Cytokines are highly important peptide mediators which are involved in cell signalling and communication. Proinflammatory cytokines like TNF-α, IL-1, and IL-6 contribute to bone loss by stimulating osteoclastogenesis and increasing bone resorption. These cytokines activate signaling pathways that accelerate osteoclast development and activity, which leads to enhanced bone loss. This book compiles pertinent publications which demonstrate the role of cytokines in periodontal diseases in order to assess the role of pro-inflammatory interleukins in alveolar bone resorption and that increased alveolar bone loss was positively related with elevated levels of pro-inflammatory cytokines. The results indicate that increased levels of inflammatory cytokines have a role in the destruction of alveolar bone.