You walk into the treatment room and introduce yourself to your newest patient.
“Doc, I always get cavities. I guess I inherited soft teeth from my mother.”
How do you respond to this?
Are Cavities Genetic?
The top result of a google search says this,
“About 60% of the risk for tooth decay appears to be due to genetic factors.”
Does this mean that there is a single gene disposing you and your patients for dental caries? No.
A 2019 meta-analysis identified,
“47 novel and conditionally-independent risk loci for dental caries.”
That’s a lot of genes that may or may not come into play.
We have genes that influence our taste preferences, genes for salivary proteins, pH control, and anti-microbial enzymes, as well as genes involved in bacterial colonization and adhesion.
Up to 60% of cavity risk in certain individuals may be genetic factors but if you look at the population as a whole, the genetic risk of dental caries is probably closer to about 9%.
Genes That Affect Individual’s Risk of Cavities
Beta-Defensin 1 (DEFB1)
Beta-defensin 1 (DEFB1) is a frequently studied gene known to confer protection from dental caries. DEFB1 rs11362 polymorphism is associated with increased dental caries in the adult dentition. Individuals with the TT genotype were at seven times higher risk than those with the CC genotype. DEFB1 is a big player.
Carbonic Anhydrase VI
The secreted enzyme carbonic anhydrase VI is implicated in taste, gastrointestinal dysfunction, tooth erosion, and dental caries. One study found a positive association between the saliva buffer capacity and the C/T polymorphism.
A pediatric patient was referred to my mentor’s practice. The parent relays that their dentist was baffled because the child only had cavities on the lower front teeth.
“That’s a problem with the LYZL2 gene,” he responded excitedly.
LYZL2 codes for a bacteriolytic enzyme involved in host defense and is positively associated with caries of the mandibular anterior teeth only. A weird and selective player.
Inheriting a Lifestyle
Genetics does not explain why dental caries incidence consistently correlates to socioeconomic status.
It also does not explain why children of mothers or primary caregivers who had active decay in the past 12 months had more than double the odds of experiencing dental caries.
A fascinating twin study published in 2019 evaluated 345 twins at 6 years of age. There was no significant difference between monozygotic and dizygotic twins for any level of caries. This suggests that “environmental factors, rather than genetics, are the predominant determinant of caries risk.”
We tend to have dietary patterns and oral hygiene practices similar to those of our family members. That’s inheriting a lifestyle.
Genes at Play with Each Other
Genes play with each other. A 2019 analysis described 27 genes associated with dental caries.
Twenty-three of these genes interacted with at least one other gene. While 8 genes “were shown to be connected in interactive networks by at least 10 other genes.”
Genes play depending on their environment.
A cluster of taste receptor genes on chromosome 7 may play a plausible role in adult dental caries as identified in a 2021 genome-wide association study.
Another 2021 study suggests that genetic traits are contributing factors, thus dental caries are “best viewed as a downstream consequence.” This supports utilizing these specific traits as good points of intervention.
Treat the Person, Not the Players
Not only are our individual genes and their expressions unique, so are our individual oral microbiomes, immune systems, and lifestyles.
This means that multifactorial diseases such as dental caries will manifest differently in each individual and our prevention measures cannot be exactly the same either.
So how do you respond to your patient who blames their cavities on genetics?
“That’s interesting. Tell me more about that.”
Utilizing this open-ended coaching language, you will likely learn their taste preferences and lifestyle patterns as well as pick up clues about their saliva, biofilm, and pH.
We will continue to learn more about genetic players in dental caries. In the meantime, we can build a picture of the risk factors and interactions in each patient’s caries risk profile and treat them as unique persons.
Photo by Andrea Piacquadio
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