Is the lower jaw formed by intramembranous ossification?

Yes, the lower jaw, also known as the mandible, is formed through a process called intramembranous ossification.

Intramembranous ossification is the process by which bone is formed directly from connective tissue, without the involvement of a cartilaginous intermediate. In the case of the mandible, the connective tissue that gives rise to the bone is called the mandibular mesenchyme.

The process of intramembranous ossification begins with the formation of ossification centers within the mandibular mesenchyme. These centers are where bone formation begins. As the ossification centers expand, they eventually merge together to form a single, continuous bone.