Nasal and Pharyngeal Airway Changes Following Three Different Rapid Palatal Expansion Protocols in Nongrowing Subjects: Effects of Miniscrew-Assisted Rapid Palatal Expansion and Surgically-Assisted Rapid Palatal Expansion with or without Pterygomaxillary Disjunction

Abstract

Objective: Comparing nasal cavity and pharyngeal airway volumes and minimum cross-sectional areas in nongrowing patients who underwent miniscrew-assisted rapid palatal expansion (MARPE) or surgically assisted rapid maxillary expansion (SARME) with and without pterygomaxillary disjunction (PD). Methods: Pretreatment and post-expansion cone beam computed tomography scans of 30 patients (mean age: 18.6 years), diagnosed with maxillary transverse deficiency, were grouped into three (n = 10 each) according to expansion protocol: 1) MARPE; 2) SARME without PD [SARME-PD(-)]; 3) SARME with PD [SARME-PD(+)]. In NemoStudio software, eleven linear measurements were used to evaluate nasal and maxillary skeletal parameters. Eight airway measurements were used to evaluate the volume and minimum cross-section of the nasal cavity, nasopharynx, retropalatal region, and retroglossal region. Intragroup and intergroup changes were evaluated for statistical significance at P < 0.05. Results: Nasal lateral, nasal floor, external maxillary, palatal, and maxillary intermolar widths significantly increased in all groups. In MARPE, nasal cavity and nasopharynx volumes and minimum cross-sectional area increased significantly. Nasopharyngeal volume increased significantly in SARME-PD(-), whereas nasal cavity volume and minimum cross-sectional area decreased significantly in SARME-PD(+). MARPE group showed greater expansion in nasal lateral width than SARME-PD(-) and SARME-PD(+) groups. Mean changes in nasal cavity volume, minimum cross-sectional area, and nasopharyngeal volume were significantly greater in MARPE than in SARME-PD(+). Conclusions: MARPE group showed greater increases in linear and volumetric measurements. However, differences were statistically insignificant compared to SARME-PD(-). Retropalatal and retroglossal parameters were unaffected in all groups. PD did not provide substantial advantage.