Classification and Treatment of Prominent Mandibular Angle

Abstract.

In Oriental culture, the contour of the mandibular angle is important for feminine facial shape because a woman who has a wide and square face is thought to have had an unhappy life. A prominent mandibular angle, which does not coincide with the natural look, produces a characteristic quadrangle, coarse, and muscular appearance. So Oriental women who have a prominent mandibular angle want to have an ovoid, reduced, and slender face by aesthetic mandibular angle resection. Many satisfactory corrections of a prominent mandibular angle by various operative techniques have been reported. But reasonable morphologic classification and treatment were not reported. So we classified prominent mandibular angles into four groups by morphology and operated on the patients according to their classification with different modalities: no square shape but only a reduced gonial angle in the profile view—class I, mild form; severe mandibular angle protrusion with lateral protrusion—class II, moderate form; a definite square-shaped angle (class II) with masseteric hypertrophy—class III, severe form; and combined prominent mandibular angle and chin deformity—class IV, complex form. We use angle ostectomy through the intraoral route alone or with an additional external stab incision for class I. An external stab incision to set up the reciprocating saw is sometimes helpful in class I cases because there is no lateral protrusion of the angle. For class II cases, we use conventional intraoral angle ostectomy only or angle splitting ostectomy with contouring. For class III cases, we use angle splitting ostectomy and contouring with partial masseteric myectomy. In class IV, we use angle ostectomy and additional genioplasty. During 7 years, we have performed 46 cases of mandibular angle resection. Of the mandibular angle resection cases, 19 were class I, 15 were class II, 9 were class III, and 3 were class IV. A total of 42 patients were satisfied with the postoperative results. For reasonable and satisfactory final results, classification according to the mandibular angle shape and suitable treatment according to the classification are essential.