Consequences of mouth breathing and/or open mouth posture: A scoping review with consideration of the ICF framework

The terms open mouth posture (OMP) and/or mouth breathing (MB) are often used synonymously in the research literature and lack clear diagnostic distinction. In orofacial dysfunctions, they are regularly observed symptoms and critical factors in treating myofunctional or occlusal disorders (Grabowski & Stahl, 2008). However, whether OMP and MB occur as consequences or predisposing factors is unclear. This scoping review examines the documented consequences of OMP and/or MB. The research included selected search terms across six databases and gray literature. From 887 English-language studies spanning 20 years, 54 studies were analyzed after a blinded screening process. The results were categorized and coded based on the ICF and ICF-CY frameworks (WHO, 2024). Consequences of OMP and/or MB were identified in several domains. In the category of body functions, they affect mental, sensory, and movement-related functions. Within body structures, the head, neck, and facial regions are primarily impacted. Activities and participation issues include learning difficulties and communication challenges. Environmental factors involve social and psychosocial issues, such as stigmatization and limited social participation. The reviewed studies exhibit limitations, including methodological diversity, varied target populations, and different study designs, reducing generalizability. Inconsistent, often subjective, and poorly described measurement methods further complicate interpretations. Despite these challenges, the findings highlight the importance of early diagnosis and intervention to mitigate long-term health consequences. They also underscore the diverse effects of OMP and/or MB and the necessity for multidisciplinary treatment approaches.
Grabowski, R., & Stahl, F. (2008). Open Mouth Posture in Children – Frequency and Effects. Orthod Kieferorthop, 40, 101–109. https://doi.org/10.1055/s-2008-1004785
World Health Organisation (WHO) (2024). Modernized ICF Online Browser - International Classification of Functioning, Disability and Health. https://icd.who.int/browse/2024-01/icf/en