Background & Aims
Temporomandibular disorder (TMD) is a general term that embraces several dysfunctions involving the temporomandibular joint, the masticatory muscles, and associated structures.(1) Pain and maximum mouth opening (MMO) outcomes are commonly evaluated in clinical and research fields.(2) Pain is the main reason patients seek treatment, but limited mouth opening seems to be a sign presented only in some TMD patients.(3,4) Conversely, some authors have suggested that an extended mouth opening may be an important sign for TMD development, but this still lacks understanding regarding patterns and cut-offs.(3,5,6) Thus, the aim of this study was to verify the prevalence of different joint mobility degrees (low, regular, and extended mobility) in painful TMD patients. The secondary aim was to verify whether there is a correlation between pain intensity and jaw mobility in these individuals.
Methods
One hundred and four painful TMD subjects were included. A physical therapist applied the Diagnostic Criteria for TMD (DC/TMD)(7) to verify the presence of TMD and to measure mouth range of motion (ROM). A digital caliper was used during the physical examination, and the measurements were taken according to the DC/TMD protocol. The pain-free opening (PFO) and maximum unassisted opening (MUO) were added to the vertical incisal overlap and used for statistical analyses. Opening ROM < 40 mm was considered low mobility, between 40mm and 50 mm regular mobility, and >50 mm extended mobility.(3,5,7) Orofacial pain intensity was verified using the Numeric Pain Rating Scale (NPRS) and categorized as mild (?3), moderate (between 4 and 6), and severe (?7). A non-parametric chi-square test was used to compare the prevalence of low, regular, and extended ROM in painful TMD participants. Spearman’s rho was used to analyze the correlation between pain intensity and jaw ROM.
Results
The sample was composed of 104 participants (80% women; median age 33 years, IQR: 25–41; median orofacial pain intensity 6, IQR: 4–8; 30% muscle pain, 70% joint and muscle pain; 4% acute TMD, 94% chronic TMD, 2% missing). Of those, 42.3% presented PFO <40 mm, 40.4% had PFO between 40 and 50 mm, and 17.3% presented PFO > 50 mm (?²(2) = 12.077, p=0.002). Regarding MUO, 8.7% had <40 mm, 29.8% presented regular ROM, and 61.5% presented MUO > 50 mm (?²(2)=44.212,p<0.001). When categorizing NPRS, 18.3% had mild pain intensity, 32.7% had moderate pain, and 45.2% presented severe pain (3.8% missing values). A negative and weak correlation was found between PFO and pain intensity (r=-0.202; p=0.044) and between MUO and pain intensity (r=-0.298; p=0.003).
Conclusions
A recent study investigated the most common therapy outcome measures in TMDs, and MMO was the second most used measure.(2) Despite its great importance in function, it is crucial to select an optimized way to evaluate painful TMD patients. The DC/TMD proposes three opening measures: PFO, MUO, and maximum assisted opening.(7) Our results showed a high prevalence of participants with low mobility considering PFO. However, when assessing MUO, the participants with extended ROM were more prevalent. Both measures showed a weak correlation with pain intensity, which is expected considering the complexity of pain and its multiple domains.(8) However, clinical trials usually aim to improve MMO (besides pain intensity), and we found a higher prevalence of extended jaw mobility in painful TMD participants. Thus, our results suggest the need for further investigations in order to select the best clinical measure to evaluate opening ROM in painful TMD patients.
References
1 – International Classification of Orofacial Pain, 1st edition (ICOP). Cephalalgia. 2020;40(2):129-221. doi: 10.1177/0333102419893823.
2 – Ooi K, Aihara M, Matsumura H, Matsuda S, Watanabe Y, Yuasa H, et al. Therapy outcome measures in temporomandibular disorder: a scoping review. BMJ Open. 2022;12(8):e061387. doi: 10.1136/bmjopen-2022-061387.
3 – Zhang Q, Yuan S, Deng K, Li X, Liang Y, Wu A, et al. Correlation of patients’ demographics and clinical symptoms with temporomandibular disorders. Cranio. 2023;41(5):432-439. doi: 10.1080/08869634.2020.1866923.
4 – Ângelo DF, Mota B, João RS, Sanz D, Cardoso HJ. Prevalence of Clinical Signs and Symptoms of Temporomandibular Joint Disorders Registered in the EUROTMJ Database: A Prospective Study in a Portuguese Center. J Clin Med. 2023;12(10):3553. doi: 10.3390/jcm12103553.
5 – Nosouhian S, Haghighat A, Mohammadi I, Shadmehr E, Davoudi A, Badrian H. Temporomandibular Joint Hypermobility Manifestation Based on Clinical Observations. J Int Oral Health. 2015;7(8):1-4.
6 – Kulesa-Mrowiecka M, Piech J, Ga?dzik TS. The Effectiveness of Physical Therapy in Patients with Generalized Joint Hypermobility and Concurrent Temporomandibular Disorders-A Cross-Sectional Study. J Clin Med. 2021;10(17):3808. doi: 10.3390/jcm10173808.
7 – Schiffman E, Ohrbach R, Truelove E, Look J, Anderson G, Goulet JP, et al. Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) for Clinical and Research Applications: recommendations of the International RDC/TMD Consortium Network* and Orofacial Pain Special Interest Group†. J Oral Facial Pain Headache. 2014;28(1):6-27. doi: 10.11607/jop.1151.
8 – Raja SN, Carr DB, Cohen M, Finnerup NB, Flor H, Gibson S, et al. The revised International Association for the Study of Pain definition of pain: concepts, challenges, and compromises. Pain. 2020;161(9):1976-1982. doi: 10.1097/j.pain.0000000000001939.
Presenting Author
Taísi Antunes da Cunha
Poster Authors
Taísi Antunes da Cunha
PhD
Universidade Nove de Julho
Lead Author
Nathalia Rosa
BSc
Universidade Nove de Julho
Lead Author
Alcylene Carla de Jesus dos Santos
MSc
Universidade Nove de Julho and State University of Bahia
Lead Author
Cindy Nakamura
MSc
Universidade Nove de Julho
Lead Author
Fabiana Xavier
BSc
Universidade Nove de Julho
Lead Author
Melissa Luiza Moura
MSc
RM Physiotherapy Clinic
Lead Author
Daniela Biasotto-Gonzalez
PhD
Universidade Nove de Julho
Lead Author
Topics
- Specific Pain Conditions/Pain in Specific Populations: Orofacial Pain