Rapid Maxillary Expansion and Nasal Patency of the Down Syndrome Pediatric Population

Objectives: Down syndrome (DS) is the most common aneuploid disorder at birth. Phenotypic characteristics include general axial hypotonia and maxillary hypoplasia with relative macroglossia contributing to constricted maxillary arch and nasal obstruction. This prospective study assesses the effect of rapid maxillary expansion (RME) on nasal permeability of DS children using acoustic rhinometry (AR) data. To our knowledge this is the first such study performed in a DS population. Methods: AR have been performed in 24 DS children aged between 5 and 12 years (who were randomly allocated to RME and control groups) prior to expansion (T0), immediately after maximum expansion (approximately 1 month) (T1) and after a 5-month period of retention (T2); the data between the 2 groups were compared. Results: On average, RME children showed a significant increase in the nasal volume from T0 to T1, which persisted through T2. A significant difference was noticed in the evolution of the minimal cross-sectional area (MCA) for RME children. Children in the control group did not show any significant improvement. The distance from the MCA does not show any significant difference with time in both groups. Nevertheless, in the RME group a noticeable change is observed, becoming more anterior, between T0 and T1, with almost no change at the last stage (T2); in contrast, results from the control group are not consistent with time. Conclusion: Rapid maxillary expansion produced a significant augmentation of nasal volume, P