The complexity of the equine skull makes the temporomandibular joint a difficult area to evaluate radiographically. The goal of this study was to determine the optimal angle for a complementary radiographic
projection of the equine temporomandibular joint based on a computed tomography (CT) cadaver study. CT
was performed on six equine cadaver heads of horses that were euthanized for other reasons than temporomandibular joint disease. After the CT examination, 3D reconstruction of the equine skull was performed to subjectively determine the angle for a complementary radiographic projection of the temporomandibular joint.
The angle was measured on the left and right temporomandibular joint of each head. Based on the measurements obtained from the CT images, a radiographic projection of the temporomandibular joint in a rostral451ventral-caudodorsal oblique (R45oV-CdDO) direction was developed by placing the X-ray unit 30o laterally, maintaining at the same time the R451V-CdDO angle (R45oV30oL-CdDLO). This radiographic projection was applied to all cadaver heads and on six live horses. In three of the live horses abnormal findings associated with the temporomandibular joint were detected. We conclude that this new radiographic projection of the temporomandibular joint provides superior visualization of the temporomandibular joint space and the articular
surface of the mandibular condyle.