The sucking instinct is a natural reflex that allows children 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. This is not to say that sucking a finger or a thumb indicates the child is under excess stress, but rather that stress may cause the child to suck more than if there were a less stressful environment.

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.

Commonly found with thumb sucking. The pressure of the thumb forces the lower incisor teeth to tip toward the tongue.

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.

The formation of the upper jaw is too narrow to match 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.

Before the age of five, sucking rarely causes permanent jaw formation problems, although the front teeth may be moved out of alignment. 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 and some action is generally required.

Some children suck a lot harder than others and thus create a more pronounced jaw problem. Others suck well into their teens without any affect on tooth position or jaw structure.

If it is less than once an hour each day and the thumb or finger fall out at night, the habit is seldom a problem even after the age of five. However, if the child sucks all night beyond this age, some action may be required.

Try to get the infant started on a pacifier. A pacifier does not cause less damage, but it is easier to phase out. Research indicates that no particular kind of pacifier is superior to another, so use whatever works best.For the child over the age 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 can evolve into a form of negative attention.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 difficulty of stopping the habit.Instead spend some extra time on favorite activities, such as stories, a movie, or playing a game or a 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. The appliances 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.