Ontogenesis of the Human Temporomandibular Joint: 2. Development of the Temporal Components

¹ School of Dentistry, Faculty of Medicine, University of Geneva, Geneva, Switzerland

The embryologically unique origin of the temporomandibular joint from two separately (in time and space) developing blastemas was further studied in relation to temporal structures. Both coronal and sagittal sections of 11 human fetuses from the 24 mm to 72 mm crown-rump (C-R) stage showed that the glenoid blastema developed in close relationship with the primordial quadrate-meckelian joint to form the bony temporal joint components, including the capsular elements of the upper joint story. The disk developed independently of the tendon of the external pterygoid muscle as a derivative of both the condylar and the glenoid blastemas.