Internal Nasal Valve Change Following Miniscrew-assisted Rapid Palatal Expander

Objectives: The internal nasal valve (INV) is the narrowest cross-sectional area within the nasal cavity and has been associated with nasal obstruction. Anatomically, the roof of the mouth is the floor of the nose and midpalatal disjunction can potentially affect the anatomy and physiology of the nasal cavity. Therefore, we propose that miniscrew-assisted rapid palatal expander (MARPE) can enlarge the internal nasal valve angle.

This study’s objective is to validate MARPE as an effective means for INV amplification and, in turn, potentially improve nasal obstruction. MARPE ensures expansion of the underlying basal bone therefore changes in the internal nasal valve angle may be greater than those of the rapid palatal expander (RPE) which depends more on dentoalveolar expansion.
Methods: Institutional Review Board approval was obtained at UCLA. A prospective cohort study included subjects undergoing MARPE from January 2014 to June 2018 with available before and after expansion cone beam computed tomography in an orthodontic office setting. 29 patients (16 females and 13 males) met the inclusion criteria. The internal nasal valve parameters were measured using Invivo6 ™ Software (version 6.0.3). Inter-rated reliability of all pre- and post-expansion parameters was measured. Significant change in the INV angle was evaluated using paired T-test with significance set at p-value <0.05.
Results: Twenty-nine patients between the ages of 14 and 32 who received MARPE had their left and right internal nasal valve angles measured. All items tested had a significant change (P<0.0001). INV angle right increased by a mean of 2.97 degrees, INV angle left increased by a mean of 2.13 degrees, and the nasal airway width increased by a mean of 1.51mm.
Conclusions: MARPE enhanced the INV angle.