Follicular cysts, classified as malformative odontogenic cysts, are twice more frequent in males than females.
They are the second in frequency after periapical cysts, representing 20% of all odontogenic cysts, but they are the most frequent type of odontogenic cyst in the first decade of age.
Follicular cysts typically contain the impacted tooth inside of them; they grow after that the dental crown has formed due to regressive phenomena, with accumulation of fluid, semifluid or gas between the epithelium of the organ of the reduced enamel and the enamel of the tooth.
The Authors refer a case report in which a male patient manifested the typical clinical-radiological changes compatible with the diagnosis of follicular cyst in the area of 7.4 – 7.5: the tooth impacted in the cyst is not in arch, with consequent delayed eruption of teeth 3.4 and 3.5.
The patient did not present symptoms of pain, but a slight increase in volume of the left hemimandible to the vestibular level. The cyst was identified during a routine radiological examination.
On the radiological examination, the follicular cyst is a unilocular radiotransparency, with well-defined sclerotic radiopaque borders surrounding the impacted tooth. The cyst can be in a central position with the dental crown placed at the center, or in a lateral position with the cyst developing at one side of the tooth.
In this case, there is also a rhizolysis of the contiguous tooth. On the histological examination we noticed that the cyst was covered by non-keratinized stratified flat epithelium, with signs of muciparous cells in continuity with residues of the enamel organ.
The fibrous wall had, instead, a chronic phlogistic infiltrate, composed of plasma cells and lymphocytes and agglomerations of fibroblasts.
The next follow-up at seven days revealed a restored anatomy of perilesional soft tissues.
A correct and complete surgical enucleation of the follicular cyst is fundamental in order to avoid the possible and unpleasant transformation into ameloblastoma of the epithelium covering the cyst or the rarer intraosseous mucoepidermoid carcinoma.
F. Inchingolo 1-4, A. D. Inchingolo1, M. Tatullo 2, M. Marrelli 4 , A.M. Inchingolo 3, F. Carbotti 1, A. Palladino 1, M. De Carolis 1, V. Angelini 1 , A.D. Inchingolo1, G. Dipalma1-4
1 Department of Odontostomatology and Surgery, University of Bari, Bari, Italy
3 Department of Odontostomatology and Surgery, University of Milano, Milano, Italy
4Department of Maxillofacial Surgery, Calabrodental Srl, Crotone, Italy