Changes in the nasal airway and nose morphology after miniscrew-assisted rapid palatal expansion in young adults

Abstract

Maxillary expansion can affect hard and soft tissue of nasomaxillary complex as well as teeth. We evaluated changes in the volume and cross-sectional area of the nasal airway after nonsurgical miniscrew-assisted rapid palatal expansion (MARPE) in young adults. Furthermore, we measured changes in the nose width and height after MARPE. Fourteen patients (mean age, 22.7 years; 10 women and 4 men) with a transverse discrepancy who underwent cone beam computed tomography (CBCT) before (T0), immediately after (T1), and 1 year after (T2) nonsurgical MARPE were included in this study. Three landmarks [anterior nasal spine (ANS), choanae, and the third cervical vertebra (C3)] and four reference planes (two horizontal and two vertical) were used as landmarks to obtain measurements for volume and area. Seven landmarks and six linear distances were used to measure the nose. The volume of the nasal cavity and nasopharynx, the cross-sectional area of the anterior, middle, and posterior segments of the nasal airway, and the nose width and height were measured and compared among the three time points using paired t-tests. The volume of the nasal cavity showed a significant increase at T1 and T2 (P < 0.05), while that of the nasopharynx increased only at T2 (P < 0.05). The anterior and middle cross-sectional areas significantly increased at T1 and T2 (P < 0.05), while the posterior cross-sectional area showed no significant change throughout the observation period (P > 0.05). Overall width and height of the nose and nostrils did not change significantly. Nose height decreased immediately after MARPE, but it was recovered to the initial height one-year after expansion. The width of the nose increased 1.2 mm during T0-T2 (P < 0.05). There were no differences for other measurements during T1-T0, T2-T1, and T2-T0 (P > 0.05). Our results demonstrate that the volume and cross-sectional area of the nasal cavity increased after MARPE and were maintained at 1 year after expansion. Therefore, MARPE may be helpful in expanding the nasal airway. Furthermore, the width of the nose was the only measurement that showed significant changes one year after MARPE, although the amount was clinically insignificant. This result suggests that MARPE has little clinical effects on the morphology changes of the nose and nostrils.