterior midline bone heights of the mandible (the stomion-to-menton distance) and maxilla (the subnasale-to-stomion distance) (R2), and the CA, were used to evaluate the outcome of the procedure. Comparing the preoperative and postoperative parameters revealed that there was a significant decrease in both R1 (1.25±0.15 versus 1.09±0.12) and R2 (1.94±0.24 versus 1.58±0.11). Although CA increased from 107.3±8.2° preoperatively to 112.4±7.0° postoperatively, this value was still within the normal range. In addition to providing effective and significant aesthetic improvements, the drawer-genioplasty is safe and involves no complications.