OMS key terms

A developmental cyst of the jaw arising from dental lamina remnants, lined by parakeratinized stratified squamous epithelium with a corrugated surface. It grows along the bone with minimal expansion and has a high recurrence rate after enucleation.

A benign but locally aggressive epithelial odontogenic tumor of the jaws, most often in the posterior mandible. It is radiolucent, frequently multilocular, and treated with resection to obtain clear margins because simple curettage leads to recurrence.

A predominantly white mucosal patch or plaque that cannot be rubbed off and cannot be attributed clinically or pathologically to any other disease. It is a clinical diagnosis of exclusion with malignant transformation potential.

A fiery red mucosal patch that cannot be explained by any other condition. It carries a higher risk of severe dysplasia or invasive carcinoma than leukoplakia and always requires biopsy.

Histologic alteration of oral epithelium showing architectural and cytologic atypia, graded mild, moderate, or severe. Severe dysplasia and carcinoma in situ carry substantial risk of progression to squamous cell carcinoma.

Removal of a representative sample of a lesion for histopathologic diagnosis, including the most suspicious area and adjacent normal tissue. It is preferred for large lesions where excisional biopsy would be disfiguring.

Complete removal of a lesion with a margin of surrounding tissue for both diagnosis and treatment. It is appropriate for small, accessible lesions thought to be benign, and the specimen is oriented for the pathologist.

Exposed irradiated bone that fails to heal for more than three months in the absence of tumor recurrence. It results from radiation-induced hypovascularity and hypocellularity, often triggered by extraction or trauma.

Exposed bone or bone probed through a fistula in the maxillofacial region persisting more than eight weeks in a patient on antiresorptive or antiangiogenic therapy, with no history of head and neck radiation.

A drug that binds to hydroxyapatite and inhibits osteoclast-mediated bone resorption, used for osteoporosis, malignancy-related hypercalcemia, and bone metastases. Intravenous and potent formulations increase the risk of medication-related osteonecrosis of the jaw.

Inhalation of 100% oxygen at greater than one atmosphere of pressure, increasing dissolved oxygen and promoting angiogenesis and fibroblast activity. It is used adjunctively for osteoradionecrosis and compromised wound healing.

A horizontal osteotomy separating the maxilla from the midface above the apices of the teeth, allowing repositioning of the lower maxilla in orthognathic surgery. It is commonly combined with a mandibular procedure for skeletal correction.

A mandibular ramus osteotomy that splits the mandible sagittally into proximal and distal segments, permitting advancement, setback, or rotation of the tooth-bearing segment. It is the most common mandibular orthognathic procedure.

Surgical correction of dentofacial skeletal discrepancies, usually combining osteotomies of the maxilla, mandible, or both with presurgical and postsurgical orthodontics. Goals include function, facial balance, and airway improvement.

Two surgical approaches to cystic lesions: enucleation removes the entire cyst lining, while marsupialization creates a window to decompress the cyst and allow the cavity to shrink before definitive removal. Choice depends on size and proximity to vital structures.

Administration of a sedative and a neuromuscular blocker in quick succession to secure the airway and reduce aspiration risk. It is used when a patient is at risk of regurgitation or has a full stomach.

A bedside airway assessment grading visibility of pharyngeal structures with the mouth open and tongue protruded. Higher classes suggest a more difficult laryngoscopic view and prompt airway planning.

A structured decision pathway for managing anticipated or unexpected difficulty with ventilation, laryngoscopy, or intubation. It emphasizes limiting attempts, calling for help, and moving to rescue techniques such as supraglottic devices or surgical airway.

Creation of an emergency airway through the cricothyroid membrane when intubation and ventilation fail. It is a rescue technique in a cannot-intubate, cannot-ventilate situation.

The upper limit of local anesthetic drug that may be given, calculated from the patient's weight and the drug's milligram-per-kilogram maximum. It prevents systemic toxicity and is adjusted for epinephrine content and patient factors.

Adverse systemic effects of local anesthetics, including tinnitus, metallic taste, seizures, arrhythmias, and cardiovascular collapse. Management includes airway support and intravenous lipid emulsion in severe cases.

A vasoconstrictor added to local anesthetics to slow absorption, prolong anesthesia, and reduce bleeding. It also lowers peak plasma levels and risk of systemic toxicity but must be used cautiously in cardiac patients.

Paroxysmal, lancinating facial pain in the distribution of the trigeminal nerve, often triggered by touch, chewing, or cold. Carbamazepine is first-line therapy, with surgery reserved for refractory cases.

A group of conditions affecting the temporomandibular joint, masticatory muscles, or both, producing pain, limited opening, and joint noises. Management begins with conservative therapy such as education, soft diet, and physical therapy.

Regional muscle pain associated with trigger points that refer pain on palpation. It is a common component of temporomandibular disorders and responds to conservative therapy and trigger point management.

An intraoral image showing the entire tooth and its surrounding periapical tissues. It is used to detect apical pathology, root fractures, and bone loss, and is interpreted with a paralleling technique for accuracy.

