Does sucking your thumb really ruin your teeth?

child sucking thumb
She's adorable now, but is she ruining her teeth?
Elke Van de Velde/Digital Vision/Getty Images

Babies discover their thumbs in the womb, and many parents have sonogram pictures of their children sucking on the digit to prove it. New parents may become grateful for that thumb sucking habit in the first few months, as it stops the baby from crying and temporarily distracts the young one from other matters, such as hunger. Some parents may encourage sucking on a thumb or on a pacifier, based on research that suggests a link between night-time sucking and decreased risk of sudden infant death syndrome (SIDS) [source: Vance]. But there comes a time when parents fear the sight of that thumb headed toward their child's mouth, particularly parents unduly influenced by the views of Sigmund Freud, who considered thumb sucking a manifestation of infantile sexuality.

For most people, though, concerns about thumb sucking are a bit more cosmetic. In "Gone With the Wind," one scene that displays Rhett Butler's gift for fathering his young daughter Bonnie comes when he confides in the matronly Mrs. Merriwether that he can't stop the girl from sucking her thumb. Mrs. Merriwether is emphatic -- the habit must stop, or the lovely Bonnie will ruin the shape of her mouth. With this scene, Rhett Butler becomes one of the many parents concerned about the results of this seemingly innocent habit, and Rhett didn't even have to face an army of expensive orthodontists to come to the result. The alleged dangers of sucking on a thumb or a pacifier are so severe that it's become one of those issues that perfect strangers feel comfortable commenting upon, much the way they feel comfortable rubbing a pregnant belly before the birth.


But is thumb sucking worth all this fuss? It is, after all, an extremely common habit; about 80 percent of babies and children suck their thumbs at some point [source: O'Connor]. Sucking on a thumb (or any finger) is a normal reflex in children that soothes them in times of stress; it's essentially a security blanket that happens to be attached to one's body (a fortunate development for parents who've endured the agony of a missing blanket). Many children outgrow the habit on their own, but for those who don't, what are the consequences?

How Thumb Sucking Ruins Teeth

father reading to child who is sucking his thumb
"Once upon a time, there was a boy who sucked his thumb. He grew up to have buck teeth."
Thomas Barwick/Digital Vision/Getty Images

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.


Lots More Information

Related HowStuffWorks Articles


  • American Dental Association. "Thumbsucking, Finger Sucking, and Pacifier Use." WebMD. 2004. (July 10, 2009)
  • Cettina, Teri. "Still thumb-sucking?" Parenting. March 2008.
  • Kutner, Lawrence. "Parent & Child." New York Times. Sept. 2, 1993. (July 10, 2009)
  • Nagourney, Eric. "Experts Revisit Perils of Thumb-Sucking." New York Times. Jan. 1, 2002. (July 10, 2009)
  • O'Connor, Anahad. "The Claim: Thumb Sucking Can Lead to Buck Teeth." New York Times. Sept. 27, 2005. (July 10, 2009)
  • "Pacifiers: Are they good for your baby?" Mayo Clinic. Aug. 31, 2007. (July 10, 2009)
  • "Thumb-Sucking: Topic Overview." WebMD. Sept. 12, 2008. (July 10, 2009)
  • Ulene, Valerie. "Now's the time to stop thumb sucking." Los Angeles Times. March 5, 2007.
  • Vance, Gaia. "Pacifiers dramatically cut risk of cot death." New Scientist. Dec. 9, 2005. (July 10, 2009)