Mouth breathing and its relationship to some oral and medical conditions: physiopathological mechanisms involved

Introduction : Excessive mouth breathing may be related to different oral and medical conditions, but the underlying mechanisms for these complex interactions are not fully understood. Objective : To explore the possible physiopathological mechanisms involved in the relationship between mouth breathing and some oral and medical conditions. Material and Methods: A review of the literature was performed by using PubMed, Scielo and Hinari. Relevant and updated articles were selected. Results: Mouth breathing has been linked to oral conditions such as dry mouth and lips, dental caries, periodontal disease, secondary halitosis, craniofacialdeformity and malocclusion, as well as abnormal swallowing. It is also related to medical conditions such as altered head, neck and body posture, obstructive sleep apnea, poor physical and learning performance,and asthma. Among the physiopathological mechanisms that may  explain that relationship are chronic hypoxemia with hypercapnia, increased water and energy lose, decreased growth hormone release, inflammatory and oxidative mediators release, large load on the upper back and neck muscles, deformity in the airway passage and craniofacial deformities. Conclusions : Physiopathological mechanisms underpinning the relationship between mouth breathing and oral and medical diseases vary from biochemical, physiological and immunological deficiencies to anatomical effects. More studies are needed to explore a causal relationship. Key words: Mouth breathing, dental caries, periodontal disease, halitosis, malocclusion, sleep apnea, performance, posture, asthma. RESUMEN Introduccion: La respiracion bucal excesiva puede relacionarse con diferentes afecciones bucales y medicas, pero los mecanismos involucrados en tan complejas interacciones no son comprendidos totalmente.  Objetivo : Explorar los posibles mecanismos fisiopatologicos involucrados en la relacion entre la respiracion bucal y algunas afecciones bucales y medicas. Material y Metodos : Se realizo una revision de la literatura a traves de PubMed, Scielo y Hinari. Se seleccionaron articulos relevantes y actualizados sobre el tema. Resultados : La respiracion bucal se ha relacionado con afecciones bucales como: boca y labios secos, caries dental, enfermedad periodontal, halitosis secundaria, deformidad craneofacial y mal oclusion, asi como deglucion  anormal. Tambien se relaciona con afecciones  medicas como: alteracion de la postura corporal, de la cabeza y el cuello, apnea obstructiva del sueno, pobre desempeno fisico y del  aprendizaje y  asma. Entre los mecanismos fisiopatologicos involucrados en esa relacion estan: hipoxemia cronica con  hipercapnia, incremento de la perdida de agua y energia,  disminucion de la liberacion de hormona del crecimiento, liberacion de mediadores inflamatorios y oxidativos, sobrecarga en la espalda alta y musculos del cuello,  deformidad en la via aerea y deformidades craneofaciales. Conclusiones : Los mecanismos fisiopatologicos involucrados en la relacion entre la respiracion bucal y algunas afecciones bucales y medicas incluyen deficiencias bioquimicas, fisiologicas, e inmunologicas, asi como  efectos anatomicos.Se requiere realizar mas estudios para explorar una relacion causal. Palabras clave: respiracion bucal, caries dental, enfermedad periodontal,  halitosis, maloclusion, apnea obstructiva, desempeno,  postura, asma.