Michaels L
Institute of Laryngology and Otology, University of London, England.
J Otolaryngol. 1988 Feb;17(1):22-8.
In a study of 20 ears from embryos and early fetuses, 16 contained structures recognizable as precursors of the epidermoid formation (EF). The earliest were small, but later they took the form of a long epithelial bud which emanated from the tip of the tubotympanic recess or Eustachian tube. At a later stage still the EF protruded into the lumen of the Eustachian tube. The early formation of the tympanic membrane, the middle ear cavity and the osseous tympanic ring all take place in the vicinity of the EF precursor. It is possible that the EF precursor may act as an organizer, playing a prominent part in the migration of the first pharyngeal pouch towards the first branchial groove and the development of the middle ear and tympanic membrane.
在一项对胚胎和早期胎儿的20只耳朵进行的研究中，16只耳朵含有可识别为表皮样形成（EF）前体的结构。最早的结构很小，但后来它们呈长上皮芽的形式，从咽鼓管隐窝或咽鼓管的尖端发出。在更晚的阶段，EF突入咽鼓管腔。鼓膜、中耳腔和骨性鼓膜环的早期形成都发生在EF前体附近。EF前体有可能作为一个组织者，在第一咽囊向第一鳃沟的迁移以及中耳和鼓膜的发育中发挥重要作用。
