When does bone development begin and end?

Answer 1

Most bones develop from cartilage. In the second month of fetal development, much of the skeleton is made of cartilage, and at about the third month, osteocytes begin to develop and release minerals which lodge into the spaces in between the cartilage cells, turning it into bone, which is called ossification. In a few bones, though, like parts of the skull, is develops directly without forming cartilage first.

Bones continue to develop after birth, and between early childhood and late adolescence, bone cells gradually replace the cartilage in long bones of limbs. The area where this takes place is the epiphyseal plate, wich is composed of cartilage cells which divide, pushing old cells out towards the middle of the bone. As the older cells die, the are replaced by new ones, and growth continues until the bone has replaced all of the cartilage of the epiphyseal plate.

At this point, bones no longer elongate, and a person has usually reached their full height. When bone is completely finished developing, a person is generally in their late 20's or early 30's.

Answer 2

Bone development begins in the fetus during the third month of pregnancy and continues until early adulthood, around age 25. During childhood and adolescence, bones continue to grow in size and density through a process called bone modeling. After reaching peak bone mass in early adulthood, bone remodeling occurs throughout life to maintain bone strength and repair damage.