What is Prognathism and How is it Treated?

Prognathism refers to a structural abnormality of the face that causes a marked protrusion of either the upper or lower jaw. Maxillary prognathism, also known as an overbite, is more common and not always as noticeable as mandibular prognathism, more commonly known as an underbite. This condition frequently causes the teeth of the lower jaw to cover the upper teeth in a way that adversely affects breathing, appearance, speaking, biting and chewing.

In children, moderate to severe prognathism can cause long-term problems with speech, such as the development of a noticeable lisp or the inability to enunciate certain words properly. When permanent teeth emerge, prognathism can cause them to grow in at an improper angle. In the majority of prognathism cases, orthodontic intervention is necessary to correct any problems associated with crooked or slanted teeth.

What Causes Prognathism?

Prognathism affects individuals of all ages and has been shown to be caused by a variety of factors. These include:


  • Hereditary factors, such as a family history of protruding or abnormal jaws
  • A medical condition or genetic disorder, such as Crouzon Syndrome or Down Syndrome
  • Growth hormone disorders that cause excessive growth of the jaw

During an evaluative consultation, the maxillofacial and oral surgeon will assess the patient’s type of prognathism and level of protrusion. Any symptoms related to the condition, such as difficulty breathing, talking or eating, will be noted. In addition, the patient will be asked to identify any other symptoms that may be associated with the prognathism, as a protruding jaw may indicate other, more complicated medical issues. Family history may be discussed as well in order to determine why and approximately when the condition developed, as well as how the jaw is expected to change in the future.

In addition to the initial assessment, the surgeon may order a variety of diagnostic tests in order to more accurately determine the severity of the condition. One or more of these tests may be necessary:

  • X-rays of the entire skull
  • Panoramic dental x-rays
  • Bite imprints to allow for the construction of a mold

How is Prognathism Treated?

In most cases of prognathism, a combination of maxillofacial surgery and orthodontic treatment is used to correct the malocclusion, or misalignment, of the jaws. Depending on the type and severity of the condition, the procedure may involve surgical modification to one or both of the jaws. The patient is placed under general anesthesia while oxygen is administered through a nasal tube so as to allow the surgeon unobstructed access to the mouth.

Though many patients are apprehensive about scarring following this surgery, the procedure does not usually require any visible incisions in the skin. Instead of approaching the jaw from the exterior, the surgeon makes cuts to the gums to expose the jaw. The bone is then cut and shifted as necessary to correct the abnormal protrusion. Often the jaws are not wired together. The jaws are held together with small plates and screws that aid in the eventual permanent relocation of the jaw bones and a proper bite. Correcting prognathism helps restore a more natural and symmetrical appearance.

If you or your child suffer from prognathism and are interested in correcting the condition, call today to schedule your free initial consultation. Your condition and expectations regarding the surgery will be discussed, as will the course of treatment that is best for you.

Face and Jaw Surgery Center serves all of North Dakota and North West Minnesota including Moorhead, MN and East Grand Forks, MN

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