US doctors have carried out what they say is the most extensive face transplant ever performed.

The operation at the University of Maryland gave Richard Norris a new face, including jaw, teeth and tongue.

The 37-year-old has lived as a recluse for 15 years after being severely injured in a gun accident, and wore a mask whenever he went outside.

The surgery was funded by the US Navy, which hopes the techniques will help casualties from Iraq and Afghanistan.

Surgeons who carried out the 36-hour operation say it was part of a series of transplant operations lasting 72 hours, using organs from one donor in five patients including Mr Norris.

He lost his lips and nose in the accident, and only had limited movement of his mouth.

The lead surgeon says Mr Norris will now get his life back.

"Our goal is to restore function as well as have aesthetically pleasing results," said Eduardo Rodriguez.

The team at the University of Maryland say Mr Norris is now brushing his teeth and shaving, and has regained his sense of smell.

The US government estimates that 200 wounded troops might be eligible for face transplants.

The first face transplant was performed in France in 2005, on a woman who was mauled by her dog.

In 2010 surgeons in Spain carried out the world's first full face transplant.

Face transplant surgery

Image caption Extensive face transplant surgery has transformed the face, and life, of Richard Norris, who lived as a recluse for 15 years after losing his nose, lips and teeth in a gun accident.

Image caption A CT scan shows the areas of Mr Norris's face damaged by the accident. He underwent a number of life-saving operations during which surgeons carried out some reconstructive surgery, but he still had limited movement of his mouth.

Image caption The first stage of the face transplant operation was to remove the damaged areas - including the skin over his forehead and the reconstructed nose and jaws which had been made from tissue using other parts of Mr Norris's body.

Image caption Surgeons, aided by computer modelling, then worked to transplant facial tissue, a portion of tongue, teeth and jaws from the donor. Underlying muscles and nerves which enable expression and sensation were also transplanted.