Clinical study of the skeletal Cl III malocclusion patients after 2-phase surgical-orthodontic treatment

ABSTRACT

The purpose of this study was to evaluate the result after 2-phase surgical-orthodontic treatment without preoperative orthodontic treatment for the skeletal Cl III malocclusion patient and to obtain an adequate protocol on the bases of this result. This retrospective study of ten patients who underwent 2-phase treatment were done to evaluate 1) the surgical stability and relapse pattern 2) the facial esthetics 3) the TMJ problem 4) the total time of the treatment. Results were followed 1) The horizontal relapse of the mandible was 26.8% and didn't show significant differences compared to the conventional 3-phase treatment. But, it was considered that this amount of relapse was the sum of true relapse and autoratation of mandible due to decreased vertical dimension during orthodontic treatment. 2) It was estimated that there's no difference on the ratio of anterior facial height between the subjects and the normal patients. On the horizontal analysis, the mandible of the subjects was located more anteriorly than that of the normal patients. This result showed that there was a need for the accurate preoperative esthetic evaluation and the additional methods for reducing the relapse due to the occlusal interference. 3) Wide variation was noted on the TMJ symptoms of the subjects, however, it was estimated that there's no significant differencees of symptoms compared to that of the conventional 3-phase treatment on literatures. 4) The average of the overall period of treatment was 20.8 months and we obtained reduction of the treatment time compaired to 3-phase treatment on many literatures. Most of the results of this study were similar to the findings of the 3-phase treatment(preoperative orthodontic-orthognathic surgery-postoperative orthodontic), but total time of the treatment was shorter in patients with 2-phase treatment than in those with the conventional 3-phase treatment. With 2-phase treatment, we experienced many advantages compared to the conventional method considering that it was favarable conditions for the teeth, it had the flexibility for the treatment, and it could be the adequate treatment approach for the stomatognathic system. Although this retrospective pilot study had some limitations, due to small samples, the authors would hope that it could serve as a guide for the future reaearches, and the clinical applications.