Computerized 3-dimensional study of the embryologic development of the human masticatory muscles and temporomandibular joint.
OBJECTIVE
In this study, the development of human embryonic temporomandibular joint (TMJ) and masticatory muscles were investigated by using computed 3-dimensional reconstructions.


METHODS
Sixteen human embryos and fetuses, ranging from 6.5 to 107 mm crown-rump length, were examined.


RESULTS
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 to the malleus. The temporal, masseter, and pterygoid muscles develop from the so called "temporal muscle" primordium, and the temporal muscle was in continuity with the masseter muscle until 14 weeks of fetal life.


CONCLUSIONS
The study shows that the muscles of mastication arise from a single primordium. It also confirms the presence of a ligamentous attachment between the lateral pterygoid muscle and the malleus.
Oğütcen-Toller
M
M
Department of Oral and Maxillofacial Surgery, Dental Faculty of Ondokuz Mayis University, Samsun, Turkey.
Keskin
M
M
D003198:Computer Simulation; D005314:Embryonic and Fetal Development; D005865:Gestational Age; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008022:Ligaments / Q000196:embryology; D008307:Malleus / Q000196:embryology; D008406:Masseter Muscle / Q000196:embryology; D008410:Masticatory Muscles / Q000196:embryology*; D008953:Models, Anatomic; D011626:Pterygoid Muscles / Q000196:embryology; D013703:Temporal Muscle / Q000196:embryology; D013704:Temporomandibular Joint / Q000196:embryology*