Background & Aims

Central Sensitization (CS) is the increased responsiveness of nociceptive neurons in the central nervous system to their normal or subthreshold afferent input (1). It is characterized by a reduced pain threshold and an increased receptive area (2,3), attributed to peripheral and central alterations that facilitate the passage of nociceptive stimuli. The CS Inventory (CSI) has been applied in clinical settings to identify symptoms of CS.
Temporomandibular disorders (TMD) involve the temporomandibular joints and associated tissues, causing orofacial pain (4). Although some studies have shown that central sensitization may be present in chronic cases of TMD (5–9), the possible confounders of this relationship are not clear.
We aimed to investigate the association between painful TMD and the CSI score and to assess the presence of confounders of this association, considering the presence of migraine, depression, parafunctional oral behaviors, mandibular disability, and widespread pain.

Methods

This is a cross-sectional study, conducted during the COVID-19 pandemic, approved by the local Ethics Committee (27067319.0.0000.5416). Women with and without self-reported orofacial pain complaints signed the Informed Consent Form, answered the TMD Pain Screener (10), and went through an online physical examination to determine the presence of painful TMD (11).
The CSI (12) was used to identify symptoms of CS. As possible confounders, the following questionnaires were applied: Headache Screening Questionnaire (13), Patient Health Questionnaire-9, Oral Behavior Checklist, Jaw Functional Limitation Scale (10), and the Nordic musculoskeletal questionnaire (14).
A single regression investigated the association between the CSI and TMD, and a multiple regression investigated the effect of the other outcomes as possible confounders. Confounding was considered present when the association between TMD and CSI changed more than 10% after adding a possible confounder to the regression model.

Results

Women with (n=42) and without (n=53) TMD were included. The CSI was highly correlated with the presence of painful TMD (R=0.799), the PHQ-9 (R=0.787), the number of painful regions (R=0.721), and the presence of Migraine (R=0.691). The JFLS was moderately correlated with the CSI (R=0.514).
The single regression analysis confirmed the association between the CSI score and the presence of painful TMD (R2=0.639; p-value< 0.001). Then, a multiple regression was conducted including the variables that were at least moderately correlated (R>0.5) with both the CSI and the presence of painful TMD. Therefore, the variables considered as possible confounders of the association were the presence of migraine, depression, the number of painful regions of the body, and the presence of parafunction. The results showed a reduction of more than 10% on the b-values after adjusting the association between the CSI score and the presence of painful TMD, indicating that they confounded that association

Conclusions

The positive association between the presence of painful TMD and the CSI score was confounded by migraine, symptoms of depression, widespread pain, and parafunctional oral habits.

References

1.https://www.iasp-pain.org/Education/Content.aspx?ItemNumber=1698.
2.Woolf CJ. Central sensitization: Implications for the diagnosis and treatment of pain. Pain. 2011;152(SUPPL.3):S2-S15.
3.Chichorro JG, Porreca F, Sessle B. Mechanisms of craniofacial pain. Cephalalgia. 2017;37(7):613-626.
4.de Leeuw R, Klasser GD, eds. Orofacial Pain. Guidelines for Asssessment, Diagnosis and Management. 6th ed. Quintessence Publishing Co; 2018.
5.Oono Y, Wang K, Baad L, Futarmal S, Kohase H, Svensson P. Conditioned pain modulation in temporomandibular disorders (TMD) pain patients. Exp Brain Res. 2014.
6.King C, F W, Currie T, Mauderli AP, Fillingim RB, Riley JL. Deficiency in endogenous modulation of prolonged heat pain in patients with Irritable Bowel Syndrome and Temporomandibular Disorder. 2009;143(3):172-178. doi:10.1016/j.pain.2008.12.027.Deficiency
7.Kothari SF, Baad-hansen L, Oono Y, Svensson P. Somatosensory assessment and conditioned pain modulation in temporomandibular disorders pain patients. Pain. 2015;156(12):2545-2555.
8.Fernández-de-las-Peñas C, Galán-del-Río F, Fernández-Carnero J, Pesquera J, Arendt-Nielsen L, Svensson P. Bilateral widespread mechanical pain sensitivity in women with myofascial temporomandibular disorder: evidence of impairment in central nociceptive processing. J Pain. 2009;10(11):1170-1178.
9.Pfau DB, Rolke R, Nickel R, Treede R, Daublaender M. Somatosensory profiles in subgroups of patients with myogenic temporomandibular disorders and fibromyalgia syndrome. Pain. 2009;147(1-3):72-83.
10.Pereira FJ, Gonçalves DAG. Diagnostic Criteria for Temporomandibular Disorders: Assessment Instruments (Brazilian Portuguese ). 2019.
11.Exposto FG, Castrillon EE, Exposto CR, Mara D, Costa F. Remote physical examination for temporomandibular disorders. Pain. 2021;00(00).
12.Caumo W, Sipmann RB. The Central Sensitization Inventory validated and adapted for a Brazilian population?: psychometric properties and its relationship with brain-derived neurotrophic factor. J Pain Res. 2017;10:2109-2122.
13.Lopes EP, Oliveira AB, Gonçalves DADG, et al. Translation and cross-cultural adaptation of the Headache Screening Questionnaire into Brazilian Portuguese. Musculoskelet Sci Pract. 2022;102574.
14.De Barros ENC, Alexandre NMC. Cross-cultural adaptation of the Nordic musculoskeletal questionnaire. Int Nurs Rev. 2003;50(2):101-108.

Presenting Author

Luiz Felipe Tavarez

Poster Authors

Letícia Calixtre

PhD. PT.

Universidade de Pernambuco - Campus Petrolina

Lead Author

Hedwig Aleida van der Meer

PhD. PT

Academic centre for dentistry amsterdam - The Netherlands

Lead Author

Luiz Felipe Tavarez

Universidade Federal de São Carlos - Brazil

Lead Author

Corine Mirjam Visscher

Academic centre for dentistry amsterdam - The Netherlands

Lead Author

Ana Beatriz Oliveira

UFSCar

Lead Author

Daniela Gonçalves

Faculdade de Odontologia de Araraquara, UNESP- Brazil

Lead Author

Topics

  • Specific Pain Conditions/Pain in Specific Populations: Migraine
  • Specific Pain Conditions/Pain in Specific Populations: Orofacial Pain