For Max, Select the area you want to work on. Right click and scroll over "convert to" and choose editable poly. Then on the far right of the screen where it says selection, pick polygon. Head back over to your model and select the polygons you would like to flip (hold ctrl to select more than one). Right click and choose "Move". Now hold down shift and slowly move the mouse. Once you release the left mouse button a dialog box will pop up. Click OK. Now go back to the right side of the screen where you originally clicked "polygon" and look down until you see "Flip". Click it.
Tada
Also, you can then bridge the polygons together using border, but I'm unsure if this really matters any.
Ctrl + f to flip normals.
But then it won't display on the other side, correct? That's the problem, for the wolves teeth, they will have to display on both sides