## Overview A dentigerous cyst (also called ear tooth or heterotopic polydontia) is a congenital anomaly in which dental tissue develops in an abnormal location, most often at the base of the ear. It typically presents in young horses as a swelling with a draining tract that does not respond to antibiotics. Complete surgical excision is curative. ## Causes Misplacement of dental epithelium during embryonic development from the first branchial arch. ## Diagnosis Clinical appearance of a draining tract near the ear base plus radiographs or computed tomography showing tooth-like structures. Computed tomography aids surgical planning. ## Treatment Surgical excision of the cyst and associated dental material. Prognosis is excellent when removal is complete. ## Recovery and Prognosis Excellent. Recurrence is rare after thorough excision. ## Prevention None (congenital).
chronic draining tract at the base of the ear in a young horse; intermittent discharge; non-responsive to antibiotics; tooth-like structure on imaging
## Overview A dentigerous cyst (also called ear tooth or heterotopic polydontia) is a congenital anomaly in which dental tissue develops in an abnormal location, most often at the base of the ear. It typically presents in young horses as a swelling with a draining tract that does not respond to antibiotics. Complete surgical excision is curative. ## Causes Misplacement of dental epithelium during embryonic development from the first branchial arch. ## Diagnosis Clinical appearance of a draining tract near the ear base plus radiographs or computed tomography showing tooth-like structures. Computed tomography aids surgical planning. ## Treatment Surgical excision of the cyst and associated dental material. Prognosis is excellent when removal is complete. ## Recovery and Prognosis Excellent. Recurrence is rare after thorough excision. ## Prevention None (congenital).
chronic draining tract at the base of the ear in a young horse; intermittent discharge; non-responsive to antibiotics; tooth-like structure on imaging