A dry socket also referred to as alveolar osteitis is a post operative complication that interferes with the healing process that takes place after a tooth extraction.
Blum defined alveolar osteitis as “post operative pain inside and around the extraction site , which increases in severity at any time between the first and third day after the extraction ,accompanied by a partial or total disintegrated blood clot within the alveolar socket with or without halitosis”.
Predisposing Factors
1. Extraction Site
Dry sockets occur more frequently in the mandible than the maxilla due to thick cortical bone resulting in poor perforation of blood supply the mandible. It occurs more commonly in the extraction of the third molars.
2. Gender
It occurs more frequently in females than males due to possible hormonal cause. Sweet and Butler(1938) reported that the incidence of dry socket in females is 4.1% compared to males.
3. Trauma
Difficult extractions occur in older and dense bone which may have a decreased vascularity. Birn proposed that trauma from extraction and aggressive curettage cause the inflammation of the alveolar osseous medulla which leads to the release of cell mediators. This causes fibrinolytic activity.
4. Smoking
Smoking reduce the neutrophil chemotaxis and phagocytosis thus impairing the production of immunoglobulin.
Nicotine the active drug in tobacco is absorbed though the oral mucosa. This drug increases the platelet aggregation thereby increasing the risk of microvascular thrombosis and peripheral ischemia. Proliferation of fibroblast and macrophages is also inhibited.
The incidence of dry socket was significantly higher in smokers (12%) than in non-smokers (4%) , but, there is a strong association between the amount of smoking and the incidence of dry socket.
5. Vasoconstrictors
Vasoconstrictors in the local anesthetics used for extraction may also contribute to the formation of dry
socket. Vasocinstrictors cause temporary local ischemia which increase the risk of developing alveolar osteitis.
6. Microorganisms
Bacteria may also play a contributing factor in the etiology of dry socket. Delayed healing may occur due to the presence of microorganisms like Enterococcus, Streptococcus viridans, Bacillus coryneform, Proteus vulgaris, Pseudomonas aeruginosa, Citrobacter freundii, Escheria coli. Nisan et al (1983) proposed that the anaerobic bacteria Treponema denticola showed plasminogen like fibrinolytic activity.
7. Oral Contraceptives
Lily observed that the dry socket occurred three times more frequently in females on oral contraceptives than in those who were not taking them.
Oral contraceptives elevate plasma fibrinolytic activity which affects the stability of the clot after extraction. They elevate the factors II, VII, VIII, X and plasminogen thereby increasing the lysis of blood clot.
8. Radiotherapy
Radiotherapy to the head and neck results in a decreased blood supply to the mandible.
