INI-CET MDS key terms

Alternating light and dark microscopic bands in enamel that reflect the changing direction of enamel prisms as they pass outward from the dentinoenamel junction toward the surface, improving fracture resistance.

Enamel region where prisms decussate in complex interwoven bundles, most often seen beneath cusps and incisal edges, where masticatory loads are highest.

Basic structural unit of enamel, a tightly packed crystalline column formed by one ameloblast, running from the dentinoenamel junction to the outer surface with a keyhole cross-section.

Interface where enamel meets dentin, scalloped in outline, with a high organic content that makes it a zone of stress concentration and a barrier to crack propagation.

Dentinal region in which the odontoblast process has been destroyed and the tubule is empty, appearing dark in ground sections and following injury or caries.

Irregular reparative dentin deposited on the pulpal wall opposite an irritant only by surviving odontoblasts or odontoblast-like cells, reducing tubular continuity and wall thickness.

Regular tubular dentin secreted by pre-existing surviving odontoblasts in response to a mild stimulus such as slow caries or attrition, preserving the original tubule pattern.

Double layer of epithelial cells continuous with the cervical loop that guides root dentin formation and, after breaking up, leaves epithelial rests of Malassez in the periodontal ligament.

Remnants of the Hertwig epithelial root sheath lying in the periodontal ligament near cementum; they can proliferate into radicular cysts when stimulated.

Junction between the crown's enamel and root cementum, occurring as cementum overlapping enamel, butt joint, or a gap leaving exposed dentin in roughly that order of frequency.

Not a dental term; in the cerebral cortex it is a visible stripe of myelinated fibers. In dental histology the analogous banding is Hunter-Schreger; do not confuse the two.

Most common odontogenic cyst, arising from epithelial rests of Malassez within a periapical granuloma driven by necrotic pulp; lined by non-keratinized stratified squamous epithelium.

Chronic inflammatory lesion at the root apex composed of granulation tissue, lymphocytes and macrophages, usually in a necrotic pulp, and the precursor of most radicular cysts.

Mixed odontogenic hamartoma, compound type with tooth-like denticles and complex type with a disorganized mass of enamel, dentin and cementum; commonest odontogenic tumor and usually non-aggressive.

Benign but locally aggressive epithelial odontogenic tumor of the jaws, classically multilocular radiolucency in the posterior mandible with root resorption, high recurrence after enucleation.

Ameloblastoma variant presenting as a single cyst, often in a younger patient; luminal and intraluminal types respond well to enucleation, mural invasion requires wider resection.

Microscopic arrangement of parallel rows of cuboidal tumor cells in a hyaline basement-membrane-like material, characteristic of calcifying epithelial odontogenic tumor (Pindborg tumor).

Radiographic appearance of a narrow, elongated radiolucent band within a widened periodontal space, suggesting a vertical root fracture, especially in endodontically treated teeth.

Curved radiolucent halo following the root outline and turning up at the apex, a radiographic clue to vertical root fracture, often best seen on angled periapical views.

Three-dimensional X-ray imaging using a cone-shaped beam and flat detector, giving high-resolution bone and tooth images at lower dose than medical CT, useful for canals and implants.

Radiographic study of salivary ducts after retrograde injection of contrast medium, showing ductal dilation, strictures, stones and the classic snowstorm appearance in Sjogren syndrome.

Distance from a coronal reference point to the apical limit of instrumentation, usually 0.5 to 1 mm short of the radiographic apex, confirmed by apex locator and radiograph.

Narrowest point of the root canal near the cementodentinal junction, the historical target of instrumentation and the site where pulp tissue ends and periapical tissue begins.

Device that measures impedance or ratio of frequencies between two electrodes in the canal to locate the apical constriction, accurate in the presence of blood or mild exudate.

Microscopic debris of dentin and pulp remnants left on canal walls by instrumentation; it blocks tubules, harbors bacteria, and is removed by chelators such as EDTA.

Irrigant that dissolves necrotic tissue and kills bacteria by chlorination and saponification; used at 0.5 to 5.25 percent, with extrusion causing severe tissue damage.

Broad-spectrum antiseptic that binds to oral and dentinal surfaces and is released slowly; used as endodontic irrigant and adjunct mouthrinse, with rare anaphylaxis and taste disturbance.

Scoring system grading visible bacterial deposits on defined tooth surfaces, used to quantify oral hygiene and compare groups or visits; Silness-Loe and Quigley-Hein are common variants.

WHO index recording periodontal status of index teeth by probing depth categories, bleeding and calculus, used for population surveys rather than individual diagnosis.

Distance from the cementoenamel junction to the base of the probing pocket, a measure of past periodontal destruction that does not change with gingival margin position alone.

Direct structural and functional connection between living bone and the surface of a loaded implant without intervening soft tissue, assessed clinically by absence of mobility and radiolucency.

Inflammatory lesion around an implant with progressive bone loss beyond expected remodeling plus bleeding on probing; unlike periodontitis it can progress rapidly and has no true attachment apparatus.

Horizontal surgical separation of the maxilla above the apices of the teeth, allowing repositioning of the lower maxilla in three planes for dentofacial deformity correction.

Mandibular ramus procedure splitting the bone sagittally to allow the tooth-bearing segment to move, with broad medullary contact for healing; risks include inferior alveolar nerve injury.

Rapidly spreading bilateral cellulitis of the submandibular, sublingual and submental spaces from a lower molar infection, threatening the airway and needing urgent decompression and drainage.

Restricted ability to open the mouth, conventionally maximal interincisal opening under about 35 to 40 mm, caused by muscle spasm, infection, trauma or tumor.

Undesirable contacts on the non-working side during lateral excursion that can destabilize a restoration or dentition and should be eliminated in occlusal adjustment.

Maxillomandibular relationship in which the condyles articulate with the thinnest avascular portion of their discs, independent of tooth contact, used as a reproducible reference for complete dentures.

Vertical difference between the mandible at rest position and in maximum intercuspation, generally 2 to 4 mm in the molar region and a guide to occlusal vertical dimension.

Angle between the A point, nasion and B point lines, expressing the anteroposterior skeletal relationship of maxilla to mandible; a positive value indicates maxillary prognathism relative to the mandible.

Stage of bone development estimated from hand-wrist radiographs or cervical vertebral shape, used to time growth modification and decide whether orthodontic treatment can still influence growth.

Appliance that preserves arch length after premature loss of a primary tooth, either fixed or removable, chosen by dental age and eruption sequence of the succeeding tooth.

Removal of the coronal pulp with retention of the vital radicular pulp, used in primary molars with caries approaching the pulp and no signs of irreversible inflammation.

Topical agent combining silver's antimicrobial action with fluoride's remineralizing effect, arresting active caries lesions and used where restorative care is difficult; it blackens arrested lesions.

Common eponym for calcifying epithelial odontogenic tumor, a benign but locally infiltrative epithelial tumor of the posterior mandible with calcifications and amyloid-like material.