Scientists have created part of the jaw joint in the lab using human adult stem cells:
They say it is the first time a complex, anatomically-sized bone has been accurately created in this way.
It is hoped the technique could be used not only to treat disorders of the specific joint, but more widely to correct problems with other bones too.
The Columbia University study appears in Proceedings of the National Academy of Sciences.
The bone which has been created in the lab is known as the temporomandibular joint (TMJ).
Problems with the joint can be the result of birth defects, arthritis or injury.
Although they are widespread, treatment can be difficult.
The joint has a complex structure which makes it difficult to repair by using grafts from bones elsewhere in the body.
The latest study used human stem cells taken from bone marrow.