1. Figure 1. Illustrating confounders with a directed acyclic graph. A.A. Akinkugbe et al. J DENT RES 2016;0022034516639920 Copyright © by International & American Associations for Dental Research

2. Figure 2. Illustrating confounders and mediators with a directed acyclic graph and the unintended consequences of estimating direct causal effects by adjusting for mediators. A.A. Akinkugbe et al. J DENT RES 2016;0022034516639920 Copyright © by International & American Associations for Dental Research

3. Figure 3. Illustrating colliders with a directed acyclic graph and the unintended consequences of adjusting for colliders. A.A. Akinkugbe et al. J DENT RES 2016;0022034516639920 Copyright © by International & American Associations for Dental Research

4. Figure 4. Illustrating with a directed acyclic graph, variables that are simultaneously confounders and mediators and the unintended consequences of adjusting for such variables. A.A. Akinkugbe et al. J DENT RES 2016;0022034516639920 Copyright © by International & American Associations for Dental Research

5. Figure 5. The causal effect of received treatment on health care cost is confounded by compliance. A.A. Akinkugbe et al. J DENT RES 2016;0022034516639920 Copyright © by International & American Associations for Dental Research