Abstract : This study examined the role of the endodontist regarding non-odontogenic toothache. Recently, many useful diagnostic instruments and apparatuses have become available for endodontic treatment, such as microscopes and cone-beam computed tomography. These yield more accurate findings than previously available in endodontic treatment. However, patients having no detectable findings using these tools or other methods are considered to have non-odontogenic toothache associated with unsympathetic pain. Their chief complaint is severe pain, the cause of which cannot be found upon dental examination. In these cases, we also must consider the patient’s mental state : the patient has intense pain, without any notable cause. After a thorough dental examination, a psychiatrist and psychosomatic dentist perform a medical interview ; a psychological diagnosis may be suggested. Psychogenic factors have been closely linked to pain of this type. Specialists, specifically psychiatrists and psychosomatic dentists, must treat these patients both somatically and psychologically. It appears that psychological factors play a key role in the increased sense of pain. Therefore, endodontists also must acquire the psychiatric knowledge necessary to thoroughly treat these patients.