It’s all in the Genes Series: Part 1 – What roles do genetics play in your smile?

Our genetic code, those ladders of nucleotides embedded deep in our family trees, can have a significant impact our oral health. Tooth enamel thickness, tooth and jaw alignment, the development and eruption of wisdom teeth, and the strength of defense proteins in your saliva all stem from those of your ancestors. These each also contribute to how susceptible we are to more serious oral problems like gum disease and dental caries. Mary L. Marazita, the director of University of Pitsburgh School of Dental Medicine’s Craniofacial and Dental Genetics Center claims that right around 60% of tooth decay risk factors seem to be linked to genetic shortcomings. That’s quite a majority.

Getting Things (Mis)Aligned
You’re parents individual tooth spacing and the proper or improper alignment of the jaw, palette, and sinus passage all play a major role in your current dentition. Several studies have connected the jaw size with teeth alignment. When the jaw is larger than the teeth need, they can have gaps where food particles and bacteria can build up more easily. Another genetically created gap issue is Diastema, or a wide space between the two anterior top teeth. Oppositely, if a person’s DNA makes for a smaller jaw, the teeth can come in crowded and superimposed. The prevalence of this genetic problem in a large majority of younger people has been speculated by scientists to be a lasting bit of evolution. As we’ve evolved, our jaws have minimized because our food is no longer as tough, so we don’t require big teeth to break it down.
This same linage of evolution influences your wisdom teeth development. While your jaw may have changed, the wisdom teeth didn’t on most people, which is why they often come in cracked, crooked, or disturbing other teeth.


The Interplay of Saliva and Enamel
As mentioned before, your saliva and enamel also can be greatly influenced by your DNA. When it comes to the hard surfaces of your teeth, the thicker the better. Enamel battles constantly with bacteria and plaque. Cavities, tooth sensitivity, and even tooth loss can happen when your DNA makes for a weaker or thinner coat of tooth armor.
Likewise, your saliva can be a wink link in oral defense if your genes dictate it so. A person’s saliva is key in metabolizing the nutrients in food so they can be absorbed and utilized by the body, and such nutrients as calcium, potassium and magnesium also contribute to strengthening your tooth structures. Scientists have discovered gene variants that are better at this breakdown via saliva than others.


Vulnerability to Gum Disease
In addition to genes influencing our susceptibility to cavities, our genetic make-up may have a huge impact on the health of our gums. Blood flow and saliva availability, as well as the sensitivity of our gums to damage and plaque all can be designated by our family history. Some people have gums more prone to gingivitis, the swelling and bleeding of the gums, even when they maintain a regular and healthy teeth cleaning regiment. Often times, these genetically modified gums break down more easily, leading to gum recession, gum disease, and tooth loss.

The microbial ecology, or communities of bacteria in your mouth, and the way your immune system reacts to them through the gums can also be influenced by genetics, allowing the “sugar bugs” to thrive rather than keeping them at bay. This also contributes to gum disease.


Other Genetically Modified Tooth Dangers
The cravings and preferences for various foods are also connected to our genetics. Our tongue and sense of smell work together to play out the traits in our genetic make-up. For example, certain variants lean us toward sweets. Other favorite or least liked foods due to taste or if we can perceive the flavors at all. These can influence our diet, and thus, our oral health.

Please come back here on Friday, where part two of our Genes Series will explains how dental genetics are a key part of forensic science.

Read part 2 of the article here.

About Mark C. Marchbanks, D.D.S.

Dr. Mark Marchbanks has practiced dentistry in Arlington Texas since 1983. He enjoys caring for patients young and old. You can find Dr. Marchbanks on
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