An unusual microscopic pattern of foreign body reaction as a complication of dry socket management.

Foreign body reactions in the oral cavity are relatively common, frequently resulting from iatrogenic causes. Depending on the nature of the foreign material, various microscopic patterns may be observed, causing diagnostic difficulties. Recognition of the ensuing unusual microscopic pattern, especially for cases in which the possibility of a foreign body reaction is not entertained in the clinical differential diagnosis, necessitates sufficient degree of suspicion, familiarization with the spectrum of microscopic appearances, and careful clinicopathologic correlation. Medicated dressings of various compositions are commonly placed for prevention or management of dry socket (or alveolar osteitis, a common postoperative complication of tooth extraction) and may be a cause of foreign body reaction. Here, we report a foreign body reaction to a medical dressing material in a postextraction socket, with an unusual microscopic pattern bearing resemblance to parasitic infestation.