Regional cutaneous and muscle sensitivity does not mediate changes in active mouth opening in temporomandibular disorders: a cross-sectional study

Background: One of the main goals of treatment in temporomandibular disorder (TMD) patients is to improve mouth opening range of motion. However, it is not clear which factors influence its alteration. The aim of this study was to compare differences in mechanosensitivity, mouth opening and psychosocial factors, between people with and without TMD, to evaluate if changes observed in active mouth opening are mediated by an increase in tissues’ mechanosensitivity, and to evaluate factors related to mandibular-related disability. Subjects with and without TMD were recruited. Methods: Cross-sectional study conducted in Spain. The measured variables were the Craniofacial Pain and Disability Inventory (CF-PDI), pain intensity, pressure pain thresholds (PPT) at local points; active and passive mouth opening; the Short-Form 12 questionnaire (SF-12); the State-Trait Anxiety Inventory (STAI); and the Neck Disability Index (NDI). Multivariable regression and mediation models were constructed. Results: A total of 179 subjects (85 with TMD) were included. Subjects with TMD had less mouth opening range of motion, and lower PPT. Tissues’ mechanosensitivity did not mediate the reduction in active mouth opening in subjects with TMD (overall indirect effect, 0.98; 95% confidence interval, −0.87 to 3.12). Finally, no variable showed an association with CF-PDI. Conclusions: Subjects with TMD seem to have decreased mouth opening, and greater mechanosensitivity of masticatory muscles, when compared with healthy controls. Tissues’ mechanosensitivity does not seem to mediate the reduction of active mouth opening in subjects with TMD, and there seems to be no relationship between PPT measures, mental health outcomes, the NDI and mandibular-related disability.

Temporomandibular disorder; Physical therapy; Mediation; Causality

[1] Minervini G, Marrapodi MM, Siurkel Y, Cicciù M, Ronsivalle V. Accuracy of temporomandibular disorders diagnosis evaluated through the diagnostic criteria for temporomandibular disorder (DC/TDM) Axis II compared to the Axis I evaluations: a systematic review and meta-analysis. BMC Oral Health. 2024; 24: 299.

[2] Klasser GD, Goulet J, Moreno-Hay I. Classification and diagnosis of temporomandibular disorders and temporomandibular disorder pain. Dental Clinics of North America. 2023; 67: 211–225.

[3] Arribas-Pascual M, Hernández-Hernández S, Jiménez-Arranz C, Grande-Alonso M, Angulo-Díaz-Parreño S, La Touche R, et al. Effects of physiotherapy on pain and mouth opening in temporomandibular disorders: an umbrella and mapping systematic review with meta-meta-analysis. Journal of Clinical Medicine. 2023; 12: 788.

[4] Matheson EM, Fermo JD, Blackwelder RS. Temporomandibular disorders: rapid evidence review. American Family Physician. 2023; 107: 52–58.

[5] Ohrbach R, Bair E, Fillingim RB, Gonzalez Y, Gordon SM, Lim PF, et al. Clinical orofacial characteristics associated with risk of first-onset TMD: the OPPERA prospective cohort study. The Journal of Pain. 2013; 14: T33–T50.

[6] Cuenca-Martínez F, Herranz-Gómez A, Madroñero-Miguel B, Reina-Varona Á, La Touche R, Angulo-Díaz-Parreño S, et al. Craniocervical and cervical spine features of patients with temporomandibular disorders: a systematic review and meta-analysis of observational studies. Journal of Clinical Medicine. 2020; 9: 2806.

[7] Silveira A, Armijo-Olivo S, Gadotti IC, Magee D. Masticatory and cervical muscle tenderness and pain sensitivity in a remote area in subjects with a temporomandibular disorder and neck disability. Journal of Oral & Facial Pain and Headache. 2014; 28: 138–146.

[8] Šedý J, Rocabado M, Olate LE, Vlna M, Žižka R. Neural basis of etiopathogenesis and treatment of cervicogenic orofacial pain. Medicina. 2022; 58: 1324.

