Orthodontic-Surgical Approach for Treating Skeletal Class II Malocclusion with Severe Mandibular Hypoplasia in Williams Syndrome

This case report details the successful treatment of a severe malocclusion of a patient with Williams syndrome, characterized by a retrognathic profile, severe constriction of the lower arch and mandibular hypoplasia. The procedure involved symphyseal distraction and anterior mandibular alveolar osteotomy for mandibular expansion. Subsequent treatment involved LeFort I osteotomy, mandibular advancement with bilateral sagittal split osteotomy, and genioplasty, resulting in significant improvement in occlusion and facial profile. The purpose of this case report is to present the treatment outcomes of a Williams syndrome patient with severe lower arch constriction and mandibular hypoplasia, treated using an orthodontic-surgical approach.