Mouth Breathing and Craniofacial Development in Children: A Systematic Narrative Review and Clinical Implications

Background/Objectives: Mouth breathing in childhood has been associated with alterations in craniofacial growth and the development of the maxillofacial complex. However, arguments persist regarding the scale of this relationship and its clinical consequences because of the diverse nature of the available evidence. This review aims to evaluate the evidence on the relationship between mouth breathing and maxillofacial development in children. Methods: A systematic narrative review with qualitative synthesis was conducted using databases such as PubMed/MEDLINE, SciELO, Cochrane Library, Google Scholar, and institutional academic repositories. Studies in English and Spanish that evaluated mouth breathing and its impact on craniofacial growth in children were included. The selection process involved reviewing titles, abstracts, and full texts against set inclusion and exclusion criteria. Results: The analyzed studies show a consistent association between mouth breathing and maxillofacial developmental abnormalities, including maxillary narrowing, high-arched palate, increased vertical growth pattern, and a higher prevalence of malocclusions. Likewise, considerable heterogeneity was observed in the diagnostic criteria used to define mouth breathing and to evaluate craniofacial development among the included studies. Furthermore, characteristic cephalometric changes were identified in patients with mouth breathing compared to nasal breathers. Conclusions: Evidence suggests a consistent association between mouth breathing and craniofacial alterations in children, including structural and dentofacial changes. Nonetheless, the variety in methods and the reliance on observational data restrict the ability to confirm definitive cause-and-effect links. Early identification and interdisciplinary management may help reduce the progression and severity of associated craniofacial alterations.