Primary Maxillary Deficiency Dentofacial Deformities: Occlusion and Facial Esthetic Surgical Outcomes.

PURPOSE: The purpose of this study was to document the malocclusion and facial dysmorphology in patients with primary maxillary deficiency (PMD) and chronic obstructive nasal breathing before treatment and the outcomes after bimaxillary orthognathic, genioplasty, and intranasal surgery.

MATERIALS AND

METHODS

A retrospective cohort study of patients with PMD undergoing bimaxillary orthognathic, chin, and intranasal surgery was implemented. The predictor variables were grouped into demographic, anatomic, operative, and longitudinal follow-up categories. The primary outcome variables were the initial postoperative occlusion achieved (T2; 5 weeks postoperatively) and that maintained long-term (T3 or T4; >2 years after surgery). Six occlusion parameters were assessed: overjet, overbite, coincidence of dental midlines, Angle classification, and molar vertical and transverse positions. A second outcome variable was facial esthetic results. Photographs were analyzed to document 7 facial contour characteristics.

RESULTS

Sixty-six patients met the inclusion criteria. Age at operation averaged 22 years (15 to 55 yr). The study included 18 women (27%). Most patients (57 of 66; 86%) achieved and maintained a favorable occlusion for each parameter studied long-term (mean, 5 yr). The need for a 3-segment Le Fort I was strongly associated with long-term posterior malocclusion. Facial dysmorphology before surgery included the appearance of a prominent chin (56%), flat labiomental fold (61%), prominent lower lip (88%), prominent nose (77%), sunken midface (100%), flat cheekbones (82%), and recessed upper lip (73%). Before surgery, 82% of patients exhibited at least 5 of the 7 key facial contour deformities. Correction of all 7 facial contour deformities was confirmed in 92% of patients in the long-term. In 8% of patients, an overly prominent-appearing chin persisted.

CONCLUSION

Using orthognathic techniques, most patients with PMD achieved and maintained a corrected occlusion long-term. In unoperated patients, a "facial esthetic type" was identified. Bimaxillary orthognathic and chin surgery proved effective in correcting associated facial dysmorphology in most patients.