In a large crowd, the total number of teeth of all people combined divided by the total number of heads. In a well eduated crowd with reasonable oral hygene,
one would expect the tooth to
head ratio to be close to 32:1. If you were to attend a monster truck rally or a wrestling match, one would expect the tooth to
head ratio to be around 12:1. At a bluegrass concert it can sit around the
5:1 or 4:1 area.