French physicians on Friday defended their decision to perform the world's first partial face transplant on a 38-year-old woman, saying horrific wounds from a dog bite in May probably could not have been repaired through conventional reconstructive surgery and had left her largely unable to eat, drink or talk.

When the woman first saw her new face on Monday, "she said, 'Thank you very much,' " Bernard Devauchelle, a microsurgeon and one of the chief physicians on the transplant team, said at a news conference.

"She was very happy, compared to what she used to have," added Jean-Michel Dubernard, a transplant specialist who was co-leader of the team. The woman has requested that her name be withheld.

News of the operation brought criticism from some medical ethicists, who questioned whether a high-risk transplant should be performed for cosmetic reasons on patients who do not have life-threatening injuries. There also are potential psychological ramifications for patients in swapping one of the most personal and individual features of a body, which for many people is a reflection of persona.

At the news conference, members of the medical team reported that the woman was in stable condition at Edouard Herriot Hospital in Lyon, 285 miles southeast of Paris. Her body so far has shown no signs of rejecting the new face, one of the biggest risks in the procedure, they said.

Two medical teams totaling about 50 people performed the procedures in a hospital in Amiens, about 70 miles north of Paris, near the patient's home. The work began at about 10:30 p.m. Saturday with the removal of a triangular patch of face from a brain-dead woman -- including her nose, lips and chin. The final grafting onto the recipient concluded at about 4 p.m. Sunday, the doctors said.

No bones were transplanted during the operation, which involved muscles, cartilage, skin, arteries, veins and nerves.

The patient was moved this week to a hospital here in Lyon for long-term observation and therapy. Doctors said she was starting to stretch and exercise the muscles of her new face, was able to talk coherently and was beginning to eat and drink without assistance.

They said it would be about six months before she regained fuller sensitivity in her face, although "the risk of rejection will last for a lifetime," Devauchelle said.

Surgical teams in the United States and Britain have been preparing to conduct face transplants for several years, but in addition to the technical challenges, the operations have been delayed by ethical considerations.

The French physicians said they expected some criticism and questions about the ethics of the operation. Dubernard ran into similar controversy in 1998 when he performed the first hand transplant. Three years later, the patient had the hand amputated. His physicians said he had failed to take the necessary drugs and follow the proper therapy, and so his body rejected the hand.

At the news conference Friday, team members denied rushing into the facial operation in order to claim a medical first. It was "an exceptional situation triggering an exceptional solution," said Philippe Domy, director general of Amiens University hospital.

"She could no longer eat normally, she had great difficulty speaking, and there is no possibility with plastic surgery today to repair the muscles around the mouth which allow people to articulate when they speak and not spit out food when they eat," said Carine Camby, director general of France's Biomedicine Agency, an arm of the Health Ministry that coordinates organ procurement.

Devauchelle said the woman's gums were getting progressively drier, increasing the urgency of performing the operation. A range of experts had concluded that the damage was "nearly impossible to repair" by conventional reconstructive surgery, Dubernard said.

"When I saw the patient and how disfigured she was, I didn't have any doubts that we needed to do it," Dubernard said of the transplant. "My philosophy, our philosophy, is that we are doctors and we have a patient with a very severe disfigurement related to a dog bite. . . . As doctors, if we have the possibility to improve our patient, that's what we can do."

While the psychological impact of a face transplant is potentially extreme, according to other experts, so are the potential ramifications of not performing a transplant and leaving people to suffer in isolation and depression, embarrassed to show their grossly disfigured faces in public.

The doctors said the woman had lost her chin, lips and the tip of her nose in the attack , but they left the circumstances murky. Dubernard said the woman was bitten at night by her own dog. He said she awoke after taking a sleeping pill and may have fallen or done something else to startle the animal. Some news services said she may have stepped on it.

Dubernard, a Harvard-educated surgeon who is also a 19-year member of the National Assembly, France's lower house, denied media reports that on the night of the attack the woman had tried to overdose on sleeping pills. He said reporters had exploited and misinterpreted remarks by the woman's estranged 14-year-old daughter. "There was no suicide" attempt, he said.

The point is sensitive because medical authorities say that transplant patients must be psychologically prepared for the associated health risks and the years of treatment and therapy. Patients typically must take large doses of medicine for the rest of their lives -- often increasing the risk of cancer -- to ensure that their immune systems do not reject their new organ or body part.

A physician who took part in preliminary meetings about the partial face transplant, Jean-Pierre Chavoin, secretary general of the French society of plastic surgery, told the Associated Press that the woman seemed "to have quite a depressive profile." Laurent Lantieri, another doctor who reviewed her case, has also questioned whether she was psychologically suited to the operation.

Camby said the woman was fit for the operation. She "received many psychiatric examinations. The psychiatrists decided that she understood the surgery and that she accepted all of the consequences. . . . The patient signed a document with all the recommendations and risks laid out," Camby said.

The woman had an infusion of bone marrow stem cells from the donor in a second operation Thursday and is scheduled to have a second such procedure next Thursday, doctors said. They said they hoped the marrow transplant, an experimental procedure, would help the patient's immune system adapt to her new face and lower the chances of rejection.

Citing French privacy laws, doctors refused to divulge any information about the donor, except to say that she was brain-dead and that she was a multi-organ donor whose family had approved the face transplant. Doctors would not describe the circumstances of her brain death, nor would they say whether she was biologically alive at the time that her face was removed. Neither would they say whether the donor had approved of her face being transplanted.

Earl Owen, a transplant pioneer from Australia who consulted on the operation, said the fact that no bones were transplanted would reduce the changes in the woman's ultimate appearance.

"She still has her own eyes, which are a lot of a person's expression," Owen said in an interview with the Sydney Morning Herald, adding that she would look more like her old self than like the donor. "We'd expect she'd turn out to be a pleasant-looking girl."

Physicians in Amiens grafted part of a face onto a disfigured woman Sunday.