Modeling Details - Game Character Development with Maya - page 252

FIGURE 4.47 Select the edges around the opening of the mouth.
4. Extrude the edges inward, adding two divisions to the extrusion ( Figure 4.48a ) .
Do this by setting Divisions to 3 for polyExtrudeEdge1 in the Channel Box.
FIGURE 4.48 Create the cavity of the mouth.
5. Weld together all the vertices at the very end to create a point ( Figure 4.48b ).
6. Select the edges on both the top and the bottom of the extrusion, as highlighted in
Figure 4.48c .