Lip Incompetence, Mouth Breathing, (And Mouth Tape?)

Lip incompetence is probably something most people have not heard of. It is normal for children under the age of 13-17 to have a lips apart resting face. (1) In late adolescents and adults however, it is a condition where the lips cannot form a seal when your jaw is at rest without straining.  It should not be confused with mouth breathing as breathing through the nose can happen with the mouth open. It can cause a variety of dental, health, and social problems. For these reasons it should be diagnosed and correct as soon as possible. It is generally very easy to detect, but in some cases it can be tricky. If you suspect you may have this condition, consult with your dentist as soon as you can.

The Causes

Allergies, deviated septum, enlarged tonsils, tongue-tie, tongue thrust habit, neurological problems,  weak muscle tone, etc. can lead to an incorrect resting jaw position where the teeth are further apart than normal. This can cause the teeth to grow in too far, a condition known as super-eruption. It can also lead to the chin appearing recessed, a condition known as retrognathia. The normal relationship of the upper front teeth (incisors) to the inner portion of the lower lip is such that the lower lip should be in contact with the upper teeth when the lips are together, and the jaw is at rest. This is what dentists must look for in patients younger than 17. As I mentioned earlier, younger patients don’t always keep their lips together. As long as the upper front teeth CAN rest on the inner portion of the lower lip and there is no other problem like a deviated septum, there is little cause for concern.(2) As the jaw recedes, this harmonious relationship can cause improper facial and dental arch development making it difficult to keep the lips together at rest.

The Complications

There are many issues that can arise with lip incompetency. The most obvious is that the face does not develop properly. The face can appear longer than usual, the chin and appear set back, and the inside of the lip can protrude to the outside.

As the face matures, proper arch form and tooth position are dictated by the position and tone of the tongue, cheeks and other facial muscles. Crooked teeth and incorrect dental arch forms are typically seen with lip incompetence due to the inharmonious pressures the facial and chewing muscles place on the teeth and jaws.

Speech impediments can also be a consequence when the jaws, teeth and lips are not in the proper relationship.

Lip incompetence does not mean mouth breathing. Patients can and often do keep their lips together by straining to do so. But in instances where patients stop trying to approximate their lips, they will become mouth breathers and the mouth can become dry, a condition known as xerostomia. Since the saliva serves to protect the teeth, gums and aid in digestion, problems such as increased tooth decay, gum disease, thrush, halitosis, burning mouth and indigestion are not uncommon. (3) There is also evidence that mouth breathing leads to ADHD. (4)

Diagnosis And Treatment

The diagnosis and treatment of lip incompetence is multidisciplinary. Since quite often the underlying issue is breathing, ear nose and throat specialists can help. Allergists may also be part of the team. Poor muscle tone may be of neurological origin, but toxicology and nutrition may also be a factor. Therefore neurologists, nutritionists and toxicologists can be part of the team. Finally, dentists can identify tongue-ties and other issues that may lead to lip incompetency.

Depending on the causative factors and the severity, there are many treatment options. In the case of tongue-ties and enlarged adenoids, surgery may be an option. In the case of poor muscle tone, orofacial myofunctional therapy can help. Orofacial myofunctional therapists use a combination of exercises and appliances to correct lip incompetency. Orthodontics often helps, sometimes in combination with oral maxillofacial surgery to correct jaw size discrepancy.

Finally, I want to mention mouth tape. It sounds like a joke, but it does exist. It is just what it sounds like-tape that goes over the mouth at night to help you breathe through your nose. It is used to help people stop snoring. This is clearly not the best solution; it is literally a band-aid treatment. It can help, especially when the treatment is prolonged as in the case of orthodontics.  I must warn you not to use regular tape which is not designed to adhere to the skin and can cause harm.

If you suspect you or someone close to you may suffer from lip incompetence, a dental check-up is a solid place to start.