The prevalence of temporomandibular disorder and temporomandibular morphology among diverse chronotype profiles

ABSTRACT

This study investigates the influence of chronotype on the prevalence of temporomandibular joint disorders (TMD) and the morphology of temporomandibular joint (TMJ). According to the Morningness–Eveningness Questionnaire-Self-Assessment, the participants were divided into morning group (n = 30), intermediate group (n = 83), and evening group (n = 30). Thirty participants were randomly selected from the intermediate group for subsequent examination and measurements. The morphology of TMJs was investigated using questionnaire and clinical examination form in Diagnostic Criteria for Temporomandibular Disorder. Meanwhile, the morphological results of TMJs were measured from cone-beam computed tomography images. The prevalence rate of TMD in the morning group (23%) was significantly lower than that in the intermediate group (56.7%), while there was no difference between the evening (53.4%) and intermediate groups. As to morphological measurements, there was no significant difference among three groups in mediolateral width of condylar process, anteroposterior width of condylar process, radius of condyle, medial joint space, lateral joint space, condylar stress angle, horizontal condylar inclination, width of glenoid fossa, depth of glenoid fossa, and posterior joint space, while there was a significant difference in horizontal condylar angle (p = 0.00490), articular eminence inclination (p < .0001), anterior joint space (p = 0.0163), and superior joint space (p = 0.0004). The morphology of TMJ in the morning group was better than that in the evening and intermediate groups. An association was found between TMD prevalence, temporomandibular morphology, and chronotype.

KEYWORDS:

• Circadian rhythm
• temporomandibular disorder
• temporomandibular joint
• temporomandibular morphology
• CBCT

Disclosure statement

No potential conflict of interest was reported by the author(s).

Ethical approvel

Our study was approved by the Medical Ethics Committee in the Third Affiliated Hospital of Sun Yat-sen University (reference [2020]02-109-01) and is registered in the Chinese Clinical Trial Registry (ChiCTR, www.chictr.org.cn). The registration number is ChiCTR2100052415.

Additional information

Funding

This work is supported by the National Natural Science Foundation of China [No. 82271021], the Guangdong Basic and Applied Basic Research Foundation, China [No. 2021A1515010460], the Science and Technology Projects in Guangzhou, China [No. 202102080157], and Guangdong Financial Fund of High – Caliber Hospital Construction [KF2020110101].