A French woman has become the first person to receive a face transplant.
The operation apparently lasted several hours where tissues, muscles, arteries and veins were taken from a brain-dead donor and attached to the patient's lower face.
The woman had reportedly lost her nose, lips and chin after being savaged by a dog.
After the controversial operation, the surgeons stressed that the woman will not look like her donor, and neither will she look like she did before the attack.
She will apparently instead have a "hybrid" face.
This is the first face transplant using skin from another person although it has been technically possible to carry out such a transplant for some years, with teams in the U.S., the UK and France researching the procedure.
It seems that skin from another person's face is better for transplants as it produces a better match than skin from another part of the patient's body, which could have a different texture or colour.
But until now the ethical concerns of a face transplant, and the psychological impact to the patient of looking different has held teams back.
Although doctors in the UK are able to perform such transplants, concerns regarding immunosuppression, the psychological impact and the consequence of technical failure have so far prevented ethical approval of the procedure.
According to reports the 38-year-old French patient from the northern French town of Valenciennes received extensive counselling before her operation, which took place at the weekend at a hospital in Amiens.
The tissues, muscles, arteries and veins needed for the transplant were taken from a multi-organ donor in the northern city of Lille, who was brain-dead.
The operations were carried out by a team led by Professor Bernard Devauchelle and Professor Jean Michel Dubernard, and in a statement, the hospital said the woman had been gravely disfigured in the attack in May this year and has been unable to speak or eat properly since.
The woman wishes to remain anonymous and is in "excellent general health" and the graft is said to look normal.
Should a face transplant fail it is unclear whether an individual could be left worse off.
As with any other transplant patient, the woman will have to take immunosuppressant drugs to help her body cope with the donated tissue.
Experts working in this area say many could benefit from the procedure, including 10,000 burns victims in the UK, but say there are medical, and ethical, concerns to do with facial transplants
Some warn that blood vessels in the donated tissue could clot, the immunosuppressants could fail and the patient's risk of cancer could be increased.
As the transplant must come from a beating heart donor, permission would be needed for the face to be removed before the ventilator was switched off.
The extent of facial expression which will occur in the long term is unknown and experts say that as the skin has a tendency to strongly promote rejection by the immune system, immunosuppression would need to be kept at high levels for prolonged periods of time.
The Royal College of Surgeon's facial transplantation working party, says that if the transplant is successful, it will be a major breakthrough in facial reconstruction and a major step forward for the facially disfigured.