Underbite 

With an underbite, the lower jaw bites too far in front of the upper jaw. Here the incisors sometimes meet edge to edge or even bite the wrong way round, one behind the other, in what is known as a crossbite. In medicine, the underbite has many names: e.g. mandibular prognathism, Class III or prognathism of the lower jaw.

Why treat an underbite

There are three reasons to treat an underbite. Firstly, functional problems such as difficulty chewing and pain in the jaw joint (TMJ) are resolved, and patients' pronunciation (many of them lisp) is often improved. Because with this malocclusion the upper and lower teeth do not interlock harmoniously but often meet edge to edge, or shift as a result of incorrect pressure, damage can occur to the teeth themselves and to the tissues that support them.

In addition, the procedure also achieves a major aesthetic improvement: visually, the underbite gives patients' facial features a certain hardness and aggressiveness. Treatment makes the facial features softer, finer and more harmonious, which removes the psychological obstacles associated with a facial deformity.

Finally, there are also psychological reasons to correct an underbite: because the malocclusion is also visually unappealing, it affects the self-esteem and self-confidence of many of those affected.

Why the analysis is so important

To make the result of treatment as perfect as possible, a thorough analysis is needed at the start. First, we have to find out whether the lower jaw really is too far forward or only appears to be:

• False prognathism (pseudo-Class III): In some cases, the lower jaw only appears to be too far forward at first glance. In fact, however, the upper jaw is underdeveloped. The middle third of the patient's face looks sunken. The lower jaw therefore looks too large, even though it is actually normal in size.
• True prognathism: In other cases, the lower jaw really is too far forward. There are many reasons for this: on the one hand, heredity plays a major role. On the other hand, functional disorders can also mean that the stimuli for upper jaw growth are missing. Typical functional disorders include tongue dysfunction, an enlarged tongue or obstructed nasal breathing and the mouth breathing associated with it. Finally, cleft lip and palate is a special case that inhibits the growth of the upper jaw.

Some patients have both types of prognathism.

Treatment of mandibular prognathism

The Eltz Institut offers two treatment options.

• Orthodontic treatment: The malocclusion can be treated particularly well in growing children up to about the age of 12. After that, treatment is only possible again in adulthood, and then only if the Class III problem is confined to the teeth.
• Orthodontic treatment & jaw surgery: In most cases of mandibular or Class III prognathism, a combination of orthodontic treatment and jaw surgery is required. This type of treatment requires close cooperation between the orthodontist and the oral and maxillofacial surgeon, who must coordinate the diagnosis and treatment from the very beginning. In addition, the patient must be fully informed by both specialists before treatment begins.

Why the Eltz Institut

We are an international reference centre for combined orthodontic and surgical treatment (orthognathic surgery)

• Pioneers and experts in combined orthodontic and surgical treatment
• Pioneers and experts in the orthofacial approach, which looks at the face as a whole to maximise the aesthetic results
• Technology at the highest level worldwide
• Clinic awarded by Doctify for outstanding achievement in orthodontics, 2022
• Located in the centre of Vienna.