Sato Masaru, Maruoka Yutaka, Kunimori Kentaro, Imai Hideki, Kabasawa Yuji, Ichinose Shizuko, Harada Kiyoshi, Omura Ken
Department of Oral Restitution, Division of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
J Oral Maxillofac Surg. 2007 Aug;65(8):1517-25. doi: 10.1016/j.joms.2006.10.041.
Studies of changes in the surrounding soft tissue in association with distraction osteogenesis in the maxillofacial region, where various different kinds of tissue are tightly packed, are rare. In this study, we performed morphological and immunohistochemical investigations of muscle tissue during mandibular distraction osteogenesis.
Japanese white rabbits were divided into 2 groups. In 1 group, the mandibular bone was distracted at a rate of 1 mm/day (DO group), whereas in the other group it was advanced by 10 mm all at once (O group). The cross-section of the anterior belly of the digastric muscle was examined using hematoxylin and eosin, periodic acid-Schiff (PAS), and proliferating cell nuclear antigen (PCNA) staining methods, as well as scanning electronmicroscopy (SEM).
In the DO group, the cross-section of muscle bundle revealed no remarkable changes. In PAS staining, type II fibers gradually disappeared with distraction, but eventually reappeared after a period of consolidation. In the SEM photographs, striation-like laminated structures were evident in the control and the 3-mm distraction, ambiguous in the 6-mm distraction, and not evident in the 10-mm distraction. In contrast, the structure appeared to be restored in the consolidation for 1 week thereafter. In the PCNA immunostaining, the numbers of PCNA-positive nuclei increased during periods of distraction, but subsequently tended to decrease gradually.
Although minute injuries were induced in muscle fibers in association with distraction osteogenesis, it is suggested that muscle fibers regenerate starting in the distraction period and thus can adapt to the environment.
在颌面部，各种不同组织紧密排列，关于牵张成骨过程中周围软组织变化的研究较少。在本研究中，我们对下颌骨牵张成骨过程中的肌肉组织进行了形态学和免疫组织化学研究。
将日本白兔分为2组。一组以下颌骨每天1mm的速度进行牵张（牵张成骨组），而另一组一次性前移10mm（对照组）。使用苏木精-伊红染色、过碘酸-希夫（PAS）染色、增殖细胞核抗原（PCNA）染色方法以及扫描电子显微镜（SEM）检查二腹肌前腹的横截面。
在牵张成骨组中，肌束横截面未显示出明显变化。在PAS染色中，II型纤维随着牵张逐渐消失，但在一段时间的巩固后最终重新出现。在SEM照片中，对照组和3mm牵张时可见条纹状层状结构，6mm牵张时不清晰，10mm牵张时不明显。相比之下，此后巩固1周时结构似乎恢复。在PCNA免疫染色中，PCNA阳性核的数量在牵张期间增加，但随后逐渐趋于减少。
尽管牵张成骨会导致肌肉纤维受到微小损伤，但提示肌肉纤维在牵张期开始再生，从而能够适应环境。
