Abstract
BACKGROUND: To date, no validated assessment of motor imagery (MI) ability with temporomandibular disorders (TMD) exists preventing identification of good imagers and appropriate MI use during TMD rehabilitation. OBJECTIVE: To assess the reliability and construct validity of the previously developed Tongue and Mouth Imagery Questionnaire (TMIQ) compared with the gold-standard Kinaesthetic and Visual Imagery Questionnaire (KVIQ-10). METHODS: Both KVIQ-10 and TMIQ assess MI ability using vividness (i.e. clarity/brightness for visual MI, (V) MI; or intensity for kinesthetic MI, (K) MI) of MI using a 5-point Likert scale (1: no image/sensation, 5: clear/intense image/sensation). The KVIQ-10 was administered once (test) and the TMIQ twice (test-retest) to heathy participants and patients with TMD. Questionnaire validity was investigated using concurrent validity (Pearson correlation and paired t test); TMIQ-test-retest reliability (intraclass correlation coefficients, ICCs); internal consistency (Cronbach ⍺) and the factorial structure (principal factor extraction). RESULTS: A total of 94 participants were included (n = 47 per group). The mean vividness scores of the KVIQ-10 and the TMIQ were significantly correlated, and not significantly different for both groups indicating concurrent validity. ICCs in the control group (range: 0.82-0.90), and in the TMD group (range: 0.75-0.82) indicated good reproducibility. The Cronbach ⍺ values were all above 0.94, indicating excellent reliability. Two factors were extracted corresponding to (V) MI and (K) MI, and explained 66% of total variance. CONCLUSION: The TMIQ is a valid and reproducible MI questionnaire showing excellent internal consistency and, therefore, can be used to assess imagined movements of the TM region in healthy individuals and patients with TMD.