Dimensional changes of upper airway after rapid maxillary expansion evaluated with cone beam computed tomography

PurposeThe objective of this research study was to assess the effect of rapid maxillary expansion treatment on nasal cavity, upper airway, as well as facial height and convexity using cone beam computed tomography (CBCT).MethodsWe evaluated 15 patients with maxillary width deficiency treated with rapid maxillary expansion (RME). Patients were subjected to CBCT at the beginning of the RME treatment and again after the retention period of 4 months in order to measure the changes of retropalatal and retroglossal airways, nasal cavity and cephalometric parameters. The measurements of the before and after RME scans were compared using a paired t test.ResultsThe average increase of the retropalatal airway volume (2.31 mm3) and the total upper airway volume (3.23 mm3) was statistically significant (p = 0.04 and p = 0.05 respectively), while the change in retroglossal airway volume (0.92 mm3) was not significant. Significant increase was observed in the transverse distances of the anterior, middle and posterior areas of the lower third of nasal cavity following the RME treatment (p = 0.008, p = 0.003 and p = 0.002 respectively). No significant difference was observed in the cross-sectional areas passing epiglottis (EP), soft palate (SP) and posterior nasal spine (P) planes or other cephalometric parameters before and 4 months after the treatment.ConclusionsThe RME treatment resulted in significant increase in the transverse width of the nasal cavity, as well as upper and retropalatal airways. However, this effect was not observed for the cross-sectional areas of the upper airway, anterior and posterior facial heights and facial convexity following RME treatment.