The cyst arises from the separation of the follicle from the crown of an unerupted tooth, and although it may involve any tooth, the mandibular third molars are the most commonly affected. Dentigerous cysts are frequently discovered when radiographs are taken to investigate a failure of tooth eruption, a missing tooth or malalignment. There is usually no pain or discomfort associated with the cyst unless it becomes secondarily infected. Radiographs show a unilocular, radiolucent lesion characterized by well-defined sclerotic margins and associated with the crown of an unerupted tooth. While a normal follicular space is 3 to 4 mm, a dentigerous cyst can be suspected when the space is more than 5 mm.
Most dentigerous cysts are solitary.
Bilateral and multiple cysts are usually found in association with a number of syndromes including cleidocranial dysplasia and Maroteaux-Lamy syndrome. In the absence of these syndromes, bilateral dentigerous cysts associated with the mandibular third molars are rare. Here, we report the unusual occurrence of nonsyndromic bilateral dentigerous cysts associated with mandibular third molars. Intraoral examination revealed an extensively restored dentition and clinically absent third molar teeth. No extraoral swellings or tenderness in relation to the mandibular third molars was noted.