Cambodia Dentistry Exit Exam key terms

The basic structural unit of enamel, a tightly packed crystalline column of hydroxyapatite running from the dentino-enamel junction toward the tooth surface, whose orientation and decussation determine how enamel resists and propagates cracks.

The scalloped interface where enamel meets dentin, formed during tooth development; its irregular contour spreads stress and its shape influences caries progression and the appearance of cervical lesions.

Dentin laid down after tooth eruption in response to irritation such as caries, attrition or restorative preparation; it is less tubular and more irregular than primary dentin and slows pulpal insult.

Mineralized tissue covering the root surface, thinner at the cervical margin and thicker apically. Its acellular and cellular types anchor periodontal ligament fibers and adapt to tooth movement and function.

The fibrous connective tissue between cementum and alveolar bone that suspends the tooth, transmits occlusal force, provides proprioception, and supplies cells for repair and remodeling of the attachment apparatus.

The portion of maxilla and mandible that forms and supports the tooth sockets; it develops with the tooth, remodels continuously under occlusal load, and resorbs after tooth loss.

The ophthalmic, maxillary and mandibular branches of cranial nerve V. The maxillary and mandibular divisions carry sensation from teeth, periodontium, mucosa and skin, and their branches are the targets of local anesthesia.

The fascial space between the medial pterygoid muscle and the mandibular ramus containing the inferior alveolar and lingual nerves and vessels; it is the target region for the inferior alveolar nerve block and a route for spread of infection.

A cyst whose lining is derived from tooth-forming epithelium, such as a radicular or dentigerous cyst. It is usually asymptomatic, expands slowly, and is distinguished from other jaw lesions by clinical, radiographic and histologic features.

A locally aggressive benign epithelial odontogenic tumor, most often in the posterior mandible, typically presenting as a painless multilocular radiolucency. It requires adequate resection because conservative removal carries a high recurrence rate.

A developmental odontogenic cyst with a thin corrugated epithelial lining and tendency to grow along the bone rather than balloon it. It recurs frequently, may occur in multiple numbers in a syndrome, and needs long follow-up.

A predominantly white patch or plaque of the oral mucosa that cannot be rubbed off and cannot be attributed to another disease. It is a clinical diagnosis requiring biopsy to exclude dysplasia or carcinoma.

A clinical presentation of the oral mucosa with an increased risk of developing squamous cell carcinoma, including leukoplakia, erythroplakia, oral submucous fibrosis and proliferative verrucous leukoplakia; management includes biopsy and surveillance.

The most common oral malignancy, arising from mucosal epithelium and often associated with tobacco, areca nut and alcohol use. Early lesions may resemble benign ulcers, so persistent lesions require biopsy without delay.

Inflammation of the dental pulp, usually caused by caries or trauma. Reversible pulpitis produces sharp pain provoked by stimuli and relieved on removal, while irreversible pulpitis gives spontaneous or lingering pain and requires pulp therapy.

The distance from a coronal reference point to the apical limit of instrumentation, usually the apical constriction or radiographic apex. Accurate determination prevents short or over instrumentation and reduces treatment failure.

The narrowest point of the root canal near the cemento-dentinal junction, generally considered the ideal endpoint for cleaning and shaping because it marks the transition from pulp to periapical tissue.

The three-dimensional filling of a cleaned and shaped canal with a core material and sealer to prevent bacterial re-entry and entomb remaining organisms; length, taper and density of the fill are key quality criteria.

A layer of dentin debris and organic material created by instrumentation of canal walls or cavity preparation. In endodontics it may harbor bacteria, so irrigants and chelating agents are used to remove it.

The micromechanical and chemical adhesion of restorative material to tooth structure, achieved by etching, priming and adhesive application; reliable bonding conserves tissue and reduces microleakage and postoperative sensitivity.

The interdiffusion zone formed when adhesive resin penetrates etched, demineralized dentin and polymerizes among collagen fibers; its quality strongly influences bond strength and seal of composite restorations.

The vertical relationship of the maxilla and mandible when the teeth or occlusal rims are in contact; it guides prosthesis design and must be preserved or carefully altered to avoid functional and esthetic problems.

A maxillomandibular relationship in which the condyles articulate with the thinnest avascular portion of their discs, independent of tooth contact; it is a repeatable reference for recording jaw position in prosthodontics.

