Abstract: This case report presents the examination, diagnosis, and treatment process of a patient with severe periodontitis and skeletal Class Ⅱ malocclusion undergoing combined orthodontic and orthognathic therapy. Before treatment, the patient exhibited deep overjet and deep overbite, bilateral distal occlusion, and extensive alveolar bone loss reaching one-half to one-third of the root length. After comprehensive periodontal systemic treatment, presurgical orthodontic therapy was performed to improve dental compensation, followed by orthognathic surgery to correct the skeletal disharmony between the maxilla and mandible. Postsurgical orthodontic treatment was used to fine-tune the occlusion. Throughout the treatment, strict periodontal maintenance was maintained, plaque control was emphasized, and light forces were applied during orthodontic movement. The combined treatment significantly improved the patient's occlusion, resulting in normal overbite and overjet, with stable and satisfactory occlusal outcomes observed at follow-up.

Key words: periodontitis, skeletal class Ⅱ malocclusion, combined orthodontic-orthognathic treatment