title: Pressure pain thresholds fluctuate with, but do not usefully predict, the clinical course of painful temporomandibular disorder.
abstract: Central sensitization elicits pain hypersensitivity and is thought to be causally implicated in painful temporomandibular disorder (TMD). This causal inference is based on cross-sectional evidence that people with TMD have greater sensitivity than controls to noxious stimuli. We tested this inference in the Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA) prospective cohort study of 3258 adults with no lifetime history of TMD when enrolled (visit 1). During 5 years of follow-up, 1 group labeled "persistent TMD cases" (n=72) developed first-onset TMD by visit 2 that persisted ⩾ 6 months until visit 3. Another group labeled "transient TMD cases" (n=75) developed first-onset TMD at visit 2, which resolved by visit 3. Randomly sampled "controls" (n=126) remained TMD-free throughout all 3 visits. At each visit, pressure pain thresholds (PPTs) were measured by algometry at 10 cranial and bodily sites. In persistent TMD case patients, mean PPTs reduced 43 kPa (P<.0001) between visits 1 and 2 and thereafter did not change significantly. In transient TMD case patients, mean PPTs reduced 41 kPa (P<.001) between visits 1 and 2, and then increased 20 kPa (P<.001) by visit 3. These patterns were similar after excluding cranial sites symptomatic for TMD. Importantly, visit 1 PPTs had no clinically useful prognostic value in predicting first-onset TMD (odds ratio [OR]=1.07, P=.15). Among first-onset case patients, visit 2 PPTs were modest predictors of persistent TMD (OR=1.36, P=.002). In this longitudinal study, PPTs reduced when TMD developed then rebounded when TMD resolved. However, premorbid PPTs poorly predicted TMD incidence, countering the hypothesis that PPTs signify mechanisms causing first-onset TMD.
authors.affiliation: Center for Pain Research and Innovation, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Dental Ecology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. Electronic address: gary_slade@dentistry.unc.edu.
authors.forename: Gary D
authors.initials: GD
authors.lastname: Slade
authors.affiliation: Center for Pain Research and Innovation, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Dental Ecology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: Anne E
authors.initials: AE
authors.lastname: Sanders
authors.affiliation: Department of Oral Diagnostic Sciences, University at Buffalo, Buffalo, NY, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Ohrbach
authors.affiliation: Department of Community Dentistry & Behavioral Science, University of Florida, Gainesville, FL, USA.
authors.forename: Roger B
authors.initials: RB
authors.lastname: Fillingim
authors.affiliation: Department of Neural and Pain Sciences, University of Maryland School of Dentistry, Baltimore, MD, USA; Brotman Facial Pain Center, University of Maryland School of Dentistry, Baltimore, MD, USA.
authors.forename: Ron
authors.initials: R
authors.lastname: Dubner
authors.affiliation: Center for Pain Research and Innovation, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Endodontics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: Richard H
authors.initials: RH
authors.lastname: Gracely
authors.affiliation: Center for Pain Research and Innovation, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Endodontics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Bair
authors.affiliation: Center for Pain Research and Innovation, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Endodontics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: William
authors.initials: W
authors.lastname: Maixner
authors.affiliation: Department of Neural and Pain Sciences, University of Maryland School of Dentistry, Baltimore, MD, USA; Brotman Facial Pain Center, University of Maryland School of Dentistry, Baltimore, MD, USA.
authors.forename: Joel D
authors.initials: JD
authors.lastname: Greenspan
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology*; D011312:Pressure; D013705:Temporomandibular Joint Disorders / Q000503:physiopathology*; D055815:Young Adult
keywords: Algometry; Epidemiology; Longitudinal studies; Pressure pain thresholds; Temporomandibular disorder