Treatment of a Class II Division 1 malocclusion with a severe unilateral lingual crossbite with combined orthodontic/orthognathic surgery.

A 24-year-old woman had a Class II Division 1 malocclusion with a severe unilateral crossbite. The crossbite was due partially to the maxilla being much wider than the mandible, allowing the mandibular left canine and first and second premolars to overerupt, impinging on the palatal tissue in habitual occlusion. The maxillary left segment from the lateral incisor to the first molar also overerupted producing 2 planes of occlusion. The malocclusion was treated successfully with comprehensive orthodontics, combined with a 2 piece Lefort I osteotomy procedure, a 3 tooth mandibular segmental osteotomy procedure, and a bilateral sagittal split osteotomy procedure.