(1) Imaging quiz case 4 Dentigerous cyst.

(2) The treatment for a dentigerous cyst is surgical removal.

(3) Dentigerous cysts develop from follicular epithelium and begin when fluid accumulates between layers of reduced enamel epithelium and the crown of the unerupted tooth.

(4) According to the X-ray features of the dentigerous cysts in jaws, four radiologic types of these cysts were presented.

(5) Methods:46 cases of dentigerous cysts were selected. We analyzed the position of these cysts, their adjacent normal structures and normal erupted teeth.

(6) Results Ameloblastoma, keratinous cyst and dentigerous cyst were the most commonly seen, accounting for 70% cases.

(7) Results Dentigerous cyst is one of the main causes of embedded teeth, only second to retained deciduous teeth, dental crowding.

(8) Histologically, dentigerous cysts are lined by stratified squamous nonkeratinizing epithelium.

(9) Dentigerous cyst (DC) is a common odontogenic cyst developed abnormally around unerupted maxillary or mandibular teeth.

(10) Methods Epithelial cells and fibroblast from ameloblastoma, keratocyst, dentigerous cyst, radicular cyst and oral mucosa were cultured and observed by phase-contrast microscope.

(11) However, it is extremely rare that dentigerous cyst exists in bilateral central incisor area and proximal wall of the right maxillary sinus simultaneity, which is why we report it.

(12) Results The more and higher DNA contents and the proliferating ploidy of keratocyst and ameloblastoma than those of radicular cyst and dentigerous cyst indicate the active proliferating potential.

(13) Dentigerous cysts are the second most common type of cyst in the jaw. 4% of patients with unerupted teeth have a dentigerous cyst.

(14) Objective To observe the therapeutic effects of fenestration in the treatment of dentigerous cyst in mixed dentition stage.

(15) Conclusion Fenestration can keep the teeth and bone in the treatment of dentigerous cyst in the mixed dentition stage.