Bernard Devauchelle said the patient regained consciousness 24 hours after the groundbreaking operation.
"There were no post-surgical problems," he said at doctors' first news conference on the French transplant that has set off a debate among scientists over ethics.
"The patient was awake at the 24th hour and ... her first word was 'merci,'" Devauchelle said. Behind him were projected images of the facial portions that were transplanted — a section of the nose, lips and chin.
The director of the hospital in Amiens, northern France, where the transplant was carried out last Sunday said the surgery was required because the recipient's case was exceptional.
"We are in an exceptional situation that required an exceptional response," said Philippe Domy.
The 38-year-old woman, whose identity has not been disclosed, was mauled by a dog in May, leaving her with severe facial injuries that her doctors said made it difficult for her to speak and eat.
However, the French news agency AFP quotes her daughter as saying the 38-year-old woman lost part of her face following a suicide attempt.
The family dog apparently used its jaws to try to wake her after she took an overdose of sleeping pills.
The donor was a brain-dead woman.
"It's like any other organ transplant where you have a willing donor family kind enough to recognize the need of a recipient who is missing a critical structure," said Dr. Peter Costantino, an expert on facial reconstructive surgery at St. Luke's-Roosevelt Hospital Center on CBS News' The Early Show. "In this case, instead of it being a liver or kidney, it's the large portion of a woman's face."
Leading transplant surgeon Jean-Michel Dubernard acknowledged that he had initial reservations in the planning stages of the surgery. But he added that when he saw the extent of the woman's disfigurement, "I no longer hesitated for a second."
Several other surgeons say the French medical team ignored official ethical advice, reports CBS News correspondent Elaine Cobbe. The panel had previously objected to full face transplants but said partial ones could be considered under strict circumstances, which included first trying normal surgery.
Carine Camby, director-general of the agency under the French health ministry that coordinates organ procurement said the woman was warned that she risked becoming a center of media attention because the surgery was a world's first.