Thumb and Finger Sucking

June 12, 2023, Kyle Isaacs

Baby with yellow pacifier in a yellow seatDoes your child suck their thumb, fingers, pacifier, blanket, or other object? Or did you do any of those when you were little? If you did, do you remember how it made you feel? Sucking can and does provide comfort, and it is a common and normal activity that babies do. So common, in fact, that about 90% of all babies start sucking their hands within 2 hours of being born. The sucking reflex, for example, happens when the roof of a baby’s mouth is touched. The baby will begin to suck when this area is stimulated, which helps with nursing or bottle feeding. They start sucking even before they are born, somewhere around 32 weeks in utero, but the ability to suck is not completed until about 36 weeks in utero. During an ultrasound, you can even see a baby sucking a thumb or finger. Sucking not only helps soothe a baby, but it is also important for nutrition; that is, being able to nurse or take a bottle. Unfortunately for those babies born prematurely, they may not have a strong sucking reflex and may need help with feeding.

When a pacifier, thumb, fingers, or even a blanket is in the mouth, they touch the roof of the mouth or palate, and this triggers the release of those feel-good chemicals, serotonin, and dopamine. These chemicals help to calm and relax babies and help decrease anxiety. It is amazing that babies learn how to soothe themselves using a thumb or finger or with a caregiver’s help. This type of sucking is non-nutritive and can also be achieved with the tongue unless tied or restricted.

Okay, so we now know that sucking is normal and needed to soothe and provide nutrition. I bet you are wondering what gives, what more do you need to know about sucking. Let’s look at what happens with the tongue when there are objects in the mouth. When things are on top of the tongue, then the tongue cannot suction up to the palate. To help have the best jaw growth and to be able to breathe through the nose, we want the tongue to be suctioned up in the palate all the time unless we are eating or talking. Having the tongue up also makes it easier to breathe through the nose. Over time if a child continues to suck on a thumb or other object, it is more likely the jaws will not grow properly, increasing tooth crowding, mouth breathing, tooth decay, gum disease, speech and sleep issues (including sleep apnea), bed wetting, disruptions in brain development, problems with the TMJ, behavior issues, and so much more.

Countless times I have heard from parents that dental and medical professionals told them that there are no lasting problems using a pacifier, thumb, or other objects to suck on as long as the habit is stopped by the time the permanent teeth start to come in or erupt in the mouth. Depending on the child, this could be anywhere from 4-7 years of age. By this time, a lot of growth is already done, so the sooner non-nutritive habits stop, the better, ideally by six months –1 year of age, as this gives more time for the tongue to help shape the palate. Unfortunately, when an object is in the mouth, it rests on the tongue, completely preventing the tongue from living in the roof of the mouth. When the tongue sits low in the mouth, children and adults are more likely to mouth breathe (which is unhealthy) and have sleep apnea. As time goes on and a toddler or child continues to use a thumb, finger, pacifier, or other objects to suck on, it is more likely to affect speech and breathing. It contributes to underdeveloped jaws that can impact a child throughout their life. When the jaws are underdeveloped, this can often lead to tooth crowding and increase the need for orthodontics. When the jaws are underdeveloped, your child is more likely to have sleep disturbances which can affect their behavior, increase bed wetting, affect brain development, and as an adult, increase their chance of having sleep apnea which is connected with many poor health issues.

But don’t despair. There are things you can do to help. If you are unsure if there is an issue or how to proceed, have an airway assessment with an Orofacial Myofunctional therapist or an airway-focused dentist.


Read more:

Mouth Breathing and Sleep Issues – Blog by Kyle Issaccs

MouthHealthy – Thumbsucking