Organ culture providing an articulating function for the temporomandibular joint.

Cranial bases of 5 days old mice along with the temporomandibular joints and the whole mandibles were maintained in organ culture for one, two or three weeks. A device consisting of an electric motor rotating a bar with three magnets was developed for providing an articulating function for the temporomandibular joints. The tissue samples were attached to the end of a lever arm inside a container and a piece of iron was fixed to the other end of the lever arm to allow it to be lifted magnetically every 45 seconds. This movement pressed the other end of the lever arm downwards, submerging the tissues in the medium. As the anterior end of the mandible was attached to a wire above the tissues with a silk thread while the rest of the tissue sample moved downwards, a rotating movement was produced in the mandibular joint. Control mandibles were cultured without any such movement in the temporomandibular joints. The reactions in the condyles were studied macroscopically after alizarin red injections and microscopically with haematoxylin and eosin, alcian blue, osteoid and von Kossa stains. The condylar processes had increased 0.6 mm in length in functional organ culture, 0.4 mm more than the sham-cultured condyles. Osteoid formation was more marked in the latter and calcification had proceeded closer to the superior surface of the cartilage than in the condyles cultured with articulatory function. The organ culture system developed here obviously resembles the situation in vivo more closely than do previously available organ culture systems and is the first in which it has been possible to provide the function necessary for maintaining growth. The system also seems suitable for culturing organs in which tissue size has previously been a limiting factor.