[9] Idáñez-Robles AM, Obrero-Gaitán E, Lomas-Vega R, Osuna-Pérez MC, Cortés-Pérez I, Zagalaz-Anula N. Exercise therapy improves pain and mouth opening in temporomandibular disorders: a systematic review with meta-analysis. Clinical Rehabilitation. 2023; 37: 443–461.

[10] Li C, Zhang Q. Comparison of imaging findings of 714 symptomatic and asymptomatic temporomandibular joints: a retrospective study. BMC Oral Health. 2023; 23: 79.

[11] GBD 2021 Oral Disorders Collaborators. Trends in the global, regional, and national burden of oral conditions from 1990 to 2021: a systematic analysis for the Global Burden of Disease Study 2021. The Lancet. 2025; 405: 897–910.

[12] Beaumont S, Garg K, Gokhale A, Heaphy N. Temporomandibular disorder: a practical guide for dental practitioners in diagnosis and management. Australian Dental Journal. 2020; 65: 172–180.

[13] Perry SK, Emrick JJ. Corrigendum: Trigeminal somatosensation in the temporomandibular joint and associated disorders. Frontiers in Pain Research. 2024; 5: 1454278.

[14] Zicarelli CAM, Santos JPM, Poli-Frederico RC, Silva RA, Barrilec F, Barrette G, et al. Reliability of pressure pain threshold to discriminate individuals with neck and low back pain. Journal of back and musculoskeletal rehabilitation. 2021; 34: 363–370.

[15] von Elm E, Altman DG, Egger M, Pocock SJ, Gøtzsche PC, Vandenbroucke JP. The strengthening the reporting of observational studies in epidemiology (STROBE) statement: guidelines for reporting observational studies. Journal of Clinical Epidemiology. 2008; 61: 344–349.

[16] Lee H, Cashin AG, Lamb SE, Hopewell S, Vansteelandt S, VanderWeele TJ, et al. A guideline for reporting mediation analyses of randomized trials and observational studies. JAMA. 2021; 326: 1045.

[17] Fernández-Matías R. Calculating the sample size in health sciences: recommendations and practical guide. Journal of Move & Therapeutic Science. 2023; 5: 481–503.

[18] Hayes AF. Introduction to mediation, moderation, and conditional process analysis: a regression-based approach. 3rd edn. Guilford Press: New York, USA. 2022.

[19] Euasobhon P, Atisook R, Bumrungchatudom K, Zinboonyahgoon N, Saisavoey N, Jensen MP. Reliability and responsivity of pain intensity scales in individuals with chronic pain. Pain. 2022; 163: e1184–e1191.

[20] Orellana-Donoso M, Romero-Zucchino D, Fuentes-Abarca A, Aravena-Ríos P, Sanchis-Gimeno J, Konschake M, et al. Infraorbital canal variants and its clinical and surgical implications. A systematic review. Surgical and Radiologic Anatomy. 2024; 46: 1027–1046.

[21] Gandek B, Ware JE, Aaronson NK, Apolone G, Bjorner JB, Brazier JE, et al. Cross-validation of item selection and scoring for the SF-12 health survey in nine countries. Journal of Clinical Epidemiology. 1998; 51: 1171–1178.

[22] La Touche R, Pardo-Montero J, Gil-Martínez A, Paris-Alemany A, Angulo-Díaz-Parreño S, Suárez-Falcón JC, et al. Craniofacial pain and disability inventory (CF-PDI): development and psychometric validation of a new questionnaire. Pain Physician. 2014; 17: 95–108.

[23] Alfonso Andrade Ortega J, Damián Delgado Martínez A, Almécija Ruiz R. Validation of a Spanish version of the neck disability index. Medicina Clínica. 2008; 130: 85–89.

[24] Julian LJ. Measures of anxiety: state-trait anxiety inventory (STAI), beck anxiety inventory (BAI), and hospital anxiety and depression scale-anxiety (HADS-A). Arthritis Care & Research. 2011; 63: S467–S472.

[25] Ferrari S, Cribari-Neto F. Beta regression for modelling rates and proportions. Journal of Applied Statistics. 2004; 31: 799–815.

