Development of the mandibular condylar cartilage in human specimens of 10–15 weeks’ gestation

Abstract

This study analyses some morphological and histological aspects that could have a role in the development of the condylar cartilage (CC). The specimens used were serial sections from 49 human fetuses aged 10-15 weeks. In addition, 3D reconstructions of the mandibular ramus and the CC were made from four specimens. During weeks 10-11 of development, the vascular canals (VC) appear in the CC and the intramembranous ossification process begins. At the same time, in the medial region of the CC, chondroclasts appear adjacent to the vascular invasion and to the cartilage destruction. During weeks 12-13 of development, the deepest portion of the posterolateral vascular canal is completely surrounded by the hypertrophic chondrocytes. The latter emerge with an irregular layout. During week 15 of development, the endochondral ossification of the CC begins. Our results suggest that the situation of the chondroclasts, the posterolateral vascular canal and the irregular arrangement of the hypertrophic chondrocytes may play a notable role in the development of the CC.

An Immunohistochemical Study of Matrix Components in Early‐Stage Vascular Canals Within Mandibular Condylar Cartilage in Midterm Human Fetuses

“…Mérida‐Velasco et al () reported detailed observations of the early developmental process of VCs. They suggested that the mesenchymal invagination forming VC appears during 10–11 weeks of gestation and that the deepest posterolateral VC was completely surrounded by the hypertrophic chondrocytes at 12–13 weeks of gestation.…”

“…They suggested that the mesenchymal invagination forming VC appears during 10–11 weeks of gestation and that the deepest posterolateral VC was completely surrounded by the hypertrophic chondrocytes at 12–13 weeks of gestation. All the VCs that Mérida‐Velasco et al () described contained blood vessels. Thus, the VCs that Mérida‐Velasco et al () described seemed to correspond to the VCs but not to the PVCs in the present study.…”

“…All the VCs that Mérida‐Velasco et al () described contained blood vessels. Thus, the VCs that Mérida‐Velasco et al () described seemed to correspond to the VCs but not to the PVCs in the present study.…”

“…The VCs in the condylar cartilage seem to be derived from invaginations of perichondral mesenchyme (Blackwood, ; Mérida‐Velasco et al, ; Rusu et al, ). In addition, based on histochemistry, immunohistochemistry, and electron microscopy, Blumer et al () demonstrated that cartilage canals were an extension of the vascularized perichondrium.…”

“…Linss and Möller et al () described similar findings in fetuses of 31–39 weeks of gestation. Mérida‐Velasco et al () made detailed observations and then created 3D‐reconstructions of the early developmental process of VCs. They reported that VCs appear during 10–11 weeks of gestation.…”