Shortly after the woman's injury, Dr. Bernard Devauchelle, head of face and jaw surgery at Amiens University Hospital, decided that the woman was a candidate for a partial face transplant and sent an urgent request for help in locating a donor to the French Biomedicine Agency, which oversees the allocation of organs for transplant in France. The window for a successful transplant was narrow, the doctors said, because the wound was developing scar tissue.

Dr. Benoît Lengelé, a Belgian surgeon who assisted in the transplant, said the woman would have required at least three or four traditional plastic surgery operations to rebuild her face with skin flaps from other parts of her body, but the results would never have been aesthetically or functionally satisfactory.

Meanwhile, the woman's injury had made it difficult for her to talk or even drink and eat, because food and liquid spilled easily from her mouth. The doctors said her ability to open her jaw was also progressively diminishing as her wounded tissue stiffened. In July, Dr. Devauchelle consulted with Dr. Dubernard, who visited the woman in early August.

"The moment she removed her mask, which she always wore, I had no more hesitation," Dr. Dubernard said Friday.

No information was given about the donor, a brain-dead woman whose anonymity is protected by law. She was located on Saturday at a hospital in the northern city of Lille, 85 miles from Amiens.

Brain-dead patients in France are presumed to be organ donors unless they have made explicit provisions to the contrary, and approval by next of kin is not normally required. But given the delicacy of the case, the donor's family was consulted about the possible harvesting of part of the donor's face during the initial interviews that are undertaken to ensure that the deceased had not given instructions preventing organ donations.

A special team of psychologists worked with the family on Saturday afternoon as the doctors involved were notified that a potential donor had been found. By midnight Saturday, Dr. Devauchelle, who led the surgical team, was in Lille to begin harvesting the face while another team of surgeons in snowy Amiens began removing scar tissue from the patient in preparation for the transplant.