title: Sigmoid plate dehiscence: congenital or acquired condition?
abstract: OBJECTIVE
  The imaging features of sigmoid plate dehiscence-induced pulsatile tinnitus have been presented. The origin of the sigmoid plate dehiscence, however, remains unclear. Our aim was to assess the prevalence and extent of sigmoid plate dehiscence on computed tomography (CT) images in multiple age groups to determine whether this condition is more likely to be congenital or acquired.
  
  
  METHODS
  We retrospectively reviewed contrast-enhanced CT images of sigmoid plates of temporal bones in 504 patients. Each temporal bone was characterized as normal or dehiscent. Patients were then subcategorized into four age groups, and the prevalence and extent of dehiscent sigmoid plates in each group were calculated and compared.
  
  
  RESULTS
  Overall, 80 patients had sigmoid plate dehiscence, nine of whom had it bilaterally. In successively older age groups, the prevalences of sigmoid plate dehiscence were 18.9%, 20.1%, 14.5%, and 12.7%, respectively. Respective average anteroposterior bony defect diameters were 3.7±1.7, 3.0±1.3, 3.1±1.5, and 3.0±1.1 mm. Respective average vertical bony defect diameters were 3.6±2.3, 2.6±1.2, 3.2±1.5, and 3.0±1.7 mm. The prevalence and extent of sigmoid plate dehiscence were not statistically different among the four age groups.
  
  
  CONCLUSIONS
  The similar radiologic prevalence and extent of dehiscent sigmoid plates among the age groups suggest that the dehiscence is more commonly a congenital than an acquired condition.
authors: Capital Medical University, Beijing Tongren Hospital, No 1 Dong Jiao Min Street, Dongcheng District, Beijing 100730, China. Electronic address: lzhtrhos@163.com.
authors: Zhaohui
authors: Z
authors: Liu
authors: Capital Medical University, Beijing Tongren Hospital, No 1 Dong Jiao Min Street, Dongcheng District, Beijing 100730, China. Electronic address: lijingxbh@yahoo.com.cn.
authors: Jing
authors: J
authors: Li
authors: Capital Medical University, Beijing Friendship Hospital, No 95 Yongan Road, Xicheng District, Beijing 100050, China. Electronic address: zhaopengf05@163.com.
authors: Pengfei
authors: P
authors: Zhao
authors: Capital Medical University, Beijing Friendship Hospital, No 95 Yongan Road, Xicheng District, Beijing 100050, China. Electronic address: chrislvhan@126.com.
authors: Han
authors: H
authors: Lv
authors: Capital Medical University, Beijing Friendship Hospital, No 95 Yongan Road, Xicheng District, Beijing 100050, China. Electronic address: derc007@sina.com.
authors: Cheng
authors: C
authors: Dong
authors: Jining No. 1 People's Hospital, No. 6 Health Street, Jining 272100, China. Electronic address: wenjuanliu@163.com.
authors: Wenjuan
authors: W
authors: Liu
authors: Capital Medical University, Beijing Friendship Hospital, No 95 Yongan Road, Xicheng District, Beijing 100050, China. Electronic address: cjr.wzhch@vip.163.com.
authors: Zhenchang
authors: Z
authors: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003392:Cranial Sinuses / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D013701:Temporal Bone / Q000000981:diagnostic imaging*; D014012:Tinnitus / Q000000981:diagnostic imaging* / Q000209:etiology; D014057:Tomography, X-Ray Computed
keywords: Computed tomography; Dehiscence; Pulsatile tinnitus; Sigmoid plate