The present invention recognizes that there exists a need for the treatment diseases, disorders and conditions that cause or are related to bad breath in general. The present invention provides devices and methods to address this need. A first aspect of the present invention is an oral device for a subject. A second aspect of the present invention is a method of treating a subject for a disease, disorder, condition, or a combination thereof, of the oral cavity with a device of the present invention. A third aspect of the present invention is a method of treating a subject for a disease, disorder, condition, or a combination thereof, of the oral cavity.