When children reach the age of 6 years, the teeth that erupt at the end of the dental row, behind the second molar, are the first permanent molars, which are customarily called “sixth-age teeth” because they erupt around the age of 6. It is familiar that permanent teeth will stay with you for the rest of your life. “The “sixth-aged tooth” plays a special role in the masticatory organ and, in terms of function, is the central point of physiological forces. It has a large crown, a large number of cusps, a large chewing area, a large angle of bifurcation and is particularly strong; moreover, it is located in the middle of the entire dental arch and becomes the main pillar of the dental arch, which some people call “the key”. This tooth is important for maintaining the normal alignment of the upper and lower jaw teeth, maintaining the correct occlusal relationship and ensuring the normal development of the jaw and face. The “sixth age tooth” is the earliest permanent tooth to erupt, and when it first erupts, its hard tissue is very thin, the sulcus of the sympathetic surface is not well developed, and the calcification is poor. Moreover, it erupts at the time when children’s milk and permanent teeth are alternating, some parents still think that “six-year-old teeth” are the milk teeth to be replaced in the future and neglect the requirements of oral hygiene and dental protection for children, making it susceptible to caries. Therefore, the significance of protecting children’s “sixth-age teeth” is especially important. The “sixth age teeth” are permanent teeth, and if they are lost or extracted, they can cause permanent missing teeth. Its early loss will not only greatly reduce the chewing function of children, but also affect the development of the jawbone and cause the tilt of neighboring teeth and the elongation of the opposite jaw teeth, resulting in the disruption of the occlusal relationship, which has a very negative impact on the physical and mental health of children. Therefore, we should teach our children to be hygienic and clean from an early age, and to create a good habit of brushing their teeth in the morning and evening and rinsing their mouths after meals. If you find that the teeth are not developed normally or have caries, you should treat them early.