recommendations that are made by the authors. It also may account for some of the contradictory findings that have been reported in the literature. As the result of the basic studies of Miles and Burke et al [1,2] and several well-controlled clinical studies, the principles of proper antibiotic prophylaxis have been established for general surgery, and they are applicable to the field of oral and maxillofacial surgery. These principles are (1) that the intended procedure must carry a significant risk of postoperative infection, (2) that the correct antibiotic must be selected, and (3) that the antibiotic is administered properly. To these principles one may add a fourth principle: not to rely solely on prophylactic antibiotics to prevent postoperative infections.
Risk of infection
Although such factors as age of the patient, nutritional status, nature of any underlying disease, presence of necrotic tissue, and a decreased blood supply can increase the potential for postoperative infection, perhaps the most important factor is wound contamination. Altemeier et al [3] developed a classification of general surgical wounds relating contamination to the risk of infection. In this classification, operative wounds are categorized as clean, clean-contaminated, contaminated, or dirty, with contamination resulting from planned or unplanned entry into the respiratory, gastrointestinal, or genitourinary tracts. Because of the difference in host response to such contamination and oral contamination, this classification cannot be used for intraoral wounds. It can be modified, however, to