Effects of fixed functional orthodontic treatment in hypodivergent and hyperdivergent class II patients-a retrospective cephalometric investigation

ObjectiveTo compare skeletal and dentoalveolar changes after orthodontic treatment of class II malocclusion in patients with hypodivergent and hyperdivergent growth patterns through cast splint fixed functional appliances (FFA).Materials and methodsN = 42 out of n = 47 patients with mandibular plane angles < 34 & DEG; or & GE; 34 & DEG; were divided into a hypodivergent (n = 24) and a hyperdivergent (n = 18) group. All patients received a single-step mandibular advancement protocol through an FFA. Lateral cephalograms were analyzed after initial leveling and alignment (T1) and immediately after FFA removal (T2). The therapeutic effect was calculated through comparison with age-matched controls from a growth survey. Statistical significance was set at p < 0.05.ResultsHypodivergent and hyperdivergent patients showed different treatment outcomes, but significant differences existed only for overbite and interincisal angle. Nearly all measurements suggested similar treatment-related changes for both groups with exception for dentoalveolar parameters.ConclusionTreatment with FFA causes similar skeletal and dentoalveolar effects in hypodivergent and in hyperdivergent patients. The correction of overjet and molar relationship is mainly caused by dentoalveolar changes.

Automated summary

This study compared the skeletal and dentoalveolar changes in patients with hypodivergent and hyperdivergent growth patterns after orthodontic treatment using fixed functional appliances (FFA). The results showed that there were differences in treatment outcomes between the two groups, but significant differences were only found in overbite and interincisal angle. Almost all measurements suggested similar treatment-related changes for both groups, except for dentoalveolar parameters.