title: Limited evidence to demonstrate that the use of hyperbaric oxygen (HBO) therapy reduces the incidence of osteoradionecrosis in irradiated patients requiring tooth extraction.
abstract: METHODS
  The search covered Medline from January 1948 through March 2008. The subject search by the authors used the following key phrases: Prophylactic hyperbaric oxygen (HBO); preventing osteoradionecrosis (ORN); HBO; ORN; HBO and ORN; HBO, ORN, and dental extractions; HBO and dental extractions; ORN and dental extractions; prophylactic HBO and dental extractions. The authors used EndNote 8.01 (Thomson Reuters, Philadelphia, PA) to perform the search, to import reference data, and to manage the imported references. The electronic search yielded 696 articles. Following further review, which evaluated for compliance to inclusion criteria and data quality, 14 articles were selected for assessment.
  
  
  METHODS
  The efficacy of HBO use in irradiated patients.
  
  
  METHODS
  The presence of osteoradionecrosis (ORN).
  
  
  RESULTS
  The authors assessed the quality of the 14 studies in their review using separate criteria for observational studies (cohort and case-control) and for randomizedcontroltrials (RCT). Therewas only 1RCTamongthe 14studies selected. Among the observational studies, 5 articles specified the type of cancer. Among these 6 studies, only 2 studies evaluated patients with nasopharyngeal carcinoma. Another article assessed patients with cancer of the oral cavity, the oropharynx, and the face. Eight articles did not provide any information about the type of cancer. In 7 of the 14 studies, no HBO was used. Of the remaining 7 that had HBO, 4 used the protocol of Marx et al(1): 20 dives of 90 minutes each, breathing 100% humidified oxygen at 2.4 atm of absolute pressure before surgery, and 10 dives after surgery. Three studies did not mention the specific protocol. The use of antibiotics as adjunctive therapy was noted in 7 studies: 4 studies used antibiotics preoperatively and postoperatively, and only 3 studies used antibiotics postoperatively. Of the 14 articles, 10 articles reported a definition of ORN. Six articles described ORN as exposed bone that had been irradiated and had been present for 3 to 6 months. In another study, the bone necrosis was described as developing in 2 forms: minor, as a series of small sequestra that separated spontaneously after periods of weeks or months, and major, where necrosis involved the entire thickness of the jaw with pathologic fracture inevitable. Information provided on the method of extraction used was limited, with only 3 of the 14 reports stating the method (nonsurgical or atraumatic extraction). Primary closure was attempted or used in 3 studies, whereas 2 noted that primary closure was not used. Five studies did not indicate either the method of extraction or whether there was primary closure. The only one randomized, prospective, controlled trial in this systematic review-Marx et al(1)-compared the incidence of ORN in head-and neck-irradiated patients who required dental extractions. They had 2 groups: one group received prophylactic HBO, whereas the other group received antibiotics. The HBO group had a lower incidence of ORN compared with the antibiotic group (5.4% vs 29.9%). In the cohort and observational studies, the occurrence rate of ORN in the prophylactic HBO patients was in the range from 0% to 11% (median, 4.1%), whereas in the non-HBO patients the range was from 0% to 29.9% (median, 7.1%).
  
  
  CONCLUSIONS
  The systematic review by the authors did not identify any reliable evidence to either support or refute the efficacy of HBO in the prevention of postextraction ORN to irradiated patients. As a result, additional controlled clinical trials will be needed to address this important question.
authors.affiliation: Massachusetts General Hospital and Harvard School of Dental Medicine, Boston, Massachusetts, USA. sungkiangchuang@gmail.com
authors.forename: Sung-Kiang
authors.initials: SK
authors.lastname: Chuang