Maturation of human lingual papillae during second and third trimesters: a fetal histo-morphological study

Abstract Introduction: The aim of this study was to describe the histological changes of tongue in a growing fetus. There are very few studies on histogenesis of tongue in human fetuses. Therefore the present study was carried out to describe the histogenesis of human fetal tongue at different gestational ages. Material and Methods: The present cross sectional study was conducted on 20 fetuses (both males and females). The tissue sections including both the anterior two thirds and the posterior one third of the tongue were dissected. The slides were stained with Hematoxylin and Eosin (H & E) for microscopic observation. The images were analysed digitally using ImagePro Premier 9.1 Software. Results: At 20th week, the tongue was lined by stratified squamous non keratinized epithelium and the different types of papillae were distinguishable. No taste buds were observed along the vallate papillae. The glandular and muscular components were well differentiated. At 24 weeks of gestation and the surface of the tongue was lined by non-keratinized stratified squamous epithelium. At 36 weeks the thickness of the epithelium was significantly reduced and the vascularity of lamina propria was increased. Conclusion: As the prenatal development of the human lingual papillae during the irst trimester is already known through the literature, the present study highlighted the structural maturation of the papillae during second and third trimesters.