Contemporary Orthodontics & Dentofacial Orthopedics

James R. Waters, DDS, MSD, PA

Board Certified Treatment for Children, Teens and Adults

When is it best to fix an Underbite?

There are many hats your orthodontist wears when treating your family. Of course there is the straightening of crooked teeth and the restoration of a functional and beautiful smile. But Orthodontists are not only the experts in moving teeth, Orthodontists are specialists in Dentofacial Orthopedics (manipulating growth and development to correct skeletal problems) and many problems seen in teeth such as crowding/ crossbites/ underbites/ impacted teeth are symptoms of larger problems having to do with the size or position of the supporting bones.

“Orthodontists are specialists in Dentofacial Orthopedics”

The term underbite implies upper teeth that fit behind the lower teeth where the lower jaw cannot be postured or pulled back to place lower teeth behind the upper teeth. This can be from a small or short upper jaw, excessive growth of the lower jaw or a combination of both. We can also have a pseudo-underbite if the front teeth hit poorly and the lower jaw shifts forward.

Underbite: Example A

Underbite: Example B

Underbite: Example C

Correction will depend on the portion due to upper jaw position/size and the occlusion; lower jaw growth cannot be stopped or even altered significantly making correction more likely with other means for which we will reserve a future blog (mandibular surgical cases). For this current discuss, we will consider the most common type of underbite which is due mostly to upper jaw deficient growth (maxillary hypoplasia).

As seen in the cases above, there are different degrees of the same problem which can manifest simply as dental malocclusions (crowding with an end-on bite) up to a full underbite with deepbite. Below you can also appreciate the lack of midface and lip support creating a concave profile.

Patient Example A

Patient Example B

Correction of the malocclusion, when performed early and correctly, will change the face and restore a more ideal profile. This is particularly important since the nose and chin will continue to grow through life creating a more and more pronounced concavity in the face. Now consider these same patients after Dentofacial Orthopedic treatment to restore arch width and pull their upper jaws forward out of crossbite:

A. Before Treatment

A. After Treatment

B. Before Treatment

B. After Treatment

Time in treatment usually runs 6mo to correct the underbite. Limited braces may be considered for an additional 6 to 12 months if the crowding is severe enough to affect the bite even after correction of the underbite or if we are trying to further reduce the need for later treatment.

Follow the progression of the case below:

Before Treatment

During Treatment

After Treatment

You can easily appreciate the malocclusion and see how the upper arch is “folded back” behind the lower teeth. The upper arch was expanded to restore arch width and then braces were employed on the front teeth only to restore an ideal arch shape and align incisors. Following removal of the early appliances, the patient was monitored until all teeth erupted and growth subsided; no further treatment was needed (no full braces). In truth, this is not the norm; full braces are usually still required following early interceptive Orthopedics but when the expansion is just right, the correction of the underbite is adequate and growth of the lower jaw is more normal, it is possible to make most of the correction early. Even if there is further treatment, the main concern is to correct the facial profile and prevent jaw surgery later; anything additional is a bonus.

And consider when a young patient has to go to school with the following bite:

This patient was told by her dentist that she would have to wait until age 17 for surgery before correcting the malocclusion. Not only is this not correct, but it is a terrible way to leave a teenage girl. Within only 9 months, photos were taken following early interceptive orthopedics and limited braces (see below):

Clearly no parent would chose to wait and perform surgery later, allowing their child to endure the teasing and embarrassment of the initial malocclusion when they could correct the bite early and leave the child with a beautiful and normal smile over the same period.

Hopefully this will provide some comfort and advise for parents that are seeking out treatment options for their children with underbites; treatment age is best from 7 for more severe cases up to age 10 for milder cases. After 10 years old early treatment can be more difficult due to less compliance and a transitioning dentition from baby teeth to permanent teeth (as the baby teeth resorb and lose their roots, they provide less and less anchorage to move the bones). Once the patient is 11 to 12, we have to consider different options and timing for treatment which I will address in a future post.

If you have questions or comments concerning this or any orthodontic question, please feel free to make a complimentary new-patient appointment at either my Steiner Ranch location or my North-central Austin location on West 35^th street and MoPac.

Dr. James R. Waters is a 1996 graduate from UTHSC Dental School in San Antonio, 1997 graduate of Advanced Dentistry from the UNMC in Nebraska and the 2001 Valedictorian graduate from the prestigious Saint Louis University Orthodontic Program receiving the J.P. Marshall award for clinical excellence in 2001. He holds a Bachelor’s Degree in Science, Doctorate in Dental Surgery, a post-doctorate certificate in Advanced Dentistry, post-doctorate Degree in Orthodontics & Dentofacial Orthopedics and a Master of Science Degree in Orthodontics. Dr. Waters and his wife of 19 years live in Austin, TX with their 4 children where he has a thriving, multi-faceted Specialist practice with locations in Steiner Ranch and North-Central Austin. You can learn more about Dr. Waters at BracesAustin.com.