Thumb sucking is the childhood habit of putting the thumb in the mouth for comfort or to relieve stress. Babies and young children derive the feeling of security and relaxation when sucking their thumbs or fingers. The activity is normal for infants and toddlers, but should decrease by ages three to four and stop by age five.
Parents tend to be more concerned with thumb sucking than is actually warranted. Thumb sucking can affect the healthy development of teeth and mouth, which may cause more problems later on. Prolonged thumb activity produces significant problems with chewing, speech, and facial appearance.
Thumb-sucking isn’t “bad” for the teeth as such; but long term persistence in thumb sucking could interfere with the proper development of your child’s mouth. When baby teeth start to fall out and are replaced by permanent teeth, thumb sucking then becomes a problem. Also, the intensity of thumb sucking could result in future dental problems.
Effects on Teeth
Persistence in thumb sucking affects the development of the mouth. For teeth, thumb sucking after the age of three could result in:
- a reshaped jawbone given its soft and pliable nature
- mis-aligned teeth growing out of position
- narrower dental arches
- protruding front teeth which may be more susceptible to injury
- “open bites” that would require extensive orthodontic treatment to straighten
As well as the effect on teeth, thumb sucking could affect the growth of a child’s palate (roof of the mouth). This in turn could lead to:
- poor tongue placement and movement
- chewing and swallowing difficulties
- speech problems
- development of insecurities given any consequential deformities
Other physical effects
Children who suck their thumbs a lot, and for a long time, often develop an ugly callous on the thumb. Infections of the thumbnail (paronychia) are also common – look for redness, swelling, tenderness, or a crust or puss.
Thumb-sucking can also lead to increased ingestion of lead, something to think about if your baby regularly spends time in an older building, which could be your home, a child care setting or a school.
Another possible problem is an increased risk of pinworms in children who frequently put their thumbs or fingers in their mouths. Pinworms are common. These tiny parasites live in the intestine and lay eggs on the skin surrounding the anus. These parasites can cause itching, vaginal irritation and sleep disturbance.
Psychological effects
By age 3 or 4, children who are still sucking their thumbs are likely to feel self-conscious about it. They may be teased. These issues increase as the children grow older. If you confront your thumb-sucking child and he absolutely denies that the thumb-sucking bothers him, it almost certainly means that he is protecting himself from the discomfort by pretending that it’s not there.
Ruminating
Sometimes babies and young children get into the habit of sucking and chewing on their tongue until their last meal comes up, somewhat the way a cow does, a practice known as ruminating.
Pediatricians now recommend that no action against thumb-sucking be initiated during the first two or three years. In the older child, an environmental cause for thumb-sucking should be sought and eliminated; for cases where thumb-sucking is an empty habit, parents are urged to remind the child gently only if the child wants to quit.
Parents should stop children who persist in thumb sucking. Children usually stop by about 2-3 years of age, although some do continue beyond the age of five years. Parents should find positive ways to encourage their child to stop.