Periodontal Attachment Loss: Loss or destruction of periodontal tissue caused by periodontitis or other destructive periodontal diseases or by injury during instrumentation. Attachment refers to the periodontal ligament which attaches to the alveolar bone. It has been hypothesized that treatment of the underlying periodontal disease and the seeding of periodontal ligament cells enable the creating of new attachment.Periodontal Pocket: An abnormal extension of a gingival sulcus accompanied by the apical migration of the epithelial attachment and bone resorption.Periodontal Index: A numerical rating scale for classifying the periodontal status of a person or population with a single figure which takes into consideration prevalence as well as severity of the condition. It is based upon probe measurement of periodontal pockets and on gingival tissue status.Dental Plaque Index: An index which scores the degree of dental plaque accumulation.Periodontal Diseases: Pathological processes involving the PERIODONTIUM including the gum (GINGIVA), the alveolar bone (ALVEOLAR PROCESS), the DENTAL CEMENTUM, and the PERIODONTAL LIGAMENT.Gingivitis: Inflammation of gum tissue (GINGIVA) without loss of connective tissue.Dental Devices, Home Care: Devices used in the home by persons to maintain dental and periodontal health. The devices include toothbrushes, dental flosses, water irrigators, gingival stimulators, etc.Periodontitis: Inflammation and loss of connective tissues supporting or surrounding the teeth. This may involve any part of the PERIODONTIUM. Periodontitis is currently classified by disease progression (CHRONIC PERIODONTITIS; AGGRESSIVE PERIODONTITIS) instead of age of onset. (From 1999 International Workshop for a Classification of Periodontal Diseases and Conditions, American Academy of Periodontology)Tooth Mobility: Horizontal and, to a lesser degree, axial movement of a tooth in response to normal forces, as in occlusion. It refers also to the movability of a tooth resulting from loss of all or a portion of its attachment and supportive apparatus, as seen in periodontitis, occlusal trauma, and periodontosis. (From Jablonski, Dictionary of Dentistry, 1992, p507 & Boucher's Clinical Dental Terminology, 4th ed, p313)Tooth Migration: The movement of teeth into altered positions in relationship to the basal bone of the ALVEOLAR PROCESS and to adjoining and opposing teeth as a result of loss of approximating or opposing teeth, occlusal interferences, habits, inflammatory and dystrophic disease of the attaching and supporting structures of the teeth. (From Boucher's Clinical Dental Terminology, 4th ed)Gingival Hemorrhage: The flowing of blood from the marginal gingival area, particularly the sulcus, seen in such conditions as GINGIVITIS, marginal PERIODONTITIS, injury, and ASCORBIC ACID DEFICIENCY.Chronic Periodontitis: Chronic inflammation and loss of PERIODONTIUM that is associated with the amount of DENTAL PLAQUE or DENTAL CALCULUS present. Chronic periodontitis occurs mostly in adults and was called adult periodontitis, but this disease can appear in young people.Gingival Recession: Exposure of the root surface when the edge of the gum (GINGIVA) moves apically away from the crown of the tooth. This is common with advancing age, vigorous tooth brushing, diseases, or tissue loss of the gingiva, the PERIODONTAL LIGAMENT and the supporting bone (ALVEOLAR PROCESS).Dental Scaling: Removal of dental plaque and dental calculus from the surface of a tooth, from the surface of a tooth apical to the gingival margin accumulated in periodontal pockets, or from the surface coronal to the gingival margin.Oral Hygiene: The practice of personal hygiene of the mouth. It includes the maintenance of oral cleanliness, tissue tone, and general preservation of oral health.Dental Plaque: A film that attaches to teeth, often causing DENTAL CARIES and GINGIVITIS. It is composed of MUCINS, secreted from salivary glands, and microorganisms.Gingival Crevicular Fluid: A fluid occurring in minute amounts in the gingival crevice, believed by some authorities to be an inflammatory exudate and by others to cleanse material from the crevice, containing sticky plasma proteins which improve adhesions of the epithelial attachment, have antimicrobial properties, and exert antibody activity. (From Jablonski, Illustrated Dictionary of Dentistry, 1982)