How Thumb Sucking Impacts Children’s Teeth Development

Thumb sucking and pacifiers. Those go hand in hand with raising children—and it seems like young kids everywhere use one or another to sooth themselves as they fall asleep. While a 2016 study shows thumb sucking may prevent allergies in kids, continuing the habit beyond the age of 5 can negatively impact a child's oral health.

Thumb sucking is okay as long as the habit stops after 5 years of age. After 5 years of age, the child’s permanent teeth will begin erupting—the first molars, the incisors on the lower arch—and thumb sucking will cause the child to develop an anterior open bite, where the teeth in the front do not come together and, as a result, the tongue has a lot more space to thrust forward. Because of this, the child may also develop speech impediments, because she cannot pronounce certain sounds due to the teeth not closing correctly and the tongue thrusting forward.

If your child breaks the thumb-sucking habit by age 5 without any orthodontic intervention, the open bite will usually close on it’s own by age 10 or 11, depending on the severity.

Another thing is the upper arch will form in a v-shaped arch—kind of elongated forward—because of the constant pressure of the thumb on the upper teeth. That creates a cross bite, or scissor bite, in the back.

A cross bite needs to be corrected by expanding the arch with a special appliance called a palate expander. The palate expander could also be used in combination with a habit-breaking appliance to correct both problems.

To break the thumb-sucking habit, the first recommendation is to talk to the child and encourage him to minimize the habit as much as possible. For example, it shouldn't be done for the whole day. Some kids don’t do it during the day because they’re involved in activities, but when they go to sleep, they start sucking their thumb. It still needs to be broken in that case.

If that doesn’t work, the parent can always bring the child to the orthodontist, who can talk to the child. Sometimes kids forget they need to work on breaking the habit, and parents are caught up with their work that they forget to remind the child. What I advise is to put up sticky notes all over as reminders for the child to take her thumb out of her mouth. Some parents also try thumb guards.

As a last resort, there are habit-breaking appliances the orthodontist can cement in the child’s mouth. They come in different forms to prevent either tongue thrusting or thumb sucking. It has a roller that prevents the thumb from getting into a secure position in the mouth, and that will break the habit.