Elastin at the Hinge Portion of the Eustachian Tube Cartilage in Specimens from Normal Subjects and Those with Cleft Palate

The density of elastin in the intermediate portion between the lateral lamina and the medial lamina of human eustachian tube (ET) cartilage was examined in six normal adults, seven normal children, and six children with cleft palate (CP) in order to obtain information about how the physical properties of the ET cartilage differ as a function of age and presence of CP. Cross sections of the midcartilaginous portions of the ETs that had been stained with Weigert's elastin stain were photographed at uniform magnification, the area for study was projected, and the meshlike area of the ET cartilage that stained elastin-positive was represented on paper by lines. A digitizer was used to measure the total length of all the lines representing elastin in each photomicrograph, and the mean was determined for each of the three groups. The mean density of elastin was significantly greater in normal adults than in normal children (Student's t test, t = 2.781; p< .02). It was also significantly greater in normal children than in CP children (Wilcoxon t = 24.0; p< .05). These results appear to indicate that CP children have poorer elasticity in this area of the ET cartilage, which might cause functional obstruction (floppiness) of the ET in those children.