All You Need to Know About Micrognathia

All You Need to Know About Micrognathia

What is Micrognathia or “Small Jaw”?

We do not often think about the jaw contour when we think about our facial profile. There is typically a vision of a well-defined nose, symmetrically placed features, naturally big eyes, absence of fatty deposits and so on. It is only when the jaw profile is not as it should be, that we realize its importance.

One such condition is micrognathia, or a small lower jaw. Just as the term suggests, micrognathia, or small jaw, refers to a condition where the lower jaw is undersized according to facial bony proportions. This most commonly happens as a result of a jaw growth disturbance caused by genetics, early trauma or infection in the growth centres of the jaw bone.

Micrognathia can be treated in several ways, including genioplasty, mandibular advancement and distraction osteogenesis. Distraction osteogenesis is one of the most commonly used approaches to treat severe micrognathia in adults – distraction osteogenesis surgery in Delhi is performed by oral and maxillofacial surgeons.

How prevalent is Micrognathia?

Micrognathia is fairly prevalent among infants – around 1 in every 1500 babies are born with micrognathia. In most of these cases, micrognathia resolves on its own as the child grows older and their bone structure, including the jaw, also grows. However, depending upon the cause of micrognathia, it may not naturally resolve, and some people may retain or acquire it as adults as well.

corrective jaw surgery in delhi

Have questions or want to get started? We are ready to help you with a smile!

    Causes of Micrognathia

    Causes of Micrognathia may be broadly divided under two heads –

    1. Congenital – a person may have a genetic predisposition to a small jaw (for instance, either parent has it, or it runs in one side of the family). In addition, there are several genetic mutations and syndromes which may cause micrognathia such as –
      1. Pierre Robin Syndrome – this leads to a smaller than normal lower jaw. If this syndrome is present, then the jaw formation is slowed down inside the womb. It causes the tongue to fall back inside the mouth, making it difficult to breathe.
      2. Achondrogenesis – the pituitary gland does produce adequate growth hormone, which causes problems in bone growth, including micrognathia.
      3. Cri-du-chat syndrome and Treacher Collins Syndrome – causes facial deformities including micrognathia.


    1. Acquired – not all micrognathia cases are congenital. Though it is rare, micrognathia may also develop after birth and even during adulthood.
      1. Due to Trauma – facial trauma caused by an accident or any other injury to the face including abuse may cause facial deformity, including but not restricted to the jawbone. One consequence of such facial trauma could be micrognathia, where the upper or lower jawbone growth may be disturbed leading to a “small jaw”.
      2. TMJ Ankylosis – this is a jaw joint disorder which may be caused by either trauma or infection. When this affects the joint in the jawbone, it almost always leads to the development of small lower jaw or micrognathia.

    How can micrognathia affect me? Why to treat Micrognathia?

    Micrognathia can hamper not just your appearance but can have serious functional issues as well.

    1. Facial Deformity – the right jaw structure is critical in defining your facial profile. A small jaw or micrognathia can cause the facial profile to appear disproportionate, leading to aesthetic issues, commonly described as a “bird-face” deformity.The nose may seem disproportionately large, or there may be the appearance of a double chin due to an almost non-existent jawline. This can severely dent self-confidence and esteem levels, leading one to avoid social situations and in extreme cases may even lead to anxiety or depression.
    2. Sleep Apnea – micrognathia may cause blockages to the air passage of the body, which may obstruct air flow, resulting in lack of oxygen intake and sleep disruption. In mild cases, it may cause snoring, in severe cases, it may cause reduced flow of oxygen to the brain. This may lead to memory loss, accidents due to drowsiness, diabetes and heart disease, and increased risk of strokes.
    3. Speech Problems and Lip Trap – in cases of lower jaw micrognathia, the tongue may fall back inside the mouth, and the upper teeth may lie on the lower lip. This may cause problems with speech – one may have trouble forming words or struggle with conditions like a lisp.
    4. Malocclusion – Micrognathia may also lead to malalignment of teeth in some cases, scientifically known as malocclusion. This may cause not only aesthetic problems, but also functional issues like trouble in eating or in speech.
    5. TMJ Problems – in many cases, micrognathia may also cause problems like pain and discomfort, problems in chewing, and clicking and locking of the jaw joint.

    Treatment Options

    In many children who are born with micrognathia, the condition resolves itself naturally as the jawbone grows with age. In cases where that does not happen, the condition needs to be treated. For some children, a non-surgical orthodontic treatment may help manage micrognathia at an early age by means of appliances targeting jaw growth modification. Done at the right age, no further treatment may be required into adulthood. Severe micrognathia, however, may require surgical intervention as early as during infancy to open the airway and prevent respiratory distress. This is usually done by means of distraction osteogenesis.

