Outcome differences after orthodontic camouflage treatment in hypo- and hyperdivergent patients - A retrospective cephalometric investigation

Abstract

Objectives To compare diferences in outcome in skeletal and dental parameters in hypo- and hyperdivergent Class II patients after extraction of upper frst premolars and comprehensive orthodontic treatment. Materials and methods 37 Class-II-patients with dental camoufage treatment were divided into a hypo- (n=18) or a hyperdivergent (n=19) group depending on the mandibular plane angle (hypo:<34° or hyper:≥34°). Lateral cephalograms were available before (T1) and after (T2) treatment and were analyzed with customized measurements. Data from a growth survey served as a control and were used to calculate the actual treatment efect. Data were analyzed by one-sample Student’s t-tests and independent Student’s t-tests. Statistical signifcance was set at p<0.05. Results The measurements showed similar changes in both groups. The efects were mainly dentoalveolar. Hypodivergent patients showed an almost equal increase in anterior and posterior facial height, while hyperdivergent patients only showed an increase in anterior facial height. Conclusions In hyperdivergent patients, the anterior facial height increases despite camoufage treatment. This indicates a tendency towards bite opening and backward rotation of the mandible. Hypodivergent patients do not experience deepening of the bite. Clinical relevance In hyperdivergent patients with upper frst premolars extraction the anterior facial height increased diferently than in hypodivergent patients. This should be considered if a bite opening is a possible contraindication to treatment.