With the advancement of electroencephalographic procedures, neurophysiological and psychological research, the clinical applications of hypnosis are now being measured.
In 1992, 67 bone marrow transplant patients were studied to test the effectiveness of hypnosis on reducing pain, nausea and vomiting. Chemotherapy causes inflammation and ulceration of the oropharyngeal mucosa, resulting in severe pain for two to three weeks. During this period, most patients cannot eat and sometimes stop speaking because any activity exacerbates pain. Patients were divided into groups: some used hypnosis, some received cognitive behavioral coping skills training, and others had therapist contact. There was also a control group. Hypnosis was the most effective in reducing oral pain. However, nausea and vomiting were not decreased significantly.
In 1987, The University of Nebraska Medical Center College of Dentistry conducted a study to test hypnosis in maintaining compliance with the routine use of dental floss. Ninety-six patients who did not use floss were divided into two groups. Eight months later, of the group that underwent hypnosis, 67 percent were flossing daily compared to only 15 percent of the control group who had been exposed to conventional motivational techniques.
In 1984, 60 private dental patients participated in an experiment at California State University in Fresno. After spending 30 minutes receiving hypnotic treatment via tape recording, all underwent a dental procedure that routinely called for local analgesic. Dental procedures were rated "high discomfort" root canal, extraction, pulp capping, bridge preparation, crown preparation, multiple fillings or "low discomfort" filling, cementation of bridge, cementation of crown, root canal/nonvital tissue, crown buildup with post. Patients were told they could request anesthesia at any time. About 33 percent, or 12 of 36, did not request it for a high discomfort procedure. About 79 percent, or 19 out of 24, did not request anesthesia for a low discomfort procedure.