The “sixth age teeth” are the first permanent molars that erupt when children are 6 years old, so they are commonly called “sixth age teeth”, and in some places they are called “first big teeth” or Some places call it “first big tooth” or “first disc tooth”, one on the top and one on the bottom, and the scientific name is “first permanent molar”. Once erupted, this tooth cannot be replaced and will accompany people for the rest of their lives, and is the longest and most powerful molar in the human mouth. What are the important roles of the “sixth age teeth”? First, the cheeks are supported during childhood because the anatomical part of the “six-year-old teeth” is located at the position of the two intersections between the vertical line in the middle of the two eyes and the line extending from the two corners of the mouth. Therefore, if the “six-year-old teeth” are missing or skewed, it will have a certain impact on the beauty of the facial contour in adulthood. Secondly, “six-year-old teeth” are the teeth with the strongest and most stable roots in our mouth, and their existence is the key to maintaining the correct occlusal relationship of teeth, which is an important symbol for dentists to judge whether the occlusal relationship of teeth is normal or not, and the arrangement of other teeth should be determined by “six-year-old teeth” as a reference. The alignment of other teeth should be determined with reference to the “six-year-old teeth”. Third, for a long time, the “six-year-old teeth” serve as the main chewing function of children, and as children grow older, two pairs of permanent teeth will grow in order after the “six-year-old teeth”: the second molar and the third molar. However, these two pairs of molars will not erupt until after the age of 12, and some people do not grow third molars throughout their lives. In addition to the continuous loss and replacement of milk teeth, until the age of 12, the child’s chewing function is, to a large extent, undertaken and completed by the “sixth age teeth”. Because the “six-year-old teeth” is an important pillar of the jaw face, plays an important role in maintaining the relationship between the upper and lower dental arches, so the “six-year-old teeth” in dentistry is called the “lock and key” of the dental occlusion relationship. Therefore, in dentistry, “six-year-old teeth” is called the “lock and key” of the dental occlusion, which shows its importance in our oral cavity. Because the “six-year-old teeth” are the newly erupted teeth in children’s tooth replacement period, there are many incompletely calcified places on the surface, which are easy to occur caries (tooth decay); at the same time, the “six-year-old teeth” erupt earlier, which is the longest time for permanent teeth to exist in the oral cavity and is deeply influenced by the oral environment. At this stage, children’s own oral cleaning ability is relatively weak, and oral hygiene is generally not well maintained, so it is easy to occur caries; plus it erupts just in the mixed tooth row stage, that is, there are both milk teeth and permanent teeth in the mouth, and the “six-age teeth” and milk molars look very similar, parents can not easily identify, if parents If parents lack the awareness of oral health care and can’t take children to oral health check regularly, and the protection of “six-age teeth” is not in place, caries will occur easily. To protect the “sixth age teeth”, first of all, parents should know the “sixth age teeth”. The eruption of “six-year-old teeth” is usually between 6 and 7 years old for boys, and a little earlier for girls, which is more common between 5 and a half years old and 6 years old. At this stage parents should pay more attention to the oral situation of children, frequent oral examination, found that there are new teeth erupted should be more protective. It is important to have regular oral health checkups, and it is recommended that children should have oral checkups with a pediatric dentist every three months during their adolescence, so that dental problems can be detected and treated correctly and in a timely manner, and the pediatric dentist will accurately inform the eruption of “six-year-old teeth” and make appropriate The pediatric dentist will accurately advise on the eruption of the “sixth age teeth” and make appropriate recommendations. It is recommended that the “sixth age teeth” should be sulcus closed within two to three years of their eruption to prevent tooth decay.