THE RELIABILITY OF MEASURING PAIN EXTENT IN PATIENTS WITH TEMPOROMANDIBULAR DISORDERS AND THE ASSOCIATION BETWEEN PAIN EXTENT AND CLINICAL FEATURES

Pitance L1,2, De Longhi B3, Gerard E2, Cayrol T1, Roussel N4, Cescon C5, Falla D6, Barbero M51Université Catholique de Louvain / Institut de Recherche Expérimentale et Clinique, Neuro-musculo-Skeletal Lab (NMSK), Brussels, Belgium, 2Cliniques Universitaires Saint-Luc, Oral and Maxillofacial Surgery, Brussels, Belgium, 3Université Catholique de Louvain, Brussels, Belgium, 4University of Antwerp, Medicine and Health Sciences, Antwerp, Belgium, 5University of Applied Sciences and Arts of Southern Switzerland, Rehabilitation Research Laboratory 2rLab, Manno, Switzerland, 6University of Birmingham, Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), Birmingham, United KingdomBackground: Pain drawings (PDs) are frequently used to assess patients with pain and are included within the Diagnostic Criteria for Temporomandibular Disorders (DC-TMD). The PD helps clinicians to identify the presence of widespread pain or other regional pain conditions.Purpose: This study examines the association between pain extent extracted from the PD and clinical features in patients with temporomandibular disorders (TMD). Furthermore, the test-retest reliability of quantifying pain extent and pain location from five body diagrams representing different body regions was assessed (mouth, right and left profile of the head, and dorsal and frontal view of the full body).Methods: Forty patients with painful TMD, assessed by the Diagnostic Criteria for Temporomandibular disorders (DC-TMD - Axis 1), participated. Each patient shaded two consecutive electronic PDs using a digital tablet. A customized software quantified the pain extent for each body chart and presented the pain location according to standardized anatomical grids. Clinical features were evaluated. Secondary hyperalgesia was assessed via the pressure pain threshold over the tibialis anterior muscle of the right leg. Questionnaires were also completed by the participants including the Central Sensitization Inventory to screen for the presence of central sensitization, the Pain Catastrophizing Scale to assess pain catastrophizing, the SF-36 to assess quality of life, the brief pain inventory (short form) to evaluate the severity of a patient´s pain and the impact of this pain on the patient´s daily functioning, the Hospital Anxiety and Depression Scale to evaluate the level of anxiety and depression, the Nijmegen questionnaire to assess hyperventilation, the Neck Disability Index to assess neck disability and the HIT-6 questionnaire to assess adverse headache impact. The reliability of pain extent was evaluated using Intraclass Correlation Coefficients (ICC) and Bland Altman plots, while reliability of pain location was evaluated using the Jaccard index. Spearman correlation coefficients were computed to reveal correlations between pain extent and clinical features.Results: Significant correlations were observed between pain extent and all measured clinical features except for secondary hyperalgesia and pain catastrophizing. The ICCs for pain extent were very high ranging from 0.85 to 0.94. The Bland Altman showed a mean difference close to zero for the five PDs showing good reliability for pain extent. The Jaccard index ranged from 0.68 to 0.80 suggesting a good reliability for pain location.Conclusion(s): Digital pain drawings are a reliable tool to quantify pain extent and pain location in people with painful TMD. Furthermore, the extent of pain perceived is associated with a number of clinically relevant features highlighting the relevance of the PD when evaluating patients with TMD.Implications: Clinicians can reliably assess the pain extent and pain location of TMD patients with a digital tablet and PD acquisition software. Measures of pain extent can facilitate clinicians in the assessment and the monitoring of people with TMD and assist clinical decision making.Keywords: Temporomandibular disorders, pain drawing, diagnosisFunding acknowledgements: Fondation Saint-Luc - Fond Hervé ReychlerTopic: Musculoskeletal; Pain & pain managementEthics approval required: YesInstitution: Cliniques Universitaires Saint-LucEthics committee: Comité d’éthique hospitalo-facultaireEthics number: BE403201627582All authors, affiliations and abstracts have been published as submitted.