Narrator: This is Science Today. You may have wondered why the dentist sometimes elects to remove wisdom teeth, even though these third molars are not impacted or causing pain. Dr. Alan Felsenfeld of UCLA's School of Dentistry says many times, dentists are trying to prevent future disease.
Felsenfeld: Many patients don't present with pain but they have periodontal defects where in fact you can trap food and cause destruction of the tooth in front of it. That's something to be concerned about and one of the reasons we like to remove these teeth is for the periodontal health of the second molar tooth.
Narrator: Even if only one set of teeth causes trouble, Felsenfeld says it's best to get all four out.
Felsenfeld: One of the things that we see commonly is that because the upper teeth are in the mouth and there are not lower teeth, there is no occlusion, that is, the tooth doesn't bite against another tooth. Our teeth are designed to have a certain self-cleansing, so that when you put some food between your teeth and you chew it, it squishes out the side and it tends to keep the teeth clean by themselves.
Narrator: But that's no excuse to skip brushing! For Science Today, I'm Larissa Branin.