Abstract: Objective: This case reports the adjunctive application of the modified periodontally accelerated osteogenic orthodontics (PAOO) technique in the combined orthodontic and orthodontic treatment of skeletal class II malocclusion. Diagnosis and treatment: The patient received combined orthodontic and orthognathic treatment after a clear diagnosis and the patient's informed consent. And a modified PAOO procedure was performed before orthodontic decompensation, including a papilla preservation incision, full-thickness flap reflection, interradicular corticotomy, alveolar bone argumentation with bone graft material but without barrier membrane, and a modified suturing technique. After orthodontic decompensation, orthognathic surgery was performed, and then postoperative orthodontic treatment was administered. Results: At the end of orthodontic decompensation, seventeen months after PAOO, the clinical effect was stable, the thickness of the labial alveolar bone and the width of keratinized gingiva increased. Meanwhile, there was no obvious gingival recession and severe periodontitis. Conclusions: The adjunctive application of PAOO in orthodontic therapy can improve patients’ periodontal phenotype and reduce the risk of periodontal complications such as gingival recession, alveolar bone fenestrations and dehiscences.

Key words: periodontally accelerated osteogenic orthodontics, corticotomy, alveolar bone argumentation, combined orthodontic-orthognathic treatment, skeletal classⅡmalocclusion