Treating Class II patients with removable plates and functional orthopedic appliances-the importance of anterior tooth inclination and direction of growth on treatment outcome.

OBJECTIVE: To determine the influence of physiological growth pattern and anterior tooth inclination on the outcome in Class II patients treated with removable orthodontic plates and functional orthodontic appliances.

PATIENTS AND METHODS: After recruiting 50 patients with an upper anterior proclination of 1-SN >or= 107 degrees for this retrospective study, another 50 patients with a retroclination of 1-SN <or= 95 degrees were also included. All patients initially presented a skeletal Class II relationship with a distoclusion of at least one premolar width in the region of the first molars. All patients were evaluated separately by gender and additionally subdivided into three subgroups with a horizontal, neutral, or vertical craniofacial configuration. Treatment with removable orthodontic plates (pretreatment) and functional orthodontic appliances was initiated in mixed dentition. Pre- and post-treatment lateral cephalograms were evaluated for each patient.

RESULTS: Dento-alveolar analysis showed that the inclination of the upper incisors changed in the direction of the clinical standard value independent of the craniofacial configuration, although full correction using removable orthodontic plates and functional orthodontic appliances was not always achieved. Similarly good treatment outcomes were achieved with regard to overjet and overbite. The lower incisors of all patients were in proclination after treatment. The ANB angle was reduced in both groups. Nevertheless, on average a skeletal Class II persisted in the Class II, Division 2 patients, while Class II, Division 1 patients with horizontal craniofacial configurations attained skeletal Class I.

CONCLUSIONS: Treatment of Class II patients with removable appliances resulted in differences depending on anterior tooth inclination (Class II, Division 1 and II, Division 2) and craniofacial configuration. These differences must be taken into account during treatment planning. Complete treatment success with regard to sagittal jaw balance is very difficult to achieve with removable orthodontic plates (pre-treatment) and functional orthodontic appliances alone in Class II, Division 1 cases with a vertical craniofacial configuration and generally in Class II, Division 2 cases. A particularly favorable constellation for removable treatment is a Class II, Division 1 situation with a horizontal craniofacial configuration and retroclined or orthognathic mandibular anteriors.