A 6-year-old Russian girl born without lips or a chin can now smile — thanks to a life-changing operation, according to a report.

Darina Shpengler underwent an 11-hour surgery at Great Ormond Street Hospital in London last week, where doctors constructed a jaw for her, the Sun reported.

Doctors have been unable to diagnose the young girl, but believe she suffers from a condition caused by “spontaneous mutations,” according to the outlet.

Her disorder has affected her ability to eat and speak, as well as laugh and smile, the Sun reported.

The recent surgery, however, is the first of a series of procedures that doctors say will give her a complete face.

“We made Darina a nice little jaw, it’s in a good position, and we introduced some more skin into her neck,” said Dr. David Dunaway in a YouTube video after the operation.

Her mother, Elena Shpengler, said the recent procedure has enabled her daughter to grin wide for the first time.

“This had changed our daughter completely and she learned to laugh,” the mom said.