Abstract: An air distributor for the supply of a blade-type motor which can be rotated about its axis by means of a sleeve with which it is integral external to a casing, the rear end plate of the blade-type motor being constituted by a ring traversed by at least three openings which are off set at angles of 120.degree., characterized in that the end of the distributor facing the said ring is shaped so as to form, on the one hand, a chamber causing the outlet openings of the motor block to communicate with one or more outlet pipes for the air toward the exterior traversing the distributor and, on the other hand, a surface in direct contact with the said ring, on which surface there merges a feed duct for air traversing the said distributor originating from the compressed air source.Application: to hand-held dental instruments.