Computerized three dimensional evaluation of the embryologic development of the human temporomandibular joint

Abstract

In this study, the development of human embryonic temporomandibular joint (TMJ) and surrounding structures were investigated with computerized three-dimensional reconstructions. Total number of 16 embryos and fetuses, ranging from 6.5 to 107 mm CRL, were examined. Until the 10(th). week there were no signs of the disc, joint spaces and capsule formation of the TMJ. At 10 weeks a cleft in the mesenchyme between the condylar process and temporal component was formed as a first sign of the lower TMJ space. At 11 to 12 weeks another cleft was observed to form the upper TMJ space. Thus the mesenchyme between the upper and the lower TMJ spaces condensed and formed the TMJ disc. At 10 weeks, a band of mesenchyme extending from the attachment of the lateral pterygoid muscle to the condylar process was observed to pass through the medial side of the condylar process to attach the malleus.