Periodontal disease is associated with increased coronary heart disease risk: A meta-analysis based on 38 case-control studies

Figure 4 Filled funnel plot with pseudo-95%CIs of the 38 studies. Log of odds ratio (OR) represents the natural logarithm of the OR of individual studies; Standard error by Log OR represents the standard error in the natural logarithm of the OR of individual studies. A circle in the figure represents a study, while a black spot represents an unpublished study which may exist to negate the results of the meta-analysis.