The following post is a free chapter from More Chocolate, No Cavities. I hope it helps you!
Most of the time, younger siblings get more cavities than do older siblings. I cannot tell you how many times I have had families in which the oldest child (or children) had zero cavities at age eight. Then, like clockwork, the youngest sibling turns five and is finally able to have x-rays to check for cavities hiding in between the teeth, and I find eight cavities. The cavities usually present in pairs of two and are in all four likely spots. Then the mother or father, looking shocked, says, “But I did everything the same!” I used to shrug and say, “It’s weak enamel.” That was before I discovered the “cracker hypothesis.” Once you change your paradigm, the answer becomes obvious.
How can you avoid this sibling trend? Here is my extremely scientific reasoning about why younger siblings get more cavities than do older siblings: we give younger siblings crackers to keep them quiet. And remember… crackers are ten times stickier than a piece of bread because they are dried out.
Doesn’t that make sense? Firstborn children are often fed fresh fruits and vegetables (from your organic garden in the backyard, of course). By the third kid, you hardly have time for food shopping, let alone taking a shower, so you push a bowl of crackers in front of the little one to keep him quiet as you rush to fill everyone’s needs. It’s not an indictment, just a reality. I joke with parents, telling them to give younger siblings tablets to keep them quiet; they might get ADHD, but at least they won’t have holes in their teeth. My joke is sarcastic but partially true in my own household. Setting limits on screen time is important, too. Letting kids learn how to entertain themselves without food or electronics is an important life skill.
There are a few other reasons for the younger-sibling trend:
Younger siblings start most things at a younger age. Take juice, for example. If you were super awesome and waited until age five to serve apple juice (other than special occasions or bouts of sickness), you deserve the biggest parental pat on the back ever because absolutely none of your friends did such a thing. But the youngest sibling somehow starts getting juice at age two. This is simply one example, but my point is obvious: it is emotionally and practically more difficult to do things “exactly” the same as you did with your firstborn.
The biggest reason that younger sibling get more cavities, however, is the lack of awareness of the cracker hypothesis. You attribute your older children’s zero-cavities success to a relative dearth of candy, absolutely no soda, virtually no juice, and strong enamel. You don’t remember that your older children did not graze on crackers all day.
“But I got away with not flossing with my other kids,” you say. And, in fact, you did. So you knew you would be set with the second (or third) child because your children have genetically superior teeth. But combine no flossing with extra crackers and more juice, and you have the perfect setup for eight cavities at age five for the youngest sibling. Another way of stating the theory is that you got away with not flossing your first child’s teeth because she didn’t have crackers very often, didn’t graze often, and had more water. Since your first child, you’ve made other subtle changes, and, all of sudden, you could not get away with not flossing (imagine flour jammed in between the teeth for two years).
So if you want to be proactive and keep up your zero-cavity streak for your youngest children (which would be impressive with two children, amazing in three children, and otherworldly with four or more), I would focus on the three principles starting at age one. Keep the “snacking only in certain places and times” habit going. Keep the rule of only carrying around water (not even milk is allowed away from the table). And because, by default, you are going to be more imperfect with the younger children, perhaps even floss their teeth even though you did not floss the older kids’ teeth.
I am happy to report that since I have been informing parents about my prevention principles for the past four years, I have had hundreds of families make it successfully to even the third (or fourth) child with zero cavities by age five. My theories have been working in my practice, and I have fewer surprised parents. Even more importantly, I have helped countless families completely reverse the trend. Their eldest child had eight cavities, and they were able to keep the youngest child cavity-free by changing all of the unhealthy habits. In most cases, bad genetics can be overcome with enough effort started early.