MOH Oral and Dental Health Licensure Exam (Jordan) flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Tomes' process

Cytoplasmic extension of the secretory ameloblast that forms one enamel rod; its shape determines the rod cross-section and the keyhole architecture seen in mature enamel.

Oblique periodontal fibres

The most numerous principal fibre group of the periodontal ligament; they run from cementum coronally to bone and resist axially directed occlusal forces, suspending the tooth in its socket.

Dental lamina

Ectodermal band that invaginates into the underlying ectomesenchyme during the sixth embryonic week, giving rise to the enamel organs of all primary and then permanent teeth.

Odontogenic keratocyst

Developmental cyst lined by parakeratinized epithelium with a palisaded hyperchromatic basal layer; it spreads along the mandible, recurs frequently and may indicate Gorlin syndrome.

Leukoplakia

A predominantly white patch of oral mucosa that cannot be clinically or pathologically attributed to any other disease; a diagnosis of exclusion carrying a risk of malignant transformation.

Ameloblastoma

Benign but locally aggressive odontogenic epithelial tumour, commonest in the posterior mandible; it appears as a multilocular soap-bubble radiolucency and is treated by resection with margins.

Smear layer

Microcrystalline debris and collagen remnants one to five micrometres thick, created by instrumenting dentin; it must be etched away or modified to permit resin bonding and tubule sealing.

Class II cavity

Black's classification for caries on proximal surfaces of posterior teeth; restored through a proximal box preparation that preserves the marginal ridge and proximal contact relationship.

C-factor

Ratio of bonded to unbonded surface area within a cavity. High C-factor configurations such as Class I boxes develop greater shrinkage stress and require incremental layering.

Apical constriction

Narrowest point of the root canal near the cementodentinal junction, typically 0.5-1.0 mm short of the radiographic apex; it is the reference landmark for establishing working length.

EDTA irrigation

Seventeen percent ethylenediaminetetraacetic acid chelates calcium and removes the smear layer, opening dentinal tubules; it is used after sodium hypochlorite and never mixed simultaneously with it.

Apexification

Treatment of a necrotic immature tooth with an open apex, in which calcium hydroxide or an MTA plug creates an apical barrier so the canal can be obturated.

Biologic width

Combined supracrestal attachment of junctional epithelium and connective tissue, about two millimetres in total; violating it with a restoration margin causes chronic inflammation and recession.

Clinical attachment level

Probing depth plus gingival margin recession, measured from the cementoenamel junction; it records cumulative periodontal attachment loss and is used for staging periodontitis.

Grade C periodontitis

Rapidly progressing periodontitis defined by bone loss exceeding expectation for age, with percentage bone loss divided by age greater than 1.0, or by heavy smoking and uncontrolled diabetes.

Ante's law

Classic prosthodontic rule stating that the total root surface area of the abutments supporting a fixed partial denture should equal or exceed that of the teeth being replaced.

Christensen phenomenon

Posterior open space appearing between occluding teeth when the mandible moves into protrusion on an articulator with straight condylar guidance; corrected by a compensating curve and balanced occlusion.

RPI clasp

Rest, proximal plate and I-bar design for distal extension removable partial dentures; the mesial rest and minor connector reduce torquing forces on the terminal abutment.

Ludwig's angina

Rapidly spreading bilateral infection of the submandibular, sublingual and submental spaces causing a board-like floor of mouth; it threatens the airway and needs airway control, drainage and antibiotics.

Alveolar osteitis

Dry socket: fibrinolysis of the blood clot two to four days after extraction, giving severe throbbing pain and an empty socket; managed by irrigation and an obtundent dressing.

Leeway space

Difference in mesiodistal width between the primary canine and molars and their permanent successors: about 0.9 mm per maxillary side and 1.7 mm per mandibular side.

ANB angle

Cephalometric angle derived from SNA minus SNB, reflecting the anteroposterior skeletal relationship of maxilla to mandible; normally about two degrees, larger in skeletal Class II.

Hall technique

Cementing a stainless steel crown over an untreated carious primary molar, sealing the lesion without local anaesthesia or tooth preparation; effective for arresting proximal caries.

Early childhood caries

One or more decayed, missing or filled primary tooth surfaces in a child under six years; severe forms involve smooth surfaces and relate to frequent sugar and night-time feeding.

Eugenol

Phenolic oil used in zinc oxide eugenol cements as a sedative, obtundent liner; it inhibits polymerization of resin composites and must not contact bonding agents.

Transformation toughening

Mechanism by which zirconia resists crack propagation: tetragonal grains near a crack convert to monoclinic, expand and generate compressive stress that arrests the crack.

Prilocaine

Amide local anaesthetic metabolised partly to o-toluidine; overdose can cause methaemoglobinaemia, and it is supplied plain or combined with felypressin rather than epinephrine.

DMFT index

Count of decayed, missing because of caries, and filled permanent teeth per person; a cumulative measure of lifetime caries experience used in epidemiological surveys.

Specificity

Proportion of disease-free people correctly identified as healthy by a screening test; high specificity means few false positives, making the test useful for confirming disease.

Spaulding classification

Groups items as critical (enters sterile tissue, sterilize), semi-critical (contacts mucosa, high-level disinfection or sterilization) and non-critical (contacts intact skin, low-level disinfection).

Biological indicator

Ampoule or strip carrying known resistant spores, Geobacillus stearothermophilus for steam sterilizers, used weekly and per load to verify efficacy by absence of growth.

Informed consent

Voluntary agreement after disclosure of diagnosis, options, risks, benefits and alternatives, given by a competent patient who understands; documented in the record before treatment begins.