Ectopic upper third molar embedded in a dentigerous cyst of the maxillary sinus: a case report and literature review

Background Dentigerous cysts are the second most common form of a developmental cyst. These cysts might be the cause of ectopic teeth. Dentigerous cysts associated with ectopic teeth in the maxillary sinus are seldom seen in clinical practice. Case presentation We reported a 23-year-old woman who presented with nasal obstruction and facial pain on the left side 4 months ago. Three courses of antibiotics and analgesia were prescribed for her without improving the presenting features. Furthermore, extraction of the left upper second premolar and second molar, but the condition persisted. An orthopantogram and computerized tomography scan revealed the ectopic position of the left third upper molar tooth, which was embedded in a cystic lesion occupying the whole maxillary sinus. Removal of the cystic lesion with the ectopic tooth was performed with a Caldwell-Luc procedure. The histopathological evaluation confirmed the diagnosis of a dentigerous cyst. The presenting symptoms were resolved following surgery with no intra- or postoperative complications. Conclusion We are reporting another case of a dentigerous cyst occupying the whole left maxillary sinus with an ectopic left third upper molar tooth. Reporting such a case will enrich the literature regarding this rare clinical entity.