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.”
You’ve invested a lot of time and money in orthodontic treatment to improve your smile. If you’re not careful, though, your teeth could actually move back to their old positions. The reason why is related to the same natural tooth-moving mechanism we use to straighten teeth in the first place.
Teeth are held in place by an elastic, fibrous tissue called the periodontal ligament lying between the teeth and the jawbone and attaching to both with tiny collagen fibers. The periodontal ligament allows for incremental tooth movement in response to pressure generated around the teeth, as when we chew (or while wearing braces).
Unfortunately, this process can work in reverse. Out of a kind of “muscle memory,” the teeth can revert to the older positions once there’s no more pressure from the removed braces. You could eventually be right back where you started.
To avoid this, we have to employ measures to hold or “retain” the teeth in their new positions for some time after the braces come off. That’s why we have you wear a dental appliance called a retainer, which maintains tooth position to prevent a relapse. Depending on what’s best for your situation, this could be a removable retainer or one that’s fixed to the teeth.
Patients typically wear a retainer around the clock in the immediate period after braces, and then eventually taper off to just nighttime wear. Younger patients must wear one for several months until the new teeth positions become more secure and the chances of a rebound diminish. For older patients who’ve matured past the jaw development stage, though, wearing a retainer may be a permanent necessity to protect their smile.
Retainer wear can be an annoyance, but it’s an absolute necessity. Think of it as insurance on your investment in a new, more attractive smile.
If you would like more information on improving your smile through orthodontics, 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 “The Importance of Orthodontic Retainers.”