Department of Embryology, Faculty of Medicine, Universidad Autónoma de Nuevo León, Monterrey, Av. Francisco I. Madero y Dr. Eduardo Aguirre Pequeño S/N, Col. Mitras Centro., C.P. 64460, Monterrey, NL, México.
Surg Radiol Anat. 2021 Jul;43(7):1187-1194. doi: 10.1007/s00276-020-02654-w. Epub 2021 Jan 4.
To establish normal reference values for the human Tympanic Ring (TR) during prenatal development, and to describe and interpret its growth dynamics.
Fifty spontaneously aborted human fetuses aged 12-37 weeks with normal external characteristics were evaluated. The parameters measured in the TR were the cephalocaudal and dorsoventral axes, total area, thickness, height, and length and angle of the notch of Rivinus (NR). Data were subjected to statistical analysis.
The following values were obtained at the end of fetal development: cephalocaudal and dorsoventral axes, 10.03 and 8.3 mm, respectively; ratio between the two axes, 120%; total area, 65.63 mm; height and thickness, 0.88 mm and 1.10 mm, respectively; and length and angle of the NR, 4.66 mm and 26.2 degrees, respectively. There were variations in the length of the dorsoventral axis throughout fetal development that affected all other parameters, except for the cephalocaudal axis. There were no sex-based differences in TR size.
The prenatal development of the TR is dynamic as evidenced by the size variations noted throughout fetal development. Notwithstanding, this structure is a reliable and sensitive marker of developmental abnormalities of the external and middle ear.
建立人类鼓膜环（TR）在产前发育过程中的正常参考值，并描述和解释其生长动态。
评估了 50 例具有正常外部特征的 12-37 周自发性流产的人类胎儿。在 TR 中测量的参数包括前后轴和背腹轴、总面积、厚度、高度、长度和 Rivinus 切迹（NR）的角度。数据进行了统计学分析。
在胎儿发育结束时获得了以下值：前后轴和背腹轴分别为 10.03 和 8.3mm；两个轴之间的比例为 120%；总面积为 65.63mm；高度和厚度分别为 0.88mm 和 1.10mm；NR 的长度和角度分别为 4.66mm 和 26.2 度。在整个胎儿发育过程中，背腹轴的长度发生变化，影响了除前后轴以外的所有其他参数。TR 大小无性别差异。
TR 的产前发育是动态的，这从整个胎儿发育过程中观察到的大小变化中可以看出。尽管如此，该结构是外部和中耳发育异常的可靠和敏感的标志物。
