An ultrasonic toothbrush having spatially extended functionality to treat various oral diseases in addition to removing plaque and treating gingivitis is disclosed. In addition to the ultrasonically activated bristles, the toothbrush incorporates a multi directional ultrasound transducer system, which spatially irradiates the oral cavity with ultrasonic pressure waves, operational to loosen plaque, to remove periodontal bacteria from teeth and gums, and to simultaneously treat and destroy disease causing bacteria and bacterial chains on the inside surfaces of cheeks and lips, providing relief from Recurring Aphthous Stomatitis, Lichen Planus, and Mucositis. Various configurations are disclosed, including user removable and replaceable brush heads and ultrasound treatment heads. A motorized version featuring sonic frequency orbital vibration brush head and bristle tufts is described.