Morphometric study of the external and middle ear anatomy in sheep: a possible model for ear experiments.

Sheep are a potentially useful model for otologic surgical training and experimentation, currently limited by the scarcity of morphological comparisons between the structure of the ear in sheep and in humans. A detailed morphometric study of the ear in sheep was carried out using computed tomography. Measurements made with AutoCAD Release 14 were compared with measurements for the human ear reported in the literature. In general, ear structures in sheep are two-thirds the size of those in humans. The important anatomical similarities found in this study between the ear in sheep and in humans suggest that sheep may be a useful model for surgical training and experimentation in some middle ear procedures.