National Institute of Dental and Craniofacial Research Periodontal (Gum) Diseases: Causes, Symptoms and Treatment Periodontal (Gum) Diseases: Causes, Symptoms and Treatment National Institute of Dental and Craniofacial Research Gum disease National Institute of Dental and Craniofacial Research Periodontal (Gum) Diseases: Causes, Symptoms and Treatment