Histopathologic study of eustachian tube in cleft palate patients.

We studied eight temporal bones from eight individuals with cleft palates (CPs) and eight age-matched control temporal bone specimens from our collection. We used the eustachian tube (ET) and its surrounding structures in serial vertical histologic sections. The findings observed in CP specimens were as follows: 1) the angle between axial lines through the tensor veli palatini (TVP) muscle and the superior portion of the ET lumen was narrow, 2) the angle between axial lines through the lateral lamina and the medial lamina of the cartilage was wide, 3) the angle between axial lines through the TVP muscle and the lateral lamina of the cartilage was narrow, and 4) the angle between axial lines through the superior part and the inferior part of the ET lumen was wide. From these findings, we assume that the ET dysfunction that occurs in individuals with CP is the result of abnormalities of the ET and its cartilage and of abnormal anatomic relationships of these structures to the TVP muscle.