P63 and Ki-67 Expression in Dentigerous Cyst and Ameloblastomas

P63 gene is a member of TP53 and its homologous gene family. Its expression was observed in some odontogenic lesions, more expression in aggressive lesions.

This study aimed to investigate the possible diagnostic impact of P63 protein on dentigerous cysts and various types of ameloblastoma. Its expression with Ki-67 proliferation marker was also compared.

This cross-sectional retrospective study was enrolled on 25 cases of dentigerous cyst including 21 unicystic ameloblastomas and 17 conventional ameloblastomas. The expression of P63 and Ki-67 was assessed by immunohistochemical (IHC) examinations. Data were analyzed by employing Mann-Whitney and correlation coefficient tests.

P63 expression was significantly higher in ameloblastoma than unicystic ameloblastoma and dentigerous cysts. There was no significant difference between unicystic ameloblastoma and dentigerous cyst in P63 expression. A 90% cut-off point was obtained for basal layer which gave 88% sensitivity and 78% specificity to distinguish more invasive lesions from others. There was not any correlation between P63 and Ki-67 immunostaining in the three study groups.

More aggressiveness and more invasiveness of odontogenic lesions depicted higher rate and also more intensive expression of P63. Moreover, the expression of P63 protein had not any correlation with Ki-67 protein in dentigerous cysts and ameloblastomas.