Asymmetrical Jaw: Causes, When It Is Normal and When to See a Doctor

Most faces are slightly asymmetric: one side a little fuller, one jaw angle a little more prominent. It is rarely a problem, and photographs and mirrors exaggerate it. Asymmetry that has been there since childhood and is not getting worse is usually just the way the face grew.

A dental cause means the teeth, not the bones, create the unevenness. The best-known example is a crossbite on one side, which makes the lower jaw slide sideways so the chin and midline of the teeth are off-centre. Narrow arches are a common reason; see the guide on narrow jaw. Missing teeth or habits such as chewing on one side can add to it.

A skeletal cause means one jaw has grown more than the other, or one side grew differently. It can be inherited or follow an injury or joint problem in childhood. A skeletal underbite can also be uneven; see our guide on underbite teeth.

If a crossbite is shifting the jaw, widening the arch or braces can correct it, and doing it in a growing child gives the best chance. A clear skeletal difference in an adult may need braces together with jaw surgery, planned by a dentist with a surgeon. Mild asymmetry may not need any treatment. The braces and orthodontics page outlines how bite problems are treated.

See a dentist or doctor if the asymmetry is new or getting more obvious, if there is a lump or swelling that does not go, if the jaw is painful, clicks or locks, or if it is hard to open your mouth. Our page on jaw pain covers common causes. Spreading facial swelling, fever, or difficulty swallowing or breathing means same-day care, and a hospital emergency if breathing or swallowing is affected.