A rare birth defect left Hanhan's head three times the normal size. However, a team of doctors at a hospital in Changsha, Hunan province, China, implanted 3D-printed titanium to give a proper shape to the little girl's skull.

Hanhan was born with hydrocephalus, a condition in which cerebrospinal fluid is not able to drain properly from the skull, according to Dr. Gregory Lakin of the Rainbow Babies & Children’s Hospital in Cleveland. This results in an abnormally large head and excessive pressure on the brain, putting the patient at risk of permanent damage. Lakin says children whose congenital hydrocephalus is not treated early can develop vision, speech or cognitive problems.

"The brain will get thinner and stretched out," said Lakin, in a statement. "Some of these kids are bedridden because they can’t move their head. The operation gives the kid a more normal life to go out and play."

Lakin says that if Hanhan had been operated on in the U.S., surgeons likely would have removed a part of the skull to drain the fluid before reattaching the bone.

However, he believes that a 3D implant for 3-year-old girl was a viable option since the process is less time-consuming, the implant is readily available and it is less likely to affect the growth of the brain in children aged 3 and above. The Empire State Tribune reports that the surgery took place at the People’s Hospital of Hunan Province.