What is mandibular prognathism and how is it treated?
Of the different types of dental malocclusion that exist, mandibular prognathism (also known as Class III) is one of the most complex. During the growth stage, this problem in jaw development can be corrected with orthodontic treatment. However, not all children with this type of malocclusion have been treated at this stage, which is why they reach adulthood with a greater or lesser degree of mandibular prognathism. Can it be treated?
What you should know about mandibular prognathism and its treatment in adults
- What is mandibular prognathism or protruding jaw?
- What are the consequences of prognathism?
- What causes prognathism of the mandible?
- What types of mandibular prognathism or Class III are there?
- What is the treatment that corrects mandibular prognathism?
1. What is mandibular prognathism or protruding jaw?
Mandibular prognathism is a dentofacial imbalance characterised by a more forward position of the mandible, i.e. the lower arch, which protrudes more than the upper arch. This occlusion problem affects less than 3% of the population depending on origin and race. This Class III malocclusion is divided into two types depending on the origin of the problem:
- Dental Class III, in which there is an incorrect relationship between the bones of the mandible and maxilla as a result of poor placement of the teeth in their respective arches.
- Skeletal Class III, in which the maxilla is too small, the mandible is too large, or both problems occur at the same time. In this case the malocclusion is bony.
Mandibular prognathism is not always a problem in people who suffer from it, depending on the degree of severity. Generally, this malocclusion can be observed more in those adults who have an overly prominent chin. But this aesthetic defect that can affect self-esteem is not the only consequence:
2. What are the consequences of mandibular prognathism?
As we have just mentioned, mandibular prognathism can affect the aesthetics of the patient but, in the most serious cases, it can also affect the quality of life of the person who suffers from it, as it can affect functions such as chewing or even speaking normally, with lisp problems being frequent.
Furthermore, as the maxilla and mandible do not fit together correctly, and the teeth do not fit together properly with this malocclusion, it is possible to suffer contact and friction that ends up producing premature deterioration of the dental enamel. On many occasions, this occlusion problem is accompanied by a misalignment of teeth that also makes the patient more prone to caries.
On the other hand, mandibular prognathism can also cause pain in the head and jaw, as well as other conditions in the temporomandibular joint as a result of overloading it.
3. What causes mandibular prognathism?
The aetiology of Class III is diverse. There are different reasons why this problem can develop during childhood. Some of them cannot be avoided, however, there are some habits that can be prevented in order not to cause this problem:
3.1. Genetic inheritance.
As with other oral pathologies, the genetic factor is fundamental in the development of this dental imbalance. Unfortunately, this is the factor of greatest incidence in the appearance of mandibular prognathism which, on the other hand and as we have already mentioned, does not occur frequently.
3.2. Dental malpositions.
Crossbite, specifically, which is a malocclusion problem characterised by an inadequate fit of the teeth, in which the upper incisors grow in a backward position, while the lower incisors grow in a forward position, can give rise to an asymmetry in the face and an interlocking which, if not corrected, could lead to incorrect development of the bones.
3.3. Position of the tongue.
Both mouth breathing and tongue placement during the growth stage can also stimulate jaw protrusion when the jaw is low and flattened.
3.4. Early fall of the deciduous teeth.
If some teeth, especially baby teeth, fall out too early, this can lead to jaw problems that will not be corrected unless the child wears orthodontics. Over time, the absence of baby teeth would affect the eruption of the permanent teeth, and in addition, prognathism could develop, due to the tendency of the teeth to need contact.
3.5. Pituitary problems.
Mandibular prognathism has also been observed in patients suffering from syndromes associated with an anomaly of the pituitary gland, the malfunctioning of which can give rise to other diseases (acromegaly, gigantism or Crouzon’s syndrome) that cause this type of dental malocclusion to appear.
4. What is the treatment that corrects mandibular prognathism like?
The procedure for treating Class III depends on the age of the patient. In the adult stage, since mandibular development has already ceased, it would be necessary to carry out a morphological and aesthetic study to determine the best type of procedure with which to treat the problem. The treatment will depend on the type of prognathism developed.
- In cases in which the origin is skeletal, it would be necessary to carry out a combined treatment of orthodontics and orthognathic surgery, a type of maxillofacial surgery that allows the symmetry of the face to be recovered, as well as the masticatory and even phonetic functionalities.
- In cases where the origin is dental, orthodontic treatment (with braces or invisible orthodontics) would be necessary to move the lower teeth forward and the upper teeth backwards, correcting the aesthetic and functional problem.