    In cases where micrognathia is left untreated till adulthood, surgery is almost always the only course of treatment left, which must be performed by an expert oral and maxillofacial surgeon. Depending upon the nature of micrognathia, there are different surgical treatments available.

    1. Advancement Genioplasty – in this procedure, the chin bone is separated from the lower jawbone and repositioned forward. This procedure mostly targets the aesthetic concerns associated with lower jaw micrognathia. It has some role in improving breathing by means of pulling forward the neck and muscles attached to the chin bone. Chin advancement by means of genioplasty has the potential of radically improving facial appearance by giving a more defined jawline and a longer looking face. The result is permanent and stable. The use of piezosurgery prevents any injury to vital nerves and teeth, while medical grade titanium or titanium alloy screws are used to fix the chin bone into the new position.
    2. Mandibular advancement by Bilateral Sagittal Split Osteotomy (BSSO) – Moderate to severe micrognathia is accompanied by disturbed dental relationships and a degree of discrepancy that cannot be corrected without forward repositioning of the entire jaw. In this procedure, the jawbone is separated surgically from the rest of the facial structure and repositioned in a more forward position.The soft palate and tongue are also pulled away from the back of the throat and brought forward, which opens up the airway for oxygen to flow inside.This is done by means of a mandibular (lower jaw) osteotomy. The repositioned jaw is then fixed using rigid titanium plates and screws.
    3. Distraction osteogenesis – This is an advanced procedure which is performed to lengthen short or deformed bones using a metallic distractor device. Distraction osteogenesis is the procedure most commonly opted for to treat severe cases of micrognathia. A surgical cut is given in the small jawbone and a distractor device is fixed across the cut using screws. In a few days, the device is activated, leading to bone separation which in turn creates the space for new bone growth. The results of this procedure are permanent, and the benefit is that there no foreign grafts are required, nor does it require any donor site from within the body for bone harvesting. This makes it not only a safe procedure, but can also be used for larger corrections than the other techniques.

    Depending upon the nature of micrognathia, any of the surgical procedures may have to be accompanied by orthodontic tooth alignment for stable results.

    Benefits of timely treatment

    Like any other medical condition, a person suffering from micrognathia must opt for timely treatment. Where surgery is required, it must be performed at the earliest to avoid further complications and worsening of symptoms.

    How timely treatment benefits a person suffering from micrognathia or small jaw –

    1. Improved quality of life – by treating both the aesthetic and functional aspects of the condition, procedures like distraction osteogenesis or genioplasty can significantly improve all aspects of living, including functional as well as psychosocial.
    2. Improved breathing patterns – in cases where a receded jaw causes the tongue to fall back inside the throat causing sleep apnea, timely treatment can help improve breathing patterns by opening up the access to the air passage. This helps improve sleeping patterns while also avoiding the possibility of stroke, heart disease and diabetes.
    3. Improved speech – treatment of micrognathia can help patients suffering from speech issues due to the incorrect relationships of the tongue to the teeth and lips while speaking.
    4. Better appearance – treatment of micrognathia can drastically help improve the facial appearance by making the jawbone proportionate to the rest of the face. This can greatly enhance self-esteem and boost your self-confidence.
    5. Improved dental relationships and chewing efficiency – micrognathia treatment in conjunction with orthodontic treatment can lead to improved dental relationships by making sure that the jaw and the teeth are rightly aligned, as are the other structures inside the oral cavity including the tongue, and their positioning vis a vis the lips. This helps improve chewing efficiency.
    6. Improvement of TMD – treatment of micrognathia also helps with Temporomandibular disorders like pain, discomfort and clicking and locking of the jaw joint.

    The Role of The Right Surgeon

    It is important to understand the nature of your problems and consult the right expert to solve those problems. Micrognathia must be treated by a skilled oral and maxillofacial surgeon. A good surgeon will understand the exact nature of your problem and offer the right treatment plan – genioplasty, corrective jaw surgery or distraction osteogenesis. Visit Dr Sanchaita Kohli, an expert oral and maxillofacial surgeon, to understand about micrognathia and for genioplasty, mandibular advancement (BSSO) or distraction osteogenesis surgery in Delhi.

    Her approach is patient centric. Your privacy is her priority, and she offers a customized treatment plan in the best interest of her patient, depending upon the nature and severity of the problem, including micrognathia or small jaw. She also uses simulation software while planning for the surgery, making her patients an integral part of the decision-making process.

    maxillofacial surgeon in Delhi

    Dr. Sanchaita Kohli

    Oral and Maxillofacial Surgeon

    Dr. Sanchaita Kohli is an Oral and Maxillofacial Surgeon with over 13 years of training and work experience at the country’s leading dental institute, Maulana Azad Institute of Dental Sciences, enabling her to plan and manage an extremely wide variety of craniofacial deformities, jaw diseases and facial trauma.

    To book an appointment, call: +91-9871750455 or email:

    Share this post