Methods After designs the trefoil flap in the prolabium, the displaced tissuce is replaced and the columnella is lengthened, the sill is raised by the application of the trefoil flap.

• 方法前唇设计出三叶瓣后,先对移位的组织进行完全游离及复位,再将三叶瓣向鼻小柱方向掀起,延长鼻小柱及抬高鼻底。