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To investigate the correlation between the clinical diagnostic criteria of sleep bruxism and the frequency of mandibular movements during sleep.Video polysomnography was used to record 20 healthy adults with at least one of the following clinical symptoms and signs: 1) report of frequent tooth grinding; 2) tooth wear and dentin exposure with at least three occlusal surfaces; 3) masticatory muscle symptoms in the morning; 4) masseter muscle hypertrophy. The rhythmic masticatory muscle activity (RMMA) and isolated tonic activity were scored to compare the correlations with clinical symptoms and signs. Finally, the incidence of temporomandibular disorders (TMD) was investigated in patients with isolated tonic and RMMA subjects.Among the 20 subjects, RMMA events were observed (5.8±3.1) times·h⁻¹ and isolated tonic episodes were observed (2.1±0.9) times·h⁻¹. The frequency of RMMA events was significantly greater in the patients with acoustic molars than in those without (P0.05). Similarly, the frequency of RMMA events was significantly greater in the patients with tooth attrition than in those without (P0.05). However, no difference was observed between the occurrence of RMMA and the symptoms of masticatory muscles or masseter hypertrophy in the morning. The incidence of TMD was significantly higher in the patients with RMMA than in the isolated tonic patients.The clinical symptoms and signs often used to diagnose sleep bruxism are different clinical and physiological mandibular movements during sleep. RMMA during sleep can reflect the occurrence of tooth attrition and the high risk of TMD.目的 探讨夜磨牙症各临床诊断标准和睡眠时下颌咀嚼运动发生频率的相互关系。方法 运用视频多导睡眠监测方法，对20例健康成人，具有至少以下一项临床症状和体征且诊断为夜磨牙症的实验参与者进行记录：1）有牙齿频繁磨耗的报告；2）至少有3颗牙的咬合面有牙齿磨损与牙本质暴露；3）早晨咀嚼肌症状；4）咬肌肥大。对咀嚼肌节律性运动（RMMA）和孤立强直性咀嚼肌收缩发作事件进行评分。将这些变量与临床症状和体征存在的相关性进行比较。对孤立下颌强直运动发作的患者和RMMA受试者的颞下颌关节紊乱病（TMD）发生率进行调查。结果 20例受试者中，RMMA事件发作的频率为（5.8±3.1）次·h⁻¹，孤立强直性发作的频率为（2.1±0.9）次·h⁻¹。室友报告有磨牙体征的RMMA事件显著高于磨牙体征者（P0.05）；牙齿磨耗者的RMMA事件显著高于无牙齿磨耗者（P0.05）。但是，RMMA事件的发生与早晨咀嚼肌症状或咬肌肥大之间无差异。RMMA发生者的TMD发生率显著高于孤立下颌强直运动发作者。结论 常用于诊断夜磨牙症的临床症状和体征可体现在睡眠期间不同的临床和生理方面的下颌运动，即在睡眠期间RMMA可反映牙齿磨耗的发生，而且TMD的发生风险更大。.

Objectives The molocular mechanism underlying human bone marrow mesenchymal stem cells (hBMSCs) differentiation remains to be further elucidated. DLX2 has been confirmed to accelerate osteogenic differentiation which is one member of Distal-less family genes. However, how DLX2 regulates in osteogenic differentiation is still unclear. Methods The hBMSCs were isolated and identified by the antigen CD29, CD4, CD90 through flow cytometry. DLX2 expression level, molecules related signaling pathways and transcriptional markers in osteogenesis were examined by western blot and real time-PCR. Osteogenic state was weighed by the ALP Detection Kit and Alizarin red S staining. The combination between DLX2 and WNT1 was detected by Chromatin immunoprecipitation (CHIP) assay. Results The results showed that in the process of osteoblast differentiation, DLX2 was up-regulated accompanied with osteogenic transcriptional factor. DLX2 elevated cellular alkaline phosphatase activity, accelerated BMSC mineralization along with up-regulation of osteogenic-related gene expression. Besides, DLX2 is a transcription factor of WNT1, which activated the Wnt/β-Catenin signaling pathway resulting in osteogenic differentiation. Whereas, the inhibitor of β-Catenin FH535 restrained enhanced osteogenic capability induced by DLX2. Conclusions Taken together, these results suggest that by up-regulation of Wnt/β-Catenin signaling, DLX2 accelerated human osteogenic differentiation.