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Objective To test the following two hypotheses regarding the consequences of Herbst appliance (HA) insertion: 1) a significant clockwise mandibular rotation will occur and 2) the displacement of the condyles will follow the same magnitude of the changes of overjet (OJ) and overbite (OB). Methods Virtual 3D surface models of 25 patients were generated from cone-beam computed tomographs taken before treatment and immediately after HA insertion. Scans were registered on the cranial base and were analyzed using point-to-point measurements, color-coded maps, and semitransparent overlays. Statistical tests included correlation and simple regression analysis. Results Pitch rotation, ranging from -2.2° to 2.2° (mean, 0.2°), was observed in clockwise and counterclockwise directions. Condylar sagittal displacement presented a positive correlation with OJ changes. Each millimeter of OJ correction resulted in an anterior condylar displacement of approximately 0.95 mm. Vertical condylar displacement correlated with OB changes and varied mostly between 2 mm and 4.5 mm. Conclusion Immediately after HA insertion, no significant clockwise mandibular rotation was observed. The condyles were displaced anteriorly and inferiorly. Condylar anterior displacement and OJ correction presented a ratio close to 1:1. The vertical displacement of the condyles did not follow the same magnitude of OB changes.

The current concept for effective and efficient treatment of skeletal Class II malocclusion prescribes that interceptive approach should be delivered during the pubertal growth stage. However, psychosocial issues and a greater risk of dental trauma are also factors that should be addressed when considering early Class II therapy. This paper reports a case of a patient that sought orthodontic treatment due to aesthetic discomfort with the incisors’ protrusion. Two previous treatments failed because patient’s collaboration with removable appliances was inadequate. Given his history of no collaboration and because the patient was in the prepubertal stage, it was decided to try a different approach in the third attempt of treatment. Traumatic injury protective devices were used during the prepubertal stage and followed by Herbst appliance and fixed multibrackets therapy during the pubertal stage, resulting in an adequate outcome and long-term stability.