Improvement of chin profile after mandibular setback and reduction genioplasty for correction of prognathism and long chin.

摘要

This study evaluated the changes in the chin profile after using mandibular setback and vertical chin reduction genioplasty to correct mandibular prognathism associated with a long and flat chin.Sixteen consecutive patients (6 male and 10 female) underwent surgery at a mean age of 22.6 years (range = 18.2-27.8 years). The evaluation consisted of hard and soft tissue analysis before and after treatment.The results showed that improvement in facial profile, chin contour, and dental occlusion was achieved. After an average of 9.4-mm mandibular setback and 5.1-mm vertical osseous chin reduction, the thickness of soft tissue pogonion was increased by 4.0 mm, the supramentale thickness was increased by 1.8 mm, and lower-lip thickness was increased by 1.6 mm. Thus, the mentolabial fold increased from 3.4 to 4.7 mm and the mentolabial angle decreased from 153.4 to 136.9°. The vertical lip:chin ratio became normal.The results of this study demonstrated that mandibular setback combined with vertical chin reduction genioplasty offers an alternative for the treatment of patients suffering from mandibular prognathism with a long, nonprojecting chin. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article.