Doctors who successfully separated twin boys joined at the head said Monday that the 9-month-olds are expected to have a "very good chance" at a normal life.

Doctors at Christus Santa Rosa Children's Hospital in San Antonio performed the four-hour operation Friday.

"They're in two separate beds," said Richard Wayne, administrator of the children's hospital. "They're babbling. They're smiling. They're eating. They're very happy. They're beautiful little children. They're being held by the parents, and they're doing very well."

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The twins, whose family wished to remain anonymous, were joined at the top of their heads. Wayne said the veins "most dangerous" in performing a separation were not joined, though some were.

And the twins' brain tissue wasn't connected, said Micam Tullous, one of seven doctors involved in the separation.

"They had relatively normal anatomy," he said.

The children may be able to go home in about a week, doctors said. The twins were delivered at the same hospital where the surgery was performed, Tullous said.

"I think there's a very good chance that they will have a normal or near-normal outcome," Tullous said.

Conjoined twins occur in one out of 200,000 live births, and of those only one in 50 are joined at the head, Wayne said.

Wayne said the children will need further treatment, including rehabilitation and possibly minor surgery. He said the separation surgery was a first for the hospital.