The exact sites of premature hair graying and whether tooth loss causes this condition remain unknown. In this study, we aimed to explore the effect of reduced mastication on premature hair graying. Maxillary first molars were extracted from young mice, and the mice were observed for 3 months, along with non‐extraction control group mice. After 3 months, gray hair emerged in the interbrow region of mice in the tooth extraction group but not in the control group. The expression of tyrosinase‐related protein‐2 (TRP‐2) mRNA was lower in the interbrow tissues of young mice without maxillary molars than in those with maxillary molars. Tooth loss leads to interbrow gray hair growth, possibly because of weakened trigeminal nerve input, suggesting that reduced mastication causes premature graying. Thus, prompt prosthetic treatment after molar loss is highly recommended.

中文翻译：

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幼鼠上颌第一磨牙缺失导致眉间区域过早出现灰白毛发

头发过早变白的确切部位以及牙齿脱落是否会导致这种情况仍然未知。在这项研究中，我们旨在探讨减少咀嚼对头发过早变白的影响。幼鼠拔除上颌第一磨牙，与未拔除对照组小鼠一起观察3个月。3个月后，拔牙组小鼠眉间区域出现白毛，而对照组小鼠则没有出现白毛。的表达式为酪氨酸酶相关蛋白-2（TRP-2) 没有上颌磨牙的年轻小鼠眉间组织中的 mRNA 低于有上颌磨牙的小鼠。牙齿脱落导致眉间灰发生长，可能是因为三叉神经输入减弱，这表明咀嚼功能减少会导致过早变白。因此，强烈建议在磨牙缺失后立即进行修复治疗。