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Causes Of A Black Spot Inside The Cheek

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Medically Reviewed By Colgate Global Scientific Communications

Looking in the mirror and seeing a black spot inside the cheek can be alarming, but is it something serious? The good news is that a dark spot inside your cheek is probably harmless. Consider these possible causes and see your dentist for a definitive diagnosis.

Amalgam Tattoos

If the spot inside your cheek is dark blue, gray or black, it could be a leakage from a dental filling. Amalgam tattoos aren't the permanent ink decorations on your skin that you can have done at a tattoo parlor. Amalgam is the silvery substance that your dentist uses to fill cavities, and it's made from a mixture of tin, zinc, mercury, copper and silver. Sometimes, after a dentist has filled a tooth, the filling mixture leaks, leaving behind a flat, painless dark spot that doesn't grow or change shape.

According to Brigham and Women's Hospital Division of Oral Medicine and Dentistry, amalgam tattoos are permanent, but they don't cause any harm. If the mark is inside your cheek, it's unlikely anyone will see it. However, if you think the spot looks unsightly, speak with your dentist about removal options.


Smoking can leave dark stains inside the cheeks and other areas of the mouth, such as on the gums. This condition is called smoker's melanosis, and according to a study in Case Reports in Dentistry, approximately 22 percent of smokers may notice this kind of discoloration in their mouths. It occurs when the tobacco stimulates excessive melanin deposits on the inner lining of the mouth, resulting in a darker pigmentation.

While the condition is benign, patients should keep the other oral effects of tobacco use in mind and consider quitting.

Other Causes of a Black Spot Inside the Cheek

When you see a black spot inside your cheek, you may immediately be concerned that it is cancerous. Rest assured that this is not likely the case, and that treatment may not be necessary.

The Oral Cancer Foundation lists several causes of dark spots inside cheeks that aren't related to cancer. For example, the inner lining of your cheek may just be patchily pigmented. You could have a benign melanotic macule, which is a spot similar to a freckle that can appear in the oral cavity. Alternatively, if you have put pencils in your mouth in the past, the graphite may have become embedded in your mouth lining, creating a dark spot.

Very rarely, a black or dark spot on the inside of the cheek could be a sign of oral malignant melanoma or another type of oral cancer. For this reason, it's always worth seeing your dentist if you notice an abnormal spot in your mouth that doesn't go away, bleeds or grows larger. Your dentist can diagnose the cause of the black spot through an examination, and they may take a sample to send for analysis.

Maintaining a good oral health routine can reduce your fears about a black spot inside your cheek. As well as brushing your teeth twice a day and flossing once a day, regularly check inside your mouth to make sure your gums and the lining of your cheeks look healthy. Report any concerns or symptoms to your dentist, and you can work together to find a solution.

Oral Care Center articles are reviewed by an oral health medical professional. This information is for educational purposes only. This content is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your dentist, physician or other qualified healthcare provider. 

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