Surgical And Non-surgical Orthodontic Treatment Of Adult Patients With Skeletal Class â…¢ Malocclusion: A Cephalometric Study

ObjectiveComparative Study on surgical and non-surgical orthodontic treatment of adult patients with skeletal class III malocclusion to provide guidance for clinic treatment.MethodsThirty-four adult patients with skeletal class III malocclusion after successful orhtodontic or orthognathic treatment were collected. Non-surgical group consisted of 15 patients(8 male and 7 female, with average age of 22.6 years'old)treated with edgewise appliance(straight wire appliance). Surgical group consisted of 19 patients(9 male and 10 female, with average age of 24.8 years'old) treated with conbined orthodontic and orthognathic surgery. Lateral cephalometric radiographs before and after treatment of each patients were analized. using Mann-Whitney u test statistical analysis of surgical and non-surgical patients before treatment measure differences; on all surgical and non-surgical patients according to ANB angle of 0～-2°,-2°～-4°,-4°～-6°,-6°～-8°, greater than-8°is divided into five groups, statistical analysis of surgical patients in each group and the proportion of non-surgical patients; using Mann-Whitney u test statistical analysis of non-surgical patients before and after treatment, surgery and surgical patients before and after treatment in patients with non-surgical treatment measure differences in statistical analysis whether there were significant differences.Results1. Before treatment, there was difference in cephalometric Variables, ANB angle, Ll-MP angle, ANS-Me, Li-E distance was statistically significant, (P< 0.01) which ANB to-2°can be a distinction in skeletal class III malocclusion between surgical and non-surgical groups.2. After treatment of non-surgical group there is a change ANB angle (P< 0.05), but still negative, does not meet the ClassⅠfacial form was not achieved. L1-MP angle was discreased from average 86.39°to average 78.65°(P< 0.01)and nomal anterior overjet and overbite was attained through lingual inclination of lower incisors.3. The hard tissue changes were focus on the mandible after the surgical treatment, ANB angle was obviously increased (P< 0.01) and class I facial form was attained with normal anterior overjet and overbite. more significant changes were found in the soft tissues, Z(from average 76.55°to average 70.66°) (P< 0.01), Ls-E(from average-1.55mm to average 2.10mm) (P< 0.01). Li-E(from average 4.06mm to average 0. 36mm) (P< 0.01)4. After treatment, there was significant difference in ANB angle and U1-L1 value between surgical and non-surgical groups(P＜0.01). In surgical group upright of lower anterior teeth was much higher(P＜0.01) and Ls-E distance(P＜0.01) was of significant difference compared with non-surgical group.Conclusionswe got conclusion from this study as follows:1. To treat ClassⅢmalocclusion, the ANB angle, L1-MP angle and the distance of ANS-Me, Li-E and the concave extent of soft profile should take thorough consideration;2. ANB<-2°patients should be treated by orthognathic surgery, ANB＞-2°skeletal ClassⅢpatients should be based on non-surgical therapy. Surgery and non surgical critical value is ANB angle of-2°.3. Skeletal class III malocclusion with permanent dentition could be successfully treated with straight wire appliance technique and soft tissue profile could be improved. Skeletal deformity was corrected to certain degree.4. SkeletalⅢmalocclusion treated with orthodontic and orthognathic surgery could achieved class I skeletal pattern and soft tissue profile could be dramatically improved. Treatment effect of orthognathic surgery on skeletal deformity was obviously better than non-surgical treatment.