State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, The Fourth Military Medical University, 145 Changlexi Road, Xi'an, 710032, China.
State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi International Joint Research Center for Oral Diseases, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, The Fourth Military Medical University, 145 Changlexi Road, Xi'an, 710032, China.
Arch Oral Biol. 2020 Jan;109:104588. doi: 10.1016/j.archoralbio.2019.104588. Epub 2019 Oct 19.
Dental occlusion are frequently changed in clinic. Molecular responses in jaw muscles to aberrant dental occlusion are changes are attractive, yet remain are obscure.
Unilateral anterior crossbite (UAC) prostheses were applied to Sprague-Dawley rats and then ceased after two weeks to detect the reactions of the masseter, a representative jaw elevator, and the lateral pterygoid muscle (LPM), a representative jaw depressor.
Two weeks of UAC elicited mild injury of the two muscles. Myogenesis and protective reactions were detected as increases in αB-crystallin expression in the masseter after 3 days and in the LPM after 2 weeks, and increases in desmin expression in both muscles after 2 weeks. A switch in fibre types from IIb to IIx occurred in the LPM but not in the masseter. Inflammatory responses, shown by the infiltration of inflammatory cells and increases in TNF-α mRNA expression, and fibrosis responses, shown by increased mRNA expression of Type I and III collagens, appeared very mild in the two muscles. These responses were partially recovered by the cessation of UAC. During the whole process, no obvious changes were observed in mitochondrial function, as indicated by the levels of proliferator-activated receptor γ coactivator 1α, mitofusin-2 and voltage-dependent anion channel.
UAC causes injury and very limited inflammatory and fibrosis adaption in the masseter and LPM. Both muscles respond with myogenesis and protective activity. The LPM responds also with muscle fibre isoform alternations. These alterations were partially recovered by the cessation of dental stimulation at an early stage.
口腔咬合在临床上经常发生变化。颌骨肌肉对异常牙合的分子反应变化很有吸引力，但仍不清楚。
将单侧前牙反𬌗（UAC）义齿应用于 Sprague-Dawley 大鼠，两周后停止，以检测代表升颌肌的咬肌和代表降颌肌的翼外肌的反应。
UAC 持续 2 周引起了这两块肌肉的轻度损伤。在 3 天后的咬肌和 2 周后的翼外肌中，αB-晶体蛋白表达增加，表明出现了成肌反应和保护反应；在两块肌肉中，肌动蛋白表达增加表明出现了肌纤维转换。在翼外肌中出现了从 IIb 型到 IIx 型的纤维类型转换，但在咬肌中没有。炎症反应表现为炎症细胞浸润和 TNF-αmRNA 表达增加，纤维化反应表现为 I 型和 III 型胶原 mRNA 表达增加，在两块肌肉中均非常轻微。UAC 的停止部分恢复了这些反应。在整个过程中，线粒体功能没有明显变化，增殖激活受体γ共激活因子 1α、线粒体融合蛋白-2 和电压依赖性阴离子通道的水平表明了这一点。
UAC 导致咬肌和翼外肌损伤和非常有限的炎症和纤维化适应。两块肌肉都通过成肌作用和保护活性来反应。翼外肌还通过肌纤维同型转换来反应。这些改变在早期停止牙齿刺激时部分得到了恢复。
