Both of these have a bit of myth to them. If you want to know the truth about wisdom teeth, read on!
Knowing the Truth Can Set Your Teeth Free!
First of all, not everyone has to have their wisdom teeth removed. Yes, it is a common thing to have done, but it is not a requirement for all people. In fact, not everyone is even born with wisdom teeth. Some people have fewer than four, while other people have none. If you got all four of your wisdom teeth, then it is up to how those teeth come in as to whether or not you need them pulled.
Second, wisdom teeth are different than the rest of the teeth in your mouth in that they take longer to develop, and do not start to erupt for the vast majority of people until between the ages of 15 and 25. Due to the fact that most people's mouths are done growing and shifting at that point, the wisdom teeth tend to come in poorly and put pressure on the surrounding teeth. This is one of the most common causes of having them extracted.
If you want to find out how your wisdom teeth are sitting, or you want to know if you may need yours out in the near future, contact your dentist. He or she can take a look at your wisdom teeth on an x-ray, and let you know how they look. If they appear to be coming in awkwardly, they will likely have you work with a specialist for the extraction process.