<p>Dentigerous cysts are developmental odontogenic cysts that envelop the crown of an unerupted tooth and most commonly involve mandibular third molars and maxillary canines. Association with a supernumerary tooth, particularly a mesiodens, is uncommon and may create diagnostic confusion when lesions project into the periapical region of anterior teeth. We report a case of an anterior maxillary dentigerous cyst arising from a mesiodens that clinically and radiographically simulated a radicular cyst in a patient with a history of dental trauma and non-vital incisors. Conventional radiographs demonstrated a well-defined radiolucency in the anterior maxilla associated with a tooth-like structure. Cone-beam computed tomography established a pericoronal radiolucency attached at the cemento-enamel junction of the mesiodens and independent of the incisor apices. Aspiration suggested secondary infection, and definitive diagnosis was confirmed by histopathological examination. The lesion was managed by surgical enucleation with removal of the associated supernumerary tooth. The immediate postoperative period was uneventful. The rarity of this case lies in the coexistence of trauma-associated non-vital incisors, which obscured the underlying developmental origin of the lesion and created a significant diagnostic challenge. This case highlights the importance of correlating clinical findings, trauma history, vitality testing, advanced imaging, and histopathology to accurately distinguish developmental odontogenic cysts from inflammatory periapical lesions in the anterior maxilla.</p>