[The patent nasopalatine duct. A rare anomaly and diagnostic pitfall].

The patent nasopalatine duct is a rare anomaly in the anterior maxilla. During the early fetal period, a bilateral and epithelium-lined duct is formed within the primary palatal process as an oro-nasal communication. However, the duct obliterates and degenerates before birth. A persisting patent or through-and-through nasoplatine duct is therefore considered a developmental anomaly. A patent nasopalatine duct normally presents as one (or two) tiny openings lateral or posterior to the incisive papilla. In such a case, the ducts can be partially or completely probed with gutta-percha points with subsequent radiographic imaging. The patients report strange sensations such as squeaking noise, palatal drainage, nasal regurgitation, or airway communication between nasal and oral cavities; however, patients rarely complain about pain. About 40 cases have been documented in the literature. We describe two patients who have been referred to our department for evaluation of "sinus tracts" in the anterior palate. Since a patent nasopalatine duct can become a diagnostic pitfall, a thorough inspection of the mucosa around the incisive papilla is essential to avoid unnecessary endodontic or surgical interventions in the area of the central maxillary incisors.