MOHAP Dentist Exam key terms

Loss of the ability to form new memories after an event, while older memories remain intact. In dentistry it is relevant to conscious sedation, where benzodiazepines can briefly produce this effect.

A class of drugs that enhance the inhibitory neurotransmitter GABA, producing anxiolysis, sedation, and amnesia. Midazolam is the most commonly used agent for dental sedation and for managing seizures.

A drug-induced state of depressed consciousness in which the patient retains protective airway reflexes and responds to verbal or light tactile stimulation. It is used to reduce anxiety during dental treatment.

The basic structural unit of enamel, formed by an ameloblast as a long crystalline column running from the dentinoenamel junction toward the surface. Rod orientation influences caries spread and cavity preparation.

A tall, columnar cell of the inner enamel epithelium that secretes enamel matrix and then mineralizes it. Ameloblasts are lost after tooth eruption, so enamel cannot regenerate.

The interface where enamel meets dentin at the crown, characterized by a scalloped border. It is a key landmark because caries reaching this junction spreads laterally along it.

A postmitotic, columnar cell lining the pulp periphery that secretes dentin throughout life. Its process extends into the dentinal tubules, and its activity increases in response to injury.

A microscopic channel running through dentin that houses an odontoblast process and contains fluid. Fluid movement within tubules underlies dentin hypersensitivity and provides a pathway for bacterial invasion.

Dentin formed rapidly by odontoblasts in response to injury such as caries or operative trauma. It is less regular than primary or secondary dentin and serves as a protective barrier for the pulp.

Sharp, brief pain arising from exposed dentin in response to thermal, evaporative, tactile, osmotic, or chemical stimuli that cannot be explained by any other dental defect. Tubular fluid movement is the accepted mechanism.

Mild to moderate pulpal inflammation caused by stimuli such as caries or restorative procedures, in which the pulp remains vital and the pain resolves after the stimulus is removed. Treatment is removal of the cause.

Severe, prolonged pulpal inflammation that cannot heal, producing spontaneous or lingering pain that persists after the stimulus is removed. Root canal treatment or extraction is required.

The distance from a coronal reference point to the apical constriction or desired apical limit of instrumentation in root canal treatment. Accurate determination prevents over- or under-instrumentation.

The narrowest point of the root canal near the apical foramen, typically located about 0.5 to 1 mm short of the radiographic apex. It is the ideal endpoint for canal preparation and obturation.

A device that determines working length by measuring electrical impedance between the endodontic file and the surrounding tissues. It is more reliable than radiographs when the apex is not clearly visible.

A thin layer of organic and inorganic debris created on dentin and root canal walls by instrumentation. In endodontics it must be removed with chelating agents and irrigants to allow disinfection and seal.

Use of a chlorine-releasing solution to dissolve organic tissue and kill microorganisms within the root canal system. Concentration and volume vary; extrusion into periapical tissues causes severe pain and tissue damage.

A multifactorial, biofilm-mediated, diet-modulated, progressive disease that destroys hard dental tissues through acid production by bacteria fermenting sugars. It is managed by risk assessment, prevention, and restoration.

A structured community of microorganisms embedded in a polysaccharide matrix and adhered to tooth surfaces. Its metabolic activity produces acids that demineralize enamel and dentin.

A structured evaluation of disease indicators and protective and pathological factors to predict a patient's likelihood of developing new caries. It guides the intensity of preventive and restorative care.

A pathologically deepened gingival sulcus, measured as the distance from the gingival margin to the base of the sulcus. Probing depth and attachment loss distinguish pocket type and severity.

The distance from the cementoenamel junction to the base of the periodontal pocket, reflecting destruction of periodontal attachment. It is the principal measure of periodontitis severity and progression.

The junction where the crown's enamel meets the root's cementum. Its relationship to the gingival margin and attachment level is central to diagnosing recession and attachment loss.

The shallow space between the free gingival margin and the tooth surface, normally about 1 to 3 mm deep in health. It is the site where periodontal probing begins.

Direct structural and functional connection between living bone and the surface of a load-bearing implant without intervening soft tissue. It is the biological basis for dental implant success.

The component that connects the implant fixture to the prosthesis, transmitting occlusal loads and supporting the crown or framework. Its design and material influence soft tissue health and esthetics.

The vertical distance between the maxilla and mandible when the teeth or occlusion rims are in contact. It guides fabrication of complete dentures and full-mouth rehabilitation.

The difference between the vertical dimension at rest and the occlusal vertical dimension, typically 2 to 4 mm. It is a key measurement when setting denture tooth position.

A maxillomandibular relationship in which the condyles are in their most anterior, superior position against the articular eminences, independent of tooth contact. It is a reproducible reference for prosthodontic records.

A local anesthetic injection near the mandibular foramen that anesthetizes the inferior alveolar nerve, providing pulpal anesthesia for mandibular posterior teeth. Failure is often due to accessory innervation or inaccurate landmarking.

The fascial space between the medial pterygoid muscle and the mandibular ramus that contains the inferior alveolar and lingual nerves. It is the target region for the standard mandibular nerve block.

Adverse systemic effects from excessive plasma levels of local anesthetic, presenting with tinnitus, metallic taste, perioral numbness, seizures, or cardiovascular collapse. Prevention relies on dose limits and aspiration.

A system classifying malocclusion by the anteroposterior relationship of the first molars, defining Class I, II, and III. It forms the basis of orthodontic diagnosis and treatment planning.

A standardized outline of skeletal and dental landmarks drawn from a lateral skull radiograph. It is used to measure jaw relationships and plan orthodontic or orthognathic treatment.

An appliance placed after premature loss of a primary tooth to preserve arch length and guide eruption of the permanent successor. It prevents crowding and impaction in the pediatric patient.

A three-dimensional imaging technique using a cone-shaped X-ray beam to produce volumetric images of maxillofacial structures at lower radiation dose than medical CT. It is used for implant planning and complex endodontics.

An intraoral imaging method in which the receptor is placed parallel to the tooth's long axis and the beam is directed perpendicular to both. It minimizes distortion and is preferred for periapical assessment.

Infection control practices applied to all patients regardless of diagnosis, including hand hygiene, gloves, eye protection, and safe handling of sharps. They reduce transmission of bloodborne pathogens in dental settings.

Use of pressurized saturated steam to destroy all microorganisms, including bacterial spores, on reusable dental instruments. Proper packaging and cycle monitoring are required to confirm effectiveness.

A patient's voluntary agreement to treatment after receiving and understanding information about the diagnosis, proposed procedure, alternatives, risks, and consequences of refusal. It is both an ethical and legal requirement.

The ethical and legal duty to protect a patient's health information from unauthorized disclosure. It may be overridden only by law, court order, or serious public health risk.