伝音系奇形耳の臨床的考察
スポンサーリンク
概要
- 論文の詳細を見る
One hundred and twenty four cases of middle ear malformation treated at Okayama University Hospital for the past 19 years were studied.1) About 40% of middle ear malformation with normal ear canal had a slight malformation of the auricle, such as projection of the anthelix. And their conductive deafness were due to stapes anomaly or fixation of the footplate.2) In malformation with a narrow ear canal 50% had maldeveloped mastoid cells, 70% the narrow tympanic cavity, 70% the malformed malleus and 80% the malformed incus. All of stapedes had abnormalities in shape and movement, and furthermore 20% of the malleuses and incudes was fused in one mass and 60% of the incudostapedial joints was dislocated because of maldevelopment of the long process of the incus.3) In complete atresia, half of the cases had immature mastoid process, 90% had small tympanic cavities including 4 ears with deficit cavity. Almost all of malleuses and incudes were malformed. 50% of the cases had either the fused malleus &incus or the separated incus &stapes. All of stapedes were malformed or fixed. Especially in atresia with immature mastoid process and very small tymyanic cavity, the course of facial nerve was extremely unusual, i. e., the horizontal portion was very low, or the vertical portion was short and displaced more anteriorly than usual. Even in the patients with complete atresia, their inner ear apparatus located in normal site, so it seemed that there was a longer distance between horizontal semicircular canal and facial nerve than usual. A high grade malformation of the middle ear was found in the atresia with congenital palsy of the abducens or facial nerve, the immature mastoid process or persistence of embryonal connective tissues in the small tympanic cavity frequently found in Treacher-Collins syndrome.4) Mastoid pneumatisation was very poor in 50% of abnormal ear canals.5) In hereditary malformation, the middle ear findings showed a close resemblance in each other from one genealogy.6) The grade of anomaly was in correlation with narrowness of the external ear canal.7) The findings of the middle ear in the malformed one seemed as if normal development of the middle ear was discontinued by some causes, i. e., hereditary defects, intra uterine fetal injuries, fetal position in utero.
- 社団法人 日本耳鼻咽喉科学会の論文