Seeing Xue Qiaoping wearing a short jacket, a leather beret and a pink scarf, it is hard to imagine how she would look on stage with 10 tusks protruding from her mouth.

Xue is an exponent of shuaya, meaning "teeth play", a highly unusual performance that is part of pingdiao (flat tone), a local folk opera of Ningbo, Zhejiang province.

Before going on stage, actors insert tusks-which are about 6 to 8 centimeters long and taken from a male wild boar-into their mouths. The tusks are moved in and out using the mouth and tongue to reflect characters' changes of emotions, as songs are sung and lines spoken.

"Teeth play" and face-changing in Sichuan Opera is together known as xiliandongya ("face in the West and teeth in the East"). Shuaya is just a part of pingdiao, which dates back to the 17th century and has about 400 tunes in its repertoire, and lyrics are sung in the local dialect. Traditionally, the music is played with drums and bronze gongs, meaning a loud, noisy performance, but contemporary recitals include stringed instruments such as the erhu, violin and cello.

The themes of the plays usually revolve around social ethics and family relationships.

Xue, 37, joined Ninghai Xiaobaihua Yueju Opera Troupe when she was 16, being taken on with nine other apprentices by Ye Quanmin, a fifth-generation exponent of the art.

"It was very hard at first," Xue says. "I started practicing with two teeth, and wore them almost all the time, except when I was eating or sleeping."