Regarding the article in the September issue, “A 22-year follow-up of the nonsurgical expansion of maxillary and mandibular arches in a young adult: are the outcomes stable, relapsed, or unstable with aging?” we want to congratulate the authors for the conduct of the case, and, to contribute to the work, we would like to raise some considerations about the possibility of nonsurgical expansion of the maxillary arch in adults and the subsequent retention phase.

First, on the possibility of using nonsurgical expansion in the maxillary arch in adults, the authors reported that opening of the sutures is uncertain due to the rigidity of the skeletal components with advanced maturity; however, there are studies that propose a better prediction of the possibility of disruption of this suture. Angelieri et al conducted a study with cone-beam computed tomography in 140 subjects aged 5.6 to 58.4 years and described a classification for the suture and its disruption distributed in stages A to E (better to worse expansion response).

Another contribution we would like to make is on the retention phase. The article reported finding good posterior intercuspation 22 years posttreatment and despite the perimeter decrease of the arches. Greco et al showed that posterior intercuspation, regardless of the type of retention (fixed or removable), tends to improve with time, especially after the first 4 years of retention.

Of course, these studies were done after the reported treatment, and the authors would not have had access to them, but we believe that with these contributions, for a similar patient, a reader could use the strategy of evaluating the sutures with cone-beam computed tomography scans and classifying them with the criteria of Angelieri et al for better predictions of this type of therapy and that posterior intercuspation, once achieved, will tend to remain stable in the upcoming years, at least more than the transverse dimensions.