ABSTRACT
Ultrastructure of human fetuses temporomandibular joint is poorly understood specially by scanning electron microscopy and cryofracture techniques. In this work, the morphology of the temporomandibular joint (TMJ) articular disc and its insertions was examined in 12 human fetuses. Four TMJs were sectioned in the frontal and sagittal planes and five were cryofractured prior to examination using light and scanning electron microscopy. The three remaining TMJs were fixed, embedded in paraffin, sectioned and stained with HE and NMC trichrome. The articular disc inserted into the mandibular head, temporal bone, joint capsule and upper head of the lateral pterygoid muscle. The fibrous architecture of this disc was complex, with longitudinal fibers predominating in the upper and lower regions, and interposed transverse and oblique fibers predominating in the central region.