What is retrusion?

What Does retrusion Mean

The idea of retrusion is not part of the dictionary of the Royal Spanish Academy ( RAE ). The term, however, is used frequently in the field of medicine and health .

A movement backwards
Retrusion is a concept derived from the Latin word retrusio , which refers to a push or impulse backwards . Retrusion, therefore, is a movement or displacement in that sense.

Female doctor observing the position of the lower jaw

Regarding its etymology, we can analyze the aforementioned Latin term to observe its three components. We begin with the prefix re- , which in this case gives us the idea of ​​"backwards", although it can also add the nuance of "again"; We find it in words like reverberate, play, and repeat .

Next we see the word trusus ("pushed"), which is the participle of trudere ("push"). We find it in protrusion and intruder , for example, and it is also related to the Indo-European root * treud- ("push, squeeze"). Finally, the suffix -io or -ion , which indicates action and effect of , as seen in tension, depression and abscission .
This notion usually appears when analyzing how the jaw moves. The lower jaw , in this framework, can move in different ways thanks to the intervention of ligaments , bones and muscles , always maintaining contact with the upper jaw .
Mandibular retrusion
The mandibular retrusion involves projection of the lower jaw back . The opposite is protrusion , with the lower jaw moving forward. A third movement is the dduction , with a lateral transfer of the lower jaw. The jaw can also open and close .
With mandibular retrusion, the point of maximum contact between the upper and lower teeth is moved backward. This movement, in the case of humans , is quite limited, unlike what happens in rodents and other species.
It is important to mention that the retrusion and the rest of the jaw movements should not generate noise or produce pain . If these situations occur, it is likely that the individual suffers from some type of pathology that requires diagnosis and treatment.

It is also necessary to point out that there are values ​​accepted by medicine, both for retrusion and protrusion, so that if the jaw of a patient exhibits a position beyond these limits , there is a problem. It is estimated that the growth of the face should be consistent with that of the stature; in this way, the jaw must be progressively enlarged to maintain a constant relative position .

If there is no retrusion or protrusion, the jaws should be aligned
Mandibular retrognathia
If the jaw has not developed properly, the jaws can become misaligned, a condition known as mandibular retrognathia . This causes an aesthetic damage that can also be functional: to correct it, a mandibular retrusion surgery can be used.
In this case, the size of the jaw is too small compared to what is expected by the height of the patient . In general, this problem is associated with other alterations, such as in the temporomandibular joint. With regard to the origins of mandibular retrognathia, it is usually linked to genetic issues; For this reason, throughout the development of the medical history it is necessary to take a look at the family history, to detect the same problem in a close relative.
As mentioned above, treatment requires surgical intervention. As it is a skeletal problem, the surgery must be bone , although there is more than one option. If it is desired to treat only the jaw, then it is possible to move it around until it reaches the correct position. The alternative is to move both the upper and lower jaws, a surgery called bimaxillary .