Quantitative Assessment of Temporomandibular Joint Space in Bruxers: A Cross-Sectional Radiographic Study

TL;DR

This study uses CBCT scans to show that bruxism causes measurable changes in TMJ space, suggesting early detection is possible.

Contribution

The study provides quantitative evidence of TMJ space alterations in bruxers using CBCT, revealing distinct displacement patterns.

Findings

Bruxers showed significantly reduced superior joint space (SJS) and increased posterior joint space (PJS) compared to nonbruxers.

Age was negatively correlated with SJS in bruxers, indicating progressive joint space narrowing.

Male bruxers had significantly higher PJS than female bruxers, suggesting gender-based differences in TMJ response to bruxism.

Abstract

Bruxism is a parafunctional habit that can lead to significant dental and musculoskeletal complications. Chronic bruxism may impose excessive and abnormal mechanical loads on the temporomandibular joint (TMJ), potentially altering joint morphology and joint space dimensions. These changes can be subtle and asymptomatic initially, but they may progress to disorders such as disc displacement, joint pain, and functional limitations. Radiographic evaluation of TMJ space, particularly through advanced imaging modalities such as cone beam computed tomography (CBCT), offers a noninvasive means of quantifying joint space alterations. However, the relationship between bruxism and TMJ space narrowing or asymmetry remains inadequately understood, with inconsistent findings across existing literature.

To quantitatively evaluate the TMJ space in individuals with bruxism using CBCT and compare findings with matched nonbruxer controls.

A cross-sectional study was conducted on 75 patients clinically diagnosed with bruxism (age 20–45 years, 36 males, 39 females). CBCT scans were analyzed to measure anterior joint space (AJS), superior joint space (SJS), and posterior joint space (PJS) bilaterally. Data were compared to normative values from 30 age- and sex-matched nonbruxers. Independent t-test was used to compare joint space dimensions between bruxers and nonbruxers, with significance set at p < 0.05.

Bruxers demonstrated a significantly reduced SJS (2.73 ± 0.39 mm) and increased PJS (3.29 ± 0.44 mm) compared to nonbruxers (3.16 ± 0.34 mm and 2.80 ± 0.37 mm, respectively) on CBCT analysis (p < 0.001), indicating distinct condylar displacement patterns. Age was significantly negatively correlated with SJS, indicating progressive joint space narrowing with advancing age in bruxers. Male bruxers showed significantly higher PJS compared to females (p = 0.018), potentially reflecting gender-based anatomical or functional variation in response to bruxism.

The present study demonstrated that bruxers exhibit significantly increased posterior and reduced SJS dimensions compared to nonbruxers, indicating early condylar positional alterations detectable on CBCT that may aid in timely diagnosis and prevention of symptomatic temporomandibular joint disorders.

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