“Spontaneous” correction capacity of skeletal Class II malocclusions in growing patients after upper and lower arch coordination using fixed appliances: A prospective controlled clinical study

Abstract

ObjectiveTo determine the effect of arch coordination on the dentoskeletal jaw base relationship and the mandibular growth pattern in growing skeletal Class II patients. Materials and MethodsLeveling, aligning, and upper/lower arch coordination were done in 30 Class II/1 growing patients with preadjusted edgewise fixed appliances. After arch coordination was achieved without transverse discrepancy and occlusal interferences, the 6-month experimental passive observation period was started. The records were compared with 30 untreated patients who served as controls. The initial (T0) and post-coordination+observation (T1) cephalograms of two groups were analyzed and compared using standard cephalometric parameters, Pancherz analysis, and cranial base superimposition. ResultsSagittal maxillary growth in the treated group was slightly restricted, in turn resulting in a decrease in profile convexity. Mandibular sagittal growth did not differ between groups, but the mandible rotated posteriorly in the treated and anteriorly in the control group. The upper incisors were retroclined and retruded in the treated group, resulting in overjet reduction. The lower incisors were intruded in the treated group, leading to overbite reduction. The cephalometric superimposition over the stable structures of the anterior cranial base showed higher prevalence for the forward rotation with forward pogonion position and increased vertical dimension in the control group. ConclusionsUpper and lower arch coordination alone does not seem to affect mandibular growth; however, because of a posterior rotation of the mandible, it does affect the direction of mandibular growth in some patients, although not in the desired therapeutic direction. (ClinicalTrials.in.th: TCTR20170706003).