Corticotomy-assisted adult rapid maxillary arch expansion and ridge augmentation: An interdisciplinary case report with 7-year follow-up Juan Silva-Coll, a Roberto Hern andez-Orsini, b,c,d and Chin-Wei Wang e San Juan and Guaynabo, Puerto Rico, Birmingham, Ala, and Ann Arbor, Mich Adult orthodontic treatment involving maxillary transverse deficiency is a challenge for an interdisciplinary team. Surgically assisted rapid palatal expansion to segment the maxilla was once the treatment of choice, but the invasiveness, bone deficiency, and gingival recession hindered its acceptance. Corticotomy-assisted rapid maxillary arch expansion with ridge augmentation has the advantage of augmenting alveolar bony housing to accommodate and facilitate tooth movement. This approach was used to correct a severely constricted maxilla with bilateral posterior crossbite and anterior crowding in a 46-year-old man. Treatment time was 14 months. The accelerated arch expansion overcame the crossbite in 7 months, increasing intercanine distance by 5.2 mm and intermolar distance by 9.8 mm. Subsequent implant prosthesis was able to be restored in a functional normal occlusion. Satisfactory and stable clinical outcome was followed for 7 years. Corticotomy-assisted rapid maxil- lary arch expansion with alveolar bone augmentation is a novel and effective interdisciplinary approach for correcting adult maxillary transverse deficiency. Well controlled prospective clinical trails are warranted for further investigation. (Am J Orthod Dentofacial Orthop 2019;156:266-74) A dult orthodontic treatment has become popular and an integral part of the interdisciplinary treatment. Maxillary transverse deficiency 1 rep- resents a common clinical challenge for the team working to establish ideal alignment and occlusion not only for natural dentition but also for dental implant prostheses. Several approaches with fixed appliances and an expander for addressing maxillary transverse deficiency have been developed, including rapid maxil- lary expansion (RME), 2 slow maxillary expansion (SME), 3 and surgically assisted-rapid palatal expansion (SARPE). 4 Although RME and SME are effective for growing teenagers, skeletally mature adult patients may be contraindicated for such approaches. 2,3,5 Therefore, SARPE is the option of choice for mature palates. However, some disadvantages of SARPE are the resorption of buccal bone, dehiscence, and gingival recession. 4,5 In addition, increased inter–nasal alae distance or widening of the nose may result as an unde- sirable side-effect. Recently, corticotomy-assisted rapid tooth move- ment with ridge augmentation, or periodontally accelerated osteogenic orthodontics (PAOO), has gained popularity. 6,7 Such an approach combines the application of the regional accelerating phenomenon (RAP) 8 by means of alveolar bone decortication to in- crease regional bone remodeling to accelerate tooth movement and ridge augmentation procedures to over- come the deficiency of the alveolar ridge (usually buccal bone) and thus expand the “orthodontic wall.” 9 Although several studies have demonstrated the tempo- ral accelerating effect of corticotomy-assisted tooth movement, most of the studies that were included in a systemic review only demonstrate its utilization for canine retraction or exposure. 10,11 The aim of the a Private practice, San Juan, Puerto Rico. b Graduate Orthodontics, University of Puerto Rico School of Dental Medicine, San Juan, Puerto Rico. c Department of Orthodontics, University of Alabama School of Dentistry, Bir- mingham, Ala. d Private practice, Guaynabo, Puerto Rico. e Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, Mich. All authors have completed and submitted the ICMJE Form for Disclosure of Po- tential Conflicts or Interest, and none were reported. Address correspondence to: Chin-Wei (Jeff) Wang, Clinical Assistant Professor, Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Room 3323B, 1101 N University Avenue, Ann Arbor, MI 48109; e-mail, jeffwa@umich.edu. Submitted, January 2018; revised and accepted, February 2018. 0889-5406/$36.00 https://doi.org/10.1016/j.ajodo.2018.02.018 266 CASE REPORT