Department of Otolaryngology, University of Minnesota, Minneapolis, Minnesota 55455, U.S.A.
Otol Neurotol. 2010 Sep;31(7):1122-7. doi: 10.1097/MAO.0b013e3181eb3309.
Posterior semicircular canal dehiscence has been shown to cause ear symptoms.
To evaluate the incidence of dehiscence of the posterior semicircular canal, thin bone overlying the posterior semicircular canal, and the normal development of the distance between the posterior semicircular canal and posterior cranial fossa.
The shortest distance between the posterior semicircular canal and posterior cranial fossa was measured in 1,051 adult human temporal bones (557 cases), and temporal bones with a distance less than 0.1 mm were evaluated. The shortest distance also was measured in 4 fetal temporal bones (2 cases) and 110 temporal bones from children.
Of the 1,051 temporal bones, 23 temporal bones (2.2%) had a distance less than 0.1 mm between the posterior semicircular canal and posterior cranial fossa. Two temporal bones (0.2%) had posterior semicircular canal dehiscence, and 2 temporal bones had microfractures in the thin bone; however, related clinical symptoms were not confirmed. In children, the distance between the posterior semicircular canal and the posterior cranial fossa increased with age (rho = 0.68, p < 0.01).
The histopathologic incidence of posterior semicircular canal dehiscence was lower than the previous radiographic reports. The dehiscence of the posterior semicircular canal may be due to a developmental anomaly. In our study, none of the cases with a distance less than 0.1 mm had apparent symptoms related to canal dehiscence syndrome. Other factors, in addition to thinning of the bone, may be required to cause the clinical manifestations.
已经证实后半规管裂会引起耳部症状。
评估后半规管裂、后半规管上方薄骨及后半规管与颅后窝之间正常距离的发生率。
在 1051 个人类颞骨（557 例）中测量了后半规管与颅后窝之间的最短距离，评估了距离小于 0.1mm 的颞骨。在 4 例胎儿颞骨（2 例）和 110 例儿童颞骨中测量了最短距离。
在 1051 例颞骨中，有 23 例（2.2%）的后半规管与颅后窝之间的距离小于 0.1mm。有 2 例（0.2%）存在后半规管裂，有 2 例颞骨存在薄骨微骨折，但未确认相关的临床症状。在儿童中，后半规管与颅后窝之间的距离随年龄增加而增加（rho = 0.68，p < 0.01）。
后半规管裂的组织病理学发生率低于之前的影像学报告。后半规管裂可能是由于发育异常所致。在我们的研究中，距离小于 0.1mm 的病例均无明显与管裂综合征相关的症状。除了骨变薄之外，可能还需要其他因素才能引起临床表现。
