We see the results of long term thumb or finger sucking on a daily basis. Many of the children who present for their first exam will indicate that they have sucked their thumb or finger for a number of years.
So, what’s normal?
Many children will automatically cease sucking habits around age five and usually up to that point, not much damage is done. After about age seven, we start to see problems with the upper teeth being brought forward, and the early stages of permanent damage in the form of distorted bone growth. It is not for a well adjusted, healthy nine year old, or older child to have a regular sucking habit.
Why do babies do it?
Obviously it feels good! The sucking instinct is one of the baby’s natural reflexes that allows the baby to obtain nourishment. It is a normal infant activity that makes the baby feel happy and secure. Some babies seem to need to suck a lot more than others. There are apparently hereditary factors influencing the need to suck. Stress is another factor that seems to increase the need. If there is disruption in the family, the stress of that situation will precipitate a sucking habit even in older children. This is 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 more than if there were not a stressful environment.
Why worry about it?
Sucking habits can and do cause tooth malalignment or jaw deformation. The degree of disruption depends on several factors:
- How hard the child sucks
- How often and to what age
- Does the resting tongue position substitute for the thumb
The problems produced by these habits are:
Protrusive upper front teeth.
This can be a simple tooth position problem, where the upper incisor teeth were simply tipped outward. Occasionally the formation of the upper jaw can be affected, and upper jaw and teeth will warp out and away from the rest of the face.
Tipped back lower incisors.
Commonly found with thumb sucking: the pressure of the thumb forces the lower incisors backward toward the tongue. This exaggerates the protrusion of the upper incisors, making the face even more distorted.
Distortion of nasal growth.
In a long term or severe situation, the nose will appear to be tipped up. When viewing the child from the front, you can see right up the nose since it is tipped up at a severe angle by the constant pressure of the thumb on the under side of the nose. These distortions of the upper jaw and nasal complex are very difficult to reverse without long term orthodontic intervention.
Open bite.
The upper and lower front teeth do no overlap when the back teeth are together. The shape of the opening between the upper and lower front teeth may match the shape of the child’s finger or thumb. This obviously interferes with the child’s ability to bite into food and will cause problems with digestion.
Cross bite.
The formation of the upper jaw is too narrow for the lower jaw. This distortion seems to be due to the flexing of the cheek muscles during sucking. Severe bite problems occur from these prolonged forces, and must be treated before completion of growth.
What are the variables to consider?
Duration:
Before age five, there are usually no jaw deformation problems, although you may notice the front teeth getting out of line. We usually do not worry too much about these early habits. After age six or seven, the shape of the jaw may be affected, so some action should be considered.
Intensity:
Some children suck harder than others and may in turn cause more damage. In general, the harder they suck, the more damage.
Frequency:
If it is less than one hour each day, and the thumb or finger falls out at night, the habit is not much of a problem. However, if the child sucks all night beyond age five, some action may be needed. When we see a child with a sucking habit, we try to be as supportive as possible. We find out from the child firstly if they want to stop their sucking habit. If they respond in a positive manner, we advise them of a method where they are in control of the situation. A reward of some type is offered to the child if they are able to bring the habit under control. Of course there are appliances that can be used to help cease these habits, however if the child can cease the sucking on their own, this is preferable.
Never try to force or shame a child to stop a sucking habit. It is easy to appreciate how comforting the habit can be to a child. If they fail on the first try, wait a couple of months and try again.