Why do people change their teeth?

The formation of human teeth is divided into two stages. Generally, deciduous teeth begin to grow at 6 months old, and replaced teeth begin at 6 years old. After formation, there are about 30 teeth. Tooth replacement is a very normal phenomenon, and it happens to almost everyone. However, some people are very interested in tooth replacement and don’t know why this magical behavior occurs. So, why do people change their teeth? Let’s take a look at the reasons below.

Why do people change their teeth?

Humans are not the only species that shed their teeth; all vertebrates that grow teeth do so. But most mammals have "monodont teeth", that is, they have only one set of deciduous teeth and one set of permanent teeth; while other vertebrates have "multi-moth teeth", which means they can replace their teeth throughout their lives. This reminds us that the number of times teeth are replaced is related to evolutionary factors and is closely related to biological adaptability.

The ability to lose and replace teeth is a common feature of a group of homologous organs.

From the origin, the teeth of vertebrates evolved from the scales of their fish ancestors. These scales were not the fish scales we are accustomed to today, but a bony structure with a medullary cavity. Its surface is often covered with enamel composed of hydroxyapatite, whose anatomical structure is no different from that of teeth, and shark scales still retain this structure today.

The really urgent reason for tooth replacement is that the human skull grows rapidly before adulthood, but the teeth cannot grow thicker. If the deciduous teeth are retained, the gaps between the teeth will become wider, making it more prone to caries and infection, and the isolated single teeth will also become easier to break. Replacing the deciduous teeth with larger and more permanent teeth can solve this problem well.

When do people change their teeth?

The growth of human teeth is divided into three periods: the deciduous tooth period, the replacement tooth period, and the permanent tooth period.

The period of deciduous teeth: 6 months to 2 and a half years old, with a total of 20 deciduous teeth.

Tooth replacement period: Between 6 and 12 years old, the deciduous teeth fall out of the alveolar bone due to the squeezing of the permanent teeth and are replaced by permanent teeth. There are 28 to 32 permanent teeth (except for congenital missing teeth or supernumerary teeth).

Permanent teeth period: After the teeth are replaced at around 12 years old, there are only 28 teeth, and the remaining four are wisdom teeth. Of course, not everyone has the opportunity to grow wisdom teeth. Some people have one, some have two, and some may never erupt in their lifetime.

After your teeth are replaced, your permanent teeth will accompany you throughout your life.

Permanent teeth are teeth that will never be replaced throughout your life and have the strongest chewing function. However, if you do not pay attention to oral hygiene and get dental disease, your permanent teeth will fall out prematurely. Therefore, once the permanent teeth fall out, there will be no replacement teeth and no new teeth will grow. This shows the importance of permanent teeth.

Many people live to be eighty or ninety years old and still have good teeth, while some people lose only a few teeth left in their forties or fifties. Many people think that this is a normal physiological phenomenon, but it is not necessarily true.