Prenatal Development of Human Lip with Immunohistochemical Study. |
Su Jung Hong, Young Joon Lee, Yeon Sook Kim, Suk Keun Lee, Je G Chi |
1Department of Oral Pathology, Kangnung National University College of Dentistry, Gangneung, Korea. sklee@knusun.kangnung.ac.kr 2Department of Pathology, Seoul National University College of Medicine, Seoul, Korea. |
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ABSTRACT |
BACKGROUND: This study is aimed to elucidate the developmental pattern of human fetal lip by histological and immunohistochemical examinations.
METHODS: Totally 231 normal human lip tissues obtained from autopsied fetuses were fixed with 10% buffered formalin, sectioned in cross and longitudinal directions, routinely stained for H&E and performed for immunohistochemistry with antibodies of S-100 protein, proliferating cell nuclear antigen (PCNA), transglutaminase C (TGase-C), metalloproteinase (MMP)-3, MMP-10, tenascin, KL1, K8.12, E-cadherin, tissue inhibitors of matrix metalloproteinase (TIMP)-1, TIMP-2 and total keratin (TK).
RESULTS: The lip structure first appeared as an orifice of stomodeum around the 7-8th week of gestation, and a major structure of the midface was observed by the 11-12th week.
As the squamous epithelium of the lip became thick and was keratinized, the vermilion border became distinguished in the 15-16th week, and the lip structure was almost completed with the presence of orbicularis oris muscle in the lingual side of vermilion border by the 17-18th week.
Immunohistochemically, the vermilion border showed strong reactions for tenascin, E-cadherin and MMP-3 and increased positivity for PCNA, cytokeratins (TK, KL1, K8.12), and TGase-C.
CONCLUSIONS: With the above findings we suppose that the cytodifferentiation of vermilion border epithelium plays an important role for the development of human fetal lip. |
Key Words:
Fetal Development-Lip-Immunohistochemistry |
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