Why can a child’s breath smell unpleasant, should parents be concerned, how can bad breath be eliminated, and when should you visit a dentist?
What Is Halitosis?
Halitosis is a condition characterized by unpleasant breath odor. It can occur for various reasons and may be either temporary or chronic.
What Causes Bad Breath in Children?
Poor Oral Hygiene
The most common cause of bad breath in children is inadequate oral hygiene.
If dental plaque (a sticky bacterial film that forms on the teeth) and food debris are not removed through proper brushing, bacteria in the mouth have a food source. As they feed, they produce foul-smelling volatile sulfur compounds, causing a child’s breath to become sour and unpleasant.
Studies show that approximately 80–90% of halitosis cases originate in the oral cavity. Most often, the odor is caused by bacteria that break down proteins and release volatile sulfur compounds such as hydrogen sulfide and methyl mercaptan, which have a characteristic unpleasant smell.
Diet
Eating certain foods can lead to bad breath. Digestion begins with the first bite of food, and everything your child eats is broken down in the mouth, which may cause unpleasant odors.
Sulfur-containing foods such as garlic and onions can cause bad breath in both children and adults. Sulfur compounds remain in the mouth and can even be absorbed into the bloodstream.
For several hours after consuming such foods, the odor may continue to be released during exhalation.
Bacteria in the mouth “love” sugar and starch, so limiting these types of foods can significantly help prevent both bad breath and tooth decay.
Tongue Coating
Another extremely common cause of bad breath in toddlers, children, and teenagers is tongue coating. Odor-causing bacteria, food particles, and decomposing skin cells often become trapped on the back of the tongue.
Research shows that the tongue surface is the main reservoir of bacteria responsible for halitosis. In some cases, tongue coating is the primary source of bad breath even in the absence of tooth decay or gum disease.
The white appearance of the tongue is associated with debris becoming trapped between the tiny papillae on its surface. Cleaning the tongue each time a child brushes their teeth can help eliminate both bad breath and tongue coating.
Tooth Decay and Dental Infections
Bad breath in a child may be caused by dental caries. The bacteria responsible for tooth decay produce unpleasant odors. Food is more likely to become trapped in damaged areas of the tooth and is more difficult to remove.
Problems such as mouth ulcers and dental abscesses can also cause bad breath. These conditions are usually associated with trapped food particles. Bacteria feed on these particles and dental plaque, producing hydrogen sulfide, which has a rotten odor.
Gum Disease
Gum disease is associated with bad breath in people of all ages, including children. Gum disease involves inflammation and infection of the tissues that support the teeth. Although children are unlikely to develop periodontitis, the advanced form of gum disease, they commonly experience a milder form called gingivitis.
Systematic reviews show a direct relationship between the severity of gum inflammation and the intensity of bad breath. The greater the amount of plaque and gum bleeding, the higher the concentration of volatile sulfur compounds in exhaled air.
With gum problems, breath may sometimes have a metallic odor.
Gingivitis develops when soft plaque and tartar (hardened plaque) accumulate on and below the gumline. Bacteria and toxins in plaque irritate the gums, causing inflammation and persistent bad breath that does not disappear after brushing.
Infections often produce unpleasant odors, and gum disease is no exception.
Loose Pediatric Crowns or Fillings
If a child’s dental crown or filling becomes damaged or loose, food particles and bacteria can become trapped underneath. Unsurprisingly, this may lead to bad breath.
Insufficient Saliva
Saliva helps wash away food debris and bacteria from the mouth and neutralizes acids that cause tooth decay.
At night, while children sleep, saliva production slows down, which is why they may have bad breath in the morning.
This type of bad breath is temporary and usually disappears once the child brushes their teeth and saliva production returns to normal.
Dry mouth can also cause bad breath.
When insufficient saliva is produced, food particles and bacteria accumulate on the teeth, creating unpleasant odors.
Unlike normal morning breath, bad breath caused by dry mouth is not always temporary, as dryness may result from certain medications or underlying health conditions.
Enlarged Tonsils
Children with enlarged tonsils or tonsils containing deep crypts may experience bad breath. Tonsils can trap food particles, bacteria, and nasal secretions. Tonsil stones (tonsilloliths) may also form within these crypts and produce an unpleasant odor as they break down.
Allergies or Ear, Nose, and Throat Infections
Viral and bacterial infections, such as strep throat, can cause bad breath.
Bacteria in the mouth feed on mucus and secretions that drain into the throat and onto the tongue. These bacteria produce foul-smelling gases. Such conditions are often accompanied by a runny nose, nasal congestion, and fever.
Mouth Breathing
A study involving children aged 3 to 14 years, published in the journal Clinics, found that children who regularly breathe through their mouths have a significantly higher risk of developing halitosis compared with children who breathe through their noses. The authors linked this to reduced oral moisture and decreased protective effects of saliva.
Researchers suggested that the mouth becomes dry because it remains open throughout the night, resulting in bad breath in the morning.
Mouth breathing may be temporary due to nasal congestion, but it can also become a habitual behavior.
Certain Health Conditions
Conditions such as diabetes, gastroesophageal reflux disease (GERD), and, in rare cases, liver or kidney disorders may also cause bad breath in children.
Certain breath odors may indicate specific health conditions.
An acetone-like odor (similar to nail polish remover) may indicate diabetes. In diabetes, the body either does not produce enough insulin or cannot use it effectively. Normally, insulin helps glucose enter cells to provide energy. If the body cannot use glucose, it begins burning fat instead. During fat breakdown, substances called ketones are produced. Acetone is a type of ketone. Acetone-smelling breath may indicate high ketone levels in the blood, which can be toxic.
If a child’s breath smells like ammonia, it may indicate kidney disease. When the kidneys cannot adequately remove urea, it breaks down into ammonia. As a result, people with kidney disorders may have breath that smells like chemicals or ammonia.
A fecal odor from the mouth may indicate serious medical problems, including intestinal obstruction.
Certain liver diseases can also alter breath odor; however, odor alone cannot be used to establish a diagnosis.
As a rule, in severe illnesses, bad breath is not the only symptom. Therefore, parents should carefully monitor their child’s health and seek medical attention promptly when necessary.
How to Get Rid of Bad Breath in a Child
If your child has bad breath, mint drinks, chewing gum, or breath-freshening tablets are not a solution. They only mask the problem rather than address its cause.
It is important to determine the reason for the odor and rule out any diseases that may be causing it.
Research also shows that regular tongue cleaning with a tongue scraper or toothbrush significantly reduces the concentration of volatile sulfur compounds and improves breath freshness.
It is also important to follow these recommendations:
- Teach children proper oral hygiene habits;
- Provide a healthy and balanced diet;
- Ensure that your child drinks enough water;
- Teach your child to breathe through the nose;
- Visit a dentist regularly to examine your child’s teeth and oral cavity.
When to Visit a Dentist for Bad Breath in Children
If your child has tooth pain, red or inflamed gums, bleeding gums, and bad breath, schedule a dental appointment.
Your child may have dental problems such as tooth decay or gingivitis that require treatment.
If bad breath is accompanied by fever or other symptoms, consult a pediatrician.
This article does not replace a medical consultation. For complete and personalized information, please consult your dentist.