Kocaeli Health Sciences University, Derince Training and Research Hospital, Department of Otorhinolaryngology - Head and Neck Surgery, Kocaeli, Turkey.
University of Istanbul, Istanbul Medical Faculty, Department of Otorhinolaryngology - Head and Neck Surgery, Istanbul, Turkey.
Braz J Otorhinolaryngol. 2020 Jan-Feb;86(1):74-82. doi: 10.1016/j.bjorl.2018.10.002. Epub 2018 Nov 3.
Microsurgery of the ear requires complete evaluation of middle ear surgical anatomy, especially the posterior tympanic cavity anatomy. Preoperative assessment of the middle ear cavity is limited by the permeability of eardrum and temporal bone density. Therefore, middle ear exploration is an extremely useful method to identify structural abnormalities and anatomical variations.
The aim of this study is to determine anatomic variations of the middle ear in an autopsy series.
All evaluations were performed in the Forensic Medicine Institute Morgue Department. The cases over 18 years of age, with no temporal bone trauma and history of otologic surgery included in this study.
One hundred and two cadavers were included in the study. The mean age was 49.08±17.76 years. Anterior wall prominence of the external auditory canal was present in 27 of all cadavers (26.4%). The tympanic membrane was normal in 192 ears (94%) while several eardrum pathologies were detected in 12 ears (6%). Agenesis of the pyramidal eminence and stapedial tendon was found in 3 ears. While the ponticulus was bony ridge-shaped in 156 of 204 ears (76.4%), it was bridge-shaped in 25 ears (12.3%). The ponticulus was absent in 23 ears (11.3%). While complete subiculum was present in 136 of all ears (66.7%), incomplete subiculum was present in 21 ears (10.3%). Subiculum was absent in 47 ears (23%). Facial dehiscence was found in 32 ears and the round window niche was covered by a pseudomembrane in 85 ears (41.6%). A fixed footplate was present in 7.4% of all ears, and no persistent stapedial artery was seen in any cases.
The pseudomembrane frequency covering the round window niche was found different from reports in the literature. In addition, the frequency of the external auditory canal wall prominence has been reported for the first time.
耳部微创手术需要对中耳手术解剖结构进行全面评估，尤其是对后鼓室解剖结构的评估。中耳腔的术前评估受到鼓膜通透性和颞骨密度的限制。因此，中耳探查是一种非常有用的方法，可以识别结构异常和解剖变异。
本研究旨在确定尸体解剖系列中耳的解剖变异。
所有评估均在法医研究所太平间进行。本研究纳入年龄在 18 岁以上、无颞骨外伤和耳科手术史的病例。
本研究纳入了 102 具尸体。平均年龄为 49.08±17.76 岁。所有尸体中，27 具（26.4%）存在外耳道前壁突出。192 只耳朵（94%）鼓膜正常，12 只耳朵（6%）发现多种鼓膜病变。3 只耳朵存在锥体隆起和镫骨肌腱发育不全。204 只耳朵中，156 只（76.4%）桥状鼓环，25 只（12.3%）为梁状鼓环，23 只（11.3%）鼓环缺失。所有耳朵中，136 只（66.7%）存在完整的鼓环下脚，21 只（10.3%）存在不完整的鼓环下脚，47 只（23%）鼓环下脚缺失。32 只耳朵面神经管存在骨裂，85 只耳朵（41.6%）圆窗龛被假性鼓膜覆盖。7.4%的耳朵存在固定的镫骨底板，所有病例均未见永存镫骨动脉。
圆窗龛假性鼓膜覆盖的频率与文献报道不同。此外，首次报道了外耳道后壁突出的频率。
