Although distressing to many parents, infants and toddlers sucking their thumb is a common if not universal habit. Most children phase out of it by around age 4, usually with no ill effects. But thumb-sucking continuing into late childhood could prove problematic for a child’s bite.

Thumb sucking is related to how young children swallow. All babies are born with what is called an infantile swallowing pattern, in which they thrust their tongues forward while swallowing to ensure their lips seal around a breast or bottle nipple when they nurse. Thumb-sucking mimics this action, which most experts believe serves as a source of comfort when they’re not nursing.

Around 3 or 4, their swallowing transitions to a permanent adult swallowing pattern: the tip of the tongue now positions itself against the back of the top front teeth (you can notice it yourself when you swallow). This is also when thumb sucking normally fades.

If a child, however, has problems transitioning to an adult pattern, they may continue to thrust their tongue forward and/or prolong their thumb-sucking habit. Either can put undue pressure on the front teeth causing them to move and develop too far forward. This can create what’s known as an open bite: a slight gap still remains between the upper and lower teeth when the jaws are shut rather than the normal overlapping of the upper teeth over the lower.

While we can orthodontically treat an open bite, we can minimize the extent of any treatments if we detect the problem early and intervene with therapies to correct an abnormal swallowing pattern or prolonged thumb sucking. For the former we can assist a child in performing certain exercises that help retrain oral and facial muscles to encourage a proper swallowing pattern. This may also help diminish thumb sucking, but we may in addition need to use positive reinforcement techniques to further discourage the habit.

To stay ahead of possible problems with thumb sucking or the swallowing pattern you should begin regularly taking them to the dentist around their first birthday. It’s also a good idea to have an orthodontic evaluation around age 6 for any emerging bite problems. Taking these positive steps could help you avoid undue concern over this common habit.

If you would like more information on managing your child’s thumb-sucking habit, please contact us or schedule an appointment for a consultation. You can also learn more about this topic by reading the Dear Doctor magazine article “How Thumb Sucking Affects the Bite.”

It’s true — thumb sucking beyond age 4 can cause bite problems for permanent teeth. But prolonged thumb sucking is just one of a number of possible contributing factors for a bad bite (malocclusion). A dentist must identify all the factors involved when a bad bite is present — their involvement is essential for a successful treatment outcome.

A fairly benign habit for infants and toddlers, thumb sucking is related to an “infantile swallowing pattern” young children use by thrusting their tongues forward between the upper and lower teeth when they swallow. Around age 4, though, they usually transition to an adult swallowing pattern in which the tongue rests on the roof of the mouth just behind the front teeth. Thumb sucking stops for most children around the same time.

Thumb sucking beyond this age, though, can put increased pressure on incoming permanent teeth pushing them forward. This could lead to an “open bite” in which the upper and lower teeth don’t meet when the jaws are closed. The tongue may also continue to thrust forward when swallowing to seal the resulting gap, which further reinforces the open bite.

Before treating the bite with braces, we must first address the thumb sucking and improper tongue placement when swallowing — if either isn’t corrected the teeth could gradually revert to their previous positions after the braces come off. Besides behavioral incentives, we can also employ a thin metal appliance called a “tongue crib” placed behind the upper and lower incisors. A tongue crib discourages thumb sucking and makes it more difficult for the tongue to rest within the open bite gap when swallowing, which helps retrain it to a more normal position.

An open bite can also occur if the jaws develop with too much vertical growth. Like thumb sucking and improper tongue placement, abnormal jaw growth could ultimately cause orthodontic treatment to fail. In this case, though, surgery may be necessary to correct the jaw structure.

With all these possible variables, our first step needs to be a thorough orthodontic exam that identifies all the cause factors for your child’s specific malocclusion. Knowing if and how thumb sucking may have contributed to the poor bite will help us design a treatment strategy that’s successful.

If you would like more information on the causes of poor tooth position, please contact us or schedule an appointment for a consultation. You can also learn more about this topic by reading the Dear Doctor magazine article “How Thumb Sucking Affects the Bite.”

It's no secret that many of Hollywood's brightest stars didn't start out with perfectly aligned, pearly-white teeth. And these days, plenty of celebs are willing to share their stories, showing how dentists help those megawatt smiles shine. In a recent interview with W magazine, Emma Stone, the stunning 28-year-old star of critically-acclaimed films like La La Land and Birdman, explained how orthodontic appliances helped her overcome problems caused by a harmful habit: persistent thumb sucking in childhood.

“I sucked my thumb until I was 11 years old,” she admitted, mischievously adding “It's still so soothing to do it.” Although it may have been comforting, the habit spelled trouble for her bite. “The roof of my mouth is so high-pitched that I had this huge overbite,” she said. “I got this gate when I was in second grade… I had braces, and then they put a gate.”

While her technical terminology isn't quite accurate, Stone is referring to a type of appliance worn in the mouth which dentists call a “tongue crib” or “thumb/finger appliance.” The purpose of these devices is to stop children from engaging in “parafunctional habits” — that is, behaviors like thumb sucking or tongue thrusting, which are unrelated to the normal function of the mouth and can cause serious bite problems. (Other parafunctional habits include nail biting, pencil chewing and teeth grinding.)

When kids develop the habit of regularly pushing the tongue against the front teeth (tongue thrusting) or sucking on an object placed inside the mouth (thumb sucking), the behavior can cause the front teeth to be pushed out of alignment. When the top teeth move forward, the condition is commonly referred to as an overbite. In some cases a more serious situation called an “open bite” may develop, which can be difficult to correct. Here, the top and bottom front teeth do not meet or overlap when the mouth is closed; instead, a vertical gap is left in between.

Orthodontic appliances are often recommended to stop harmful oral habits from causing further misalignment. Most appliances are designed with a block (or gate) that prevents the tongue or finger from pushing on the teeth; this is what the actress mentioned. Normally, when the appliance is worn for a period of months it can be expected to modify the child's behavior. Once the habit has been broken, other appliances like traditional braces or clear aligners can be used to bring the teeth into better alignment.

But in Stone's case, things didn't go so smoothly. “I'd take the gate down and suck my thumb underneath the mouth appliance,” she admitted, “because I was totally ignoring the rule to not suck your thumb while you're trying to straighten out your teeth.” That rule-breaking ended up costing the aspiring star lots of time: she spent a total of 7 years wearing braces.

Fortunately, things worked out for the best for Emma Stone: She now has a brilliant smile and a stellar career — plus a shiny new Golden Globe award! Does your child have a thumb sucking problem or another harmful oral habit? For more information about how to correct it, please contact us or schedule an appointment for a consultation. You can learn more in the Dear Doctor magazine article “How Thumb Sucking Affects the Bite.”