A comparative study of surgical techniques on the cervicomental angle in human cadavers.

BACKGROUND: The cervicomental (CM) angle is formed by the horizontal plane of the submental region and the vertical plane of the neck. OBJECTIVE: To compare the 2-dimensional effect of 4 surgical techniques on the CM angle in a human cadaver model. DESIGN: Anatomic presurgical and postsurgical comparative study performed on human cadavers preserved with ethylene glycol. SETTING: Academic medical research center in St Louis, Mo. SUBJECTS: Twelve cadaver specimens with obtuse CM angles with heads attached to the sternum and upper thorax. INTERVENTIONS: Standard superficial musculoaponeurotic system rhytidectomy techniques were performed on all cadaver heads. Four techniques were compared: (1) platysmal plication; (2) platysmal plication and plication of the anterior bellies of the digastrics; (3) platysmal plication, plication of the anterior bellies of the digastrics, and interlocking mastoid-to-mastoid sutures; and (4) platysmal plication and interlocking mastoid-to-mastoid sutures. MAIN OUTCOME MEASURES: The comparative changes in CM angle, the distance between the mentum and CM angle (mentum-CM distance), and the distance between the sternum and CM angle (sternum-CM distance) obtained with each of the 4 surgical techniques. Anatomic characteristics of the cadavers were also noted. RESULTS: On average, the CM angle was significantly reduced after all procedures (P<.001). The mean sternum-CM distance increased significantly (P =.01). A trend toward significance was observed in the change in mentum-CM distance (P =.10). The presence of a low hyoid was significantly associated with a smaller CM angle after surgery (P =.009) and demonstrated a trend toward significance with an increase in mentum-CM distance (P =.07), but it was not significantly associated with an increase in sternum-CM distance (P =.58). After controlling for the presence of a low hyoid, the mastoid-to-mastoid suture significantly reduced the CM angle by approximately 11.3 degrees (P =.002) and the sternum-CM distance by 1.15 cm (P<.001). CONCLUSIONS: The CM angle and the sternum-CM distance were significantly affected by all procedures. The addition of the mastoid-to-mastoid suture had the greatest effect on the CM angle, and the reduction in CM angle was strongly associated with an increase in the sternum-CM distance. Presence of a low hyoid was the only preoperative factor associated with a significant postoperative reduction in CM angle.