7 Causes of Bad Breath in Children

Jan 11, 2021

Most adults know when it’s time to pop in a mint, but kids don’t always notice bad breath as quickly as we do. If you’re concerned about the way your child’s breath smells, the dental team at Stellar Kids Dentistry can help at one of their offices in Mukilteo, Mill Creek, and Everett, Washington.

Bad breath, or halitosis, is a common dental issue in people of all ages, including children. While we often associate stinky breath in kids with poor oral hygiene, that isn’t always the case. Here are some of the most common reasons for bad breath in kids:

Dry mouth

Saliva plays an important role in removing bacteria, debris, and food particles from in between your child’s teeth. When they’re mouth is too dry to produce an adequate amount of saliva, this debris can build up and create plaque — a sticky film of bacteria that causes cavities and bad breath.

Children get dry mouth for many reasons, including prolonged pacifier use, thumb-sucking, and general dehydration.

Mouth breathing

If your child often snores or breaths through their mouth more than their nose, their saliva can evaporate. This can cause dry mouth, which leads to halitosis in children.

Poor oral hygiene

Poor oral hygiene is the most common cause of bad breath in adults and children alike. This is particularly true if your child is still getting used to brushing their own teeth. To prevent bad breath — and infections! — make sure your child is brushing and flossing the right way. You can even talk to the team at Stellar Kids Dentistry about the best teeth brushing practices.

Sinus infection

A sinus infection is a common condition in which the cavities around the nasal passages fill with mucus and become inflamed. Sinus infections cause fluid to gather in the throat and nasal passages, forming collections of bacteria. Stinky breath is a common symptom of sinus infections.

If your child has bad breath that simply won’t go away with teeth brushing and mouthwash, a sinus infection may be the culprit.

Food and diet

Certain vegetables such as garlic and onions are known culprits of bad breath. But did you know that healthy meats, cheeses, and fish can also lead to stinky breath? While teething brushing and flossing can temporarily remove these pungent odors, it doesn’t eliminate them altogether.

This is because odorous molecules are absorbed into the bloodstream and partially excreted through the lungs.


Tonsillitis is typically caused by a bacterial or viral infection that inflamed the tonsils. Small white spots, redness, and visible inflammation are telltale signs of tonsillitis. Because bacteria can collect in the small pits of the tonsils, it can fester and turn into bad breath.

Small objects

Kids have a bad habit of sticking things in their mouth or nostrils. Tiny objects like beads, toys, and food can get lodged in your child’s nostrils, where they may lead to infection. If you’ve tried brushing, flossing, and mouthwash without success, a foreign object may be responsible for your child’s bad breath.

Still have questions? Call the pediatric dentists at Stellar Kids Dentistry or schedule an appointment online to learn more!