Possible Complications of an Anterior Open Bite in a Three Year Old

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At age three, I think we need to lighten up a bit and not label your child with the various terms used by this dentist. A dentist, with good intentions, can get a bit carried away by identifying and labeling some behaviors that are quite normal for this age group. What the dentist reports here are behaviors that are not cause for immediate concern or action. In the case of your son, it is apparent that your anxiety level was raised about your son's development from some of the diagnostic labels you were introduced to. I applaud the dentist for being thorough, however I want to reassure you that at this point, there is no need to spring into action with therapy or other concerns or procedures.

Let's get to some details: At age three, the predominant tongue function is still in the horizontal plane. All 3 year olds have no trouble protruding the tongue. Vertical and lateral movements of the tongue are often not well controlled. Substitution of "th" for "s" (or lisping) is a common example of this, and as well, the examples you mention are quite normal at his age level. I would not recommend having your child seen by a speech-language pathologist for therapy at this age, as this could do more harm than good in calling your son's attention to tongue placement. If, however, you feel that your child is not developing language skills appropriately, the consultative skills of a speech-language pathologist would be comforting and helpful at this time. Since you have not noted any issues with your son's speech, it is also likely that he has no language delays since you apparently understand what he is saying and he is communicating. A key feature of his speech is your report that your son can correct his pronunciations when stimulated with a verbal cue. This is an excellent sign of his being able to achieve normal speech along the developmental speech table. Many speech sounds and blended sounds are not expected to be mastered until around age 5.

Let's discuss tongue thrusting and "deviant" swallowing. I dislike the label of "deviant swallow" that the dentist used because it is not an accurate description of anything except in rare instances when a person aspirates air or food during a swallow. There is nothing deviant about a swallow from a physiological standpoint if food gets down into the esophagus and stomach rather than the lungs. Some continue to use this term rather than the more widely accepted term "tongue thrust swallow", which describes the initiation period of a swallow as involving a forward protrusion of the tongue tip between the teeth rather than an elevation of the tongue tip. Tongue thrusting itself can occur in speaking and/or swallowing. Many dentists fear that thrusting the tongue against or between the anterior (front) teeth during speaking or swallowing will move or push the teeth forward and create either incisor protrusion or an open bite at the front of the mouth. A tongue thrust can be accompanied by a forward rest posture of the tongue. When the tongue rests forward, the lower jaw is hinged open and the presence of a resting tongue between the front teeth can create an open bite over time as the front teeth are inhibited from full eruption while the back teeth overerupt because the mouth is hinged open for hours at a time beyond the normal range (whew! long sentence!). This negative process is known as "differential eruption". Clinical research has demonstrated that the forward resting posture of the tongue is linked to dental variations at the front of the mouth such as open bite, while a tongue thrust may only play a minor or contributory role. Many in dentistry continue to presume an improper cause and effect between thrusting and tooth position such as open bite or incisor protrusion. Sorry for all of this technical information, mom, but the bottom line is: don't worry about the tongue thrust at age three. By the time that the adult front teeth (incisors) erupt (age 6 onward) tongue thrusting may be of some concern, although some children spontaneously outgrow a thrust and even an open bite.

When I see a tongue thrust and a forward rest position of the tongue at rest, this serves as a clue to look at the posterior airway. That is, what you see happening at the front of the mouth should signal a need to evaluate what is happening at the back of the mouth and beyond, especially with the tonsils and adenoids.

Here is some background about tonsils and adenoids: In a child of age 3, the tonsils and adenoids are already expected to be large. You know where the tonsils are located. Their location is at the gateway between the oral cavity and the back of the throat (the oropharynx). Large tonsils can diminish the size of the opening into the oropharynx (the oral isthmus between the tonsils) and can also compete with the base of the tongue for space, causing the tongue to rest or move forward to maintain the airway. With large tonsils, the tongue may thrust forward in the beginning part of the swallow to get food past the small space between the tonsils (the oral isthmus), that is, as food is passed between large tonsils, the tongue moves forward to enlarge the airway and facilitate the swallow. In this situation, with a small airway due to large tonsils and/or adenoids, the last thing that should be done is to try to retrain the tongue out of a tongue thrust.

