Mouth Breathing Revisited: A Functional Disorder Linking Airway Physiology, Craniofacial Development, and Clinical Management

Abstract

Mouth breathing (MB) is a prevalent breathing pattern observed in both pediatric and adult populations. Although often regarded as a benign habit, growing evidence indicates that chronic MB represents a maladaptive functional disturbance with significant systemic and oral health implications. This narrative review synthesizes current evidence on the pathophysiology of MB, its effects on craniofacial development and orofacial function, and contemporary approaches to diagnosis and management, while highlighting important regional gaps in the literature. A comprehensive literature search was conducted across major electronic databases, including PubMed, Scopus, and Web of Science. To enhance retrieval sensitivity and ensure broader coverage, supplementary searches were performed using Google Scholar, alongside manual screening of reference lists of relevant articles. Available evidence consistently associates chronic MB with impaired nasal breathing, altered orofacial muscle function, characteristic craniofacial changes, and functional disturbances. It is also associated with sleep-disordered breathing and reduced oral health-related quality of life. Emerging evidence further links it to temporomandibular joint dysfunction and cervical muscle impairment, likely mediated by postural adaptation and altered neuromuscular coordination. Epidemiological and functional data from regions such as Libya remain limited, with existing research predominantly focused on structural dental outcomes rather than airway- related determinants. MB should be recognized as a modifiable functional disorder with multisystem effects. Standardized diagnostic criteria, longitudinal studies, and region-specific epidemiological investigations, particularly in underrepresented settings, are essential to advance evidence-based and contextually relevant clinical practice.