The US military has awarded Brigham and Women's Hospital a multimillion-dollar contract to pay for face transplants for veterans who have survived catastrophic war injuries in Iraq and Afghanistan, but are left severely deformed. The Department of Defense is hoping that the Boston doctors will be able to complete face transplants on six to eight patients over the next 18 months, which would nearly double the nine known procedures completed worldwide. In April, the Brigham performed its first face transplant, which was the second done in this country. The $3.4 million award, which also will be used to provide the surgery to civilians, is a signal that face transplantation could be poised to move into mainstream medicine four years after the first such operation, on a French woman, was met with fierce ethical objections. Doctors and military officials said they are unsure how many veterans will qualify, but estimate the number could be as high as 200.