This book describes the relationship between occlusion and the health of periodontium. Healthy periodontal structures and occlusal forces. Overview of occlusion including its classification, mandibular movements, normal tooth contacts which occur in chewing and swallowing , occlusal parafunctioning as in bruxism. Trauma from occlusion its classification, etiology, types and stages, its examination and diagnosis and pathologic tooth migration. Clinical evaluation procedures which includes TMJ screening, intraoral evaluation of occlusion and occlusal therapy in form of coronoplasty, bite guards, splints and treatment of bruxism.