人们常用“洁白如玉”来形容一个人的牙。牙齿的表面有一层白色半透明的牙釉抩,里面为象牙色的牙本质,所以正常的牙齿应该是白色或淡黄色,富有光泽的。然而由于多种原因,不少人的牙齿发黄,变黑或失去了光泽,他们常为此产生苦恼,医学上将这类牙齿称为变色牙。 People often use “white jade” to describe a person's teeth. The surface of the tooth has a white translucent glaze, which is ivory dentine, so normal teeth should be white or light yellow, shiny. However, for a variety of reasons, many people's teeth yellow, black or lose their luster, they often have distressed, medically called these teeth color change teeth.