Rigging: Digital Orthopedia - Blender Foundations: The Essential Guide to Learning Blender 2.6 - page 275

Fixing this problem is also easy. Leave the figure in the badly deformed state, with the control bone away
from rest position and the “left behind” mesh showing. Follow any spikes or bad mesh back to its origin,
so you can determine to which bone (or bones) they should be bound. Then, RMB select that bone and
hit the points of the spikes with the Weight Painting brush set to 1.0. They should pop into their proper
place. In the case of Figure 9.35 , it's obvious: The top front of the face should follow the head bone.
Figure 9.36 shows the problem mostly fixed, having selected the head bone and painted with a Weight
of 1.0 on the badly deformed portion of the head. All that remains to do is to hit the last few “spikes”
to force them into place.
After the problem is fixed, I kept painting the head with a full-strength brush until it was red inside and
out. With Auto Normalize enabled, this forces the head to follow the head bone and only the head
bone.
Figure 9.36 Whew.