There are two main reasons for jaundice: exogenous and endogenous jaundice.
1. Exogenous yellow teeth: Because food pigments stick to the teeth, they are yellow or gray; smoking soot, beverage, coffee, tea pigments stick to the teeth are yellow-gray.
2. Endogenous yellow teeth: teeth are affected by certain elements. Pigments are not on the surface of teeth but in the tissues of teeth. There are mainly two kinds: dental fluorosis and tetracycline teeth.
(1) Fluorosis is caused by living in areas with high fluoride content in drinking water before the age of seven. The pigments are yellow-brown patches in the enamel of the surface of the teeth. In severe cases, the surface of the teeth also has uneven defects. Generally, the incisors of the upper jaw are the most obvious, which seriously affects the aesthetics.
(2) Tetracycline teeth are caused by taking tetracycline drugs before the age of eight. Tetracycline molecules can bind with calcium in dental tissues to form extremely stable complexes, which deposit in dental tissues and make teeth colored. The whole teeth can be brown-gray or brown-yellow.