Quote - ERC (also known as JCM and many other initials) is simply a way to
link the movements of one joint or morph to another.  It's used in 
most of the major figures, often to control breast morphs from collar
or shoulder movements....

When a paragraph like the one I've shown is added to a parameter,
it will move whenever its 'master' moves.  The master figure is the 
second line (usually Figure 1 will do, but you could also put the figure's
proper name if it has one).  The master body part (here the head) is 
the third line, and the master parameter (here OpenLips)
is the fourth.  

The last line gives the 'control ratio'.  I picked 8 by observing that the 
widest usable opening on this figure was about OpenLips = 1.8,
and the teeth seemed to match when their xRotate was about 14.

Slave move / Master move = Control ratio.

so 14 / 1.8 = 8

Ah-- so only the 'open lips' morph would move the teeth, and not, say, 'yell' or 'open mouth'? If so that would be less than ideal... I wonder if it wouldn't just be easier for me to move them by hand... I'm not doing animations or anything, just simple renders. I dread getting into the technical gubbins... I'm sure I'll break something. ;)