Frequency distribution of temporomandibular disorders according to occlusal factors: A cross‑sectional study

Temporomandibular disorder (TMD) is a common condition affecting the temporomandibular joint and causes pain and discomfort. However, the role of factors contributing to this problem is still controversial. The purpose of this cross‑sectional study was to determine the correlation of occlusal factors and parafunctional habits with TMD and The determination of TMD prevalence among patients referring to Isfahan Dental School in 2017.

In this cross‑sectional study, A total of 200 patients between 20 and 50 years were examined and questioned based on the Research Diagnostic Criteria for Temporomandibular Disorders assessment instrument. The association of occlusal factors (dental relationship, lateral occlusal scheme, horizontal differences between centric occlusion and Maximum intercuspation (MI), difference between MI and mandibular resting position) and parafunctional habits (bruxism/ clenching and habits) with TMD was analyzed using Chi‑square tests and independent sample t‑test (α = 0.05). Binomial logistic regression analysis was performed with respect to confounding variables.

The prevalence of TMD in the studied sample was 58.9%. Only bruxism showed a significant difference between TMD and non‑TMD groups (P < 0.05). Other parafunctional and occlusal factors did not act as influential factors for TMD.

Parafunction may play an important role in the initiation of TMD, although other habits and occlusal factors are considered as noninfluential factors. However, larger sample size and multicenter sampling are recommended for the future studies.