Question: What is a draining sinus tract and what does it tell my dentist?
Explanation: A sinus tract is an epithelium-lined or granulation-tissue-lined channel connecting a chronic abscess to the surface, allowing pus to escape. Intraorally it opens as a gum boil. Occasionally it drains through the skin of the face, which is called a cutaneous sinus tract and is frequently misdiagnosed as a skin lesion. The tract’s opening may be some distance from the offending tooth, so dentists trace it by threading a gutta-percha point into the opening and taking a radiograph. The point leads back to the source.
Related Questions:
Why is the gum boil nowhere near the painful tooth?
Pus follows the path of least resistance through bone and along fascial planes, which can carry it several teeth away or even onto the face. The exit point reflects anatomy, not the location of the source. This is precisely why tract tracing with a gutta-percha point is performed.
Can a dental infection drain through the skin of my face?
Yes. Cutaneous sinus tracts from lower molars commonly open near the jawline or chin. They are frequently treated by dermatologists as cysts or infected lesions, sometimes for years, before the dental origin is recognised. The lesion resolves only after the tooth is treated.
Does a sinus tract heal after root canal treatment?
Typically within one to two weeks of the source being disinfected. Rapid closure is a good prognostic sign. If it persists beyond a few weeks, the diagnosis should be revisited. A vertical root fracture or a missed canal is often responsible.
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