The Role of Root Canal Treatment in Alleviating Endodontic Pain-Induced Asymmetry and Restoring Muscle Balance: A Self-Controlled Prospective Observational Study.

Abstract

This study aimed to investigate whether root canal treatment (RCT) restores muscle symmetry by measuring the thickness of masseter and anterior temporalis muscles using ultrasonography. A self-controlled prospective observational study was conducted with patients experiencing moderate-to-severe endodontic pain and masticatory laterality. Ultrasonographic measurements of masseter and anterior temporalis muscles were taken at rest and during contraction before RCT, 1 week after treatment and 3 months post-treatment. An asymmetry index was calculated to evaluate changes in muscle thickness over time. Significant increases in masseter muscle thickness were observed on the painful side, both at rest and during contraction, while the control side showed a significant increase only during contraction. No statistically significant changes were observed in anterior temporalis muscle thickness, although a similar trend was noted. The asymmetry indices decreased significantly over time, approaching zero by the third month. RCT effectively reduces muscle asymmetry caused by endodontic pain, restoring balanced masticatory function. Trial Registration: ClinicalTrials.gov identifier: NCT06853028.