Alveolar osteitis (AO) is generally defined as the complete or partial absence of blood clot in the alveolar socket with pain at or near the tooth extraction site and with or without halitosis and is also described as a dry socket (DS). Generally, it manifests about 24 to 96 h after tooth extraction (Figs. 12.1 and 12.2). Crawford (1896) originally named the condition a DS and stated, “There was no blood, no suppuration, no granulation, but a perfectly dry, clean socket”. This is the origin of the current definition.