Oral Health
Why does my tongue have ridges or indentations along the sides?
29 October 2026 · The Dentist, Al Qusais, Dubai
The short answer
Ridges or indentations along the sides of your tongue, often called a scalloped or crenated tongue, usually happen because the tongue is pressing against your teeth over and over, most commonly from clenching or grinding, or because the tongue itself is slightly swollen. It's rarely something to panic about, but it's worth mentioning to a dentist, especially if you also have jaw pain, worn teeth, or headaches, since those point to nighttime grinding that benefits from treatment.
What's actually causing the marks
The scalloping happens when your tongue is larger than the space your teeth leave for it, or when it's pushed against your teeth with enough force and frequency to leave an imprint. The most common reason by far is bruxism, which is clenching or grinding your teeth, usually at night without you knowing it. When your jaw is clenched, the tongue often braces against the inside of the lower teeth, and over months that pressure leaves visible indentations along the edges.
Mouth breathing and poor tongue posture play a role too. If your tongue rests low and forward in your mouth instead of up against the roof, it spreads out sideways and presses on the teeth constantly, not just when you're asleep. This is common in people with nasal congestion, allergies, or a deviated septum, since breathing through the mouth forces the tongue down.
Fluid retention can also cause a mildly swollen tongue that then takes on the shape of your teeth. This shows up with dehydration, some thyroid conditions, vitamin B12 or iron deficiency, and occasionally as a side effect of certain medications.
When it's more than just teeth pressure
A scalloped tongue on its own, with no other symptoms, is usually a mechanical issue rather than a medical one. But a few combinations are worth paying attention to. If you're also waking up with a sore jaw, tension headaches, or you've noticed your teeth look shorter or flatter than they used to, that points to grinding strong enough to be wearing down enamel, which is worth treating before it goes further.
If the tongue feels generally swollen, not just marked at the edges, and you're also tired, cold-sensitive, or losing hair, it's reasonable to get bloodwork done to rule out a thyroid issue or a B12 or iron deficiency. If you snore heavily or wake up gasping, scalloping can sometimes accompany sleep apnoea, since a tongue that falls back in the airway at night also presses against the teeth. None of this is something to self-diagnose from a mirror. A dentist or GP needs to actually look and, if needed, order the right test.
What to do about it
If the cause is grinding, a custom nightguard is the standard fix. It stops the tooth-on-tooth contact and takes the pressure off the tongue as a side effect, and most people notice the marks fade over a few weeks to months once the habit is managed. If mouth breathing seems to be the driver, working on nasal breathing and tongue posture during the day helps, alongside sorting out any underlying congestion.
At The Dentist in Al Qusais, Dr. Faris Alkhanafseh and Dr. Mohammad Nour check for signs of grinding as part of a routine exam, including tooth wear, jaw muscle tenderness, and tongue scalloping, so it's not something you need a separate appointment for. New patients get a first checkup free. If you've noticed these ridges and haven't had a dental check in a while, book a visit through WhatsApp or at thedentist.ae/book and have it looked at properly rather than guessing from what you see in the mirror.
This article is general information, not a diagnosis. If you are in Dubai, the free first checkup at our Al Qusais clinic is the fastest way to get an answer about your own teeth.