Glossary of Periodontal Terms – A

ABERRANT: Varying or deviating from the usual or normal course, form, or location.

ABFRACTION: Hypothetical tooth surface abrasion in conjunction with occlusal forces; data supporting this term as a discrete clinical entity are not yet available (See Abrasion; Erosion.)

ABRASION: Wearing away of a substance or structure through an abnormal mechanical process. Examples include gingival and dental abrasions due to incorrect brushing.

ABSCESS: Localized collection of purulent exudates (pus) in a cavity formed by the disintegration of tissues.

ACUTE A.: An abscess of relative short duration, typically producing pain and local inflammation.

APICAL A.: Inflammatory condition characterized by formation of purulent exudate involving the dental pulp or pulpal remnants and the tissues sun’ounding the apex of a tooth.

CHRONIC A.: I. Abscess of comparatively slow development with little evidence of inflammation. There may be an intermittent discharge of purulent matter. 2. Long-standing collection of purulent exudate. It may follow an acute abscess. See: Abscess, Residual.

GINGIVAL A.: A localized purulent infection that involves the marginal gingiva or interdental papilla.

PERICORONAL A.: A localized purulent infection within the tissue surrounding the crown of a partially erupted tooth.

PERIODONTAL A. (Parietal A.): Localized purulent inflammation in the periodontal tissues; also called lateral periodontal abscess.

PULPAL A.: Inflammation of the dental pulp characterized by the formation of purulent exudate.

RESIDUAL A.: Abscess produced by the residues of a previous inflammatory process.

WANDERING A.: Abscess in which purulent material flows along a course of decreased resistance and discharges at a distant point.

ABSORPTION: I. Passage of a substance into the interior of another substance. 2. Passage of fluids or sub tances through tissues. 3. Attenuation of radiation energy by the substance through which it passes.

ABUTMENT: Tooth, root, or implant used to support and/or anchor a fixed or removable prosthesis.

INTERMEDIATE A.: Abutment located between other abutments.

ACANTHOLYSIS: Dissolution of the intercellular attachments within the prickle cell layer (stratum spinosum) of stratified squamous epithelium.  Classically seen in pemphigus vulgaris during vesicle and bulla formation.

ACANTHOSIS: Hyperplasia of the prickle cell layer (stratum spinosum) of stratified squamous epithelium, resulting in thickened rete ridges or widening of this layer.

ACATALASIA (Acatalasemia): Deficiency in the blood and tissues of the enzyme catalase, sometimes resulting in oral ulceration and destruction of alveolar bone.

ACCRETION: Accumulation on the teeth of foreign materials such as plaque, materia alba, and calculus.

ACELLULAR: Lacking in cells.

ACHE: Any dull, continuous pain. Thought to be the psychological manifestation of c-fiber (slow, nonmyelinated) nociceptive impulses with origin outside the central nervous system.

ACQUIRED: Not congenital, but attained after birth. Examples include acquired immunodeficiency syndrome (See AIDS), acquired immunity and acquired reflexes.

ACQUIRED CENTRIC: See: Occlusion, Centric


ACTINOBACILLUS ACTINOMYCETEMCOMITANS: Small, Gram-negative, non-motile, facultatively anaerobic, rod-shaped bacteria found in subgingival and marginal plaque. A periodontal pathogen implicated in some forms of periodontitis. Linked most often with the aggressive periodontal diseases.

ACTINOMYCES ISRAELII: Gram-positive, nonmotile, non-acid fast, non-spore forming, anaerobic bacilli with a tendency to grow as branched filaments in tissues. Commensals that usually coexist peacefully with their hosts, but under some conditions emerge as opportunistic pathogens involved in infections of both soft tissues and teeth.

ACTINOMYCES NAESLUNDII: Gram-positive, non-motile, anaerobic bacteria that preferentially colonize the tongue and other mucosal surfaces; can also colonize the oral cavity prior to tooth eruption.

ACTINOMYCES VISCOSUS: Gram-positive, non-motile, facultatively anaerobic, filamentous, pleomorphic bacteria that form branched filaments. These indigenous microflora colonize the mouths of humans and other animals and are associated with gingivitis, periodontitis, and root caries.

ACTINOMYCOSIS: Clinical infection caused by a species of the genus Actinomyces. Abscess formation is common and, in the cervicofacial form of the disease, usually drains to the skin surface.

