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.