In the maxilla, these teeth are often displaced into the maxillary sinus. Classic symptoms of sinus disease such as headache, facial pain, purulent nasal discharge or nasolacrimal obstruction may occur when maxillary sinus is involved. According to a study, 45.7 percent of dentigerous cysts involved mandibular third molar. On the other hand, only 2.7 percent of dentigerous cysts involved the maxillary premolar. Mourshed stated that the incidence of dentigerous cyst has been reported as 1.44 in every 100 unerupted teeth, so dentigerous cysts involving the premolars are rare. Dentigerous cysts most commonly occur in the 2nd and 3rd decades of life. Males have been reported to be more prevalent than females with a ratio of 1.8:1. These cysts can also be found in young children and adolescents. The age of presentation of these cysts range from 3 years to 57 years with a mean of 22.5 years. These cysts are commonly single lesions. Bilateral and multiple dentigerous cysts are very rare although they have been reported. Bilateral or multiple dentigerous cysts have been reported in Maroteaux-Lamy syndrome, cleidocranial dysplasia and Gardners syndrome In the absence of these syndromes, the occurrence of multiple dentigerous cysts is rare. Sometimes multiple dentigerous cysts are suggested to be induced by prescribed drugs. The combined effect of cyclosporine and a calcium channel blocker is reported to cause bilateral dentigerous cyst
Dentigerous cyst is potentially capable of becoming an aggressive lesion.
In the mandible, buccal or lingual cortical expansion and thinning are noted.On MR imaging, the contents of the cyst display low to intermediate signal intensity on T1-weighted images and high signal intensity on T2-weighted images. The tooth itself is a zone of signal void. The lining of the cyst is thin with regular thickness and may show slight enhancement after contrast injection. Treatment and Prognosis
The treatment of choice for dentigerous cyst is enucleation along with extraction of the impacted teeth. If eruption of the unerupted tooth is considered feasible, the tooth may be left in place after partial removal of the cyst wall. Orthodontic treatment may subsequently be required to assist eruption. Similarly, if displacement of the associated tooth by the cyst has occurred and extraction may prove to be difficult, orthodontic movement of the tooth to a more advantageous location for extraction may be accomplished. Marsupialization may also be used to treat large dentigerous cysts. This permits the decompression of the cyst, with a resulting decrease in the size of the bone defect. The cyst can then be excised at a later date, with a less extensive surgical procedure. The prognosis for the dentigerous cyst is excellent, and recurrence is rare. This is related to the exhausted nature of the reduced enamel epithelium, which has differentiated and formed tooth crown enamel before developing into a cyst. Nevertheless, several potential complications must be considered. The possibility that the lining of a dentigerous cyst might undergo neoplastic transformation to an ameloblastoma has been well-documented.