Okuno Tetsuko, Suzuki Hitoshi, Inoue Akio, Kusukawa Jingo
Special Advisor, Department of Orthopedic Surgery, Yanagawa Rehabilitation Hospital, Yanagawa, Japan.
Assistant Professor, Department of Orthopedic Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
J Oral Maxillofac Surg. 2017 Sep;75(9):1891-1898. doi: 10.1016/j.joms.2017.03.005. Epub 2017 Mar 16.
Fibrodysplasia ossificans progressiva (FOP) is an extremely rare genetic condition characterized by congenital malformation and progressive heterotopic ossification (HO) caused by a recurrent single nucleotide substitution at position 617 in the ACVR1 gene. As the condition progresses, HO leads to joint ankylosis, breathing difficulties, and mouth-opening restriction, and it can shorten the patient's lifespan. This report describes 3 cases of FOP confirmed by genetic testing in patients with restricted mouth opening. Each patient presented a different onset and degree of jaw movement restriction. The anatomic ossification site of the mandibular joint was examined in each patient using reconstructed computed tomographic (CT) images and 3-dimensional reconstructed CT (3D-CT) images. A 29-year-old woman complained of jaw movement restriction since 13 years of age. 3D-CT image of the mandibular joint showed an osseous bridge, formed by the mandibular depressors that open the mouth, between the hyoid bone and the mentum of the mandible. A 39-year-old man presented with jaw movement restriction that developed at 3 years of age after a mouth injury. 3D-CT image of the jaw showed ankylosis of the jaw from ossification of the mandibular depressors that was worse than in patient 1. CT images showed no HO findings of the masticatory muscles. To the authors' knowledge, these are the first 2 case descriptions of the anatomic site of ankylosis involving HO of the mandibular depressors in the jaw resulting from FOP. In contrast, a 62-year-old bedridden woman with an interincisal distance longer than 10 mm (onset, 39 years of age) had no HO of the mandibular depressors and slight HO of the medial pterygoid muscle on the right and left sides. These findings suggest that restricted mouth opening varies according to the presence or absence of HO of the mandibular depressors.
进行性骨化性纤维发育不良（FOP）是一种极为罕见的遗传性疾病，其特征为先天性畸形以及由ACVR1基因第617位的反复单核苷酸替换导致的进行性异位骨化（HO）。随着病情进展，异位骨化会导致关节强直、呼吸困难和张口受限，并且会缩短患者的寿命。本报告描述了3例经基因检测确诊为FOP且存在张口受限的患者。每位患者的发病情况和下颌运动受限程度各不相同。利用重建的计算机断层扫描（CT）图像和三维重建CT（3D-CT）图像对每位患者下颌关节的解剖性骨化部位进行了检查。一名29岁女性自13岁起就抱怨下颌运动受限。下颌关节的3D-CT图像显示，在舌骨与下颌骨颏部之间有一座由张口的下颌降肌形成的骨桥。一名39岁男性在3岁时口腔受伤后出现下颌运动受限。下颌的3D-CT图像显示，下颌降肌骨化导致的下颌关节强直比患者1更为严重。CT图像显示咀嚼肌无异位骨化表现。据作者所知，这是关于FOP导致下颌降肌异位骨化引起下颌关节强直的解剖部位的首例2例病例描述。相比之下，一名62岁卧床女性，切牙间距离大于10毫米（发病年龄为39岁），下颌降肌无异位骨化，双侧翼内肌有轻微异位骨化。这些发现表明，张口受限因下颌降肌异位骨化的有无而有所不同。
