Thumb sucking is a habit seen in humans and other primates. It often requires placing the thumb into the oral cavity and rhythmically sucking it for a prolonged time. The child that does this finds it soothing and therapeutic.

A baby reflexively sucks on any object placed in its mouth at infancy. This is the sucking reflex responsible for breastfeeding. As soon as an infant engages in feeding, they learn that the habit can provide nourishment and a great deal of pleasure, comfort, and warmth. This behavior becomes linked with a strong, self-soothing, and pleasurable oral sensation. And as a child grows older and is eventually weaned off sucking, they can develop other methods. To continually enjoy that stimulation. And one of the methods is thumb sucking. This habit is usually not noticed after four months of age, but it can stay longer sometimes.

Moreover, it has been proven that thumb sucking can commence before birth, as early as fifteen weeks from conception. It is uncertain if this is due to voluntariness or random movements of the fetus in the womb.

Thumb sucking generally stops by the age of four. But some older children still retain the habit. And if the habit continues at this age, it can cause severe dental problems. Sometimes, this habit is continued into adulthood.

baby sucking on its thumb while sleeping
A baby sucking on its thumb while sleeping (Image source: Shutterstock)


As a baby grows, its dentition begins to form. And if thumb sucking continues for this long, it can have detrimental effects on the baby. The following are possible side effects that can occur due to thumb sucking.


The most severe side effects of thumb sucking are types of dental malocclusion. Malocclusion is a term that describes tooth misalignment that is obvious even when the moth is closed. The two types of malocclusion caused by thumb sucking are open bite and overbite.

Open bite is a type of malocclusion that occurs when the top and bottom front teeth protrude outwardly. This misalignment causes the front teeth to touch even when the mouth is closed. To correct an open bite, an orthodontic correction needs to be done.

Overbite is another type of malocclusion that occurs when the teeth become directed outward. However, in an overbite, this misalignment affects only the upper front teeth. The top teeth cover the bottom teeth when the mouth is closed. An overbite may affect the shape of the face and smile. Extensive orthodontic treatment is usually carried out to correct it.


When children suck their thumbs, the thumb becomes exposed to the moisture of the mouth, and this can cause the thumb to crack and bleed, making it easily vulnerable to infections. In addition, the thumb always looks calloused after thumb sucking. Pressure and moisture can also warp the thumbnail, causing an ingrowth or peeling.


The teeth, jaw, and palate development are greatly affected by thumb sucking. This can therefore change how a child eats and speak. In addition, thumb sucking may cause lisping and other speech impediments. For example, it can make a child find it difficult to pronounce sounds like ‘D’ or ‘T’. Without a correction, these impediments may cause deformed sounds. Overall, it makes a child’s communication difficulty.


Children who suck their thumbs may sometimes be ridiculed by their peers. This ridicule may seem like harmless fun to the perpetrators but can greatly affect a child’s self-esteem. It can even make the child socially withdrawn.

How to encourage a child to stop thumb sucking

A worried parent can use these methods to effectively stop thumb sucking in their children.

  • Pay no attention to the habit, primarily if the child uses it to gain attention. Kids use different tactics always to get what they want: whining, crying, throwing tantrums, and thumb sucking. By ignoring these tactics, a child can realize that they are not working and decide to stop the behavior.
  • Using positive reinforcement like praising and the provision of small rewards can mitigate the habit. This works by always rewarding a child whenever he/she does not suck his/her thumb.
  • Through identifying triggers that make a child suck on its thumb, ways to stop the habit are easily achieved. If thumb sucking is a stress response, identify the real issue causing the stress and provide reassurance to the child.
  • By offering gentle reminders, a child may begin to take notes whenever he/she is about to engage in the habit. Do not scold, criticize or ridicule the child.


Thumb sucking provides soothing relief for kids, so breaking the habit can be quite difficult. However, these products can help to curb the habit.

  • Thumb guard: a thumb guard is made from BPA and phthalate-free plastic and acts as a shield when worn over a child’s thumb. It is held in place with a bracelet. It is designed to stop the sucking motion when the thumb is placed in the mouth. It claims to stop thumb sucking in less than four days, but most parents see results after a week.
a thumb guard
A thumb guard (Image source: babyology.com.au)
  • Bitter nail polish: this is designed for children aged three and above. It is a bitter clear enamel over the thumb to prevent its sucking. This enamel needs to be applied after two days. It is not recommended for infants under three because they may get used to the taste due to underdeveloped taste buds.
  • Thumbuddy to love: this is a storybook that talks about how to stop thumb sucking, and it is usually directed at children between the ages of three to six. It also comes with a thumb puppet kids can wear anytime to remind them not to suck.
  • Thumb glove: this is similar to a thumb guard, but the material used to make it is different. It is made from 100 percent soft cotton fabric with Velcro for fastening. It is strapped to a child’s hand to prevent them from sucking their thumb.
  • Nip it hand stopper: this is designed to stop the arm from moving towards the mouth. It prevents the child from flexing their arm to reach their mouth. It leaves the hands free and uncovered. This makes it better than other products focused on covering the needle.
  • Baby mittens: mittens are mostly used for babies to stop them from thumb sucking, coldness, and scratching themselves. They are made from wool and can easily be worn by the baby. As a baby comes of age, they should be replaced with other products if the habit persists because they can be taken off easily.
  • Chewelry: chewlery (chew + jewelry) is a device used to satisfy the urge of thumb sucking. They are made of 100% food-grade silicone. It is free of BPA, PVC, phthalates, lead, mercury, and cadmium. It is an excellent substitute to help a toddler stop sucking without losing their satisfaction from the oral stimulation.


If these laid-down products do not work, try to figure out if the child has anxiety that has not been addressed. Then, continue using praise and positive reinforcement all day. A child cannot break out of this habit without adults’ loving and persistent support.

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