Nasal Airway Assessment Secondary To Rapid Palatal Expansion

Objectives: Nasal airway obstruction is highly prevalent with potential etiologies manifesting in functional, anatomical, and pathophysiological factors. Small changes in the internal nasal valve (INV) can lead to significant changes in airflow resistance and affect nasal function. As such, we hypothesize that midpalatal disjunction via Rapid Palatal Expansion (RPE) can increase the internal nasal valve angle and improve nasal airflow.

The aim of this study is to demonstrate RPE as a valid treatment modality for nasal airway obstruction by evaluating preoperative and postoperative objective parameters of the internal nasal valve and correlate the subjective outcome using Nasal Obstruction Symptom Evaluation (NOSE) scores.
Methods: After Institutional Review Board approval at UCLA, a prospective cohort study included subjects undergoing RPE from June 2018 to December 2018 with nasal obstruction symptom in an orthodontic office setting. The internal nasal valve parameters and amount of diastema and suture opening on expansion were measured using Invivo6 ™ Software (version 6.0.3) on reformatted cone beam computed tomography. Inter-rater reliability of all pre- and post-expansion parameters was measured. NOSE score was used for subjective Patient-reported outcome measurement. Correlation between objective and subjective outcomes were evaluated using Spearman correlation analysis.
Results: Of 150 patients, 41 patients (28 females and 13 males) met the inclusion criteria. All parameters had a significant change (P<0.0001) after expansion. NOSE score decreased by a mean of 3.80 ± 2.76, INV angle increased by a mean of 2.06 ± 1.11 degrees, INV surface area increased by a mean of 15.42 ± 8.78 mm², diastema increased by a mean of 2.07 ± 1.55 mm, suture increased by a mean of 3.48 ± 1.06 mm upon average maxillary expansion of 6.34 mm. No significant correlation was observed between the NOSE score change and measured variables.
Conclusions: RPE widens the internal nasal valve angle and surface area and improves nasal obstruction symptom.