Understanding Teeth Grinding: What You Need to Know

By Dr. Boris Zusin · Updated July 31, 2026

“So what if I grind my teeth?” This is one of the most common questions patients ask, usually right after being told a tooth is worn down. Here's why it matters, illustrated with two examples: one showing the mechanism, and one showing where it can lead if it goes unaddressed.

Example 1: Loss of Canine Guidance

Normally, the canine is the tooth that takes the contact when your jaw slides side to side, which keeps your back teeth from grinding against each other — a protective mechanism called canine guidance, or "disclusion" of the posterior teeth. When grinding wears the canine down, that protection is lost, and all of the back teeth on that side end up in contact instead, taking on destructive forces they were never meant to handle.

The comparison above shows this directly: on the left, with a worn canine, multiple back teeth are marked as being in contact during a side-to-side movement — a sign of lost guidance. On the right, with the canine restored, only that one tooth is marked, exactly how a healthy bite should function. One conservative way to fix this is bonding: restoring a worn canine back to its original shape and length re-establishes that protective guidance, so the back teeth go back to being shielded from these forces during normal jaw movement.

Example 2: What Longstanding, Untreated Grinding Can Lead To

This example shows what grinding can do left unaddressed for years: the back teeth are worn flat and the upper front teeth show severe wear as well. This is a much bigger repair — crowns, and often a bridge or implant to replace what's badly damaged — than the simple bonding used to fix Example 1. Catching grinding damage early, before it reaches this point, is exactly why we watch for it at every checkup.

Grinding Doesn't Just Wear Teeth Down — It Can Move Them

Wear and fracture are the obvious effects of grinding, but there's a subtler one: over time, teeth can actually shift position. Once grinding wears down the surfaces that used to keep opposing teeth lined up, a tooth can keep erupting — slowly emerging further out of the gum — because it no longer meets resistance from the tooth it used to bite against. Patients usually notice this as a tooth that looks "longer" than it used to, a bite that feels different than it did a few years ago, or small gaps opening up between teeth that used to be flush. It's a gradual process, which is exactly why it's easy to miss without regular checkups.

Gum disease can cause this same kind of tooth movement through a different mechanism — when it's advanced enough to affect the bone and ligament holding a tooth in place, not just the gum surface. That's covered in more detail on our early signs of gum disease page. In practice, grinding and gum disease often show up together and can compound each other, which is one more reason we check both at every visit.

Grinding and Sleep Apnea: What's the Real Connection?

Teeth grinding and obstructive sleep apnea (OSA) show up together often — research puts the overlap somewhere around 20–50% of adults who have either condition. But overlapping isn't the same as one causing the other: most current evidence doesn't establish a clear, consistent link between the two in adults specifically (the connection looks stronger and more plausible in children). The leading theory ties both to brief arousals during sleep — grinding tends to happen right at the tail end of one of these micro-wake-ups, and a breathing pause is one of the things that triggers them. So grinding may largely be a byproduct of the same sleep disruption driving the apnea, rather than something the apnea directly causes.

Why this matters for treatment: if you grind your teeth and also snore heavily, have been told you stop breathing or gasp during sleep, or feel excessively tired during the day, it's worth being screened for sleep apnea before starting with a standard night guard. A conventional guard sits over the upper teeth and can, in some patients, reduce space in the airway — not what you want if sleep apnea is part of the picture. Signs worth mentioning to your physician include loud snoring, witnessed breathing pauses, and daytime sleepiness. If that sounds familiar, our Sleep Apnea Treatment page has more on the connection — when OSA is present, airway-focused treatment is usually the better starting point, and treating the apnea often reduces the grinding as a side benefit too.