Liu Jun-Hua, Huang Wen-Hu, Xu Jiang Hong, Liu Yin, Sha Yan
Department of Radiology, Eye and ENT, Hospital of Fudan University, Shanghai 200031, China.
Department of Otolaryngology, Eye and ENT, Hospital of Fudan University, Shanghai 200031, China.
BJR Open. 2020 May 21;2(1):20200005. doi: 10.1259/bjro.20200005. eCollection 2020.
To explore the otoscopy, CT and MRI features of spontaneous temporomandibular joint(TMJ）herniation(STMJH) into the external auditory canal (EAC) through the persistent foramen of Huschke (PFH).
15 cases diagnosed STMJH were collected. The otoscopy, CT data of 15 cases and MRI data of 6 cases were retrospectively reviewed.
Otoscopy revealed a mass located in the anterior wall of the bony EAC that moved forwards and backwards during mouth opening and closing, respectively. CT showed a soft mass with bony defect in the anterior wall of the EAC, with no enhancement; the bony defect margin was well defined in all cases. The bone adjacent to the PFH was pressed and partially wrapped around the soft mass, as if "holding a ball," in seven cases. Pseudobone shell around the soft mass was observed in eight cases. Six cases included MRI scans, which showed TMJ soft tissue herniated into the EAC.
STMJHs have unique otoscopic, CT and MRI features. The examination strategy recommended is dynamic otoscopy and conventional CT, MRI can be chosen when the herniation is complicated by infection or otitis externa or when the patient has TMJ dysfunction; conservative management and follow-up observations are the main treatment strategy recommended.
Mechanical stress of TMJ on the EAC is thought to cause herniation and the special CT features, the location and size of the PFH, especially the location, are the major risk factors for TMJ herniation in patients with FH.
探讨经持续性胡氏孔（PFH）自发性颞下颌关节（TMJ）疝入外耳道（EAC）的耳镜、CT及MRI特征。
收集15例诊断为自发性颞下颌关节疝入外耳道的病例。回顾性分析15例患者的耳镜检查、CT资料及6例患者的MRI资料。
耳镜检查显示位于骨性外耳道前壁的肿物，在张口和闭口时分别向前和向后移动。CT显示外耳道前壁有软组织肿物伴骨质缺损，无强化；所有病例骨质缺损边缘清晰。7例中，与持续性胡氏孔相邻的骨质受压并部分包绕软组织肿物，形似“抱球”。8例观察到软组织肿物周围有假骨壳。6例患者进行了MRI扫描，显示颞下颌关节软组织疝入外耳道。
自发性颞下颌关节疝入外耳道具有独特的耳镜、CT及MRI特征。推荐的检查策略是动态耳镜检查和常规CT检查，当疝合并感染或外耳道炎或患者有颞下颌关节功能障碍时可选择MRI检查；推荐的主要治疗策略是保守治疗及随访观察。
颞下颌关节对外耳道的机械应力被认为会导致疝形成，而特殊的CT特征、持续性胡氏孔的位置和大小，尤其是位置，是FH患者颞下颌关节疝的主要危险因素。
