An oral hygiene device in the form of a toothbrush 10 comprises a handle section 12, a cartridge 14 containing a cleaning composition held under gas pressure, an actuating mechanism 16 and a head section 18. The cartridge has a discharge opening at a front end thereof, which includes a control valve 26 comprising a valve stem 27. The actuating mechanism 16 includes a plunger 40 and a lever formation 38 which acts on the plunger. The lever formation is acted upon by a hand-operated actuating button 58 for dispensing the plunger rearwardly for depressing the valve stem 27 for releasing cleaning composition from the cartridge causing the cleaning composition to be conveyed under gas pressure along passage 48 of the valve stem and into passages 46, 32, 37 and 29 where it is discharged via opening 31 at a distal end of the head section 18 onto bristles 28.
