Human health and medicine

Oromandibular dystonia

Oromandibular dystonia is a focal dystonia in which involuntary contractions of the jaw, tongue, and facial muscles disrupt chewing, speaking, and swallowing, typically beginning in the 50s.

Oropharyngeal cancer, or oropharyngeal squamous cell carcinoma (OPSCC), is throat cancer of the tonsils, tongue base, and soft palate, increasingly caused by HPV-16 and divided into HPV-positive and HPV-negative forms with different prognosis and treatment.

Orotracheal intubation

Orotracheal intubation is the insertion of a cuffed tube through the mouth into the trachea to secure the airway and enable mechanical ventilation, performed in about 1.6 million US patients yearly.

Orphan drug

Orphan drug: a medicine for a rare disease supported by regulatory incentives. US Orphan Drug Act 1983 (fewer than 200,000 patients, 7-year exclusivity, 50% tax credit); EU regulation 2000 (5 in 10,000, 10-year exclusivity, COMP).

Orphenadrine

Orphenadrine, sold as Norflex and usually given as the citrate salt, is a skeletal muscle relaxant and mild analgesic used for painful musculoskeletal conditions and Parkinson's disease.

Orteronel

Orteronel (TAK-700, S-TAK-700) is Takeda's oral nonsteroidal selective CYP17A1 17,20-lyase inhibitor for prostate cancer; Phase III ELM-PC 4/5 and SWOG-1216 failed overall survival endpoints and development ended in 2014.

Oct 20, 2026

Orthodontic Anchorage Procedures

Orthodontic anchorage procedures (orthodontic anchorage techniques) attach devices in the mouth to resist unwanted tooth movement, ranging from headgear and transpalatal arches to titanium miniscrews and miniplates, with miniscrew failure rates around 13.5%.

Orthodontic Appliance Design

Orthodontic Appliance Design: planning and creation of devices to straighten teeth, spanning Andrews' straight-wire brackets, functional appliances, clear aligners, and CAD/CAM and FEA design methods.

Orthodontic Appliances

Orthodontic appliances (braces, aligners, functional appliances, retainers) are devices for influencing tooth position, classified as fixed or removable, active or retaining, intraoral or extraoral; from Fauchard's 1728 bandolet to Invisalign.

Orthodontic extrusion

Orthodontic extrusion, also called forced eruption, is an orthodontic technique that slowly moves a tooth out of its socket to expose fractured or subgingival structure for restoration.

Oct 20, 2026

Orthodontic Retainers

Orthodontic retainers (fixed bonded wires, Hawley, clear vacuum-formed) hold teeth after braces; relapse affects over half of patients at 10 years without retention.

Oct 20, 2026

Orthodontic Space Closure

Orthodontic space closure is the orthodontic procedure of closing gaps between teeth, usually premolar extraction sites, using sliding or loop mechanics to move teeth along an archwire.

Orthodontic space maintenance

Orthodontic space maintenance, or space maintenance, uses fixed or removable appliances to hold the gap left by a prematurely lost primary tooth until the permanent tooth erupts.

Orthodontic Wires

Orthodontic wires, chiefly arch wires, are the force-delivering backbone of fixed braces. Evolved from gold alloy through stainless steel to superelastic and heat-activated nickel-titanium, beta-titanium, and aesthetic or bactericide wires.

Orthodontics

Orthodontics: dental specialty treating malocclusions (misaligned teeth and bites) with braces and clear aligners. About a third of children need treatment; courses last 12 months to 2.5 years; aligners suit mild-to-moderate cases, fixed appliances complex ones.

Orthodontists

Orthodontists are dental specialists trained to correct malocclusions with fixed braces or clear aligners. Also called orthodontic specialists; the largest US dental specialty, about 5% of dentists, with documented treatment risks and heavy education debt.

Orthognathic surgery

Orthognathic surgery, or corrective jaw surgery, surgically repositions the mandible, maxilla, or both via Le Fort I, BSSO, and genioplasty to treat malocclusion, facial asymmetry, and sleep apnea, combined with orthodontics.

Orthokeratology

Orthokeratology, or ortho-K, is a vision-correction method in which rigid gas-permeable contact lenses are worn overnight to temporarily flatten the cornea, correcting myopia without daytime glasses.

Orthomolecular Therapy

Orthomolecular therapy, or megavitamin therapy, uses very large doses of vitamins and body-normal substances, chiefly for mental disorders. Coined by Linus Pauling in 1968; contested by mainstream psychiatry since the 1973 APA task force report.

Orthopaedic Research Society

Orthopaedic Research Society (ORS), founded 1954 in Chicago, non-profit 501(c)(3) musculoskeletal research society; publisher of the Journal of Orthopaedic Research and JOR Spine, founding member of ICORS, OREF, and IFMRS.

Orthopaedic surgery

Orthopaedic surgery, the surgical specialty of the musculoskeletal system, supports a large journal ecosystem: 478 journals, impact factor trends, double-blind peer review, publication costs, and predatory-journal risks.

Orthopedic and rehabilitation management of Duchenne muscular dystrophy

Orthopedic and rehabilitation management of Duchenne muscular dystrophy is the set of non-drug interventions, including stretching, orthoses, physiotherapy, and spinal surgery, that preserve movement and comfort as weakness progresses.

Orthopedic cast

An orthopedic cast, also called a surgical cast, is a rigid plaster of Paris or fiberglass shell holding broken bones in position while they heal.

Orthopedic Equipment

Orthopedic equipment: nonexpendable surgical and therapy devices for bones and joints, per MeSH D009983, distinct from orthotic devices; includes instruments, fixation hardware, arthrometers, navigation and robotic systems.

Orthopedic Manipulation

Orthopedic manipulation is the controlled manual movement of the spine, extremities, and other musculoskeletal structures to increase motion, diagnose disease, reduce dislocations, or improve fracture alignment.

Orthopedic nursing

Orthopedic (orthopaedic) nursing is the nursing specialty caring for musculoskeletal patients. Key facts: MeSH specialty since 1992, NAON professional body, Orthopaedic Nursing journal since 1982, advanced practice roles, and evidence-based practice research.

Orthopedic Surgeons

Orthopedic surgeons (orthopedists) are physicians treating skeletal, joint, and musculoskeletal disorders by medical, surgical, and physical means. Named from Andry's 1741 term; about 14 years of training; subspecialties from spine to sports medicine.