短期高浓度氟对小鼠磨牙成釉细胞形态及骨形成蛋白-4表达的影响

目的:通过研究短期高浓度氟对小鼠磨牙成釉细胞形态及骨形成蛋白-4(bone morphogenetic protein-4,BMP-4)表达的影响,探讨氟牙症形成的可能机制。方法:选择4d龄的ICR小鼠共32只,随机分为2组,每组16只,再分实验动物和对照动物各半。实验动物单次腹腔注射剂量分别为10mg/kg和20mg/kg的NaF,对照动物单次腹腔注射等剂量的NaCl,注射量均为10μl/g。24h后处死动物。采用HE染色、免疫组化染色观察高浓度氟对小鼠磨牙不同分化阶段成釉细胞形态及BMP-4的表达,采用SPSS13.0软件对数据进行分析。结果:分泌早、晚期和过渡期的成釉细胞对短期暴露高浓度F-敏感,实验动物分泌晚期和过渡期的成釉细胞中BMP-4的表达明显弱于对照动物,差异有统计学意义(P<0.01),而成熟期成釉细胞未见明显变化。结论:短期高浓度氟可抑制BMP-4在分泌晚期和过渡期成釉细胞中的表达,影响釉质发育。     

Sex‐related differences in symptoms of temporomandibular disorders and structural changes in the lateral pterygoid muscle after whiplash injury

Whiplash injury is an initiating or aggravating factor of temporomandibular disorder (TMD). Although there are sex‐related differences in the mechanism of pain perception and pain control, there is a lack of research on differences in TMD after whiplash injury. We aimed to evaluate sex‐related differences in the clinical symptoms and magnetic resonance imaging (MRI) findings of patients with TMD attributed to whiplash injury. This retrospective, cross‐sectional study included 100 patients (50 women; 50 men; mean age, 37.60 years) who visited our oro‐facial pain clinic with symptoms of TMD after whiplash injury. All patients underwent detailed evaluations for history of trauma, and their clinical and MRI findings were comprehensively assessed. Women with TMD after whiplash injury perceived more pain and presented more tenderness upon palpation than did men with TMD. In addition, women showed higher volume (58% vs 26%) and signal changes (54% vs 20%) in the lateral pterygoid muscle (LPM) and more anterior disc displacement without reduction (ADDWoR) (40% vs 20%) than did men. The presence of ADDWoR (odds ratio, 10.58; P = 0.007) and condylar degeneration (odds ratio, 9.30; P = 0.015) predicted LPM volume; stressful conditions (beta = 1.34; P = 0.011) correlated with increased visual analogue scale scores, and sleep problem was associated with an increased palpation index (PI) (beta = 0.42; P < 0.001) and neck PI (beta = 0.49; P < 0.001) scores only in women. Our results showed sex‐specific differences in pain intensity, distribution of clinical and abnormal MRI findings, and their relationships, and these differences should be considered when treating patients with TMD.