Paris, France | Ten years and 36 operations later, the face transplant remains a tricky endeavour with a long list of health and mental risks to be weighed against the benefits, experts say.

A major procedure, it helps many patients resume basic tasks such as breathing, eating and speaking, and restores non-verbal communication through smiles and frowns.

For many, the big change is being able to appear in public without being stared at.

But recipients also face an uphill psychological battle living with someone else's face, and life-long reliance on immunosuppressant medicines, with their side-effects.

The drugs rein in the body's immune system, which can target a transplant organ as a foreign intruder to be attacked and wiped out.

But in checking this protective response, the body is left vulnerable to a wide array of infections and cancers.

"Anti-rejection treatments take a heavy toll on patients," Paris-based plastic surgeon Jean-Pierre Meningaud said after  announcement of the death of the world's first face graft recipient, Isabelle Dinoire.

Meningaud, who has performed seven such transplants, called for a hold on the procedure pending advances in immunosuppressing therapy.

Every single one of his patients have had at least one rejection episode, "which leads to higher doses of drugs, and with them, the risks," he told AFP.

Two of Meningaud's seven patients have died -- one of whom committed suicide.

The university hospital of Amiens-Picardie, where Dinoire's operation was performed in November 2005, said finding the right "balance" between protecting the new face and the rest of the body was a tall order.

- Finally, I'm living -On top of the risk of tumours and infections, it said, immunosuppressants can have severe side-effects such as diabetes, diminished kidney function and osteoporosis.

So far, six of the 36 people to have received face transplants globally since 2005 have died. 

The operation itself is long, complex and not without risks, and recovery is long, say the experts.

"It is important to remember that facial transplantation is still under evaluation," the university said in a statement.

"It is listed under clinical research and is not considered a routine procedure."

Maimed by her dog, Dinoire received part of a brain-dead person's face in a historic, 15-hour operation at the age of 38. 

She died in April this year from a rare tumour which the hospital said "cannot be scientifically linked to immunosuppressant treatment" she was taking.

Since the transplant, Dinoire had suffered many infections, another tumour, diminished kidney function and high blood pressure.

"There are some experts that question the risk associated with face transplantation as it is not a life-saving operation," states the Transplantation Services department of the University of California in Los Angeles.

"However, the candidates with facial disfigurement live with social isolation and fear of rejection from their appearance affecting their quality of life," according to its website.

For Meningaud's colleague Laurent Lantieri, the procedure must be reserved for severely disfigured people with no alternative, such as regular plastic surgery.

"There has not been enough of a revolution in immunology since these questions were first raised... to warrant widespread use of the technique," he said on France 5 television on Wednesday.

For face transplant recipient Jerome Hamon, however, the procedure has been a life-changer.

"I have changed, I am more open towards other people," he said on French radio after news broke of Dinoire's death.

"The looks, the teasing, it has all disappeared. I finally feel like I'm living."