The vertebrate skeleton consists of a variety of individual elements, each characterized by a specific size and shape. There are two main modes by which these skeletal elements are formed. In one mode, known as ‘intramembranous ossification’, which occurs for example in the development of the skull, mesenchymal cells directly differentiate into bone. In the other mode, known as ‘endochondral os...

It is well known that mandible bone is formed by intramembranous ossification. Mandible condyle cartilage and angular cartilage are recognized as secondary cartilage, which differs from primary cartilage in morphological and biochemical organization. These are interesting research subjects from a clinical point of view as they compose the TMJ. We examined the mandible, mandible condyle cartilag...

Osteogenesis is categorized into two groups based on developmental histology, intramembranous and endochondral ossification. The role of blood vessels during endochondral ossification is well known, while their role in intramembranous ossification, especially the intertissue pathway, is poorly understood. Here, we demonstrate endothelial Yap/Taz is a novel regulator of intramembranous ossificat...

Cellular and molecular similarities between orthotopic versus heterotopic mineral deposition are beginning to emerge. During bone formation, the major orthotopic venue, two general mechanisms drive tissue mineralization1 (Table). With endochondral ossification, an avascular cartilaginous skeletal template is first established by chondrocytes; this cartilage template calcifies and is subsequentl...

Enlarged parietal foramina are believed to be benign and familial and due to a variable degree of defective intramembranous ossification of the parietal bones. We report 2 patients with this condition in whom fetal and neonatal MR imaging studies illustrate the antenatal and perinatal evolution of this condition and the associated persistence of a falcine sinus. We discuss its relationship to t...

This study was undertaken to determine whether periosteum from different bone sources in a donor results in the same formation of bone and cartilage. In this case, periosteum obtained from the cranium and mandible (examples of tissue supporting intramembranous ossification) and the radius and ilium (examples of tissues supporting endochondral ossification) of individual calves was used to produ...

Native differences in cell shape and plasma membrane organization in contact-inhibited and transformed cells and the effects of cytochalasin B and colchicine on these cells have been examined by scanning electron microscopy and freeze fracture-electron microscopy. Confluent BALB/c 3T3 cells show a flat, polygonal shape with limited cell overlapping, some microvilli, and plasma membranes with an...