Oral medicine (sometimes termed dental medicine, oral and maxillofacial medicine or stomatology) is a specialty focused on the mouth and nearby structures. It lies at the interface between medicine and dentistry.The importance of the mouth in medicine has been recognized since the earliest known medical writings. For example, Hippocrates, Galen and others considered the tongue to be a "barometer" of health, and emphasized the diagnostic and prognostic importance of the tongue. However, oral medicine as a specialization is a relatively new subject area. It used to be termed "stomatology" In some institutions, it is termed "oral medicine and oral diagnosis". American physician and dentist, Thomas E Bond authored the first book on oral and maxillofacial pathology in 1848, entitled "A Practical Treatise on Dental Medicine".The term "oral medicine" was not used again until 1868. Jonathan Hutchinson is also considered the father of oral medicine by some.Oral medicine grew from a group of New York dentists (primarily periodontists), who were interested in the interactions between medicine and dentistry in the 1940s.Before becoming its own specialty in the United States, oral medicine was historically once a subset of the specialty of periodontics, with many periodontists achieving board certification in oral medicine as well as periodontics.[citation needed]