Various mechanical drive devices, mechanical gears, combinations thereof and medical or dental treatment devices with such mechanical drive devices or gears are described. The mechanical drive devices and mechanical gears convert a unidirectional rotational movement received by a motor drive into a multidirectional movement, so that a tool-holding device of the treatment device can be induced to a multidirectional movement, in particular to a, preferably simultaneous, lifting and rotating movement or to a lifting and oscillating rotational movement with a reduced rotational speed.