Is Your Scalloped Tongue a Sign of Sleep Apnea?

Has your tongue developed unusual features – indentations, ridges? Those are signs of a “scalloped tongue”. And while doctors say this is not anything to worry about on its own, this may indicate an underlying health issue including obstructive sleep apnea (OSA).

However, despite this potential link, this does not mean that every case is a precursor to OSA as there can be other, more probable, causes.

Possible Causes

Rarely painful but still a matter of concern, a scalloped tongue can be identified by notches, indentations or ridges that run along the edges of the tongue. The reasons for the condition are usually attributed to one of five causes:

Teeth Grinding. Grinding, or repeatedly clenching, the teeth is one of the primary causes of a scalloped tongue due to the repeated pressing of the teeth against the tongue. Teeth grinding, or bruxism, is a common dental issue but can be successfully treated once the root cause of the problem is determined.

Vitamin Deficiency. Vitamins, or the lack thereof, have a profound effect on dental health. A deficiency of vitamin B12, Niacin, Iron and Riboflavin in the diet can have detrimental effects on oral and physical well-being and this vitamin deficiency can often be denoted by a scalloped tongue as well as mouth ulcers and an inflammation of the tongue.

Hypothyroidism. An overly active thyroid gland (hypothyroidism) reduces the amount of the thyroid hormone released into the body which can lead to ridges on the tongue as well as swelling.

Dehydration. Inadequate hydration because not enough water and other liquids are being imbibed can cause the tongue to become dry and swollen and lead to a scalloped tongue.

Obstructive Sleep Apnea. A 2017 study in Japan revealed that nocturnal intermittent hypoxia (a lack of oxygen at night) led to over 1,000 participants developing scalloped tongues.

Although some linkage between OSA and a scalloped tongue has been demonstrably proven, not all OSA sufferers will have the condition nor does a scalloped tongue automatically imply a case of sleep apnea.


While the ridges and markings on a scalloped tongue may be readily visible, it is vital to determine the underlying cause or causes. Having researched a patient's medical and dental history to discover if the condition has a medical explanation, a doctor may order one or more tests to be carried out.

These include:

Blood test


An imaging test such as:


CT (Computed Tomography) scan

MRI (Magnetic resonance imaging) for detailed imaging of the mouth, teeth and tongue.

HST (Home Sleep Test) If you snore and are tired during the day, a HST is an inexpensive way to determine if OSA is a contributing factor to your scalloped tongue.

The results returned from one or more of these tests will determine the root cause of the scalloped tongue and allow the doctor to devise a suitable course of treatment.

Treatment Options

Although a scalloped tongue will usually be painless and unlikely to interfere with chewing or swallowing, this does not mean the condition should be simply ignored. Having a professional diagnosis carried out is vital as this will enable the doctor (or dentist) to decide whether there is an underlying medical explanation and what course of treatment is best.

Every case (and cause) of a scalloped tongue is different and treatment options will vary depending on the cause of the condition. The range of treatments includes:

Thyroid hormone pills if hypothyroidism is causing the problem

Antihistamines, immune-suppressing or anti-inflammatory medications

Treatment for bruxism including stress management

In rare cases where the tongue has become permanently enlarged -- or there are abnormal growths or excess tissue -- it may be necessary to undergo minor surgery to correct the problem.

If the scalloped tongue is directly attributable to OSA, there are a couple of options available to cure the problem. A simple mouthguard worn during sleep may be enough to prevent the teeth leaving indentations on the tongue -- and this is often all that is required to resolve the problem.

The other option is the use of a PAP (positive airway pressure) device which is usually recommended for OSA sufferers. These CPAP devices deliver pressurized air to the nose and mouth and this, in turn, keeps the air passage clear of obstructions. 

Because the pauses in breathing that characterize OSA are eliminated by the constant air pressure, the tongue is more relaxed, contact with the teeth is reduced to the minimum and, consequently, the likelihood of developing a scalloped tongue is minimized.

It should be stressed that the presence of a scalloped tongue does not automatically imply that obstructive sleep apnea is the cause. In all likelihood there is a far simpler explanation -- but this needs to be explored fully as OSA cannot be ruled out. 

Ridges on the tongue are not normal and any such markings, blemishes or blisters should always be thoroughly examined by a dentist or doctor.

As the saying goes “prevention is better than cure” and it is far preferable to get to the root of any dental issue rather than let the situation continue and, most likely, worsen rather than disappear!