Effect of Unilateral Nasal Obstruction on the Craniofacial Muscles in Growing Rats

Abstract

Observa los cambios en los músculos craneofaciales luego de realizar obstrucción nasal unilateral. Los desórdenes respiratorios afectan a grandes porcentajes de la población, afectando sobre todo a niños y adolescentes. Los efectos en el complejo craneofacial son grandes, alterando la función, morfología, crecimiento y desarrollo de los músculos craneofaciales. El presente estudio realizó experimentos en animales (ratas) con el objeto de observar dichos cambios; se concluyó que la obstrucción nasal unilateral afecta a los músculos craneofaciales durante la etapa de crecimiento.

Humans are nasal breathers since birth. However, the breathing pattern could be altered through life when the airway passage is obstructed. Mouth breathing caused by nasal obstruction affects the normal growth and development of craniofacial structures, including changes in the orofacial muscle function. The tongue muscles play an important role in patency of the pharyngeal airway, and changes in the breathing pattern may influence the tongue function. Moreover, nasal obstruction may also affect the function of the masticatory muscles. Thus, the aim of this study was to evaluate the effect of unilateral nasal obstruction during the growth period on the craniofacial muscles, with special attention to the contractile properties of all tongue-protruding muscles, the jaw-opening reflex, and the genioglossus muscle histochemical composition. A series of longitudinal studies with unilateral nasal obstruction on growing rats were performed, to investigate the effect of nasal obstruction on the craniofacial muscles. The results showed that unilateral nasal obstruction in rats affects the contractile properties of the tongue-protruding muscles and the histochemical composition of the genioglossus muscle. In addition, the jaw-opening reflex is also affected by nasal obstruction in late stages of growth. Therefore, we suggest that nasal obstruction alters the growth and development of the craniofacial complex structures and function.