Microscopic examination of oral sinus tracts and their associated periapical lesions

Microscopic examination of 30 sinus tracts revealedthat 100% were lined with epithelium at the surface mucosal interface. Twenty of 30 (67%) sinus tracts did not have epithelium deeper than the surface mucosal rete ridges. The remaining extension of the sinus tract was lined with granulomatous tissue. Ten of 30 (33%) sinus tracts had epithelium extending down the tract to the periapical lesion. The periapical inflammatory lesions that the sinus tracts communicated with were microscopically diagnosed as abscesses, granulomas, and cysts.⁺+The informed consent of all human subjects who participated in the experimentalinvestigation reported in this manuscript was obtained after the nature of the procedures and possible discomforts and risks had been fully explained.