Sliding osteotomy genioplasty for facial aesthetic balance: 10 years of experience.

The chin, one of the most obvious facial structures, plays an important role in the perception of the face as an instrument of communication. To alter the chin contour in a reliable manner, horizontal sliding osteotomy of the mandibular symphysis with advancement of the mobilized segment is the technique of choice for correction of the anterior posterior deficiency. This study describes surgical techniques used in aesthetic and functional surgery of the chin as well as the outcomes. Over a 10-year period, 474 patients underwent orthognathic surgery for correction of their malocclusion. Of these 474 patients, 155 were treated in combination with a sliding genioplasty (SGP) and 37 (29 women and 8 men; average age, 32 years; range, 18-47 years) had an isolated SGP. Of these patients, 33 had chin advancement and 4 had chin reduction. The mean chin advancement was a modest 4.5 mm (range, 2-7 mm), and the mean chin vertical displacement was 3.9 mm (range, 2.5-4.1 mm). All the patients in the mandibular deficiency group had a residual sagittal disproportion of the progonion relative to the subnasale (mean, -7.6 mm) and a newly created vertical disproportion, with mean lower face heights of 67.8 mm compared with mean midface heights of 65.3 mm. The surgical outcome was evaluated by analysis of pre- and postoperative photographs, analysis of pre- and postoperative measurements, and patients' self judgment. All the patients healed uneventfully without any major postoperative problems. Paraesthesia of the mental nerves occurs to some degree in almost all patients measured by the Simmon Weinstein diagnostic device. In the single sliding chin osteotomy group, no major branches of the mental nerves were transacted. Paraesthesia was only transient, usually lasting for only a few weeks. At least 1 year after the operation, normal sensitivity of the lower lip and both sides of the chin was reported by almost all of the patients (93.1%). All who had only a single genioplasty recovered totally from a neurosensory deficit. The level of satisfaction was significantly high for all the patients. The results were judged to be excellent in 73.2% and good in 23.6% of the cases. Only in 3.2% of the cases was it considered to be poor (bimaxillary surgery combined with SGP). The current findings strongly suggest that SGP is a reliable procedure for achieving harmony of the lower face. In addition, it permits a simplification of facial reconstruction and rejuvenation. The combination of chin advancement and submental recontouring can have a positive effect on facial appearance, provided the increased chin projection is appropriate.