Why do babies do it? The sucking instinct is one of a baby’s natural reflexes that allows the baby to obtain nourishment. It is a normal infant activity that seems to help a baby feel happy and secure. Some babies need to suck a lot more than others. There is a hereditary factor influencing the need to suck. Stress is another factor which increases the need. Not to say that sucking a finger or thumb indicates the child is under excess stress, but that stress may simply cause the child to suck a lot more than if there were not a stressful environment.

Why worry about it? Thumb or finger sucking habits can cause tooth misalignment or jaw deformation. The degree of disruption depends on several factors: how hard the child sucks, how often, and to what age. The common problems produced by these habits are below.

Protrusive upper front teeth. This can be a simple tooth position problem, where the upper incisor teeth are tipped forward. Occasionally the formation of the jaw can be affected, and the upper jaw and teeth will develop in a protrusive relationship to the rest of the face.

Tipped back lower front teeth. Commonly found with thumb sucking: the pressure of the thumb forces the lower incisor teeth to tip toward the tongue.

Open bite. The upper and lower front teeth do not overlap when the back teeth are together. The shape of the opening between the upper and lower front teeth may match the child’s finger or thumb exactly.

Crossbite. The formation of the upper jaw is too narrow for the lower jaw, so that the upper and lower teeth do not fit together properly. This seems to occur as a result of the flexing of the cheek muscles during sucking. There are three variables to consider: duration, intensity, and frequency.

Duration: Before the age of five, there are usually no jaw formation problems, although you may notice the front teeth getting out of line. Orthodontists do not usually make an effort to stop the habit before this age. After the age of five or six the shape of the jaw may be affected by the sucking activity, so some action should be taken.

Intensity: Some children suck a lot harder than others and may cause a lot more damage. Others suck into their teens without any affect on tooth position or jaw structure.

Frequency: If it is less than one hour each day and the thumb or finger falls out at night, the habit is not a problem even after the age of five. However, if the child sucks all night beyond this age some action may be needed.

What To Do?

Try to get the infant started on a pacifier if they show any interest in extra curricular sucking. A pacifier does not cause less damage, but it is easier to control phasing it out. Research indicates that no one particular kind of pacifier is superior to another, so use what ever works best.

For the child over five, explain the risks, offer rewards, and provide reminders such as nail polish, or a band-aid. Avoid scolding or punishment, which just does not work, and it can evolve into a form of negative attention.

When To Worry?

The child may need some emotional support, so be prepared to spend a little extra time with him or her. There is no need to talk about the sucking activity or to commiserate with the difficulty of stopping the habit. Instead, spend some extra time on favorite activities, such as stories, a movie, or playing a game or sport.

If you cannot help the child stop, the orthodontist will have some suggestions. Usually using a retainer (a removable plastic appliance that fits the roof of the mouth) will stop the habit. It changes the feeling of having the finger or thumb in the mouth, and the appliance itself seems to satisfy some of the urge to put a finger or thumb into the mouth. The appliance will need to be used six to ten months to make sure the child has stopped the habit. The orthodontist can make some corrective tooth movements with the appliance as well, if indicated. Some children will not be able to keep from removing the appliance to suck their finger or thumb. In that case, the orthodontist will suggest an appliance that is cemented to the teeth.

A Final Word

It is easy to appreciate how comforting a sucking habit seems to be to a child. It can be a big help during those early dependent years. With gentle supervision it is normally very easy to help them finish up with the habit before any damage is done.