As dentists we often hear patients say “I have bleeding gums like my mother!” or “My father, just like me, had several decayed teeth and used to visit the dentist regularly” or “Both me and my brother have crooked teeth“. Are these observations by patients a mere coincidence or is there a genetic involvement in the condition of your teeth? Let’s find out!!!!
Scientists say the 60% of the risk of tooth decay is due to genetic factors. Tooth decay or dental caries in your mouth is affected by host factors like the structure of the enamel, your body response to fight tooth decay, or the composition of saliva. Any genetic variations in these host factors may contribute to an increased risk of tooth caries. Further, you could inherit the jaw size from one parent and the tooth size from the other. This is called the jaw length tooth size discrepancy. This could lead to crowding of teeth in a person with a smaller jaw. Crooked teeth that cannot be cleaned well are prone to decay. This also means that if your parents had softer enamel, the chances are that you could have softer enamel. Altered immune response to decay causing bacteria can increase the the incidence of tooth decay.
Genetic dentistry is still in its infancy. But scientists have identified five areas where genes play a role in tooth decay
The hardness of the enamel is directly proportional to the severity of tooth decay. In simple terms, the softer the enamel, the more it is susceptible to acid attack. This makes the bacteria work their way easily into the enamel, causing decay. Your genes are the primary determinant of enamel structure, and hence they have a big effect on whether you get tooth decay.
In some developmental defects like amelogenesis imperfecta,the enamel is not formed well. this causes the chipping off of the enamel exposing the inner dentin. In severe cases of fluorosis, the enamel chips away. This is called mottled enamel.
Calcium, potassium and other elements present in your saliva are important for strong healthy teeth. It is important that these elements be properly metabolized to be useful. Your saliva plays a key role in this process. Scientists have found that some people are better at it because of their genes.
Oral bacterial community
The types of bacterial that thrive in the mouth vary from one area to another. For instance the bacteria that cause decay is different from the one that causes gum infection to the one that causes tooth abscess. The community of bacteria that live in the tongue is different. Together these communities make up your microbiome. Your body response to fight these communities of bacteria will determine your risk of developing a tooth decay.
Preference to eating sweets
You may under the impression that all kids love to eat sweets and candies. Scientists have found gene variants that show a range of “sweet preference”. Two individuals raised in similar environments could have completely different attitudes to sugary food. The one that eats more sugars will have a higher risk of developing tooth decay. Sugars that get incorporated into the plaque provide a good nutrient substrate to the bacteria. The acids produced by these bacteria cause dissolution of the enamel. The cavity thus caused makes further bacterial attack easier.
Taste ability is the measure of the variety of foods you can taste. It is your ablity to perceive certain flavours. This is a complex process. It involves your tongue and is linked to your sense of smell. Greater your ability to taste a variety of things, the less likely you develop tooth decay.
If your genes determine 60% chances of developing decay, then what determines the balance of 40% risk?
Eating harmful foods ( soda, sugary foods ), sticky starches ( potato wafers ) and the frequency of intake of these snacks
Frequency of brushing
Fluoride content in your drinking water. The fluoride is a key mineral in making your enamel strong. Fluoride forms a stronger fluorapitite crystal in the enamel that is more resistant to the bacterial acid attack.