D and the victim quarreled at the 'Diamond Mine' Lounge. A fight erupted and D bit off a piece of the victim's left ear. D was indicted for the crimes of mayhem ( G. L. c. 265, § 14), and assault and battery by means of a dangerous weapon 'to wit, teeth' ( G. L. c. 265, § 15A). D claimed that teeth cannot constitute a dangerous weapon and moved for a directed verdict. It was denied and D was convicted and appealed.