ACUTE: I. Sharp, severe. 2. Denoting the swift onset and course of a disease.

ACUTE NECROTIZING ULCERATIVE GINGIVITIS (ANUG): See: Periodontitis, Necrotizing Ulcerative.

ACUTE NECROTIZING ULCERATIVE PERIODONTITIS (ANUP): See: Periodontitis, Necrotizing Ulcerative.

ACYCLOVIR: A synthetic acyclic purine nucleoside with selective antiviral activity against many, but not all, herpes viruses.

ADENITIS: Inflammation of a lymph node or gland.

ADENOPATHY: Pathologic enlargement of glands, especially lymphatic glands.

ADENOVIRUS: A DNA virus 80 to 90 nanometers in size. It can cause respiratory illness and conjunctivitis in humans. Human adenoviruses comprise at least 31 serotypes that can be divided into three groups on the basis of oncogenicity.

ADHERENCE: The act or quality of uniting two or more surfaces or parts.

ADHESION: The property of remaining in close proximity; the molecular attraction existing between the surfaces of contacting bodies.

ADJUSTMENT, OCCLUSAL: See: Occlusal Adjustment

ADJUNCTIVE TREATMENT: Supplementary and additional therapeutic procedures. In periodontics, it generally refers to procedures other than scaling and root planing and surgical therapy, such as chemotherapy, occlusal therapy, and restorative care.

ADSORPTION: The attachment of a substance to the surface of another.

AEROBE: A microorganism that can live and grow in the presence of molecular oxygen.

AEROBIC: Environmental conditions that contain atmospheric levels of oxygen. Used in reference to microorganisms that grow optimally under these conditions. See: Facultative.

AGRANULOCYTOSIS (Granulocytopenia): A pathologic decrease in the number of circulating granulocytes-neutrophils, eosinophils, and basophils.


the progressive loss of immune function that characterizes the progression of human

immunodeficiency virus infection. This natural history is thought responsible for opportunistic, pernicious and eventually fatal conditions that include Kaposi’s sarcoma, Pneumocystis carinii pneumonia, and others. Oral lesions may include necrotizing

ulcerative gingivitis (NUG), necrotizing ulcerative periodontitis (NUP), linear gingival erythema (LGE), candidiasis, hairy leukoplakia, herpes simplex, and rapidly progressive periodontitis.

ALLELE: One of two or more different genes that may occupy the same locus on a specific chromosome.

ALLERGEN: A substance capable of producing allergy or specific hypersensitivity.

ALLERGY: The altered reactivity of a sensitized individual on exposure to an allergen.

ALLOGRAFT: See: Graft, Allograft.

ALVEOLAR BONE: See: Bone, Alveolar.

ALVEOLAR CREST: The most coronal portion of the alveolar process.

ALVEOLAR CREST FIBER: See: Fiber, Principal.

ALVEOLAR MUCOSA: See: Mucosa, Alveolar.

ALVEOLAR PROCESS: See: Process, Alveolar.

ALVEOLECTOMY: Removal of a portion of the alveolar process usually performed to achieve acceptable ridge contour in preparation for construction of a denture or placement of an implant.

ALVEOLU S: The socket in the bone into which a tooth is attached by means of the periodontal ligament.

AMINO GLYCO SIDES: A group of antibiotics (streptomycin, gentamycin, tobramycin) commonly combined synergistically with penicillins.

AMPU TATION, ROOT: Removal of a root from a tooth retained in situ.

ANAEROBE: A microorganism that can survive inpartial or complete absence of molecular oxygen.

ANAEROBIC: Used in reference to microorganisms that can survive and grow in the absence of molecular oxygen.

ANALGESIA : Absence of sensibility; the relief of pain without loss of consciousness.

ANAPH YLACTIC SHO CK: A severe, sometimes fatal, immediate allergic reaction, usually occurring seconds to minutes after exposure to an antigen and mediated via histamine.

ANA PH YLAXIS: Immediate hypersensitivity response to antigenic challenge, mediated by IgE and mast cells; typically life-threatening.

ANATOMIC CROWN: See: Crown, Anatomic.

ANATOMIC LANDMARK: A readily recognizable anatomical structure used as a point of reference.

ANESTHESIA : Loss of feeling or sensation caused by an anesthetic agent to permit diagnostic and treatment procedures.

