RT Journal Article
T1 Closure of the middle ear with special reference to the development of the tegmen tympani of the temporal bone
A1 Rodríguez Vázquez, José Francisco
A1 Murakami, Gen
A1 Verdugo López, Samuel
A1 Abe, Shinichi
A1 Fujimiya, Mineko
AB Closure of the middle ear is believed to be closely related to the evolutionary development of the mammalian jaw. However, few comprehensive descriptions are available on fetal development. We examined paraffin-embedded specimens of 20 mid-term human fetuses at 8-25 weeks of ovulation age (crown-rump length or CRL, 38-220 mm). After 9 weeks, the tympanic bone and the squamous part of the temporal bone, each of which was cranial or caudal to Meckel's cartilage, grew to close the lateral part of the tympanosquamosal fissure. At the same time, the cartilaginous tegmen tympani appeared independently of the petrous part of the temporal bone and resulted in the petrosquamosal fissure. Subsequently, the medial part of the tympanosquamosal fissure was closed by the descent of a cartilaginous inferior process of the tegmen tympani. When Meckel's cartilage changed into the sphenomandibular ligament and the anterior ligament of the malleus, the inferior process of the tegmen tympani interposed between the tympanic bone and the squamous part of the temporal bone, forming the petrotympanic fissure for the chorda tympani nerve and the discomalleolar ligament. Therefore, we hypothesize that, in accordance with the regression of Meckel's cartilage, the rapidly growing temporomandibular joint provided mechanical stress that accelerated the growth and descent of the inferior process of the tegmen tympani via the discomalleolar ligament. The usual diagram showing bony fissures around the tegmen tympani may overestimate the role of the tympanic bone in the fetal middle-ear closure.
PB Wiley
SN 0021-8782
YR 2011
FD 2011-06
LK https://hdl.handle.net/20.500.14352/95988
UL https://hdl.handle.net/20.500.14352/95988
LA eng
NO Rodríguez-Vázquez JF, Murakami G, Verdugo-López S, Abe S, Fujimiya M. Closure of the middle ear with special reference to the development of the tegmen tympani of the temporal bone. Journal of Anatomy. 2011 Jun;218(6):690-8.
DS Docta Complutense
RD 22 abr 2025