The wisdom tooth, aka the third molar, belongs to the group of chewing teeth, that is, its main functional value in grinding and grinding food. It erupts, as a rule, after 18 years. So late, because the rudiment appears at 4-5 years old, roots appear at the 8th year, at the 12th year only the crown of the tooth mineralizes. When it is time for a tooth to erupt, it often causes difficulty and pain. Perhaps even the development of inflammation or a wisdom tooth may not completely cut through and "sit" in a "bag" from the gums, which will be very painful. In this regard, at present, the third molar is increasingly losing its functional purpose. Sometimes people simply do not have the germ of this wisdom tooth and the dentition will contain 28 teeth. Do not be afraid of this, this is a completely normal evolutionary process, tk. The 3rd molar is a vestigial tooth. And it is possible that in the near future the tooth germ will stop developing altogether.
The wisdom tooth has no meaning at the moment. This is a rudiment inherited from our ancestors. Previously, people, due to coarser food, had more pronounced chewing muscles and a lower jaw, which had more teeth. Later, heat-treated food (softer) began to predominate in the human diet. The lower jaw and chewing muscles began to decrease. Extra teeth also atrophied. But their rudiments have not gone anywhere.
And wisdom teeth erupt later than the rest because they are laid later than the rest - at 4-5 years.
Due to the fact that the jaw in people has become less, the eruption of these teeth causes many problems: they interfere with neighboring teeth, erupt into the cheek, damage the gums.