Oral Habits That Can Harm Your Child's Teeth

Thumbsucking is one of the most common oral habits in young children and is generally considered normal up to around age 3. The problem arises when the habit continues beyond the age when permanent teeth begin to emerge — typically around age 6.

Persistent thumbsucking or prolonged pacifier use can lead to:

• An open bite (a gap between the upper and lower front teeth when the mouth is closed)
• Flared or protruding upper front teeth
• Narrowing of the upper jaw (palate)
• Changes in how the upper and lower teeth meet (the bite, or occlusion)

The intensity of the habit matters as much as the duration. Passive resting of the thumb in the mouth causes less displacement than active, vigorous sucking.

If your child is still thumbsucking past age 4 to 5, raise it at their next dental visit. A Specialist Pediatric Dentist can assess whether any structural changes are developing and advise on gentle habit-breaking strategies appropriate for your child's age.

Tongue thrusting refers to a swallowing pattern where the tongue pushes forward against or between the teeth, rather than resting against the roof of the mouth. It can also occur at rest.

Most infants thrust their tongue when swallowing — this is entirely normal. The habit becomes a concern when it persists into later childhood, as the constant forward pressure can cause:

• An open bite at the front teeth
• Protrusion of the upper or lower front teeth
• Speech difficulties, particularly with sounds like "s" and "z"
• Interference with normal jaw development

Tongue thrusting is not always obvious — many parents are unaware it's happening. It's often identified during a routine dental examination or when parents notice persistent gaps between the front teeth that don't close naturally.

When caught early, tongue thrusting can be addressed through targeted exercises and, in some cases, guidance from a speech therapist working alongside the dental team.

Children are natural nose breathers. When a child habitually breathes through their mouth — whether due to enlarged adenoids, nasal congestion, allergies, or structural factors — it can have significant downstream effects on oral development.

Chronic mouth breathing has been linked to:

• A long, narrow facial structure over time
• Narrowing of the dental arches
• Crowded or misaligned teeth
• A higher palate
• Dry mouth, which increases the risk of cavities and gum problems

Unlike thumbsucking, mouth breathing isn't always a behavioral habit — it can have an underlying medical cause. If you notice your child consistently breathing through their mouth, sleeping with their mouth open, or snoring regularly, it's worth raising with both their dentist and pediatrician.

Nail biting is extremely common in school-age children and is often linked to stress or boredom. From a dental perspective, it places repetitive lateral pressure on the teeth and can cause:

• Chipping or wearing down of the front teeth
• Jaw discomfort, particularly in children who are already prone to clenching
• Increased exposure to bacteria from the fingers

A similar concern applies to children who habitually chew on pencils, pen caps, straws, or clothing. The consistent force applied to specific teeth can cause gradual shifts in position over time.

These habits are usually addressed through behavioral strategies — identifying triggers, substitution techniques, and encouragement. A dental assessment is helpful to determine whether any tooth wear or shifting has already occurred.

Many parents are surprised to learn that teeth grinding, or bruxism, is relatively common in children — particularly during sleep. It's often most noticeable when parents hear a grinding sound at night.

In younger children, bruxism frequently resolves on its own. However, if it persists, it can lead to:

• Worn or flattened tooth surfaces
• Tooth sensitivity
• Jaw muscle soreness or headaches on waking
• Disrupted sleep

The causes in children are not fully understood, but stress, misaligned teeth, and airway issues are among the factors that have been associated with childhood bruxism.

If you've noticed grinding sounds, or your child is waking with a sore jaw, a Specialist Pediatric Dentist can assess the level of wear and advise on next steps. In most cases, the focus is on monitoring, managing any underlying triggers, and protecting the teeth where necessary.

Not every habit requires immediate intervention — but some warrant earlier attention than others. Consider booking a review with a Specialist Pediatric Dentist if:

• Your child is still thumbsucking or using a pacifier past age 4
• You notice a visible gap between the front teeth that doesn't close naturally
• Your child consistently breathes through their mouth, particularly at night
• You hear regular grinding during sleep, or your child wakes with jaw pain
• Your child's teeth appear to be shifting, crowding, or wearing unevenly

Early assessment allows the dental team to determine whether a habit is causing structural change and, if so, to act before permanent teeth are affected.