They regularly perform corrective jaw surgery, or re-positioning  either the top or bottom jaw.

“This often helps in chewing, speaking and also breathing difficulties,” Dr Mehanna said.

The oral and maxillofacial surgeons operate at Wood Street Specialists, in Newcastle West.

Corrective jaw surgery is usually elective and corrects some common conditions such as open bites, small lower jaw- weak chin and a protruding lower jaw, where the lower teeth sit in front of the top teeth when the mouth is closed.

“Patients usually present to their dentist or orthodontist when there are problems with the alignment and bite (occlusion) of the teeth,” Dr Mehanna said.

“In most cases, braces can help with the alignment of teeth. But there are often circumstances when the teeth cannot be aligned because there is a jaw size problem as well as a tooth position issue. 

“In such cases a combined approach is needed, which involves a period of time with braces (to help align the teeth) followed by corrective jaw surgery, which repositions the jaws so the teeth fit together properly. 

“This surgery can significantly improve both appearance, chewing and also help with breathing problems.”

Corrective jaw surgery is similar to that of facial trauma, surgery also performed by Dr Mehanna.

There are, however, important differences.

“While trauma surgery involves putting the broken bones back in their original position, corrective jaw surgery involves repositioning the jaws into a new position and securing the position with small metal plates and screws which hold the bones in their new position,” Dr Mehanna said.

“As moving the jaws also changes the way the teeth bite, it is important to have straight teeth, usually before correct jaw surgery is undertaken.”

Recent advances in technology allow surgeons to use computer planning and three-dimensional simulations to show the changes in facial appearance and bite after surgery, and to locate positions of nerves and arteries so the surgeon knows their location before the surgery.   

”Depending on the type of surgery required, corrective jaw surgery usually involves one or two nights in hospital and taking regular painkillers and a soft diet for a period of time,” Dr Mehanna said.

“While the pain is controllable, it may take some time for the swelling to settle and a few weeks till people are back to their normal diet.”

Generally, corrective jaw surgery is not performed until after the jaws have stopped growing, about 18 years of age.