Mr. Greenan is the author of “A Practical Atlas of TMJ and Cephalometric Radiology” and has been published in numerous journals and textbooks on Radiology, Orthodontics and TMJ. In addition to being a member of the American Academy of Oral and Maxillofacial Radiology, the International Association of Dentomaxillofacial Radiology, the International College of Cranio-Mandibular Orthopedics, the Academy of Osseointegration and the International Association for Orthodontics, Mr. Greenan lectures worldwide presenting lectures and hands-on programs on Dental Radiology.