잇몸 아랫쪽은 음식이나 치약, 담배 등 입안 환경변화에 바로 반응하지 않기 때문에 입 속 환경을 파악하기 좋은 샘플로 알려져 있다.
The lower part of the gums is known as a good sample to determine the environment in the mouth because it does not immediately react to changes of the environment in the mouth such as food, toothpaste, and cigarettes.