Mandibular retrognathy

In the Mandibular Retrognathy it is a shift of the lower jaw back in relation to the base of the skull. The term mandibular retrognathy refers only to the description of the position of the lower jaw, not its size. Mandibular retrognathy also does not characterize the position of the upper jaw and lower jaw relative to one another.

What is mandibular retrognathy?

In the majority of cases, the disease is hereditary. The disease exists from birth and becomes more and more pronounced in the course of the childhood and pubertal growth phases.
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The Mandibular retrognathy represents a genetically determined dysgnathia. This is understood to mean incorrect development of the jaw or teeth. In mandibular retrognathy, there is a shortened lower jaw that is surmounted by the upper jaw. The disease manifests itself in a receding chin and a protruding upper lip, creating a negative lip step.

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

causes

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

For example, disruptions to the growth of the jaw caused by inflammation of the bone marrow (medical name osteomyelitis) can promote mandibular retrognathia. Fractures of the articular processes and ankyloses can also promote the development of the disease. In addition, inflammation in the growth plates of the jaw is a possible cause of mandibular retrognathy.

Symptoms, ailments & signs

The symptoms of mandibular retrognathy are usually clearly evident and shape the appearance of the affected person. The patients have a receding chin and a protruding upper lip. Mandibular retrognathia usually occurs on both sides. In cases that are not hereditary, it can also be unilateral. Mandibular retrognathia is characterized by a considerable underdevelopment (medical term hypoplasia) of the lower jaw, which causes the chin to recline.

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

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

Diagnosis & course of disease

To diagnose mandibular retrognathy, various methods of examination can be considered, 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 a mandibular retrognathy arises very quickly.

Adequate medical examinations must be carried out to check these assumptions 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 performed by an orthodontist, for example.

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

Complications

As a rule, the patient's appearance changes significantly with this disease. For this reason, it can lead to a reduced self-esteem or to inferiority complexes. Children can also suffer from bullying or teasing at a young age and thus suffer from depression or other mental disorders.

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

The symptoms of this disease can in most cases be treated with surgery. There are no complications. In some cases, however, several interventions are necessary. This syndrome does not reduce or limit the life expectancy of the patient. Bone transplantation may also be necessary for the operation. However, there are no particular complications or complaints.

When should you go to the doctor?

Incorrect development of the human jaw must always be assessed and examined by a doctor. If the upper and lower jaw are not directly above one another, there is an impairment that must be clarified by a doctor. If you experience discomfort while chewing or pain, a doctor is needed. If ingested food cannot be sufficiently ground by the possible chewing process, there is cause for concern. If you are low in body weight or have lost weight, it is advisable to see a doctor.

If the person concerned only consumes liquid or mostly pulpy food due to the impairment, it is advisable to consult a doctor. Correction of the jaws is necessary, which is carried out dentally. If an optical change in the facial image can be seen due to the jaw positions, a doctor should be visited. If the irregularities in the jaw position increase during the growth process, a doctor should be consulted as soon as possible.

If the headache or the muscles in the neck or neck are impaired, 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 the vocalization is reduced, or if comprehensive teeth cleaning is not possible, action must be taken. A doctor's visit is necessary, as serious complications can occur in the further course without treatment.

Treatment & Therapy

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

The therapeutic measures here are similar to those of maxillary retrognathy. Various other operations are possible for the treatment of mandibular retrognathy in adults. Operations in the so-called ascending branches are possible. Here the jaw is split and the lower jaw is moved forward, using a bite key as an aid. The individual fragments are firmly fixed by means of lag screw osteosynthesis.

If the misalignment is not subjected to timely therapy, damage to the teeth and the tooth supporting structure can result. This can result in the premature loss of teeth. A forward displacement of the lower jaw can only be achieved by lengthening the ascending branches on the lower jaw bone. For this purpose, either a bone graft is required surgically, or split bone fragments are gradually pulled apart (medical term called callus distraction).

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Outlook & forecast

Mandibular retrognathia has a favorable prognosis if the person concerned takes medical care at an early stage. 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. Otherwise, the affected person will have to accept premature loss of teeth and damage to the jawbone. In addition to pain, there are impaired speech skills and eating disorders. There is a risk of deficiency symptoms and this can lead to life-threatening developments.

Oral surgery measures are initiated if you work with a doctor at an early stage. In addition to the temporary wearing of braces, surgical interventions can be carried out. Depending on the extent of the existing malpositions, several operations are necessary in the course of life. Physical changes occur within the human growth process. This process can mean that further interventions are unavoidable. Every operation is associated with risks.

In a particularly severe case, blood poisoning can also lead to a life-threatening condition. However, for some people this medical care is the only way to achieve long-term relief from symptoms. It is also a matter of routine interventions, which in most cases run smoothly. In rare cases, a bone graft is needed as a last resort for improvement.

prevention

Since mandibular retrognathy 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 through orthodontic therapy in good time and at the same time prevent possible consequential damage to mandibular retrognathy.

Aftercare

The appearance of those affected usually changes as a result of the disease. For this reason, those affected can develop a low self-esteem and inferiority complexes. Children often suffer from bullying and teasing as a result. This can lead to severe depression and other mental illnesses. Advocacy help from relatives is therefore essential to stabilize the recovery process over the long term.

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 influenced by the disease. It happens that a bone transplant is necessary for the operations. Long-term medical follow-up is therefore urgently needed to avoid further complications.

You can do that yourself

Patients with mandibular retrognathia often suffer from inferiority complexes as children due to their abnormal appearance. For those affected, the disease usually represents an enormous aesthetic flaw that affects social relationships and everyday life in childcare facilities and schools. Therefore, psychotherapeutic treatment is often indicated in order to strengthen the self-esteem of the child patient and to support the mental handling of the disease.

Orthodontic treatment is necessary in children with regard to the retracted or reduced lower jaw. The parents are responsible for regularly attending the necessary doctor's appointments and for wearing braces on a daily basis. Such therapy improves the condition, but usually does not completely eliminate the external blemish. For this purpose, further corrective measures are necessary in the course of an operation, whereby several surgical interventions are usually necessary over a longer period of time.

Particularly in the postoperative phase, those affected strictly adhere to the instructions of the responsible doctor 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. For targeted strengthening of the jaw muscles, the affected person visits a physiotherapist, with whom he practices suitable exercises.