Is it just you, or have your teeth shifted around in your mouth? Perhaps there’s a small gap where there wasn’t one before, or maybe they appear to be crowding one another, but in either case, it’s probably not in your head: teeth are capable of shifting as we age.
Even if you suffered through monthly braces-tightening in middle school, you may not be able to avoid some dental shifting over time. The process known as mesial drift is pretty common, although the amount that teeth move varies from person to person; for some, it’s hardly noticeable, while for others it’s more dramatic.
Why do teeth move even after we’ve stopped growing, or once we’ve had orthodontic intervention? The best theory that dental experts have is that in prehistoric times, when life was shorter — and much harder on our teeth — the process was meant to spread teeth through the jaw in order to make up for broken or missing teeth or damaged gums. Because many people now live well into their 80s, the shift in permanent teeth is more likely to cause overcrowding than help with eating.
There are other factors that can cause teeth to move. Genetics play a big factor: some people have adult teeth too large for their mouth, which can lead to overcrowding, and from there the pressure buildup can cause teeth to shift in order to compensate; some families are just more prone to tooth movement altogether. When you lose a tooth, the jaw naturally wants to fill in the space, and teeth may move to fill the gap. Those who grind their teeth or habitually clench their jaw may experience shifting teeth as a side effect, since the pressure can cause misalignment. Bad habits can also play a part: it’s not a myth that thumb-sucking can affect the set of your teeth, and people who don’t wear their retainers for the advised amount of time may be setting back the future set of their teeth.
Moving teeth is most often nothing to worry about, but if it begins to affect your ability to chew, becomes painful, or causes tooth decay, consult your dentist.