Association Between Mouth Breathing and the Temporomandibular System: A Narrative Review

ABSTRACT Objective Children with chronic pathological mouth breathing (MB) may alter the development of the skeletal and myofunctional systems, including the temporomandibular system, and often exhibit symptoms of temporomandibular disorder (TMD), including pain or palpation pain in the temporomandibular joint (TMJ) region, limited or deviated mouth opening and TMJ noise. This review aims to summarise the correlation between mouth breathing and TMD in children and elucidate the potential impact and possible mechanisms of MB on the development of the temporomandibular system. Methods Searches related to mouth breathing, temporomandibular joint, temporomandibular system and temporomandibular disorder were performed using PubMed and Web of Science through September 2024. A narrative review of current literature was conducted to summarise and elaborate. Literature reviews, systematic reviews, meta‐analyses, clinical trials and pre‐clinical studies focusing on the current topic were included. Results We accumulated knowledge of the clinical status of MB, correlation between MB and TMD, specifically the pathogenic factors and signalling pathways involved in MB‐related TMD pathology. Modifications in these signalling pathways result in pathological alterations within the TMJ tissues, impacting the degradation of the cartilage matrix, chondrocyte apoptosis and pain. Conclusion Multiple signalling pathways were involved in the pathological process of MB‐related TMD. Novel or improved animal models, new techniques and new therapeutic strategies targeting these pathways may be applied in MB‐related TMD studies.