An enigmatic sinus tract origin.

Diagnosis of the origin of a sinus tract is very complex. In this case report, a sinus tract stoma appeared above the left maxillary incisor, but the causative tooth was the right maxillary incisor. Incorrect diagnosis led to endodontic treatment of a healthy tooth followed by apicoectomy, which was also ineffective. An endodontic consultation revealed the true origin of the sinus tract. Five days after completing conservative endodontic treatment of the right maxillary incisor, the sinus tract disappeared. This case confirms the need to include a diagnostic tracing radiograph as part of routine diagnostic procedures.