[26] Cribari-Neto F, Zeileis A. Beta regression in R. Journal of Statistical Software. 2010; 34: 1–24.

[27] Cakir M, Yalcin Ülker GM, Erdogan Ö. Prevalence and comparison of temporomandibular disorders according to Axis I in RDC/TMD and DC/TMD: a cross-sectional study. Quintessence International. 2025; 56: 238–247.

[28] La Touche R, Paris‐Alemany A, Hidalgo‐Pérez A, López‐de‐Uralde‐Villanueva I, Angulo‐Diaz‐Parreño S, Muñoz‐García D. Evidence for central sensitization in patients with temporomandibular disorders: a systematic review and meta‐analysis of observational studies. Pain Practice. 2018; 18: 388–409.

[29] 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. The Journal of Pain. 2009; 10: 1170–1178.

[30] Hilgenberg-Sydney PB, Wilhelm JM, Pimentel G, Petterle R, Bonotto D. Prevalence of temporomandibular disorders and anxiety state levels in ballet dancers a cross-sectional study. Journal of Dance Medicine & Science. 2020; 24: 88–92.

[31] Fernandes Azevedo AB, Câmara-Souza MB, Dantas IS, de Resende CMBM, Barbosa GAS. Relationship between anxiety and temporomandibular disorders in dental students. CRANIO®. 2018; 36: 300–303.

[32] Namvar MA, Afkari BF, Moslemkhani C, Mansoori K, Dadashi M. The relationship between depression and anxiety with temporomandibular disorder symptoms in dental students. Maedica. 2021; 16: 590–594.

[33] De La Torre Canales G, Câmara‐Souza MB, Muñoz Lora VRM, Guarda‐Nardini L, Conti PCR, Rodrigues Garcia RM, et al. Prevalence of psychosocial impairment in temporomandibular disorder patients: a systematic review. Journal of Oral Rehabilitation. 2018; 45: 881–889.

[34] Delgado-Delgado R, Iriarte-Álvarez N, Valera-Calero JA, Centenera-Centenera MB, Garnacho-Garnacho VE, Gallego-Sendarrubias GM. Association between temporomandibular disorders with clinical and sociodemographic features: an observational study. International Journal of Clinical Practice. 2021; 75: e13961.

[35] Kapos F, Look J, Zhang L, Hodges J, Schiffman E. Predictors of long-term temporomandibular disorder pain intensity: an 8-year cohort study. Journal of Oral & Facial Pain and Headache. 2018; 32: 113–122.

[36] Sánchez-Torrelo CM, Zagalaz-Anula N, Alonso-Royo R, Ibáñez-Vera AJ, López Collantes J, Rodríguez-Almagro D, et al. Transcultural adaptation and validation of the fonseca anamnestic index in a spanish population with temporomandibular disorders. Journal of Clinical Medicine. 2020; 9: 3230.

[37] Mori N, Miyanaka D, Tokita M, Kawada M, Sakakibara K, Hamsyah F, et al. Job demands and temporomandibular disorders: mediating and moderating effects of psychological distress and recovery experiences. Journal of Occupational Health. 2024; 66: uiad001.

[38] Chen L, Zhang S, Tan Y, Zheng Y, Fang S, Yi Y, et al. Anxiety mediates association between sex and jaw function limitation in temporomandibular disorder patients from China. Frontiers in Neurology. 2024; 15: 1398788.

[39] Austin PC, Fang J, Lee DS. Using fractional polynomials and restricted cubic splines to model non‐proportional hazards or time‐varying covariate effects in the Cox regression model. Statistics in Medicine. 2022; 41: 612–624.

[40] Silveira A, Gadotti IC, Armijo-Olivo S, Biasotto-Gonzalez DA, Magee D. Jaw dysfunction is associated with neck disability and muscle tenderness in subjects with and without chronic temporomandibular disorders. BioMed Research International. 2015; 2015: 512792.

[41] Akram M, Cerin E, Lamb KE, White SR. Modelling count, bounded and skewed continuous outcomes in physical activity research: beyond linear regression models. The International Journal of Behavioral Nutrition and Physical Activity. 2023; 20: 57.