WASHINGTON: A US man who lost his lips, nose and teeth in a 1997 gun accident has received the most extensive face transplant to date, according to doctors at the University of Maryland Medical Center.

Richard Lee Norris, 37, had undergone several life-saving and reconstructive surgeries after the accident but had limited use of his mouth and, before the surgery, appeared as though his lower face and nose had been mashed in.

In a 36-hour operation on March 19-20, doctors at the US medical center carried out “the most extensive full face transplant completed to date, including jaws, teeth, and tongue,” the center said.

“The transplant included all facial soft tissue from the scalp to the neck, including the underlying muscles to enable facial expression, and sensory and motor nerves to restore feeling and function,” chief plastic surgeon Eduardo Rodriguez said in a statement.

“Our goal is to restore function as well as have aesthetically pleasing results,” he added.

Norris had spent the past 15 years living as a recluse, wearing a surgical mask and only shopping at night in order to avoid the staring of others, according to a report by MSNBC.

The world's first full face transplant took place in Spain, with doctors at Vall d'Hebron hospital in Barcelona showing off their work in July 2010.

The first successful partial face transplant was performed in France in 2005 on Isabelle Dinoire, a 38-year-old woman who had been mauled by her dog.