directed at the bones of the jaws causes several changes to the tissue, resulting in decreased blood supply. Menstrual cycle The menstrual cycle could be a determinant risk factor in the frequency of alveolar osteitis. Studies have shown that because of hormonal changes, women in the middle of menstrual cycle and the ones taking oral contraceptives (birth control pills) have a higher tendency of having alveolar osteitis after their tooth extraction surgery. It is recommended that elective surgeries be performed during the menstrual period in both users and non-users of oral contraceptives, to eliminate the effect of cycle-related hormonal changes on the development of alveolar osteitis. Diagnosis Dry socket typically causes pain on the second to fourth day following a dental extraction. Other causes of post extraction pain usually occur immediately after the anesthesia/analgesia has worn off, (e.g., normal pain from surgical trauma or mandibular fracture) or has a more delayed onset (e.g., osteomyelitis, which typically causes pain several weeks following an extraction). Examination typically involves gentle irrigation with warm saline and probing of the socket to establish the diagnosis. Sometimes part of the root of the tooth or a piece of bone fractures off and is retained in the socket. This can be another cause of pain in a socket and causes delayed healing. A dental radiograph (X-ray) may be indicated to demonstrate such a suspected fragment. Prevention Some evidence suggests that rinsing with chlorhexidine (0.12% or 0.2%) or placing chlorhexidine gel (0.2%) in the sockets of extracted teeth reduces the frequency of dry socket. Another review concluded that preventative antibiotics reduce the risk of dry socket (and infection and pain) following third molar extractions of wisdom teeth in healthy individuals. The authors questioned whether treating 19 people with antibiotics to prevent one infection would do more harm overall than good, in view of the potential side effects and also of antibiotic resistance. Nevertheless, there is evidence that some individuals, based on a clinical assessment of their conditions, who are at clear risk may benefit from antibiotics. There is also evidence that antifibrinolytic agents applied to the socket after the extraction may reduce the risk of dry socket. Some dentists and oral surgeons routinely debride the bony walls of the socket to encourage hemorrhage (bleeding) in the belief that this reduces the incidence of dry socket, but there is no evidence to support this practice. It has been suggested