The Effect of RAMPA Therapy on the Volumetric Evaluation of the Nasal Cavity and Sinus: A Comparative Statistical Analysis in Patients with Clear Versus Opacified Paranasal Sinuses

Objectives: This study aimed to comprehensively evaluate and compare the therapeutic effects of Right Angle Maxillary Protraction Appliance (RAMPA) therapy on nasal airway volume in pediatric patients, specifically differentiated by their baseline radiological paranasal sinus status. The objective was to quantify airway volume changes (absolute and percentage) in clear and opacified sinus groups, investigate the influence of age, sex, and treatment duration on these changes, and elucidate potential differences in the underlying mechanisms of airway expansion between groups. Study Design: A retrospective comparative cohort study design was employed. This study includes a “clear sinus group” of 26 patients (mean age: 6.6 years) with radiologically clear sinuses at baseline and an “opacified sinus group” of 20 patients (mean age: 6.8 years) diagnosed with rhinosinusitis and exhibiting significant sinus opacification on baseline CBCT scans. Upper airway volumetric measurements were performed using CBCT scans acquired pre- (T1) and post-treatment (T2), with data analyzed using Invivo 5 software. Results: RAMPA therapy significantly increased upper airway volume in both cohorts. The clear sinus group showed an approximate 18% mean increase (4886.9 mm3 absolute), while the opacified sinus group demonstrated a remarkably greater 61% mean increase (11,192.8 mm3 absolute). This difference was statistically significant. In the clear sinus group, airway volume gain positively correlated with treatment duration (p = 0.0303). Conversely, no significant correlation was found in the opacified sinus group (p = 0.288), suggesting rapid obstruction relief as a dominant mechanism. Sex did not significantly influence outcomes, and age was not a strong independent predictor of volume change magnitude. Conclusions: RAMPA therapy effectively increases upper airway volume in pediatric patients, with a substantially greater effect in those with baseline sinus opacification due to rapid obstruction resolution complementing skeletal changes. The mechanism of action differs by sinus status, with clear sinus patients showing gradual, duration-dependent skeletal adaptation and opacified sinus patients exhibiting immediate, duration-independent gains primarily from sinus clearance. These findings provide crucial insights for tailored clinical decision-making.