Hello i work with maya 4 1 i have make a half human face with subdivisions But when imake duplicate or copy the all head is ok but there is a seam 2 i try to use the polygon mirror & subdiv surface /mirror but i see a distrub to the new half by the way when i try the command extude face i read is nonmifold but my problem is to erase the seam thank you all for your help