Transverse maxillary dimensions and upper airway morphology in mouth- and nasal-breathing children aged 10–12 years: A CBCT-based study

Introduction: Mouth breathing (MB) is a dysfunctional respiratory pattern that may affect craniofacial development by altering maxillary arch width and upper pharyngeal airway morphology. Early identification is critical to prevent long-term dentofacial and airway complications. This study aimed to compare maxillary arch width and upper airway morphology between mouth- and nasal-breathing children aged 10–12 years using Cone Beam Computed Tomography (CBCT). Materials and methods: In this cross-sectional study, 30 children (15 mouth breathers and 15 nasal breathers) underwent CBCT imaging. Transverse maxillary arch dimensions were measured at four points: maxillary width at molars (MWM), intermolar width (IMW), maxillary width at canines (MWC), and intercanine width (ICW). Upper airway morphology was assessed using volumetric (nasopharyngeal volume [NPV], oropharyngeal volume [OPV]) and cross-sectional area (nasopharyngeal area [NPA], oropharyngeal area [OPA]) measurements. In dependent t-tests were used to compare group differences with 95 % confidence level. Results: The MB group showed significantly reduced maxillary arch widths (MWM, IMW, MWC, ICW) and diminished upper airway volume and area (NPV, OPV, NPA, OPA) compared to nasal breathers (p < 0.001 for all parameters). Conclusion: Mouth breathing in school-aged children is associated with measurable reductions in maxillary arch width and upper pharyngeal airway dimensions.