# The prevalence of masticatory muscle pain in healthy individuals with class I and class II malocclusion: a cross-sectional study

## TL;DR

This study found that masticatory muscle pain is common in healthy individuals with different types of malocclusion, but there was no significant difference between the groups.

## Contribution

The study provides new evidence that malocclusion types do not significantly influence the prevalence of masticatory muscle pain.

## Key findings

- All groups showed a high incidence of myalgia, regardless of malocclusion type.
- No significant difference in muscle pain was found between class I and class II malocclusion groups.
- Symptoms of functional disorders were common, suggesting the need for screening in healthy individuals.

## Abstract

The etiopathogenesis of TMD is complex and involves multiple factors. The role of occlusal abnormalities in the painful form of TMD remains controversial. This study aimed to determine the prevalence of myalgia in patients with class I and class II malocclusion.

A total of 256 generally healthy patients, aged 25–30, with class I and class II malocclusion, were examined. Medical histories and physical examinations were conducted using the DC/TMD Form. Based on the clinical findings, the patients were divided into three groups: Group I consisted of patients with class I malocclusion; Group II included patients with class II malocclusion and proclined incisors; and Group III comprised patients with class II malocclusion and retruded incisors. Within each group, cases with muscle pain and those without were identified based on the data from the DC/TMD Form.

All studied groups (Groups I, II, and III) showed a high incidence of myalgia. However, statistical analysis did not show a significant difference in the overall occurrence of muscle pain between the groups, nor were there significant differences in pain incidence when examining individual muscles among the groups.

No association was found between malocclusion and the occurrence of muscle pain. However, the more frequent presence of symptoms related to functional disorders, such as myalgia, highlights the need for screening and treatment even in generally healthy patients.