Four-dimensional visualization of mandibular movement in the Class III patient before and after combined orthodontic and orthognathic treatment

Abstract

To analyze the results of jaw motion before and after combined orthodontic and orthognathic surgical treatment in the Class III patient. A 33-year-old male with Class III malocclusion (ANB -2°, Wits -3 mm) was referred for facial deformity and malocclusion. After orthodontic preparation, a bimaxillary mandibular first orthognathic surgery was performed. After bilateral sagittal split osteotomy (BSSO) the lower jaw was shifted on the right for 3 mm right and was cw rotated for 4 mm. Le Fort I osteotomy with segmentation was performed to move the maxilla forward for 6 mm and cw rotate for 4 mm. Four-dimensional visualization of the mandibular movement was made using Planmeca 4D jaw motion system. The valuable quantitative data regarding lower jaw movement and measurement information were exported and analyzed. The maximum aperture during opening-closing movement differ before (38.7 mm) and after surgery (32.1 mm) for 6.6 mm. After surgery horizontal displacement in the maximum left lateral excursion increased by 7.6 mm and in the maximum right lateral side by 4.6 mm. Protrusion increased by 0.9 mm after surgery. Combined orthodontic and orthognathic treatment can improve soft tissue, skeletal, dental relationship, and functional results.