Dr. Breen is an Otolaryngologist — Head and Neck surgeon with sub specialization and board certification in Otology and Neurotology. His clinical focuses and interests include: Chronic ear disease and cholesteatoma, treatment for hearing loss, including cochlear implantation, bone conduction hearing devices, and stapedotomy, vestibular schwannoma and other tumors of the ear and lateral skull base and pulsatile tinnitus. He has been actively involved with the education of residents and fellows. His research and publication efforts have examined treatments for ear and skull base diseases as well as applications of temporal bone imaging techniques.