BLOCK A.: Local anesthesia of a nerve trunk.

GENERAL A.: Depression of the central nervous system caused by anesthetic agents and characterized by simultaneous hypnosis, analgesia, and varying clegrees of muscular relaxation, including-typically, the loss of protective laryngeal reflexes.

INFILTRATION A.: Local anesthesia of terminal nerves.

LOCAL A.: Loss of sensation in a localized area of the body, but without central effect.

REGIONAL A.: Local anesthesia of a regional body area.

TOPICAL A.: Anesthetic effect produced by the application of an anesthetic agent to a surface area.

ANGINA PECTORIS: Paroxysmal thoracic pain with feeling of suffocation and impending death; usually due to anoxia of the myocardium and precipitated by effort or excitement.

ANGULA R CHEILITIS: See: Cheilitis, Angular.

ANKYLOGLOSSIA (Tongue-Tie): Partial or complete fusion of the tongue with the floor of the mouth or the lingual gingiva due to an abnormally short, mid-line lingual frenulum, resulting in restricted tongue movement.

ANK YLO SIS: I. Joint: fibrous or bony fixation. 2. Tooth: fusion of the tooth and the alveolar bone.

ANODONTIA : Congenital absence of the teeth. See: Oligodontia.

ANOMALY: A deviation from the usual form, location, or arrangement of a structure.

ANTAGONIST, DENTAL: A tooth in one jaw that articulates with a tooth in the opposing jaw.

ANTERIO R GU IDANCE: The influence on mandibular movement resulting from contact of opposing anterior teeth.

ANTIBIOTIC: Molecules or agents produced by microorganisms that have the capacity to kill or inhibit the growth of other microorganisms.

ANTIBODY: Serum proteins that are induced following interaction with an antigen. They bind specifically to the antigen that induced their formation thereby causing or facilitating the antigen’s neutralization. See: Immunoglobulin.

ANTICOAGULANT: Any substance or agent that inhibits or prevents the coagulation of blood.

ANTIGEN: Any substance recognized by the immune system that induces antibody formation.

ANTIMICROBIAL THERAP Y: The use of specific agents for the control or destruction of microorganisms, either systemically or at specific sites.

ANTISEPTIC: An agent that inhibits the growth and development of microorganisms.

ANTISPA SMODIC: An agent capable of preventing or relieving convulsions or muscular spasms.

ANTRUM: A cavity or chamber, especially in a bone.See: Sinus.

MAXILLARY A CA. of Highmore).: The air cavity in the body of the maxilla, lined with respiratory epithelium, that normally lies superior to the roots of the premolars and molars and generally extends from the canine or premolar region posterior to the molar or tuberosity region. It communicates with the middle meatus of the nose.

APERTURE: An opening or orifice.

APEX, TOOTH: The anatomic end of a tooth root.

APHTHA: An ulcer of the oral mucous membrane. Multiple ulcers are termed apthae.

HERPETIFORM A.: Characterized by clusters of multiple, shallow ulcers throughout the oral cavity. Almost continuous in nature.

MAJOR A.: Large, scarring, recurrent aphthae, which may last for weeks or months. Previously termed periadeni’ tis

MINOR A.:’ The most common form of recurrent aphthae. Also known as a canker sore. Shallow, painful, non-scarring ulcers surrounded by an erythematous halo that are usually found on movable, non-keratinized oral mucosa.

APICAL CURETTAGE: See: Curettage, Apical.

APICOECTOMY: The surgical removal of the apex of a tooth root.

APLASTIC: Without development; not forming.

APOPTOSIS: Cell death via fragmentation into membrane-enclosed particles that can be phagocytosed by other cells.

APPROXIMATION: The state of being near or close together, as in root approximation.

ARACHIDONIC ACID: A 20-carbon essential fatty acid that contains four double bonds (5, 8, II, 14- eicosatetraenoic acid); the precursor of prostaglandins, prostacyclins, thromboxanes, and leukotrienes.

A.RACHNIA. PROPIONICA.: See: Propionibacterium Propionus.

ARCH, DENTAL: The curved composite structure of the natural dentition and the alveolar ridge, or the residual bone after the loss of some or all of the natural teeth

ARCHITECTURE: A term with an appropriate modifier, commonly used in periodontics to describe gingival and/or bony form.

