We want to thank the authors for reporting a novel approach for rapid maxillary expansion (RME) in skeletally mature patients (Echchadi ME, Benchikh B, Bellamine M, Kim SH. Corticotomy-assisted rapid maxillary expansion: a novel approach with a 3-year follow-up. Am J Orthod Dentofacial Orthop 2015;148:138-53). However, a few questions arose regarding the methodology described. The authors did not comment on the interdigitation pattern of the midpalatal suture in spite of taking a pretreatment computed tomography scan of the patient. Considering the patient’s age, mentioning the status of the midpalatal suture would have been beneficial in justifying the treatment plan chosen. It is not clear in the methodology whether any orthopedic separation at the midpalatal suture was desired. Since this approach is being advocated as an alternative to surgically assisted rapid palatal expansion, which aims to achieve expansion by separating the 2 halves of the maxilla at the midpalatal suture, the nature of the expansion expected with a corticotomy-assisted RME should also be commented upon. Was the corticotomy on the buccal cortical plate done only to induce an inflammatory response, or was it desired to help in the expansion of the maxillary arch? Was the corticotomy done only in the single (buccal) cortical plate sufficient to circumvent the resistance from the midpalatal suture? No justification has been mentioned.

In this case report, the expansion was said to be RME; however, the expansion schedule followed was 1 mm per week for 8 weeks after the corticotomy. The schedule advocated for RME is typically 0.5 to 1 mm of expansion per day in routine practice. So how did the authors justify calling their approach RME? Also, it is documented in the literature that the maximum inflammatory response to the regional accelerated phenomenon is within the first few weeks after the procedure. What was the rationale behind not following the routine RME protocol of 0.5 to 1 mm per day that would have further reduced the duration of treatment?

Changes in the inclination of the maxillary posterior teeth (Table IV of the article) indicate dental expansion with palatal inclination of the maxillary posterior teeth. Another question that arose was whether only dental expansion was sufficient to resolve an arch length discrepancy of 17 mm in the maxillary arch or whether some skeletal expansion was achieved. We would like the authors to share the changes in transverse skeletal dimensions, if any. Although the authors reported taking a posttreatment computed tomography scan for evaluating buccal bone thickness, they did not comment on the transverse skeletal changes in the maxilla and the status of the midpalatal suture.

Raising a full-thickness mucoperiosteal flap leads to bone loss ; hence, in most procedures involving a full-thickness mucoperiosteal flap, bone grafting is done. How did the authors justify an increase in bone mass without an adjunctive bone graft in the region?

Since the results of this case report are very promising, we would appreciate it if the authors could share their views.