Jpn. J. Oral Biol., 24: 520-522, 1982. Proliferation of epithelial rests in periodontal ligament of rats induced by 1-butyl-1-nitrosourea

Odontogenic tumor is one of the tumors of great significance in the oral region. The process of its development remains obscure. It seems very advantageous in the investigation of dontogenic tumor to establish experimental models in laboratory animals. However, experimental attempts of induction of odontogenic tumor have not been very successful. In recent years, the carcinogenic property of nitroso derivatives has been confirmed in various organs including oral apparatus, and induced odontogenic tumor and its related lesions have been reported in several papers1-5) during carcinogenic experiments with this chemical. It is generally thought that odontogenic epithelia (reduced enamel epithelium, fragmented dental lamina, epithelial rests in the periodontal ligament) may well play a role in the pathogenesis of odontogenic tumors. And the epithelial rests in the periodontal ligament are known to proliferate under certain stimuli61. However, the initial stage of epithelial proliferation in odontogenic tumor has not been clarified as yet. The present study was intended to make further detailed observations in this respect.