Dear plutarch: I suspect that the big reasons teachers are instructed to ban gum chewing is related to mischief resulting from misuse of gum that has lost its flavor. Like pressing it into braids of girls' hair, putting it in seats just before victim sits down. One side of gum chewing that bothered me was tendency to swallow air enough to promote impolite eructation. I wonder what makes dogs enjoy chewing a bone so much.

A dental health URLabout gum chewing.http://www.massdental.org/public/health.cfm?doc_id=112