新生児側頭骨の顔面神経管裂隙の出現頻度とその部位について—側頭骨病理組織標本による

Dehiscence of the Facial Canal of Newborn Baby

　はじめに

　顔面神経管裂隙とは側頭骨の顔面神経管にしばしば存在する骨欠損部であり，中耳手術の際の顔面神経麻痺の原因の1つでもあり，中耳炎の顔面神経への炎症の波及路ともいわれている^1,2）。成人側頭骨における顔面神経管裂隙の病理組織学的検討の報告はあるが^3〜5），新生児あるいは乳児における顔面神経管裂隙についての報告は極めて少ない^4）。今回われわれは，帝京大学耳鼻咽喉科学教室の側頭骨病理コレクションの新生児側頭骨5例8耳の顔面神経管裂隙の出現頻度とその部位について検討したので，ここに報告する。

The location and size of dehiscence of the facial canal were determined from histologic examination of 8 newborn temporal bones. Dihiscence was found in all temporal bones. A total of 37 dehiscences were found and the average number of dehiscence was 4.6 per of the temoral bones. The average width of dehiscence was 0.46 mm. 75.7% of the dehiscences were located in the horizontal segment and 24.3% in the vertical segment.

The average number of dehiscence per newborn temporal bone was higher and the percentage of dehiscence of the vertical segment of the newborn temporal bone was higher than that of adult. These findings support the theory that dehiscence appears due to incomplete fusion of the bone wall during the facial canal development process in the embryonal stage.