RT Journal Article
T1 Transient contribution of the sphenoid ala major to the socket of the temporomandibular joint in near‐term fetuses
A1 Hirouchi, Hidetomo
A1 Takeuchi, Yuki
A1 Yang, Tianyi
A1 Yamamoto, Masahito
A1 Hayashi, Shogo
A1 Murakami, Gen
A1 Rodríguez Vázquez, José Francisco
A1 Abe, Shinichi
AB The temporomandibular joint (TMJ) is a complex structure that plays a vital role in the movement of the jaw. Some anatomy and dental textbooks show that, at the medial margin, the TMJ capsule attaches to a suture between the sphenoid ala major and the temporal bone squamosa. In near-term fetuses, the ala major extends posterolaterally to approach the TMJ. In this study, we aimed to investigate the contribution of the sphenoid ala major to the socket of the TMJ in near-term fetuses. We examined histological sections from 22 human fetuses (approximately 15-40 weeks). At midterm, the lateral and superior walls of the TMJ cavity were formed by the temporal bone squamosa, whereas the ala major was distant from the joint. However, at near-term, the ala major formed the medial wall of almost the entire part of the joint cavity. The top of the TMJ was attached to both the squamosa and ala major, with the condylar head consistently separated from the sphenoid by the joint disk. We observed a significant descent of the middle cranial fossa in near-term fetuses, which brought the ala major close to the TMJ. This transient position of the TMJ near the sphenoid is likely due to brain enlargement and posterolateral growth of the ala major. After birth, occlusion causes the anterior growth of the mandibular fossa of the squamosa, which moves the ala major away from the TMJ. Similarly, the lateral growth of the sphenoid toward the squamosa suture may also stop in children.
PB Wiley
SN 1932-8486
YR 2024
FD 2024-05-24
LK https://hdl.handle.net/20.500.14352/109143
UL https://hdl.handle.net/20.500.14352/109143
LA eng
NO Hirouchi H, Takeuchi Y, Yang T, Yamamoto M, Hayashi S, Murakami G, Rodríguez-Vázquez JF, Abe S. Transient contribution of the sphenoid ala major to the socket of the temporomandibular joint in near-term fetuses. Anat Rec (Hoboken). 2024 Nov;307(11):3574-3581. doi: 10.1002/ar.25507
DS Docta Complutense
RD 13 abr 2025