What is facial palsy?

Facial palsy is a form of facial paralysis which commonly affects one side of the face.

Associate Professor Tan Bien Keem, Singapore General Hospital's head and senior consultant of plastic, reconstructive and aesthetic surgery, operated on Ms Shirley Leong.

He said facial palsy is caused by damaged facial nerves which can be due to a viral infection, trauma or a tumour. Patients experience sagging in the face and have difficulty smiling and closing their eyes.

Prof Tan, who has seen only about 20 patients here with facial palsy in his 20 years of practice, said it's a rare condition that affects 23 in 100,000 in the US.

Thankfully, facial reanimation surgery can help patients regain function of their facial muscles. The surgery involves transferring a small muscle from another part of the body, like the upper thigh or chest, to the face.

Prof Tan said: "The nerve endings in the muscle are connected to the biting or smiling nerves in the face, and the new muscle will start to pick up blood.

"The surgery is like completing an electrical circuit."

The operation, which has a success rate of 90 per cent, takes four to six hours and scars are hidden, added Prof Tan.

He urged those with the condition to seek treatment quickly.

"Younger patients get better results. The longer you delay treatment, the less effective it will be."