揭秘牙齿中的VIP 5类牙齿需重点保护

　　PREMOLARS

　　前臼齿

　　Adults have eight premolar teeth, two next to each canine tooth in the upper and lower jaw. Their job is to chew and grind up food.

　　成人长有八颗前臼齿，分别位于上下颚犬齿后端，他们主要负责咀嚼与研磨食物的工作。

　　PROBLEMS: Premolars are more vulnerable to gum abrasions, caused by brushing teeth too harshly. This can lead to inflammation and, in the long term, gum -disease (causing teeth to fall out).

　　问题：错误的刷牙方式常常会致使前臼齿的牙龈“受伤”，久而久之，则会引起牙龈疾病（从而发生脱落的现象）。