Temporomandibular dysfunction experience is associated with oral health-related quality of life: an Australian national study.

Background: There are very few studies of the association between temporomandibular dysfunction (TMD) and oral health-related quality of life (OHRQoL) in a representative sample from the Asia-Pacific region. Accordingly, we aimed to quantify the association of TMD with OHRQoL dimensions and overall measurement scores in a representative sample of Australian adults while accounting for a range of confounders, and statistically estimating whether TMD experience is meaningfully associated with OHRQoL.

Method: Australia's National Survey of Adult Oral Health 2004-2006 data were used. The outcome variables were the Oral Health Impact Profile (OHIP-14) domains and overall scores while the main exposure was self-reported Diagnostic Criteria Question for TMD. The analysis accounted for confounders including oral health status obtained from the oral examination, demographics, socioeconomics, health behaviours and health including perceived stress subscales of the PSS-14. We conducted complex samples analysis while using Cohen's f effect size to estimate whether the association is meaningful.

Results: TMD prevalence was 9.9% (95% CI: 8.4-11.6%) among 4133 Australian adults. TMD experience was associated with impairments to the seven OHIP-14 OHRQoL domains (P < .05) with higher impairments observed in physical pain (B = 0.82, 95% CI: .45-1.20, P < .001), psychological discomfort (B = 0.68, 95% CI: .29-1.06, P = .001) and psychological disability (B = 0.52, 95% CI: .20-.84, P = .001) in adjusted multivariate analyses. The difference in the mean OHIP-14 scores for those reporting TMD (Mean = 13.1, 95% CI: 12.0-14.0) and those who did not (Mean = 6.6, 95% CI: 6.0-6.8) was significant (t = 7.51, P < .001). In an adjusted multivariable model for OHIP-14 scores, TMD experience was associated with higher OHIP-14 scores (B = 3.34, 95% CI: 1.94-4.75, P < .001) where the Cohen's f was .022. Further, perceived stress subscales: perceived distress and perceived control were associated with TMD experience and OHIP-14 scores (P < .05).

Conclusion: Lower OHRQoL was observed in Australian adults who reported TMD experience but with small clinical importance which might support considering TMD in regular dental care. The higher impairments observed in physical pain, psychological discomfort and psychological disability domains of OHRQL can help clinicians and researchers focus their attention on these domains. The confounding effect exhibited by the perceived stress subscale might support their inclusion in future TMD and OHRQoL research.