Mandibular Retrognathia

Mandibular retrognathia is a backward displacement of the lower jaw in relation to the base of the skull. The term mandibular retrognathia refers only to the description of the position of the mandible, but not to its size. Mandibular retrognathia also does not characterize the position of the upper and lower jaw in relation to one another.

Mandibular Retrognathia

What is Mandibular Retrognathia?

According to Topbbacolleges, mandibular retrognathia is a genetically determined dysgnathia. This refers to malformations of the jaw or teeth. Mandibular retrognathia is a shortened lower jaw over which the upper jaw protrudes. The condition manifests itself in a receding chin and a protruding upper lip, creating a negative lip step.

In the context of mandibular retrognathia, a so-called bird’s face appears in profile view. This is a consequence of the relative receding position of the lower jaw, which is too small. When the mouth is closed, the front teeth of the upper jaw clearly protrude in front of those of the lower jaw, which often bites into the palate.


The development of a mandibular retrognathia can be due to various causes. In the majority of cases, the disease is hereditary. The disease is present from birth and becomes more and more pronounced in the course of childhood and pubertal growth. In addition, there are other causes that can be responsible for the formation of mandibular retrognathia that are not hereditary.

For example, disorders in relation to the growth of the jaw caused by inflammation of the bone marrow (medical term osteomyelitis ) can promote mandibular retrognathia. Fractures of the articular processes and ankylosis can also promote the development of the disease. Inflammation in the growth plates of the jaw is also a possible cause of mandibular retrognathia.

Symptoms, Ailments & Signs

The symptoms of mandibular retrognathia usually appear clearly and characterize the appearance of the affected person. Patients have a receding chin and a protruding upper lip. Mandibular retrognathia usually occurs bilaterally. In non-hereditary cases, it can also occur unilaterally. Mandibular retrognathia is characterized by a significant underdevelopment (medical term hypoplasia) of the lower jaw, which causes the chin to recede.

This results in a so-called distal bite or overbite. In individual cases, mandibular retrognathia can occur in combination with maxillary prognathism. This is a misalignment of the teeth in the upper jaw. If mandibular retrognathia occurs in joint fractures and ankylosis, the affected person sometimes has restrictions when opening their mouth.

The incisors are often elongated because they lacked natural resistance during the growth phase, for example in the form of the upper front teeth. During the final bite, the lower incisors touch the palatal mucosa. In the context of mandibular retrognathia, other syndromes occur in many cases, such as sleep apnea syndrome.

Diagnosis & disease progression

Various methods of examination can be used to diagnose mandibular retrognathia, which are used in the individual case depending on the severity of the disease. In principle, the clinical symptoms in the form of the receding chin and the overbite are so characteristic that the suspicion of mandibular retrognathia arises very quickly.

These suspicions must be checked by means of adequate specialist medical examinations in order to be able to make a reliable diagnosis and order appropriate therapeutic measures. In many cases, X-ray examinations are the method of choice for diagnosing mandibular retrognathia. These can be carried out by an orthodontist, for example .

The X-ray clearly shows the misalignment of the upper and lower jaw. The individual characteristics of the mandibular retrognathia can also be determined here. A specialist diagnosis is required in any case in order to be able to differentiate mandibular retrognathia from any other diseases of the jaw.


As a rule, with this disease there is a significantly changed appearance of the patient. This can lead to reduced self-esteem or inferiority complexes. Children can also suffer from bullying or teasing at a young age and thus develop depression or other mental disorders.

Most sufferers continue to suffer from an overbite as well. It is not uncommon for the disease to cause problems when opening and closing the mouth, so that there are also restrictions on food and liquid intake. This can eventually lead to malnutrition or dehydration. Due to the reduced aesthetics, those affected also suffer from social difficulties and possibly from exclusion.

In most cases, the symptoms of this disease can be treated by surgery. There are no complications. In some cases, however, several interventions are necessary. The patient’s life expectancy is also not reduced or limited by this syndrome. Bone transplantation may also be necessary for the operation. However, there are no particular complications or symptoms.

When should you go to the doctor?

Malformations of the human jaw must always be examined and examined by a doctor. If the upper and lower jaws are not directly above each other, there is an impairment that needs to be clarified by a doctor. If there is discomfort when chewing or pain, a doctor is needed. There is cause for concern if ingested food cannot be adequately ground up by the possible chewing process. If your body weight is low or you are losing weight, you should consult a doctor.

