Various Effects of Thumb Sucking for a Child’s teeth and jaw

Published on August 5, 2021, Updated on August 25, 2021

Thumb sucking is one of the most common habits during childhood. It is a child’s natural reflex to suck something (whether it’s a pacifier, a finger, or their thumb) when they get anxious, nervous, frustrated, or even when they are bored. It is also a means of knowing more about their surroundings. However, as they grow up and their teeth begin to develop, thumb sucking becomes harmful because it can cause changes to the shapes and locations when their permanent teeth erupt. Learn more about the effects of thumb sucking as you review this article.


Read Teeth Grinding in Children at Night

What are the possible effects of habitual sucking for kids?

Prolonged thumb sucking can cause harmful effects on your child’s teeth alignment and jaw shape. This is because children’s jaws grow around anything that is constantly held in the mouth. Such effects include the following:


When children continue to suck their thumbs when they reach the age of 2, they will likely develop a form of malocclusion known as buck teeth. This is a condition wherein the upper teeth overlap the lower ones as a result of the jaws not properly aligned. Typically, there is a 2mm distance between the upper teeth and the lower teeth. Moreover, if this habit does not stop when they reach 5 years old or beyond that, it can cause harmful effects not only to the children’s primary teeth but also to their permanent teeth as soon as they erupt.

Open Bite

Aside from an overbite, kids sucking their thumbs for a long period may also develop an open bite as a result of their thumbs being regularly placed between their teeth. This bite issue is characterized by the misalignment of teeth when the mouth is closed.

Problems in speech and swallow pattern

Thumb sucking not only causes teeth misalignment but also can affect children’s way of speech and when they swallow. This is because of the frequent onward and backward movements of the tongue when they suck their thumbs. Thus, developing issues for a kid’s swallow pattern. Moreover, a lisp may form and cause some difficulties in a child’s speech.

Alterations in the jaw’s shape

A thumb sucker’s jaw development can be significantly affected and changed due to this habit. The tongue’s position is lowered from thumb sucking. Due to this, increased pressure is applied on the jaw and can result in the underdevelopment of the top jaw leading to a smaller high palate. This abnormal position of the tongue as well as having a thumb inside the mouth applies abnormal pressures in both the upper and lower jaws.

Changes to facial growth pattern

Frequent sucking on the thumb causes some alterations on a child’s jaws making them misaligned. This leads to the abnormal development of the facial structure due to the lack of symmetry.

Difficulty in breathing through the nose

A smaller and higher palate may lead to breathing problems due to the structure of the nasal and sinus passages being affected. A child may develop sleep-disordered breathing if his or her palate is narrow.

Sensitivity of the palate

Repeatedly sucking the thumb can cause the roof of the mouth to become more sensitive. This is because the thumb is constantly in contact with the palate.


An infection caused by germs or bacteria can occur especially if the child did not wash his or her hands properly. In addition, there is a high chance that germs are present in the corners of a child’s fingernails.



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