Fossa caries refers to caries that occurs in the fossa and pitting of the molars or premolars, as well as in the lingual fossa of the anterior teeth. In the early stage of fossa caries, no pain is felt, only discomfort from hot and cold stimuli. It can be differentiated from hyperpigmentation by clinical examination, for example, if no substantial defects are found in the oral cavity with an oral probe, it is hyperpigmentation. If fissure caries is detected clinically, fillings and other related treatments should be carried out as soon as possible. The fossa will form a cavity with a small mouth and a large bottom, and if it is not detected and treated in time, the tooth will be corroded into an empty shell, and the inside of the tooth will be filled with decayed material. So it is important to deal with such caries as early as possible when you come across them. Children can also be checked as early as possible, if the fossa is not yet caries, as early as possible for fossa sealing prevention, you can effectively avoid the occurrence of fossa caries.