Yanhua Dong,* Xueman Zhou,* Jie Xiang, Yunhao Zheng, Yingcheng Zheng, Xin Xiong, Jun Wang

State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Xin Xiong; Jun Wang, West China Hospital of Stomatology, Sichuan University, No. 14 section 3, Renmin South Road, Chengdu, 610041, People’s Republic of China, Email drxiongxin@scu.edu.cn; wangjunv@scu.edu.cn

Objective: This cross-sectional study aimed to investigate the association between insomnia and the presence of temporomandibular disorders (TMD) and its subtypes in orthodontic patients.
Methods: A total of 648 adult orthodontic patients (158 males and 490 females, median age 26) were included and completed a questionnaire containing sociodemographic information, insomnia severity index (ISI), the five major temporomandibular disorder symptoms (5Ts) checklist, and self-reported sleep bruxism. Presence of insomnia and TMD of the included patients was determined according to the diagnostic criteria, and statistical analyses were conducted as appropriate to compare ISI-related scores between TMD and non-TMD participants. Further, multivariable regressions were performed to detect the potential correlation between insomnia and TMD in orthodontic patients.
Results: Orthodontic patients with TMD scored significantly higher in both the individual items and the total sum of ISI than those without TMD. More patients were bothered by insomnia in the TMD group than the non-TMD counterparts (26.6% vs 16.7%, p=0.003). After adjusting for confounding variables, insomnia was found to be significantly correlated with TMD in orthodontic patients (OR=1.677, 95% CI 1.128, 2.511). Subgroup analysis of TMD subtypes showed a significant positive association of insomnia with pain-related TMD (OR=2.007, 95% CI 1.331, 3.015).
Conclusion: Insomnia was associated with a higher prevalence of pain-related TMD rather than intra-articular TMD in orthodontic patients.

Keywords: temporomandibular disorders, pain, insomnia, orthodontic treatment