There are two sets of teeth in a person’s life, namely the milk teeth and the permanent teeth. The baby teeth start to erupt 6 months after birth and are complete by the age of 2 years. They are replaced by permanent teeth from the age of 6 to 14 years. The permanent teeth will last for the rest of their lives. So what happens when permanent teeth erupt in the elderly and even new teeth grow after each ministry has lost its teeth? The reasons are as follows: 1, buried teeth and blocked teeth: people called “wisdom teeth” third molar and cuspids (tiger teeth), often due to its late eruption, by other teeth occupy the position, can not grow smoothly, buried in the bone, some people until the elderly teeth are partially or completely lost, the resistance of such teeth is lifted, only then Some people do not erupt until they have lost some or all of their teeth in old age. It is easy to be mistaken for new teeth. 2, extra teeth (also known as extra teeth): extra teeth are more than the normal number of teeth, its morphology is often similar to the group of teeth where it occurs, slightly smaller, extra teeth usually erupt in the normal time, but may also be buried in the jawbone, until after the loss of teeth in old age to erupt. 3, the number of teeth related to: some elderly people with normal number of original teeth, and after the loss of most and all of the new teeth to form a normal size, this situation is extremely rare, the mechanism is not yet known, to be studied in depth. The new teeth grown in the above cases will not have any adverse effects on the body, and if the periodontal teeth are healthy, it is also conducive to the restoration of other missing teeth.