This book is a concrete base of understanding on how collagen in the skeleton of the periodontium. Collagen serves immense functions related to the structural integrity of the body as well in the periodontal mechanism. As collagen forms building block of body structures, any defect in collagen results in disorders, such as osteogenesis imperfecta, Ehlers-Dalnos syndrome, scurvy, systemic lupus erythematosus, systemic sclerosis, Stickler syndrome, oral submucous fibrosis, Marfan syndrome, epidermolysis bullosa, Alport syndrome. It presents with a rapid turnover rate which along with its biochemical composition would thereby help in determining a pathological involvement causing periodontal destruction. This book discusses the role of collagen in health as well as disease.