An arcuate shaped lower jaw is provided with {TAIL ~ an inner end} and {HEAD ~ a backside} 
An arcuate shaped lower jaw is provided with { TAIL ~ an inner end } and { HEAD ~ a backside }
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD