Objective To study the expression of the estrogen receptor (ER) and type Ⅱ collagen in the mandibular con-dylar cartilage of the human embryo.Methods The expression and localization of ERα, ERβ, and type Ⅱ collagen in the mandibular condylar cartilage of the human embryo were examined through hematoxylin-eosin (HE) and immunohistoche-mistry staining.Results Type Ⅱ collagen was primarily localized in the transitional and hypertrophic layers of the condylar cartilage. ERα was mostly expressed in the transitional and hypertrophic cartilaginous layers of the condylar cartilage. ERα was evenly distributed in the cell, whereas ERβ was localized in the nuclei. No expression of type Ⅱcollagen and ER was found in the fibrage and the proliferative layer although minimal expression was found in the calcified cartilage.Conclusion The distribution of ER and typeⅡ collagen in the mandibular condylar cartilage was consistent. Estrogen can selectively combine with different subtypes of ER that regulate the ability of the condylar cartilage cells to secrete type Ⅱ collagens.
