Retrogenia is one of the malocclusions. A characteristic feature of the face of patients with such a defect is the convexity of the subnasal area and the receding of the lower lip. The chin becomes flattened and recessed, and the lower part of the face becomes elongated. What are the causes of retrogeneity and how is it treated?

Retrogeniais a malocclusion associated with the inhibition of the front growth of the mandible, as well as with other changes in its structure, including:

  • the shortened mandibular body is bent downwards
  • there is a distinct depression in the lower edge of the shaft just in front of the enlarged angle of the mandible
  • the mandibular branch is usually shortened
  • the filthy tuberosity is not developed
  • in the facial features, apart from the flattening and receding of the chin, the elongation of the lower part of the face is observed
  • sometimes open bite, despite significant compensation elongation of the anterior alveolar part of the mandible

Retrogenia - reasons

Retrogenia is a developmental defect that intensifies as a result of a history of rickets. The second cause is arthropathy of the temporomandibular joints. In these cases, there is a restriction or abolition of the forward movements of the mandible. When the mobility of the temporomandibular joint is maintained, the functional test is also negative, because during the extension movement, the bite opens significantly and both facial features and intraoral conditions deteriorate.

Retrogenia in combination with other craniofacial deformities can also be observed in Patau's syndrome.

Classification of retrogeny

There are 2 types of retrogeny.

  1. Functional retrogenia , where the muscles responsible for mandibular retraction are too strong. This situation leads to a retraction of the chin. However, it is still possible to set it correctly by sticking out the jaw by the patient.
  2. Morphological retrogenia , in which the chin is flattened and retracted, extending the lower parts of the face. This defect is caused by a disruption in the growth of the mandible. It can also cause pronunciation problems if there is too much gap between the incisors.

Retrogenia in newborns

During growth, the mandible enlarges its dimensions anteriorly faster than the maxilla. The retrogenia observed in the newborn is diminishing.Also, the vertical growth of the mandible is intense so that the bone adjusts to the growth of the maxilla. The erosion of the teeth affects the structure of the mandible:

  • mandibular angle decreases
  • branch is more vertical
  • shaft becomes more horizontal

As a result, the position of the occlusal plane also changes - in a newborn baby it runs through the head of the mandible, but when the first teeth erupt, it lowers.

Retrogenia - treatment

Treatment of the morphological backside consists in putting an orthodontic appliance on the patient. However, this method does not lead to a significant improvement in facial features and is treated as an introduction to further treatment. The most effective method is a mandibular osteotomy. It involves the mobilization of bone segments, i.e. cutting off the bones with special surgical tools.

A maxillofacial surgeon can also perform a two-jaw surgery by shortening the body of the mandible and intraoperatively positioning the jaw in relation to the mandible with the help of an orthodontist.

Category:

Dentistry and Orthodontics