Quantitative analysis of masticatory muscle changes by Eichner index using diffusion-weighted imaging

Area of Science:

• Biomedical Imaging
• Quantitative Histology
• Dental Occlusion

Background:

• Diffusion-weighted imaging (DWI) offers insights into microscopic water diffusion.
• Quantitative evaluation of masticatory muscle histology using DWI related to occlusal changes is limited.
• Assessing masticatory muscle changes due to occlusal relationships is crucial for understanding oral health.

Purpose of the Study:

• To quantitatively assess histological changes in masticatory muscles using DWI based on the Eichner index.
• To investigate the relationship between apparent diffusion coefficient (ADC) values and occlusal status.
• To explore correlations between ADC values, age, and sex in masticatory muscles.

Main Methods:

• Analysis of 201 patient MRI studies from November 2017 to April 2018.
• Categorization of patients by Eichner index, age, and sex.
• Statistical analysis including Kruskal-Wallis, Mann-Whitney, multiple regression, and Spearman correlation to compare mean ADC values.

Main Results:

• Significant differences in mean ADC values were observed across Eichner index groups, with the lowest in group C (P < 0.001).
• A negative correlation was found between ADC values of the masseter and lateral pterygoid muscles and age (P < 0.001).
• Significant differences in ADC values were noted between sexes (P < 0.001).

Conclusions:

• Masticatory muscle ADC values differ significantly based on the Eichner index.
• DWI-derived ADC values show potential for quantitative evaluation of masticatory muscles affected by occlusal status.