Paço João, Branco Carla, Estibeiro Hugo, Oliveira E Carmo Diogo
Hospital Cuf Infanto Santo, Lisbon, Lisbon, Portugal.
Otolaryngol Head Neck Surg. 2009 Jun;140(6):884-8. doi: 10.1016/j.otohns.2009.01.009. Epub 2009 Apr 5.
To document the anatomic relationship of the posterosuperior segment of the tympanic membrane.
Point-prevalence study of postmortem material.
One hundred seventy temporal bones from adults without history of otologic pathology were studied. The anatomic details of the tympanic membrane were observed, histology was documented on 30 sectioned bones, and, with the use of the scanning electron microscope, lamina propria was studied in 40 bones.
We established that the posterosuperior quadrant was the largest, representing 28.7 percent of the total area of the eardrum. This feature implies that this quadrant is more likely than are the other quadrants to exhibit changes prompted by pressure challenges. We also verified that the posterosuperior part of tympanic sulcus, above the chorda tympanic nerve, lost its depth in an unexpected way in 60 percent of the cases. In association, we established that at this level there was a decrease in annulus caliber. In 25 percent of cases, by the absence of the circular fibers of lamina propria, the posterosuperior quadrant had only the radial fiber layer.
Anatomic and morphologic details in posterosuperior quadrant were newly described and may explain the greater incidence of retraction pockets and marginal perforations that provide origin for the cholesteatoma.
记录鼓膜后上象限的解剖关系。
对尸检材料进行现况调查研究。
研究了170例无耳科病理病史的成人颞骨。观察了鼓膜的解剖细节，对30例切片颞骨进行了组织学记录，并使用扫描电子显微镜对40例颞骨的固有层进行了研究。
我们确定后上象限最大，占鼓膜总面积的28.7%。这一特征表明，与其他象限相比，该象限更有可能出现由压力挑战引起的变化。我们还证实，在60%的病例中，鼓索神经上方的鼓膜沟后上部以一种意想不到的方式变浅。与此相关，我们确定在这个水平上，鼓环口径减小。在25%的病例中，由于固有层环形纤维缺失，后上象限仅存在放射状纤维层。
新描述了后上象限的解剖和形态学细节，这可能解释了胆脂瘤起源的内陷袋和边缘穿孔发生率较高的原因。