The adenoids are a mass of lymphoid tissue attached to the back and top of the nasopharynx. You will not be able to visualize them by looking in your son's mouth since they are hidden behind and above the soft palate. In some children, the adenoids are so large that they obstruct or partially obstruct the back entrance into the nose. As a result, a child is forced to breathe through the mouth. Pediatricians are well equipped to follow the development of the tonsils and adenoids. Just because tonsils and/or adenoids are large does not signal the need for their removal. Pediatricians are appropriately conservative about surgically removing tonsils and adenoids. There is growing evidence that these lymphoid tissue masses can help the development of the body's immunological development, experience and responses, since their location can act as a filtering thermostat for what is being introduced into the throat, nose and lungs during breathing.

The tonsils and adenoids have a growth cycle. They are expected to be large by age three and remain large until around age 12, when these lymphoid tissue masses then go through a process of self-reduction in size called involution or atrophy of tonsils and adenoids. Without surgery, many individuals have little or no tonsils and adenoids remaining by age 20 simply as a normal process of the growth cycle which involves tissue proliferation and then involution. Where there is a history of tonsillitis or adenitis in childhood, the growth and involution cycle for tonsils and adenoids may not conform to the norm.

You commented about grandpa's "cathedral" palate with other facial feature differences. While there was not enough information provided about gramps to give you feedback about what characterizes him, I encourage you not to worry now about any inherited problems. Whatever comes up in the future can be addressed when and if it becomes a problem, such as the thrust or speech misarticulations.

Gramps has a high-vaulted hard palate. When this occurs, the dental arch tends to be a bit narrower from the canines back to the molars, while a flat palatal vault is more often linked with a wider dental arch. There is no problem with having a high-arched palate or a flat hard palate, although I still hear many commenting on their palatal vault as if something is wrong. A high vaulted palate is typically a very normal finding.

Your son's thumb sucking habit may be linked to his developing open bite if the thumb is in his mouth for hours per day. Nonetheless, I would not recommend trying to get the thumb out of his mouth at age 3. It provides comfort and tastes good. Actually, during thumb sucking, the body releases endorphins into the system, resulting in a pleasurable experience; thus, there is a biochemical encouragement for the continuation of this habit. In dentistry, we do not worry about thumb sucking until around age 6. Below age 6, most of us would accept the development of an open bite rather than work to cease the sucking habit. However, myofunctional clinicians would begin working to eliminate a sucking habit at age 5 years because youngsters who go to school with a sucking habit can experience teasing, learning and socialization problems. But for your 3 year old, I would advise ignoring the thumb, the thrusting and the open bite for several years. For the near future, you will find is that as long as your son is sucking his thumb, the tongue thrusting will not spontaneously resolve.

Here is a bit of advice that should serve you well: if anyone in dentistry ever wants to insert an appliance into your child's mouth for thumbsucking or tongue thrusting, please decline the invitation. In my opinion, there is no place for appliances in habit treatment, and I am prepared to vigorously argue this opinion with any in dentistry who may disagree. Behavioral (non-invasive and non-punitive) approaches to habit cessation work well. The problem with appliances is not only that they are punitive but also, and just as important, appliances tend to hinge the lower jaw open. This encourages continued eruption of back upper teeth through differential eruption. The result is an increase in an open bite.

One last thought. The dentist recommended your seeing a speech-language therapist so as to prevent lisping or tongue thrusting later on. I disagree with this recommendation. The idea of preventing something that is not a problem at present need not apply here. At age 3, I would, instead, encourage your son to be the terrific but terrible kiddo that he is supposed to be without calling attention to his speech or tongue functions. My only concern is the grinding of the teeth, and that is more of a problem for you than your son since it can be an awful thing to listen to. Tooth wear can be a concern, and here your pediatric dentist should monitor the situation; however, the wear is on baby teeth and can also be tolerated until adult teeth erupt unless the wear is severe.

I do appreciate that the dentist told you many things about your son's orofacial development. It is good for you to keep an eye on things. As mentioned above, I disagree with the dentist for the use of negative labels which has caused you enough concern to ask for information here. For that I am grateful, and I hope that this short tutorial will help you put everything into a perspective that will help you relax about your son. Good luck, and please write again if you have further concerns.

Robert M. Mason, DMD, Ph.D. is a speech-language pathologist (CCC-ASHA Fellow), a dentist, and orthodontist. He is a Past President of the American Cleft Palate-Craniofacial Association, a professional, interdisciplinary organization specializing in problems associated with facial and oral deformities. Dr. Mason has studied and written extensively about orofacial examination, developmental problems related to the tongue, and the anatomy and physiology of the speech and hearing mechanisms. His reports have appeared in speech, dental, medical, and plastic surgical journals and texts. He is considered to be an expert in tongue thrusting, tongue tie, and other problems related to tongue functions and speech.