Study Healthy subjects (n) Gingivitis subjects (n) Mild perio subjects (n) Moderate perio subjects (n) Chronic perio subjects (n) Generalized aggressive severe subjects (n) Chronic with immunosuppressant subjects (n) Conclusion
Bostanci et al., (GCF) [68] 21 22     28 25 11 GCF RANKL &OPG were oppositely regulated in periodontitis groups.
Bostanci et al., Gingival tissue [69] 9 8     11 12 10 RANKL/OPG ratio increased in all periodontitis groups.
Lu et al. (GCF and gingiva) [6] 4       20     GCF RANKL, but not OPG was elevated in periodontitis groups.
Mogi et al., (GCF) [70] 28   27 58   47   RANKL/OPG ratio was significantly elevated in periodontitis groups.
Liu et al., (Gingival tissue) [71] 6     27   25   RANKL/OPG was elevated in
periodontitis groups.
Kawai et al., (gingiva and blood) [72] 12       32     sRANKL, but not OPG was significantly higher in periodontitis gropus.
Wara-aswapati et al., (gingiva and plaque) [73] 15       15     RANKL/OPG ratio was significantly higher in perioidontitis groups
Garlet et al., (gingival tissue) [74] 10 7     20 16   RANKL/OPG and MMP/TIMP expression determined disease progression/severity
Nagasawa et al., (gingival tissue) [75] 2       30     OPG is induced by LPS-stimulated gingival fibroblast.
sRANKL: Soluble Receptor Activator of Nuclear Factor-Kappa B Ligand; TIMP: Tissue Inhibitors of Metalloproteinases; LPS: Lipopolysaccharides; perio: Periodontitis
Table 1: Summary of human studies evaluating the RANKL and OPG in Periodontal Disease.