Table 4.
Univariate associations between self-reported jaw clicking and jaw locking as etiologic risk factors measured categorically and incidence rate of first-onset TMD, OPPERA prospective cohort study, USA (2006–2011)
| Putative risk factor | Category | N | Site-adjusted(1) TMD incidence rate (% of people per annum) | Study site-adjusted effect(2) | Site, demographic adjusted effect(3) | P-value | Imputed values for loss to follow-up(4) | P-value |
|---|---|---|---|---|---|---|---|---|
| TMJ noises in last month | 1 or more | 546 | 4.41 | 1.47 (1.11, 1.93) | 1.58 (1.19, 2.08) | 0.001 | 1.61 (1.21, 2.13) | <0.001 |
| 0 [ref] | 2151 | 2.99 | ||||||
| Pain with TMJ noises in last month | Yes | 45 | 6.21 | 1.87 (0.91, 3.79) | 1.97 (0.96, 4.00) | 0.062 | 1.95 (0.96, 3.96) | 0.064 |
| No [ref] | 2645 | 3.22 | ||||||
| TMJ noises before last month | 1 or more | 599 | 4.54 | 1.56 (1.19, 2.04) | 1.69 (1.28, 2.22) | <0.001 | 1.66 (1.25, 2.19) | <0.001 |
| 0 [ref] | 2099 | 2.90 | ||||||
| In last month, could not open mouth wide for any reason | Yes | 60 | 8.80 | 2.71 (1.62, 4.51) | 2.66 (1.58, 4.44) | <0.001 | 2.46 (1.42, 4.24) | 0.001 |
| No [ref] | 2648 | 3.15 | ||||||
| Prior to one month ago, could not open mouth wide for any reason | Yes | 172 | 5.13 | 1.61 (1.07, 2.42) | 1.67 (1.10, 2.51) | 0.014 | 1.59 (1.03, 2.45) | 0.035 |
| No [ref] | 2533 | 3.15 | ||||||
| In the last month, could not close jaw from wide-open position | Yes | 51 | 5.02 | 1.53 (0.72, 3.25) | 1.55 (0.72, 3.28) | 0.260 | 1.52 (0.69, 3.32) | 0.290 |
| No [ref] | 2654 | 3.21 | ||||||
| Prior to one month ago, could not close jaw from wide-open position | Yes | 115 | 4.49 | 1.38 (0.80, 2.36) | 1.39 (0.81, 2.38) | 0.230 | 1.40 (0.81, 2.41) | 0.220 |
| No [ref] | 2600 | 3.20 |
Adjusted rates computed using Poisson regression controlling for study site (categorical variable, 4 levels). Estimated rate is for reference study site (University of Buffalo)
Rate ratio represents relative increase in incidence rate of TMD relative to reference group. Calculated using Cox proportional hazard regression model adjusted for study site (categorical variable, 4 levels).
As for footnote 2, with additional adjustment for age in years), gender (categorical, 2 levels), race/ethnicity (categorical, 2 levels) and lifetime U.S. residence (categorical, 2 levels)
As for footnote 3, with inclusion of imputed TMD rates for subjects lost to follow-up and imputed data for values missing at baseline