An arrangement of artificial teeth in complete dentures such that contacts occur simultaneously and bilaterally in centric and are maintained during eccentric movements, improving stability and reducing trauma to supporting tissues.

The distance from the gingival margin to the base of the sulcus or pocket, measured with a calibrated probe under controlled force; it is a key clinical measure but must be interpreted with attachment loss and bleeding.

The distance from the cemento-enamel junction to the base of the periodontal pocket, reflecting the cumulative destruction of attachment; it defines periodontitis severity and is more informative than probing depth alone.

A pathologically deepened gingival sulcus, classified as suprabony or intrabony according to the relation of its base to alveolar crest; it is the principal site of periodontal infection and treatment target.

A rapidly spreading bilateral cellulitis of the submandibular, sublingual and submental spaces, usually of odontogenic origin, that can obstruct the airway. It is a surgical emergency requiring airway management, antibiotics and drainage.

Infection and inflammation of medullary bone and marrow spaces, often following odontogenic infection or trauma, with pain, swelling, sequestrum formation and sometimes sinus tract; management combines antibiotics, drainage and sometimes resection.

A mandibular local anesthesia technique depositing solution near the mandibular foramen to anesthetize the inferior alveolar nerve; it is the most reliable way to anesthetize mandibular molars but carries risks of needle damage and intravascular injection.

The resistance to unwanted tooth movement provided by teeth, bone or appliances during application of orthodontic force; controlling anchorage determines whether space closure and correction of the malocclusion succeed.

Measurement of skeletal and dental relationships on a standardized lateral skull radiograph, used to diagnose skeletal pattern, plan orthodontic or surgical treatment and assess growth and treatment change over time.

The developmental stage in which primary and permanent teeth coexist, roughly ages six to twelve; it is a key period for interceptive orthodontics, caries prevention and monitoring of eruption and space.

Caries affecting primary teeth in children under six, often with rapid progression on smooth surfaces of upper incisors associated with frequent sugar exposure and inadequate fluoride; prevention targets feeding habits and oral hygiene.

Adjustment of fluoride concentration in public drinking water to a level that reduces dental caries across a population; it is a cost-effective public health measure whose benefits and risks are monitored through surveillance and evidence review.

A developmental enamel defect caused by excessive fluoride intake during tooth formation, ranging from faint white lines to pitting and discoloration; it is monitored when planning preventive programs and water fluoride levels.

Sensitivity is the proportion of truly diseased people a test correctly identifies; specificity is the proportion of truly healthy people it correctly clears. Both determine how a diagnostic test performs in screening and practice.

The probability that a person with a positive test result actually has the condition, which depends on sensitivity, specificity and disease prevalence; it falls when prevalence is low, even for an accurate test.

The proportion of a population affected by caries at a given time, often reported with the DMFT or dmft index; it describes burden rather than new disease and guides planning of preventive services.

The lowest concentration of an antimicrobial that prevents visible growth of a microorganism in vitro; it guides antibiotic selection and susceptibility reporting but must be combined with clinical judgment and dosing.

Administration of antibiotics before a procedure to prevent infection in at-risk patients, such as those with certain cardiac conditions or immunocompromise; indications are narrow and follow current guidelines to limit harm and resistance.

The ability of microorganisms to survive concentrations of an antibiotic that would normally inhibit or kill them, driven by misuse and incomplete courses; it is a reason to reserve antibiotics for clear indications in dentistry.

Infection control practices applied to all patients regardless of diagnosis, including hand hygiene, personal protective equipment, safe sharps handling and safe injection practice, to prevent transmission of bloodborne and other pathogens.

A validated process that destroys all microorganisms including bacterial spores on reusable instruments, typically by autoclave; monitoring with indicators and biological tests verifies that the process has succeeded.

A structured list of plausible conditions that could explain a patient's findings, ranked and tested by history, examination and investigations; it prevents premature closure and directs appropriate referral or treatment.

An organized, sequenced program of care addressing a patient's problems, priorities and prognosis, from emergency and disease control to definitive restoration and maintenance, agreed with the patient and reviewed over time.

A transient loss of consciousness due to reduced cerebral perfusion, often triggered by fear, pain or prolonged upright posture in dental settings; management is supine positioning, airway observation and reassurance, with recovery usually rapid.