Characteristics and corrective outcome of face asymmetry by orthognathic surgery.

PURPOSE: This study was conducted to identify the characteristics of facial asymmetry before surgery and to evaluate the facial skeletal changes and stability after 2-jaw orthognathic surgery. The ideal "double-cross grid" as fitting the key landmarks to the reference planes on posteroanterior cephalograms was set as the treatment goal.

PATIENTS AND

METHODS

Twenty-seven adult patients, 18 female and 9 male subjects, were evaluated before and after surgery and at completion of orthodontic treatment. Cephalometric measurements of posteroanterior and lateral cephalograms were obtained at 3 timings. Measurements of frontal facial photographs were recorded before and after treatment. Data from each time set were compared to evaluate surgical achievement and postsurgical stability.

RESULTS

All patients had original malocclusion of Class III in at least 1 side of the dentition except 1 patient. Total treatment duration was 15 +/- 3.5 months on average. Laterality of the patients demonstrated left-side dominance in 18 patients and right-side dominance in 9 patients. After surgery, face symmetry was improved by correction of the occlusal plane cant, incisal dental axis, and chin deviation. Symmetry of bilateral gonial width was also improved significantly with good stability. Intergonial width was reduced by 3.4 mm during treatment. Soft tissue presented similar correction by leveling oral commissures and correcting chin deviation. The maxilla was moved forward 1.25 mm and upward 1.20 mm, and the mandible was setback 4.3 mm and upward 1.5 mm as measured from lateral cephalograms. All sagittal changes remained stable after surgery.

CONCLUSION

Fitting skeletal landmarks into a double-cross grid on posteroanterior cephalogram is an attainable guide and goal for 2-jaw orthognathic correction of facial asymmetry. Symmetry was achieved and facial profile was improved after surgery and remained stable afterward. The decrease of intergonial width indicated considerable remodeling of the bilateral gonial angle after surgery.