The effect of precise reattachment of the mentalis muscle on the soft tissue response to genioplasty

Purpose: This study compares vertical and horizontal profile changes of the lower lip and chin after genioplasty with or without precise reattachment of the mentalis muscle. Patients and Methods: Ten patients in whom the mentalis muscle was isolated, identified, marked, and precisely reapproximated comprised the study group. Eleven patients treated without precise reattachment of the mentalis comprised the control group. Preoperative (3 to 6 days before the surgery) and postoperative (6 months after surgery) lateral cephalograms were analyzed to assess the horizontal and vertical soft tissue changes of the lower lip and chin area. Results: All the significant changes in the present study were noted in the vertical parameters. In most of the study group, the length of the lower lip was either maintained or increased. In the control group, the lower lip length was either preserved or decreased. The mean vertical difference between the 2 groups was nearly 6 mm. Consequently, the study group displayed the same or less of the lower incisors postsurgery compared with the original presurgery exposure in the rest position. The opposite was true for the control group, in which the exposure of the lower incisor crowns at rest increased. Similar changes were noticed in the distance from the vermilion to the reference plane. The vertical position of the soft tissue supramentale remained unchanged in the study group, whereas in the control group the soft tissue supramentale was located in an inferior position (mean = 2.14 mm). The clinical expression of this phenomena is chin ptosis. Conclusions: Precise reattachment of the mentalis muscle during an intraoral surgical approach produces a superior result.