Oral medicine is the discipline in the dentistry which is used for diagnosis and non-surgical treatment of oral cavity and oral manifestations of systemic disease. Oral radiology is the branch of dentistry which dealing with use of x-rays, radioactive substances, and other forms of radiant energy in diagnosis and treatment of disease. It is concerned with the oral health care of medically compromised patients and with the diagnosis and non-surgical management of medically-related disorders or conditions affecting the oral and maxillofacial region. Dental Science is a branch of medicine that is involved in the study, diagnosis, prevention and treatment of different disorders as well as diseases of dental region. It will mainly focus on structure, development and abnormalities of the teeth. A medical practitioner who is dealing dental science called dentists.