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 miniscrewassisted 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 crosssectional 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.