Tudor RA, Ramirez O, 3rd, Tate LP, Jr., et al.
A 1-month-old male American Paint Horse was evaluated for a hard swelling on the right side of the maxillary region. On radiographs there was a large, expansile outpouching of the right maxillary bone between the second and third premolar teeth. Computed tomography further characterized the expansile lesion to have a soft tissue component and to originate in the region of a caudal maxillary tooth. Surgical reconstruction of the defect was unsuccessful and the animal was euthanetized. Based on failure to find histopathologic evidence of a neoplasm or cyst, the diagnosis was a congenital malformation.