A surgical handpiece includes a housing having an interior cavity and an exterior surface adapted to be gripped by the hand of a user. A rotary drive mechanism is provided inside of the housing and includes a driven shaft with a passageway extending axially therethrough. A suction connection is provided...http://www.google.de/patents/US6152941?utm_source=gb-gplus-sharePatent US6152941 - Endoscopic cannulated handpiece motor with integrated suction control
