Xeroradiographic evaluation of the equine larynx.

The normal radiographic anatomy of the equine larynx was determine by use of xeroradiography and dissection. The body and laminae of the thyroid cartilage, the muscular process of the arytenoid cartilages, and the dorsal lamina and arch of the cricoid cartilage had radiographic evidence of mineralization (calcification) and/or ossification in clinically normal horses. There was a significant (P less than 0.01) increase in the degree of mineralization of the thyroid and arytenoid cartilages with advancing age. Horses with diagnosis of arytenoid chondrosis (arytenoid chondral dysplasia, arytenoid chondropathy) by use of endoscopy had radiographic changes that included: enlargement with increased density of the arytenoid cartilage region, abnormal patterns of mineralization (dystrophic mineralization or osseous metaplasia), abnormal contour of the corniculate process(es) and laryngeal masses, sometimes obliterating part or all of the lateral laryngeal ventricles.