To what extent can orthognathic surgery fix facial asymmetries?

Have you ever wondered why some people —celebrities in particular— tend to look way more attractive than the average Joe? Well, the real reason comes down to science. Take a look at A-listers like Kate Moss, Scarlett Johansson and Brad Pitt — these three are just some of the individuals with the “most scientifically beautiful faces”, according to researchers.

A symmetrical face is one where the left side closely mirrors the right side. They’re not perfect mirror images, but their proportions are highly similar. The good news is that no face is completely symmetrical; everyone has some degree of facial asymmetry. As an oral and maxillofacial surgeon in Singapore who conducts surgery for both medical and aesthetic purposes, I often receive questions on whether surgery is necessary to fix facial asymmetries.

Well, firstly, beauty is in the eye of the beholder. Most patients with facial asymmetries have very minor asymmetries which do not involve a functional deficit. In such cases, I usually recommend non-invasive treatments like botox or fillers. However, if a patient’s uneven jawline affects their oral health and causes other problems, then perhaps orthognathic surgery or jaw surgery should be considered.

What causes facial asymmetry?

As mentioned, some degree of facial asymmetry is normal, but some people have it more than others due to:


If your parents and other members of your family have similar asymmetrical features, chances are your asymmetry is the result of your genetics. Some genetic conditions like cleft lip and palate may also cause facial asymmetry. From my experience, most asymmetry due to genetics are usually not a cause for concern.


Several studies have demonstrated the link between ageing and facial asymmetry. While our bones stop growing once we hit puberty, cartilage does not. What this means is that our ears and nose will keep growing, leading to changes in the face. As we age, soft tissues in our face will also start to relax, contributing to the asymmetry.

Lifestyle factors

Lifestyle factors like smoking can contribute to facial asymmetries. Tobacco products contain toxins and chemicals that can constrict blood vessels, which causes the cheeks to lose elasticity. In addition, people who smoke are at higher risk for osteoporosis and decreased bone density in the jaws, which can affect facial symmetry.

Even factors like sleeping on one side and favouring one side of the mouth when chewing can lead to facial asymmetries! A 2014 study done on 147 pairs of twins show that sleep position and smoking are significant risk factors for facial asymmetry.

Health conditions

Patients with idiopathic masseter muscle hypertrophy can experience facial asymmetry due to their enlarged cheek muscles. Some conditions like Bell’s Palsy can also weaken or paralyse one side of the face. When this happens, as the patient favours the stronger side of the mouth, facial asymmetry can develop.


If you’ve been in some kind of accident whether in childhood or adulthood that’s affected your face, your jaws may be uneven after healing. Trauma such as a broken nose or deep cut can cause damage to the face. Similarly, having missing teeth due to an accident or dental extraction can change the shape of your face as bone in that area atrophies.

Should I be worried about my facial asymmetry?

For some patients, their facial asymmetry only affects their appearance. This is up to the patient to decide if they wish to rectify it through cosmetic procedures. However, if your facial asymmetry causes you functional issues, then it could be a problem. In some cases, facial asymmetry can be a side effect of conditions like obstructive sleep apnea or temporomandibular joint disorders (TMJD). For example, patients with idiopathic masseter muscle hypertrophy usually have TMJD and bruxism together with facial asymmetry.

When is orthognathic surgery a good option?

I perform orthognathic surgery for patients with:

  • Jaw deviation
  • Excessively short (hypoplastic) or long (hyperplastic) lower jaw
  • Hypoplastic or hyperplastic upper jaw
  • Jaw deformities due to accident or disease

In general, orthognathic surgery is usually a good option if you have extreme facial asymmetry that cannot be fixed with cosmetic or orthodontic procedures. For something like asymmetry because of tooth loss, I usually advise patients to try bone grafts and dental implants first before considering surgical intervention. In some cases, you may even need to get orthodontic treatment first before surgery.

Corrective jaw surgery requires a lot of planning and examination of your teeth, jaw bones and jaw joint. Even blood and heart monitoring tests will be taken to ensure you are suitable for surgery as the procedure is carried out under general anaesthesia. Your doctor will better be able to advise on the type of jaw surgery you need and to what extent.


  1. Liu, M. T., Iglesias, R. A., Sekhon, S. S., Li, Y., Larson, K., Totonchi, A., & Guyuron, B. (2014). Factors contributing to facial asymmetry in identical twins. Plastic and reconstructive surgery, 134(4), 638–646.
  2. Hosseinzadeh Nik, T., Gholamrezaei, E., & Keshvad, M. A. (2019). Facial asymmetry correction: From conventional orthognathic treatment to surgery-first approach. Journal of dental research, dental clinics, dental prospects, 13(4), 311–320.
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Categories : Face