Do third molars (or wisdom teeth) cause lower front teeth crowding?

Impacted Wisdom Teeth

Have you ever wondered whether third molars (wisdom teeth) cause your lower front teeth to be crowded? 

At Moss Vale Dental, we often see adolescents (and even people a little bit older) with crowded lower front teeth. 

These teeth generally arrive when our patients are around 17 or 18 years of age. Therefore, it is easy to make the connection that these teeth are causing crowding. 

By the way, I once spoke with a Japanese national living in Bowral, who told me that in Japan, these teeth are not referred to as ‘wisdom teeth’, but rather a different phrase which, when translated, means ‘silly teeth’. This is supposedly because the Japanese did not regard people in late adolescence as being very wise. At any rate, that’s a discussion the young people in the Southern Highlands will need to settle for themselves! 

So, what is the truth about third molars? 

Although some research found that in people who only had one third molar, there was more crowding in the half with a third molar, and in a 1982 study, more space was found when a third molar had been removed, other research did not find that wisdom teeth made crowding worse. 

Orthodontists call crowding, which happens after having braces, ‘relapse’. When you wear something to stop your teeth from moving after your orthodontic treatment is complete, those devices are called ‘retainers’.  

Research has found that relapse occurs when you do have impacted third molars but also when you don’t. In fact, it seems as though having third molars makes no difference to what happens to your teeth after braces. 

Occasionally, parents have been told that their child’s wisdom teeth are pushing on other teeth and causing crowding. Dentist Tom Southard, writing in the journal of the American Dental Association, found in his research that there is absolutely no evidence of increased pressure from wisdom teeth on other teeth. If the only reason you are removing these teeth is to decrease pressure, it probably won’t work. 

You might wonder how this sort of thing is worked out. A 2020 study randomly divided young people into two groups. Third molars were removed in one group but not in the other group. They found a 1mm reduction in space between lower incisors in the group who did have the molars removed, which is not very much at all and wouldn’t make any difference to crowding. 

Some things that do make a difference are: 

  • changes in the shape of jaws during normal growth,  
  • widths between left and right-hand side teeth during orthodontic treatment
  • lower jaws that grow more in later adolescent years than during a growth spurt at 12 or 13 years of age 
  • jaws that rotate as they grow
  • factors that are particular to individual patients. These factors include the crowns of teeth that are more triangular than rectangular and a general tendency to have more crowded teeth as we get older. 

One other reason that has been thought about is the lack of grit and toughness in our modern die. This means teeth do not wear very much at all, and by the time we reach 20 years of age, we probably have too many teeth compared to humans living 50,000 years ago. 

Of course, there are good reasons young people will continue to have wisdom teeth removed. The Moss Vale team can advise what’s best for you and your children’s teeth. 

If you have any questions about your teeth, we’re always happy to help! 

Contact the team at Moss Vale Dental on (02) 4869 3111 to make an appointment. 


57-59 Elizabeth Street

Moss Vale NSW 2577

02 4869 3111

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