an instrument for discharging water from the mouth during a dental treatment , has an ovoid , smooth - surface , edge free hollow water collection body with a front surface facing outwardly of the mouth and a rear surface facing toward the throat inlet of the mouth . two rows of orifices are provided on the rear surface and alternately on the rear and front surfaces for receiving a water mixture from the patient &# 39 ; s mouth . a mounting tube projects from the front surface and at at an angle to the axis of the body for connection to a water discharge tube for drawing water from the body .