Overjet

When a shortened lower jaw is overhung by the upper jaw, this is known as an overjet. The malocclusion is also referred to as mandibular retrognathia or Class II. Specifically, the first molar in the lower jaw sits further back than the first molar in the upper jaw.

Why treat it?

There are three very good reasons to treat mandibular retrognathia.

• Functional reasons: If the malocclusion is not treated in time, damage to the teeth and the periodontium (the tissues that support the teeth) can occur, which can lead to premature tooth loss. Furthermore, the malocclusion can impair chewing and speech. Finally, it can lead to jaw joint (TMJ) problems: a condition that causes pain (e.g. jaw joint pain, headaches, neck and back pain) and muscle cramps.
• Psychological reasons: Because the malocclusion is visually unappealing, it affects the self-esteem and self-confidence of many of those affected.
• Health reasons: The risk of sleep apnoea should not be underestimated. Mandibular retrognathia can lead to breathing problems during sleep because the airways are narrower than normal. In those affected, breathing often stops several times a night. Snoring is usually the only indicator of this condition. The apnoea causes poor sleep, leaving you feeling sleepy and tired. In extreme cases, this condition can even be fatal.

Correcting mandibular retrognathia not only gives patients back their quality of life but also restores the aesthetic balance between the upper and lower jaw. Functional problems or more serious conditions such as sleep apnoea are prevented.

Causes of mandibular retrognathia

In most cases, mandibular retrognathia is genetically inherited and can be attributed to insufficient growth of the lower jaw. It can also be made worse by environmental factors such as finger sucking, allergies, poor breathing function, atypical swallowing or chronic mouth breathing. There may also be other factors behind retrognathia, such as a retruded chin that does not project forward, or it may be a purely dental problem.

Treatment options

If treatment starts early, in childhood, orthodontic treatment alone is usually sufficient, because the growth of the upper and lower jaw can be harnessed and influenced. Treatment can begin in young children from the age of four. The orthodontic treatment is carried out with removable appliances. These can actively influence the growth of the jaws, so an underdeveloped jaw can be supported in its growth. If the upper jaw is too narrow, a palatal expander (rapid palatal expansion, which widens the palatal suture) can also be used. The jaw has not yet fully fused, so this appliance can encourage the upper jaw to grow wider.

In adults, the jaws stopped growing long ago, and this makes orthodontic treatment more difficult. Orthodontic treatment is therefore carried out with fixed braces, which use specific appliances to move the jaws in relation to each other and bring them into the right position. However, this is only possible up to a certain degree. At some point, orthodontic treatment alone is no longer sufficient, and combined orthodontic and surgical treatment is often needed in addition.

If you would like to have retrognathia treated, you should talk to a doctor to find out more. Every case is unique, so the orthodontist or oral and maxillofacial surgeon has to assess, diagnose and treat the condition according to each individual’s needs.

Why the Eltz Institut

We are an international reference centre for combined orthodontic and surgical treatment

• Pioneers and experts in combined orthodontic and surgical treatment
• Pioneers and experts in the orthofacial approach, which looks at the face as a whole in order to maximise the aesthetic results
• Technology at the highest level worldwide
• A clinic repeatedly honoured by Doctify for outstanding achievement in orthodontics