An extraoral image capturing both jaws, teeth, and supporting structures in a single view. It is useful for broad screening but has lower resolution and more distortion than intraoral images.

Three-dimensional imaging using a cone-shaped X-ray beam to produce volumetric data of the maxillofacial region. It is used for implant planning, impacted teeth, and endodontic assessment at lower dose than medical CT.

The principle of keeping radiation exposure as low as reasonably achievable while obtaining the diagnostic information needed. It guides selection of imaging modality, exposure settings, and collimation.

The distance from the gingival margin to the base of the sulcus or pocket, measured with a calibrated probe. It is a key clinical measure of periodontal attachment loss and disease severity.

The distance from the cementoenamel junction to the base of the periodontal pocket, reflecting cumulative attachment loss. It is more reliable than probing depth alone for tracking periodontal disease over time.

A classification system describing periodontitis by severity and extent (stage) and by rate of progression and risk (grade). It guides prognosis, treatment planning, and recall intervals.

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

The mechanical stability of an implant immediately after placement, determined by bone density, implant geometry, and surgical technique. Adequate primary stability allows immediate loading in selected cases.

Surgical augmentation of deficient alveolar bone using autogenous or substitute material to support implants or correct ridge defects. Graft consolidation and remodeling determine the timing of implant placement.

Establishing the distance from a coronal reference point to the apical constriction for instrumentation and obturation. Electronic apex locators and radiographs are used together to avoid over- or under-instrumentation.

A device that measures electrical impedance to locate the apical constriction within the root canal. It improves accuracy over radiographs alone, especially in curved or overlapping canals.

Three-dimensional filling of the cleaned and shaped canal space with a core material and sealer to prevent reinfection. Adequate length, taper, and density are assessed radiographically.

Use of flexible nickel-titanium files rotated in the canal to shape and clean it efficiently. The alloy's superelasticity allows negotiation of curved canals with reduced transportation and ledging.

A circumferential collar of sound tooth structure at least 1.5 to 2 mm high that encircles a crown and resists lever forces on the root. It improves the prognosis of endodontically treated teeth.

A restoration placed in a prepared root canal to retain a crown when insufficient coronal tooth structure remains. The post provides retention, while the core replaces lost tooth structure.

The process of luting a restoration to tooth structure using a cement that fills the space between them. The choice of cement depends on the restorative material and the retention needed.

Measurement of skeletal and dental relationships on a standardized lateral head radiograph using angular and linear norms. It guides orthodontic diagnosis and orthognathic treatment planning.

Evaluation of a child's remaining growth using hand-wrist radiographs or cervical vertebral staging. It helps time growth-modifying orthodontic treatment and orthognathic surgery.

Early treatment of developing malocclusions to remove or reduce causative factors and guide growth. Examples include space maintenance, habit correction, and early crossbite correction.

Removal of the coronal pulp while preserving the radicular pulp in a primary or young permanent tooth. It is used for vital pulp therapy when inflammation is limited to the coronal tissue.

A preformed metal crown cemented over a prepared primary molar to restore form and function. It is durable and commonly used after pulpotomy or for extensive caries in primary teeth.

Complete removal of the pulp tissue from the crown and roots of a primary tooth, followed by filling with a resorbable material. It is indicated when the radicular pulp is irreversibly inflamed or necrotic.

Administration of antibiotics before a procedure to prevent infection in at-risk patients, such as those with prosthetic joints or certain cardiac conditions. Regimens follow current guideline criteria rather than routine use.

Pre-procedural antibiotics given to selected patients with cardiac conditions at high risk of endocarditis before invasive dental procedures. Eligibility and regimens are defined by current national guidelines.

Infection occurring at or near a surgical incision within a defined postoperative period. Prevention includes aseptic technique, appropriate skin or mucosal preparation, and judicious antibiotic use.

A designated area kept free of microorganisms during an invasive procedure, maintained with sterile drapes, instruments, and gloves. Breaks in technique require correction before the procedure continues.

A transient loss of consciousness due to reduced cerebral perfusion, commonly triggered by pain, anxiety, or prolonged standing. Management includes supine positioning, airway protection, and monitoring of vital signs.

A severe, rapidly developing systemic hypersensitivity reaction with airway, breathing, or circulatory compromise. Intramuscular epinephrine is the first-line treatment, followed by airway support and fluids.

A stepwise protocol for recognizing and managing acute events in the dental setting, including positioning, airway, circulation, and drug administration. Regular team rehearsal improves outcomes.

A structured plan that lists the patient's problems, ranks them by urgency, and links each to specific diagnostic, preventive, and restorative steps. It sequences care and documents informed consent.

Systematic evaluation of patient factors such as caries risk, periodontal risk, medical status, and behavior to guide prevention and treatment intensity. It is repeated over time as conditions change.

A patient's voluntary agreement to treatment after receiving understandable information about diagnosis, options, risks, benefits, and alternatives. It is documented and can be withdrawn at any time.