"Once upon a time, there was a boy who sucked his thumb. He grew up to have buck teeth."

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How Thumb Sucking Ruins Teeth

There are two important factors that indicate whether thumb sucking (or pacifier use) will damage teeth: age and intensity. Most dentists agree that the habit won't harm baby teeth, but it should be addressed by the time that permanent teeth arrive, which is around age 6. Once the baby teeth are gone, the potential damage has a greater likelihood of becoming permanent or requiring the attention of an orthodontist. This damage could include abnormal alignment of teeth, known as a malocclusion, as well as damage to the structure of the roof of the mouth. Perhaps most noticeable among the dental difficulties are buck teeth, which result when the pressure of the thumb pushes the top teeth out and away from each other. The changes in dentition could also cause speech problems, such as a lisp. It's possible that malocclusions will take care of themselves once the child stops sucking his or her thumb, but movement of the teeth will probably involve dental work.

The intensity of thumb sucking will affect the extent of the damage. If a child forcefully sucks his or her thumb from day one, then the habit could impact the shape of the mouth and the position of the teeth before permanent teeth even come in. On the other hand, if a child places a thumb in his or her mouth only occasionally, with little to no sucking, then it's less likely to cause a permanent problem. Children may continue to indulge in this action at times of exhaustion or boredom.

Still, even if a child sucks his or her thumb occasionally and with very little pressure, it's usually beneficial to their burgeoning kindergarten social life to put the habit to rest. Doctors and dentists suggest providing positive reinforcement to children for not sucking their thumbs, as opposed to negative comments when they do suck, which may only increase the stress and, by extension, the sucking. Have a dentist explain potential pitfalls of thumb sucking, and remember that these children are almost like little addicts: Children usually require the desire to quit, and even then, it will take about 30 to 60 days to let go of the urge to suck [source: Kutner].

To help children along, parents can put socks or gloves on their little hands, particularly at nighttime. As a last resort, parents might consider a dental device that can be attached to the roof of the mouth; these devices usually make it painful to suck a thumb. An easier and less expensive option, however, might be remembering that kids tend to suck thumbs when they're stressed. Consider whether the child is facing some sort of pressure or anxiety, perhaps in the form of a new baby in the house or a new school. Comforting the child's worries may ease their need to turn to their thumb.