Most practices don’t spend a lot of time thinking about the role addiction can play in shaping their daily activities. After all, orthodontics is about correcting small physiological imperfections preprogrammed by the body’s genetic code. But orthodontists are on the frontline of one of the most common human addictions. What’s more, it’s a good bet that you too were afflicted by this addiction. Non-nutritive sucking, better known as thumb sucking, isn’t just a habit. It’s considered by many psychologists to be human’s first true addiction.
Calling it an addiction might seem like an insignificant change in semantics. But viewing thumb sucking through the prism of addiction can help clinicians better understand some critical aspects of the condition, making it easier to address cessation and treatment.
Generally speaking, addiction is a dysfunction of the brain’s reward, motivation and memory circuitry. Addictions start out as habits, healthy feedback loops that tell the brain to associate input (say, chocolate) with pleasure (yum). This stimuli/reward association is essential to life, driving everything from our most basic needs (food, water and sleep) to intellectually abstract concepts (morality, creativity and self-actualization). So habits begin and continue because they enhance life in some way. Habit transforms to addiction when the consequences turn negative.
This is certainly true with thumb sucking.
Thumb sucking is an activity found in humans, apes and chimpanzees and interestingly, ring tailed lemurs. Thanks to MRI’s, we now know that thumb sucking in humans is common prenatally, starting as early as 15 weeks after conception.
Statistics vary depending on the methodology, but all agree that the percentage of children who suck their thumb is over 85%. Considered instinctual because it’s an inherited action, the behavior is deep rooted within the body’s evolutionary blueprint. It’s a spontaneous action that can occur when a child is tired, bored, hungry or in need of comfort.
Scientists know that thumb sucking provides direct psychological benefits, allowing infants to self-sooth, a skill essential in developing healthy rest and sleep habits. Brain scans show thumb sucking can do more than just soothe, providing the newborn with feelings of euphoria, security and being wanted. The benefits of going to the thumb aren’t just mental for the child. Because thumb sucking prevents the infant from using energy while crying, studies show thumb suckers can recover from illness faster and enjoy shorter hospital stays. Studies show that thumb sucking also helps regulate peristalsis in the infant, allowing them to digest food more efficiently, and that it helps children become emotionally independent at an earlier age.
For all the positive benefits, most children lose the sucking impulse in the four to five year range. The body’s timing isn’t by accident, as the permanent teeth begin erupting shortly thereafter. This is where the problems start.
Most orthodontists are familiar with the occlusion problems that adult thumb sucking can cause. Class I and II malocclusions are just the start. Thumb sucking can inhibit the full eruption of the incisors, prevent the lower jaw from developing correctly and cause improper development of the palate. These problems can open a Pandora’s Box of additional problems including speech impediments, tooth decay and TMJ problems. Depending on a variety of other factors, it can also lead to middle-ear infections, enlarged tonsils and GI disturbances. The range of outcomes is so wide because there are a number of variables including position of the digit, position of the mouth, the facial skeletal patterns and the intensity, frequency and duration of the force applied during the act of sucking.
That’s before considering the potential social implications associated with thumb sucking.
It would seem the cards are stacked against the thumb sucker. But as always, the body is an amazing machine. Just about all damage done to the oral cavity by thumb sucking vanishes when the deciduous teeth are lost and the primary teeth begin erupting. (Perhaps it’s the parents who receive the real financial benefits from the tooth fairy?)
Even once the adult teeth come in, the body can and will self-correct basic malocclusions of the primary teeth if the thumb sucking can be eliminated early enough.
If the action of thumb sucking isn’t caught early enough, it will begin interfering with typical life responsibilities, relationships or health. Thus, action becomes addiction.
As with most of the mainstream addiction cessation programs, the essential building block is that the addict must make a conscious decision to end the behavior. Of course, this is easier said than done. Appeals to logical and rational behavior can be hard for the fully developed adult brain to grasp and act upon. First, consider all of the aforementioned benefits derived from the act of thumb sucking; now consider asking a still-developing teenage brain to actively forgo what has been the most consistent comfort to them outside of their parents.
It’s a challenge, but not impossible. It’s important to understand that thumb sucking has a disproportionately negative significant social stigma attached to it. Before most clinicians get to the child, they must first deal with the parent. One of the first things to stress to parents is that thumb sucking is in no way associated with emotional immaturity or any type of developmental inhibition. Even if they know this, they are likely frustrated with their inability to end the behavior without professional help.
Typically the most effective way to influence a child (or adult) is to let them make a decision on their own. This is usually facilitated by presenting them with information about the downside of the behavior. As a trained medical professional, not to mention a fancy office and great chairside demeanor, the clinician often has credibility that the parent does not.
Positive reinforcement is the key when counseling both the parent and the child. Negative reinforcements and threats will only serve to further entrench the habit.
The conversation should be friendly and empathetic. In unthreatening but frank terms, lay out all the potential consequences of continued thumb sucking.
Behavioral therapy tells us that addicts respond best to a combination of fear of loss and hope of gain. Hopefully the parent will have done their homework on their role in eliminating the behavior. (The internet has no shortage of worthwhile information.) Resist the natural impulse to editorialize or moralize any aspect of the action.
In some cases, the action of thumb sucking may have been eliminated, only to resurface. You may need to don your detective hat and investigate events that precede the thumb sucking such as use of a security blanket, dependence on a toy, problems with sleep, nightmares, excessive nervousness can offer you information on potential psychological triggers. If you deduce that the oral habit might be associated with an emotional problem, you might need to recommend a psychological consultation.
Many parents will ask about physical deterrents. There are an amazing number of products and ideas out there designed to interrupt the behavior including thumb and finger guards (“Thumb Buddy to Love” wins the award for best name), arm and elbow devices and a number of taste and texture deterrents. And of course you’ve got orthodontic deterrents such as the palatal crib. They can all play a supporting role, but none will succeed without being accompanied by the appropriate mindset.
Reading for Young Children
– “Thumbs Up, Brown Bear” by Michael Dahl
– “David Decides” by Susan Heitler
– “Little Thumb” by Wanda Dionne
Additional Reading: CCO Case File: Thumb and Lower Lip Sucker by Dr. Raffaele Spena