Updated Clinical Considerations for Dental Implant Therapy in Irradiated Head and Neck Cancer Patients Takako Imai Tanaka, DDS, FDS RCSEd, 1, 2 Hsun-Liang Chan, DDS, MS, 2 David Ira Tindle, DDS, MS, 2 Mark MacEachern, MLIS, 3 & Tae-Ju Oh, DDS, MS 2 1 Department of Biomedical & Diagnostic Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI 2 Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI 3 A. Alfred Taubman Health Sciences Library, University of Michigan, Ann Arbor, MI The article is associated with the American College of Prosthodontists’ journal-based continuing education program. It is accompanied by an online continuing education activity worth 1 credit. Please visit www.wileyonlinelearning.com/jopr to complete the activity and earn credit. Keywords Dental implant; head and neck cancer; irradiation; survival rate; oral rehabilitation. Correspondence Takako I. Tanaka, 2700 MLK Jr. Blvd., Detroit, MI 48208-2576. E-mail: tanakata@udmercy.edu The authors deny any conflicts of interest. Accepted November 11, 2012 doi: 10.1111/jopr.12028 Abstract An increasing number of reports indicate successful use of dental implants (DI) during oral rehabilitation for head and neck cancer patients undergoing tumor surgery and radiation therapy. Implant-supported dentures are a viable option when patients cannot use conventional dentures due to adverse effects of radiation therapy, including oral dryness or fragile mucosa, in addition to compromised anatomy; however, negative ef- fects of radiation, including osteoradionecrosis, are well documented in the literature, and early loss of implants in irradiated bone has been reported. There is currently no consensus concerning DI safety or clinical guidelines for their use in irradiated head and neck cancer patients. It is important for health care professionals to be aware of the mul- tidimensional risk factors for these patients when planning oral rehabilitation with DIs, and to provide optimal treatment options and maximize the overall treatment outcome. This paper reviews and updates the impact of radiotherapy on DI survival and discusses clinical considerations for DI therapy in irradiated head and neck cancer patients. Cancer of the oral cavity and pharynx, the largest group of head and neck cancers, is the ninth most common cancer in males in the United States. 1 Approximately 40,000 people will be newly diagnosed with oral cancer with a 5-year survival rate of 57%. 2 Surgery is a well-established treatment and may include radiotherapy (RT) and/or chemotherapy. 3 Reconstruc- tion of major surgical defects is required for a majority of the cases, followed by rehabilitation of missing teeth and restoring orofacial function. Use of implants for prosthetic reconstruction has dramati- cally increased due to advancements in materials science and surgical techniques during the past three decades. 4 Implant- supported dentures seem to be a viable option, especially when RT’s adverse effects, such as oral dryness or fragile mucosa, along with compromised anatomy, hamper the use of conven- tional removable dentures. 5 An increased number of reports indicate successful implant- supported prostheses in irradiated cancer patients. 6-10 How- ever, the negative effects of radiation are well documented, 11 and several studies in both animals and humans have shown an increased risk of early loss of dental implants (DI) in ir- radiated bone. 12-14 There is currently no consensus about the predictability, safety, or clinical guidelines for DI therapy in irradiated head and neck cancer patients. This paper reviews the impact of RT on DI therapy and discusses updated clinical considerations for DI therapy in those patients. RT and its adverse effects Cancer cells are in a continuous state of mitosis. Ionizing radia- tion produces energy that injures or destroys cells by damaging nuclear DNA or altering the molecular characteristics of indi- vidual cells. 2 Most patients with head and neck cancer receive between 50 and 70 Grays (Gy) as a curative dose. For con- comitant use, 45 Gy are used preoperatively and 55 to 60 Gy postoperatively. These doses are typically fractionated over a period of 5 to 7 weeks, once a day, 5 days a week, with a daily dose of approximately 2 Gy. 2 Normally, each daily treatment lasts about 10 to 15 minutes. Fractionated radiation is used be- cause in general, normal tissue repairs sub-lethal DNA damage better than tumor tissue, especially in the low-dose range. Adverse effects of RT include mucositis, hyposalivation, loss of taste, radiation caries, trismus, and osteoradionecrosis (ORN) of the jaw. ORN, ischemic necrosis of bone, is one of the most serious complications. 11 Initial changes in bone caused by irradiation result from direct injury to the remodeling system (osteocytes, osteoblasts, and osteoclasts). In addition, vascular 432 Journal of Prosthodontics 22 (2013) 432–438 c  2013 by the American College of Prosthodontists