What Are the Effects of Thumb Sucking on the Teeth and Mouth?

Not every instance of thumb sucking leads to harm to the teeth or oral structures. For instance, merely resting a thumb in the mouth without much motion usually does not create problems. Conversely, active, frequent thumb sucking with significant movement can affect primary (baby) teeth, although these changes often correct themselves once permanent teeth erupt. Persistent, forceful thumb sucking can occasionally shift the alignment of a child’s permanent teeth and influence the jaw or the contour of the palate. Additionally, thumb sucking can introduce dirt, bacteria, and viruses into your child’s mouth.

A study published in Pediatrics reported that children who suck their thumbs were less prone to allergic reactions later in life to things like pollen and dust mites. So deciding when—or if—to discourage thumb sucking depends on multiple considerations.

Long-term consequences of thumb sucking on the mouth

Vigorous thumb sucking can lead to a number of dental and oral consequences because of the repeated pressure exerted by the thumb and the sucking action on the teeth, jaw, and the roof of the mouth. Possible outcomes include:

• an overbite, in which the front teeth stick out beyond the jaw and mouth
• other bite abnormalities, such as the lower teeth tilting inward toward the back of the mouth or an open bite, where the upper and lower teeth don’t meet when the mouth is closed
• alterations to jaw shape, which can affect tooth alignment and speech patterns, potentially causing a lisp
• increased sensitivity of the palate

Most of these problems either resolve or do not develop if thumb sucking fades by the time permanent teeth appear. Children who continue frequent, forceful thumb sucking for an extended period may face a higher likelihood of these issues.

What to do if you spot bite or tooth problems

Children should begin routine dental checkups by age 1. If you later observe that your child’s front teeth are protruding or if their bite seems abnormal, consult a pediatric dentist about your concerns.

Permanent teeth generally begin to come in around age 6, but the mouth can be affected earlier in ways that may or may not self-correct. For that reason, it’s wise to seek advice from a healthcare provider sooner rather than later if you’re worried.

How long is it safe for a child to suck their thumb?

If your child is older than 4 and continues to frequently suck their thumb during the day, or if you’re uneasy about the behavior, speak with their pediatrician or dentist. They can suggest methods or approaches to help your child stop, or in some cases recommend allowing the behavior to cease naturally despite potential effects on baby teeth.

Many children stop on their own between ages 2 and 4. Ongoing, persistent thumb sucking beyond that period may alter the positioning of permanent front teeth and the shape of the mouth.

How to help your child quit thumb sucking

If you plan to help a child stop sucking their thumb, understand that success is most likely when the child is motivated to quit. The approach may vary with the child’s age.

For older children, a conversation can often be enough—especially if peers have teased them about it. Peer influence can be an effective discouragement for kids starting preschool or kindergarten. If a child resists attempts to stop, it’s usually best to avoid making it a focus; attention can inadvertently reinforce the behavior.

Other strategies to encourage stopping include:

Identify triggers for thumb sucking

Some children suck their thumbs when bored, tired, anxious, or hungry. If the habit serves as a calming mechanism during stressful moments, try to determine and address the underlying source of the anxiety. If thumb sucking occurs at other times, redirect them to activities that occupy their hands, like drawing or tossing a ball. Avoid turning thumb sucking into a way to gain attention, whether positive or negative.

Use positive encouragement

Involve your child in stopping by praising them when they refrain from thumb sucking or by using a reward chart where they mark successes with stickers.

Provide gentle reminders

If your child thumb sucks out of habit, calmly prompt them to stop. Expect to repeat reminders many times. This approach is effective chiefly when the child wants assistance to quit.

Ask the dentist for guidance

Your child’s dentist can explain the potential dental consequences of continued thumb sucking in a way the child can understand.

Consider an orthodontic appliance

There are both removable and fixed orthodontic devices designed to interfere with thumb sucking. A pediatric orthodontist can advise which option may suit your child best.

Try thumb shields

Various soft plastic or fabric thumb guards available over the counter can remind a child not to suck their thumb. They can be worn continuously or only during times when the child is most likely to thumb suck. At night, covering the thumb with a glove, mitten, or sock may help if the child sucks their thumb while sleeping. If the habit occurs exclusively during sleep, remember the child cannot consciously control it.

Why do children suck their thumbs? | Benefits

Thumb sucking is a calming, instinctive action that starts before birth. Infants often continue this comforting behavior after birth, which can help them fall asleep. For some children, the habit persists into toddlerhood and serves as a self-soothing tool during stressful situations.

According to the American Dental Association, most kids stop thumb sucking between ages 2 and 4.

Thumb sucking versus pacifiers

Avoid replacing a thumb-sucking habit with a pacifier habit. Pacifier use poses similar risks for dental issues as thumb sucking and can become contaminated when dropped. The main advantage of a pacifier is that it can be taken away to help break the habit.

Also consider natural remedies like the toothache plant for soothing mouth discomfort, but consult a healthcare professional before trying new treatments.

Takeaway

Thumb sucking is a natural reflex that begins before birth and often continues through age 2 or longer. While it commonly resolves on its own, sustained, forceful thumb sucking beyond age 4 can sometimes harm the mouth, affecting tooth alignment and palate shape, and it may expose children to germs. Parents can support their child in breaking the habit, and a pediatric dentist or pediatrician can provide guidance and treatment options.