The cause(s) of dry socket are not completely understood. Normally, following extraction of a tooth, blood is extravasated into the socket, and a blood clot (thrombus) forms. This blood clot is replaced with granulation tissue which consists of proliferating fibroblasts and endothelial cells derived from remnants of the periodontal membrane, surrounding<unk>  bone and gingival mucosa. In time this in turn is replaced by coarse, fibrillar bone and finally by mature, woven bone. The clot may fail to form because of poor blood supply (e.g., secondary to local factors such as smoking, anatomical site, bone density and conditions which cause sclerotic bone to form). The clot may be lost because of excessive mouth rinsing, or disintegrate prematurely due to fibrinolysis. Fibrinolysis is the degeneration of the clot and may be caused by the conversion of plasminogen to plasmin and formation of kinins. Factors which promote fibrinolysis include local trauma, estrogens, and pyrogens from bacteria. Bacteria may secondarily colonize the socket, and lead to further dissolution of the clot. Bacterial breakdown and fibrinolysis are widely accepted as major contributing factors to the loss of the clot. Bone tissue is exposed to the oral environment, and a localized inflammatory reaction takes place in the adjacent marrow spaces. This localizes the inflammation to the walls of the socket, which become necrotic. The necrotic bone in the socket walls is slowly separated by osteoclasts and fragmentary sequestra may form. The bones of the jaws seem to have some evolutionary resistance to this process. When bone is exposed at other sites in the human body, this is a much more serious condition. In a dry socket, healing is delayed because tissue must grow from the surrounding gingival mucosa, which takes longer than the normal organisation of a blood clot. Some patients may develop short term halitosis, which is the result of food debris stagnating in the socket and the subsequent action of halitogenic bacteria. The main factors involved in the development of dry socket are discussed below. Extraction site Dry sockets more commonly occur in the mandible than the maxilla, due to the relatively poor blood supply of the mandible and also because food debris tends to gather in lower sockets more readily than upper ones. It more commonly occurs in posterior sockets (molar teeth) than anterior sockets (premolars and incisors), possibly because the size of the created surgical defect is relatively larger, and because the blood supply is relatively poorer at these sites. Dry socket is especially associated with extraction of lower wisdom teeth. Inadequate irrigation (washing) of the socket has been associated with increased likelihood of dry socket. Infection Dry socket is more likely to occur where there is a pre-existing infection in the mouth, such as necrotizing ulcerative gingivitis or chronic periodontitis. Wisdom teeth not associated with pericoronitis are less likely to cause a dry socket when extracted. The oral microbiota has been demonstrated to have fibrinolytic action in some individuals, and these persons may be predisposed to developing dry sockets after tooth extraction. Infection of the socket following tooth extraction is different from dry socket, although in dry socket secondary infection may occur in addition. Smoking Smoking and tobacco use of any kind are associated with increased risk of dry socket. This may be partially due to the vasoconstrictive action of nicotine on small blood vessels. Abstaining from smoking in the days immediately following a dental extraction reduces the risk of a dry socket occurring. Surgical trauma Dry socket is more likely to occur following a difficult tooth extraction. It is thought that excessive force applied to the tooth, or excessive movement of the tooth burnishes the bony walls of the socket and crushes blood vessels, impairing the repair process. Vasoconstrictors Vasoconstrictors are present in most local anesthetics and are intended to increase the length of analgesia by reducing blood supply to the region which reduces the amount of local anesthetic solution that is absorbed into the circulation and carried from the local tissues. Hence, use of local anesthetics with vasoconstrictors is associated with an increased risk of dry socket occurring. However, on occasion, use of local anesthetic without vasoconstrictors would not provide sufficient analgesia, especially in the presence of acute pain and infection on maxillary teeth, meaning that the total dose of local anesthetic may need to be increased. Adequate pain control during the extraction is balanced against an increased risk of dry socket. However, the use of 3% mepivacaine without epinephrine in inferior<unk>  nerve blocks has been found to have a similar anesthetic effect to that of lidocaine with 1:100,000 epinephrine, save for a shorter duration of action, and, as such, this may be considered as an alternative in simple mandibular extractions. Radiotherapy Radiotherapy 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<unk> . 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<unk>  after their tooth extraction surgery. It is recommended that elective surgeries be performed during the menstrual period in both oral contraceptives users and non-users to eliminate the effect of cycle-related hormonal changes on the development of<unk> .
Alveolar osteitis
Osteonecrosis of the jaw
Osteomyelitis
Osteoradionecrosis
Osteochondrosis
Osteitis
Medication-related osteonecrosis of the jaw
Osteochondritis