Fistulous tract

Fistulous tract (Lat. fistula) is a pathological canal in the gum or bone through which inflammatory products (exudate) are discharged from the inflammation site at the root of the tooth to the outside. This is a peculiar drainage tract created by the body to reduce pressure within the inflammation site.

Etiology and pathophysiology

A fistula forms when purulent inflammation at the apex of the root (abscess) breaks through the cortical plate of the jaw and penetrates under the mucous membrane. A specific opening (fistula tract orifice) appears on the gum, often with purulent discharge. The appearance of a fistula is usually accompanied by a reduction in acute pain as the pressure in the focus decreases. The fistula tract from the pathological focus around the tooth root can open not only on the gum but also in the maxillary sinus, nasal cavity, or on the skin of the face or neck.

Clinical significance

The presence of a fistula is a reliable indicator of pulp necrosis and chronic bone destruction (apical periodontitis). A fistula cannot heal on its own until the cause — the infection inside the tooth — is eliminated. Treatment requires thorough processing of root canals or, in advanced cases, tooth extraction.