Underbite: definition, causes and treatments

Underbite (forward jaw) is a common case of malocclusion.

If, at first sight, the problem is mainly aesthetic, the prognathia also causes dysfunctions that affect breathing, eating (and therefore digestion) and pronunciation. What treatments are available to correct this malposition?

Nutrident reviews the causes of prognathia, as well as the orthodontic and surgical solutions that can rectify this malformation

What is prognathia?

Not to be confused with retrognathia, prognathism is a frequent case of dental malocclusion (misalignment of the teeth). It is characterized by a too advanced position of the mandible in relation to the jawbone. Therefore, one of the two jaws is more advanced than the other.

Three types of prognathia

This orthodontic disorder is also called the “chin forward phenomenon”. We distinguish three types:

• Underbite mandible: mandible too prominent
• Underbite jaw: overly prominent jawbone
• Bimaxillary prognathism: both jaws are too prominent

Causes of undershot chin

The prognathia has two origins. It may come from your inherited genetic makeup. It may otherwise be related to certain behaviors, most often at the time of mouth and teeth formation, for example, thumb sucking in children.

Consequences of prognathia

Like any dental malocclusion, the prognathic jaw has physical and psychological repercussions:

• Cosmetic discomfort;
• Chewing problems;
• Pronunciation Defects;
• Malposition for caries;
• Joint pain.

What are the solutions to rectify prognathia?

Depending on the age and the progress of the prognathia, two types of treatment are possible: orthodontics and/or surgery.

It is important to know that a single orthodontic treatment may not be sufficient if the prognathic problem has been present for a long time. Therefore, a surgical intervention is also recommended. Moreover, a skeletal origin of the pathology obliges, in the majority of the cases, to resort to surgery.

The orthodontic solution

If the prognathia is detected at an age when the mouth is still forming (during childhood), orthodontic treatment is very effective. In a context of developing teeth, wearing braces easily prevents the lower jaw from advancing, while easily stimulating the progression of the upper jaw.

If prognathia runs in your family, consider telling your dentist about it so that he or she is aware of it when examining your child. The earlier the condition is detected, the easier it is to correct.

Orthodontic solutions for adults

In adulthood, orthodontics can also help correct this mandibular malposition. However, as mentioned above, the corrections are much less obvious, requiring a surgical intervention later on.

Wearing a dental prosthesis allows the upper incisors to be repositioned until they are in contact with the lower incisors in the case of a maxillary prognathia for example.

In the case ofa mandibular prognathia, the maxillary incisors are put under pressure so that they are placed in front of the mandibular incisors.

To do this, we recommend that you turn to invisible orthodontic methods, which guarantee efficiency and discretion. And why not choose Dr Smile's clear aligners? The treatment of German origin has been a huge success in France.

Before contacting a certified dentist, first check if the method is suitable for you. You can do this by clicking on the button below.

Mandibular surgery

If orthodontics does not work or if you started your treatment too late, only mandibular surgery will do. This is a major operation that can take up to two hours and is performed under general anesthesia. However, it has the advantage of obtaining resounding results

Course of the intervention

The dentist cuts the mandible bone on both sides to separate it. He saws off part of the bone, before repositioning the mandible and fixing it with titanium plates. The openings are sutured with absorbable sutures.

Post-operative context

The patient may stay in the hospital for up to three days and will be on fluid only for several days. It is of course closely monitored by the dental surgeon who ensures that no infection can occur. In case of pain or inflammation, the latter prescribes the appropriate treatment.

During the months following the operation, the patient must undergo orthodontic treatment to permanently set both jaws. This can take between one and two years.

FAQ

How do I know if I need to have a prognathic surgery?

Beyond the physical complexes, if your prognathia causes difficulties in chewing food, an operation could be an interesting solution.

What is the difference between prognathia and retrognathia?

When the chin is backward and receding, the upper teeth are too far forward and the lower jaw is too far back, we speak of retrognathia. Conversely, when the mandible is advanced in relation to the upper jaw, we speak of prognathia.