If the affected person only eats liquid or mostly mushy food due to the impairment, it is advisable to consult a doctor. A correction of the jaws is necessary, which is carried out dentally. If an optical change in the facial appearance can be seen due to the position of the jaw, a doctor should be consulted. If the irregularities in the jaw position increase during the growth process, a doctor should be consulted as soon as possible.

In the case of a headache or an impairment of the muscles in the throat and neck, the person concerned needs medical help and support. Sleep, concentration or attention disorders are further indications that should be investigated. If the mouth cannot be opened sufficiently, if there is reduced vocalization or if comprehensive tooth cleaning is not possible, there is a need for action. A doctor’s visit is necessary because serious complications can occur later if treatment is not carried out.

Treatment & Therapy

Various methods are available for the treatment of mandibular retrognathia, which are adapted to the individual case. During the growth phase, the affected patient should undergo orthodontic treatment. If this therapy is successfully completed, reconstruction of the chin or the lower jaw is required in most cases.

The therapeutic measures here are similar to those of maxillary retrognathia. Various other operations can be used to treat mandibular retrognathia in adults. Operations are possible in the so-called ascending branches. Here the jaw is split and the lower jaw is moved forward using a bite wrench as an aid. The individual fragments are stably fixed using lag screw osteosynthesis.

If the misalignment is not treated in time, damage to the teeth and periodontium can result. This can result in the premature loss of teeth. Forward displacement of the mandible can only be achieved by lengthening the ascending branches of the mandible. For this purpose, orthodontic surgery either requires bone grafting or split bone fragments are gradually pulled apart (medical term callus distraction ).

Outlook & Forecast

Mandibular retrognathia has a favorable prognosis if the sufferer seeks medical care early. Otherwise there is a risk of irreversible damage and secondary diseases in the course of life. There can be a steady increase in health irregularities. In addition, the person concerned must otherwise accept premature loss of teeth and damage to the jawbones. In addition to pain, there are impairments in speech and eating disorders. There is a risk of deficiency symptoms and this can lead to life-threatening developments.

If you work with a doctor at an early stage, oral surgery measures are initiated. In addition to temporarily wearing braces, surgical interventions can be carried out. Depending on the extent of the existing misalignments, several operations may be necessary over the course of life. Physical changes occur during the growth process of humans. This process can mean that further interventions are unavoidable. Every operation involves risks.

In a particularly severe case, blood poisoning can also lead to a life-threatening condition. Nevertheless, for some people this medical care is the only way to achieve long-term relief from their symptoms. In addition, these are routine interventions which, in most cases, are trouble-free. In rare cases, a bone graft must be performed as a last resort for improvement.


Since mandibular retrognathia is usually a hereditary disease of the jaw, there are no effective methods of preventing the disease. The affected patients can only counteract the misalignment of the lower jaw with timely orthodontic therapy and at the same time also prevent possible consequential damage of mandibular retrognathia.


The appearance of those affected usually changes as a result of the disease. For this reason, those affected may experience low self-esteem and an inferiority complex. Children often suffer from bullying and teasing. This can lead to severe depression and other mental illnesses. Advocating help from relatives is therefore indispensable in order to permanently stabilize the recovery process.

It is important to include the social environment in the process in order to avert tension or misunderstandings. In many cases, however, repeated surgical interventions are necessary. The life expectancy of those affected is not affected by the disease. It happens that the surgery requires a bone transplant in those affected. Long-term medical follow-up care is therefore urgently needed to avoid further complications.

You can do that yourself

Due to their abnormal appearance, patients with mandibular retrognathia often suffer from inferiority complexes as children. The disease usually represents an enormous aesthetic blemish for those affected, which affects social relationships and everyday life in childcare facilities and schools. Therefore, psychotherapeutic treatment is often indicated to strengthen the self-esteem of the child patient and to support the emotional handling of the illness.

Orthodontic treatment is necessary for children with regard to the displaced or reduced lower jaw. The parents take on the responsibility for the regular attendance of necessary doctor’s appointments as well as the daily wearing of braces. Such therapy improves the condition, but usually does not completely eliminate the external blemish. For this purpose, further corrective measures are required in the course of an operation, whereby several surgical interventions are usually necessary over a longer period of time.

In the postoperative phase in particular, those affected strictly follow the instructions of the doctor in charge and the hospital staff in order to avoid side effects and complications. Speech therapy supports the patient’s ability to speak and at the same time strengthens their self-confidence. In order to strengthen the jaw muscles in a targeted manner, the affected person visits a physiotherapist, with whom he or she can study suitable exercises.