Can Chronic Nasal Obstruction Cause Dysfunction of the Paratubal Muscles and Otitis Media? An Experimental Study in Developing Wistar Rats

Objective—To quantitatively analyze modifications of the paratubal muscles in developing Wistar rats following nasal obstruction. Material and Methods—Twenty-four Wistar rats were used. Twelve were examined at 6, 8 and 12 weeks after birth and were considered normal controls. The nostrils of the remaining 12 rats were bilaterally obstructed by means of a synthetic resin 28 days after birth. The animals were sacrificed at either 2, 4 or 8 weeks after nostril occlusion. Serial sections were made in the dorsoventral plane and stained with hematoxylin–eosin. Four 5×5 μm2 areas, selected within the paratubal muscles, were histologically analyzed and the number of muscular fibers was counted manually. Results—The number of tensor veli palatini muscle fibers progressively decreased in the obstructed rats compared with age-matched normal controls and in those that had been obstructed for 4 and 8 weeks these reductions were statistically significant. Conclusion—The correct development of the paratubal muscles seems to be linked to physiological nasal breathing and is negatively affected by oral breathing.