Disrupted tenogenesis in masseter as a potential cause of micrognathia  

作　　者：Chao Liu Nan Zhou Nan Li Tian Xu Xiaoyan Chen Hailing Zhou Ailun Xie Han Liu Lei Zhu Songlin Wang Jing Xiao 

机构地区：[1]Department of Oral Pathology,Dalian Medical University School of Stomatology,Dalian,China [2]Academician Laboratory of Immunology and Oral Development&Regeneration,Dalian Medical University,Dalian,China [3]Beijing Laboratory of Oral Health,Capital Medical University,Beijing,China

出　　处：《International Journal of Oral Science》2022年第4期509-522,共14页国际口腔科学杂志（英文版）

基　　金：supported by the grants from the National Natural Science Foundation of China(81970922 to J.X.and 81771055 to C.L.)。

摘　　要：Micrognathia is a severe craniofacial deformity affecting appearance and survival. Previous studies revealed that multiple factors involved in the osteogenesis of mandibular bone have contributed to micrognathia, but concerned little on factors other than osteogenesis. In the current study, we found that ectopic activation of Fgf8 by Osr2-cre in the presumptive mesenchyme for masseter tendon in mice led to micrognathia, masseter regression, and the disrupted patterning and differentiation of masseter tendon. Since Myf5-cre;Rosa26R-Fgf8 mice exhibited the normal masseter and mandibular bone, the possibility that the micrognathia and masseter regression resulted directly from the over-expressed Fgf8 was excluded. Further investigation disclosed that a series of chondrogenic markers were ectopically activated in the developing Osr2-cre;Rosa26R-Fgf8 masseter tendon, while the mechanical sensing in the masseter and mandibular bone was obviously reduced. Thus, it suggested that the micrognathia in Osr2-cre;Rosa26R-Fgf8 mice resulted secondarily from the reduced mechanical force transmitted to mandibular bone. Consistently,when tenogenic or myogenic components were deleted from the developing mandibles, both the micrognathia and masseter degeneration took place with the decreased mechanical sensing in mandibular bone, which verified that the loss of mechanical force transmitted by masseter tendon could result in micrognathia. Furthermore, it appeared that the micrognathia resulting from the disrupted tenogenesis was attributed to the impaired osteogenic specification, instead of the differentiation in the periosteal progenitors. Our findings disclose a novel mechanism for mandibular morphogenesis, and shed light on the prevention and treatment for micrognathia.

关 键 词：IMPAIRED PREVENTION DEGENERATION 

分 类 号：R782[医药卫生—口腔医学]