Sleep disorders and their association with laboratory pain sensitivity in temporomandibular joint disorder.
OBJECTIVE
We characterized sleep disorder rates in temporomandibular joint disorder (TMD) and evaluated possible associations between sleep disorders and laboratory measures of pain sensitivity.


METHODS
Research diagnostic examinations were conducted, followed by two consecutive overnight polysomnographic studies with morning and evening assessments of pain threshold.


METHODS
Orofacial pain clinic and inpatient sleep research facility.


METHODS
Fifty-three patients meeting research diagnostic criteria for myofascial TMD.


METHODS
N/A.


RESULTS
We determined sleep disorder diagnostic rates and conducted algometric measures of pressure pain threshold on the masseter and forearm. Heat pain threshold was measured on the forearm; 75% met self-report criteria for sleep bruxism, but only 17% met PSG criteria for active sleep bruxism. Two or more sleep disorders were diagnosed in 43% of patients. Insomnia disorder (36%) and sleep apnea (28.4%) demonstrated the highest frequencies. Primary insomnia (PI) (26%) comprised the largest subcategory of insomnia. Even after controlling for multiple potential confounds, PI was associated with reduced mechanical and thermal pain thresholds at all sites (P < 0.05). Conversely, the respiratory disturbance index was associated with increased mechanical pain thresholds on the forearm (P < 0.05).


CONCLUSIONS
High rates of PI and sleep apnea highlight the need to refer TMD patients complaining of sleep disturbance for polysomnographic evaluation. The association of PI and hyperalgesia at a nonorofacial site suggests that PI may be linked with central sensitivity and could play an etiologic role in idiopathic pain disorders. The association between sleep disordered breathing and hypoalgesia requires further study and may provide novel insight into the complex interactions between sleep and pain-regulatory processes.
Smith
Michael T
MT
Johns Hopkins University School of Medicine, Department of Psychiatry and Behavioral Sciences, Baltimore, MD, USA. msmith62@jhmi.edu
Wickwire
Emerson M
EM
Grace
Edward G
EG
Edwards
Robert R
RR
Buenaver
Luis F
LF
Peterson
Stephen
S
Klick
Brendan
B
Haythornthwaite
Jennifer A
JA
D000328:Adult; D002012:Bruxism / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006930:Hyperalgesia / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D008137:Longitudinal Studies; D008297:Male; D008396:Maryland; D008875:Middle Aged; D020189:Nocturnal Myoclonus Syndrome / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D017288:Pain Threshold; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D012893:Sleep Wake Disorders / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D013706:Temporomandibular Joint Dysfunction Syndrome / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D055815:Young Adult