Validity and Reliability of the Turkish Version of the Temporomandibular Joint Ankylosis Quality of Life Questionnaire (TMJAQoL-TR) in Patients with Severe Temporomandibular Disorders

TL;DR

This study validates a Turkish version of a questionnaire to assess quality of life in patients with severe temporomandibular disorders.

Contribution

The study provides a culturally adapted and validated Turkish version of the TMJAQoL questionnaire for TMJ-related quality of life assessment.

Findings

The TMJAQoL-TR showed excellent internal consistency (Cronbach’s α = 0.879) and high test–retest reliability (ICC = 0.995).

Strong correlations were found with OHIP-14 (r = 0.772) and moderate with VAS pain scores (r = 0.312).

Exploratory factor analysis supported a two-factor structure, and no significant floor or ceiling effects were detected.

Abstract

Background: The Temporomandibular Joint Ankylosis Quality of Life Questionnaire (TMJAQoL) is a disease-specific instrument designed to assess quality of life in patients with temporomandibular joint (TMJ) ankylosis. No validated Turkish version of this scale existed prior to this study. The aim of this study was to translate, culturally adapt, and evaluate the Turkish version of the TMJAQoL (TMJAQoL-TR) in patients with severe temporomandibular disorders, including a predefined ankylosis subgroup. Materials and Methods: A total of 120 patients with temporomandibular complaints were included. Test–retest reliability was evaluated in a clinically stable subsample of 72 participants with a one-week interval. Following forward–backward translation and cultural adaptation procedures, the TMJAQoL-TR was administered together with the Oral Health Impact Profile Short Form-14 (OHIP-14), the Short Form-36 (SF-36), and Visual Analog Scale (VAS) pain scores. Reliability was assessed using Cronbach’s α, item-level Weighted Cohen’s Kappa, and test–retest Intraclass Correlation Coefficients (ICC), supported by measurement error indices (Standard Error of Measurement [SEM] and Minimal Detectable Change at 95% confidence [MDC95]). Construct validity was examined using Spearman correlation coefficients. Structural validity was investigated through exploratory factor analysis, followed by a confirmatory structural model in AMOS to evaluate preliminary model consistency. Floor and ceiling effects were analyzed using the 15% criterion. Results: The TMJAQoL-TR demonstrated excellent internal consistency (Cronbach’s α = 0.879) and very high test–retest reliability (ICC = 0.995; 95% CI: 0.992–0.997). Strong correlations were observed with OHIP-14 (r = 0.772, p < 0.01), and moderate correlations with VAS pain scores (r = 0.312, p < 0.01). No significant floor or ceiling effects were detected. A weak but significant negative correlation with the SF-36 physical role subscale suggests that TMJ-related quality of life impairment is associated with role limitations in daily activities, although the magnitude of this association was modest. Exploratory factor analysis supported a clinically coherent two-factor structure, and the AMOS structural model demonstrated acceptable consistency with this framework. Conclusions: The TMJAQoL-TR appears to be a valid and reliable instrument for assessing quality of life in patients with severe TMJ-related functional limitations. Findings from the ankylosis subgroup support potential applicability within the instrument’s original target population; however, further validation in larger ankylosis-specific samples is warranted.

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