PHYSIOLOGIC A.: A concept of soft tissue or bony form that includes positive architecture in a vertical dimension, buccal-lingual contours devoid of ledges and exostoses, and interradicular grooves.

POSITIVE A.: When the crest of the interdental gingiva or bone is located coronal to its midfacial midlingual margins.

REVERSE A.: When the crest of the interdental gingiva or bone is located apical to its midfacial and mid-lingual margins.

ARTHRALGIA : Pain in a joint.

ARTHROGRAPHY: Radiographic evaluation of a joint after injection of radiopaque contrast material.

ARTICULATION: I. The contact relationships of mandibular teeth with maxillary teeth in excursive movements of the mandible. 2. A junction or union between two or more bones. 3. A skeletal joint.

ARTICULATOR: A mechanical device representing the temporomandibular joint and jaw members to which maxillary and mandibular casts may be attached.

ARTIFACT: Any artificial product or appearance. Used in histology and radiology to signify details or apparent conditions that are unnatural and misleading, owing to imperfect technique or materials.

ASACCHAROLY TIC: The inability of an organism to catabolize carbohydrates. Generally relates to sugar metabolism.

ASEPTIC: Free from infection or septic material; sterile.

ASTRINGENT: An agent that causes contraction of the tissues, arrests secretion, or controls bleeding.

ATRAUMATIC: Not inflicting or causing damage or Injury.

ATROPHY: Diminution in size of a cell, organ, tissue, or part.

DISUSE A.: Results from inactivity.

PHYSIOLOGIC A.: Affects certain organs in all individuals as part of the normal aging process.

POST-MENOPAUSAL A.: A thinning of various tissues, such as the oral mucosa, following menopause.

SENILE A.: The atrophy of tissues due to advanced age.

ATTACHED GINGIVA: See: Gingiva, Attached.

ATTACHMENT APPA R ATUS: The cementum, periodontal ligament, and alveolar bone.

ATTACHMENT, EPITHELIAL : See: Epithelium, Junctional.

ATTACHMENT LEVEL, CLINICA L : The distance from the cemento-enamel junction to the tip of a periodontal probe during periodontal diagnostic probing. The health of the attachment apparatus can affect the measurement.

ATTACHMENT LEVEL, RELATIVE: The distance from a fixed reference point on a tooth or stent to the tip of the periodontal probe during usual periodontal diagnostic probing. The health of the attachment apparatus can affect the measurement. See: Attachment Level, Clinical.

ATTACHMENT, NEW: The union of connective tissue or epithelium with a root surface that has been deprived of its original attachment apparatus. This new attachment may be epithelial adhesion and/or connective adaptation or attachment and may include new cementum.

ATTRITION: The physiologic wearing away of a substance or structure, such as the teeth.

ATYPIA : Not conforming to type; irregular.

AUGMENTATION: The act of enlarging or increasing, as in size, extent, or quantity.

EDENTULOUS RIDGE A.: Procedures designed to correct a deformed alveolar ridge.

GINGIVAL A.: Procedures designed to increase the quantity of attached gingiva.

AUSCULTATION: The process of determining the condition of various parts of the body by listening to the sounds they emit.

AUTOGENOUS: Self-produced; not derived from an external source.

AUTOGENOUS BONE GRAFT: See: Graft, Autogenous Bone.

AUTOGRAFT: See: Graft, Autograft.

AUTOIMMUNITY: An immune response to an organism’s own tissues or components.

AUTOLOGOUS MIXED LYMPHOCYTE REACTION: A proliferative response of normal Tlymphocytes when co-cultured with autologous HLADR positive non-T-Iymphocytes.

AUTORA DIOGRAPHY: Photographic recording of radiation from radioactive material obtained by placing the surface of the radioactive material in proximity to a detector sensitive to the emitted spectrum, most commonly, X-ray film or a charge coupled device.

AVASCULA R : Lacking in blood supply (e.g., tooth enamel).

AVITA MINOSIS: A condition due to a deficiency of vitamins.

AVULSION: The complete separation of a tooth from its alveolus. See also: Evulsion.

A XIS: I. A real or imaginary straight line passing through the center of a body, such as the mandible. 2. “Long axis of a tooth,” the central lengthwise line through the crown and the root. 3. A real or imaginary straight line around which a body may rotate.

No Responses

Leave a Reply

Your email address will not be published. Required fields are marked *