Effect of hypnosis on oral function and psychological factors in temporomandibular disorders patients

This study investigated the effect of hypnosis in patients with temporomandibular disorders (TMD) with focus on oral function and psychological outcomes. Forty women (mean age +/- s.d.: 38.6 +/- 10.8 years) suffering from TMD (mean duration 11.9 +/- 9.9 years) were randomized to four individual 1-hour sessions of either hypnotic intervention or a control condition of simple relaxation. Pain intensity was assessed three times daily on a 0-10 Numerical Rating Scale. Additional outcomes were TMD-associated symptoms assessed by the Research Diagnostic Criteria examination form and questionnaire, psychological symptoms (Symptom Check List 60), pain coping strategies (Coping Strategies Questionnaire), sleep difficulties (Pittsburgh Sleep Quality Index) and use of analgesics. Data were analyzed with between-groups within-subjects anovas. The hypnosis group significantly reduced the daily NRS pain scores from 4.5 +/- 2.1 at baseline to 2.9 +/- 2.4 after treatment (P < 0.001) compared to the control group where no significant changes were found (4.2 +/- 1.4 to 3.9 +/- 1.5) (P = 0.733). Number needed to treat for a 50% pain reduction was 4.0. The hypnosis group also increased use of the coping strategy 'reinterpreting pain sensations' from 5.2 +/- 6.9 to 10.3 +/- 6.8 (P < 0.001). Both groups exhibited significant reductions in the number of painful muscle palpation sites and pain on palpation (P < 0.004), in number of awakenings due to pain (P < 0.006), and in somatization, obsessive compulsive symptoms and anxiety (P < 0.004). Hypnosis thus appears to effectively reduce some aspects of complex TMD pain.