Effect of an inductively deprived tissue environment on subspecialized cell lines of brephoplastic oral implants

Abstract

An experimental histomorphologic study was carried out to observe the differentiation and development of embryonic intraoral tissues isologously implanted into adult hamster cheek pouches. Twelve inbred adult male Syrian hamsters were challenged with solid intrapouch brephoplastic homografts, the tissues obtained from sectioning fetal mandibles and maxillae. A series of histological changes were observed during the study period of 22 weeks. Biocellular differentiation and modulation effects were reflected in the production of keratinizing epithelial cysts, bone marrow development with an exuberant proliferation of hematopoietic elements, atypical tooth-like structure, cartilagenous proliferation, formation of sebaceous units, and osseous metaplasia of collagenic aggregates. A notable observation was the transitory nature of the more subspecialized tissue forms. Dedifferential modulation to non-specialized cell types following initial persistence and proliferation of specifically directed cell lines, derived from the primitive tissues, was observed during the timecourse of the implants. Complete loss of tissue-unit integrity of some cell lines was ascribed to the qualitative and quantitative immaturity of certain cellular types in a non-inductive environment. Persistence and proliferation solely of keratohyalin synthetizing epithelium, implies a metabolic versatility of this basic cell type, and a “plateau-fixed” differential capacity, insofar as regression to a potentially more vulnerable basaloid cell line was not observed.