Fig. 1
From: Association between periodontitis and temporomandibular joint disorders
Directed graph of bidirectional two-sample MR analysis evaluating the potential causality between X and Y. Genetic variants GX can be used to estimate the causal effect of exposure X on outcome Y. Genetic variants GY can be used to estimate the causal effect of outcome Y on exposure X. The solid and dashed lines denote causal and noncausal effects, respectively. An arrow from X to Y indicates a causal effect of X on Y directly