A dentigerous cyst is the second most common form of odontogenic cyst, after radicular cysts. The cyst is more common in the mandible than in the maxilla, and is uncommon in non-dentate regions, such as the maxillary sinus, mandibular condyle, and nasal septum. A cyst in the maxillary sinus in particular may induce the expression of precipitate sinusitis and sometimes result in ophthalmic symptoms . We report a large dentigerous cyst in the maxillary sinus that was left untreated for nine years in childhood.
The patient, a 17-year-old girl, was referred to Daido Hospital with the chief complaint of spontaneous pain in the left maxilla for the past four months. An extra-oral examination revealed no swelling, redness, or asymmetric complexion. An intra-oral examination revealed that 27 and 28 were missing and there was a discharge of pus ( Fig. 1 ). A panoramic radiograph showed impacted 27 and 28 in the left maxillary sinus ( Fig. 2 ). Computed tomography (CT) showed impacted 27 and 28 and a well-defined unilocular lesion ( Fig. 3 A); 27 contacted the nasolacrimal duct ( Fig. 3 B). Based on these results, the clinical diagnosis was jaw cyst or benign tumor.
Prior to this, the patient at age 8 had reported to a primary dental clinic where radiological imaging revealed impacted teeth in the left maxillary sinus by chance. Following this, panoramic radiography was sometimes performed at the dental clinic, where imaging showed that 27 stayed in the same place for nine years, and 28 was calcified and formed a tooth crown ( Fig. 4 ). However, the pathosis was left untreated at the dental clinic because of a lack of symptoms.