Three-dimensional cone-beam computed technology evaluation of skeletal and dental changes in growing patients with Class II malocclusion treated with the cervical pull face-bow headgear appliance.

INTRODUCTION: This study aimed to 3-dimensionally quantify and compare the outcomes of growing patients with Class II malocclusion treated with the cervical pull face-bow headgear appliance in combination with full fixed orthodontic appliances. METHODS: The study sample consisted of 22 patients with Class II malocclusion with the following inclusion criteria: ANB >4.75 degrees , Class II molar relationship, and SN-GoGn <37 degrees . The mean age of patients was 12.5 +/- 1.1 years at baseline. The average treatment time was 27.7 +/- 7.3 months. Cone-beam computed tomography scans were superimposed in the cranial base, maxillary regional, and mandibular regional to evaluate growth, treatment displacements, and bone remodeling. RESULTS: Relevant statistically and clinically significant skeletal changes included average decreases in ANB (2.1 +/- 1.1 degrees ) and SNA (1.8 +/- 1.1 degrees ); posterior (1.3 +/- 1.4 mm) and inferior (4.6 +/- 2.2 mm) displacement of A-point; inferior displacements of B-point (5.4 +/- 2.8 mm) and Pogonion (5.8 +/- 2.6 mm); superior displacement of Condylion (6.9 +/- 2.4 mm); increase in mandibular length (5.4 +/- 2.0 mm); and clockwise rotation of palatal plane (1.9 +/- 1.9 degrees ). Significant proclination of the maxillary incisors (9.8 +/- 11.1 degrees ) and nonsignificant proclination of the mandibular incisors (4.7 +/- 9.6 degrees ) were also noted. CONCLUSIONS: Class II skeletal correction was primarily achieved by posterior, inferior displacement of the sagittal position of the maxilla. Change in the sagittal position of the mandible/chin (B-point, Pogonion) was not significant; rather, mandibular displacement was significant in an inferior vertical direction without backward rotation, as seen from marked condylar and ramus growth.