Dry socket is a common complication of tooth extraction. It is characterized by severe pain at the site of the extraction that tends to get worse over time. The pain generally begins a day or two following the extraction and can last for one to several weeks.

In normal conditions, a blood clot forms in the tooth socket, or alveolus, after a tooth extraction to protect the socket while it heals. When dry socket occurs, the blood clot either does not form normally or is dislodged, leaving the bony socket open and exposed to air, food particles and infection. The lack of this intact blood clot causes pain and delays healing.

Dry socket develops most commonly after extractions of particular teeth. The extractions that most frequently result in dry socket are those of the lower molars, particularly the third molars (wisdom teeth), or premolars. When these teeth are impacted, dry socket is even more likely to occur. Reports on the incidence of dry socket vary. One study by the American Association of Oral and Maxillofacial Surgeons showed that dry socket occurs in up to 13 percent of wisdom tooth extractions among patients 25 years of age and older.