Sitting in SC 200 the other day, the topic of flossing and brushing came up. I decided I wanted to write a blog about dentistry, but I wanted to do it in a way that made a connection between it and genetics. I realized that I had something to write about that I can personally relate to. After all my baby teeth fell out, I was told by my dentist that I had, what was referred to as, congenitally missing lateral incisors. For those who don’t know, your incisors are the teeth on either side of your canine teeth. I wanted to know why I didn’t have these teeth. I asked my dentist and after some researching, I found some answers.
A majority of people have thirty-two teeth. If any of these do not develop, they are referred to congenitally missing. This is also occasionally referred to as hypodontia. Ninety percent of people are born with all of their teeth, whereas the other twenty percent are missing at least one tooth. The most common teeth to be missing are your wisdom teeth. After that it’s your Premolars and then your upper and lower lateral incisors. Genetically, females are more prone to be affected by this than males. In the entire world, only about one percent of people are missing their lateral incisors. It is more common for a person to be missing both incisors, rather than only one. The failure for these to develop is referred to as agenesis which is defined as the failure of an organ to develop during embryonic growth and development.
So why does this happen? Most cases are a direct correlation from a lack of development of tissue known as dental lamina, underneath the gums. Because the tooth requires this to form, it will not do so if the dental lamina fails to develop. This can be caused by three genes that play a role in tooth development. If there is a mutation in any one of these, a tooth may not form. Although these mutations are most often associated with syndromes, congenitally missing teeth can also be genetic. Some dentists believe that we are currently in the intermediate stage of an evolutionary change in the number of teeth that humans have and that future members of the human race will only have somewhere around 20 teeth instead of 32.
So what can be done? Merely missing these teeth do not pose a medical issue however, there are ways to solve the problem to make your smile more aesthetically pleasing. If you’re missing your Wisdom teeth, then congratulations. Most people have to have theirs surgically removed. But if you’re missing your incisors, there are three methods used to solve the issue.
The first is an implant which is a metal root that integrates with your jawbone that has a crown in the top to resemble a natural tooth. This method is more complex and also requires that the patient have had reached peak oral maturity. For most men, this is around age twenty-five. This just means that if your teeth are going to shift around, they’ve stopped by this point. The second method is a bridge. For this, striations are made on the two adjacent teeth. The bridge is placed onto those two teeth and is bonded with sealant. The third option is a partial denture. This is an appliance that you can take in and out of your mouth as it rests on your natural teeth and gums.
So history shows that soon this genetic mutation will affect the whole world decreasing our total number of teeth on average. It’s interesting to be a part of the slow evolutional change. What do you think?