Abbreviations - O

O - O

O&E - O&E observation and examination

O&P - O&P ova and parasite

O-R - O-R oxidation-reduction.

O.&A. - O.&A. odontectomy and alveolectomy

O/E - O/E on examination.

O: - O: objective.

O2 - O2 oxygen

OA - OA occiput posterior.

OA - OA osteoarthritis.

O’p-DDD - O’p-DDD mitotane.

OAP - OAP osteoarthropathy.

OARG - OARG Osteoporosis and Arthritis Research Group.

OARS - OARS Osteoarthritis Research Society.

OATA - OATA Ohio Athletic Trainers Association.

OATS - OATS osteochondral autograft transfer system.

OB - OB obstetrics.

Ob-GYN - Ob-GYN obstetrics and gynecology.

OB/OJ ratio - OB/OJ ratio overbite (OB) and horizontal overjet (OJ) ratio.

OBJ - OBJ object; objective.

OBL - OBL oblique.

OBP - OBP ova blood and parasites.

OBS - OBS observer.

OBS - OBS obstetrics.

OBS - OBS organic brain syndrome.

OC - OC obsessive/compulsive.

OC - OC on call

OC - OC oral contraceptive; office call.

OCC - OCC occasionally.

OCC - OCC occiput.

OCC - OCC occupation.

OCD - OCD obsessive-compulsive disorder.

OCD - OCD osteochrondritis dissecans.

OCE - OCE comprehensive exam.

OCE - OCE observable cholinomimetic effects.

OCE - OCE odd-carbon fatty acid enriched.

oCE - oCE oligomeric carboxylesterases.

OCE - OCE oral conjugated estrogens.

OCE - OCE osteocartilaginous exostoses.

OCEs - OCEs Oct-containing composite elements.

OCF - OCF occipital-frontal circumference.

OCG - OCG oral cholecystogram.

OCP - OCP oral contraceptive pills.

OCS - OCS open canalicular system (about platelets).

OD - OD (oculus dexter) right eye.

OD - OD occupational disease.

OD - OD officer of the day.

OD - OD once daily.

OD - OD optic density.

OD - OD outer diameter.

OD - OD overdose.

ODA - ODA on day of admission.

ODN - ODN oligodeoxynucleotide.

ODS - ODS Oswestry Disability Score.

OE - OE on examination; orthopedic examination; otitis externa

OECI - OECI Organization of European Cancer Institutes.

OES - OES old English sheepdog.

OFFA - OFFA Orthopaedic Foundation for Animals.

OGE - OGE U.S.Office of Government Ethics.

OGTT - OGTT oral glucose tolerance test.

OH - OH occupational history.

OHCS(17-) - OHCS(17-) 17-hydroxcorticosteroids.

OHS - OHS open heart surgery.

OIA - OIA optical immunoassay.

OIF - OIF Osteogenesis Imperfecta Foundation.

Oint - Oint ointment.

OJ - OJ isoleucyl-tRNA synthetase.

OJ - OJ obstructive jaundice.

OJ - OJ orange juice.

OJ - OJ Orthodontist Judgment.

OJ - OJ overjet (type of maloclusion).

OL - OL open label.

OLSNA - OLSNA Orthopaedic Laser Society of North America.

OM - OM obtuse marginal artery.

OM - OM occupational medicine.

OM - OM osteopathic manipulation.

OM - OM otitis media.

OMCTS - OMCTS octamethylcyclotetrasiloxane.

OMS - OMS osteomyelosclerosis.

ON - ON optic neuritis.

ONC - ONC oncology.

ONDCP - ONDCP Office of National Drug Control Policy.

ONFH - ONFH osteonecrosis of the femoral head.

OO - OO osteoid osteoma.

OOB - OOB out of bed.

OOH - OOH out of hospital.

OOP - OOP out of plaster.

OP - OP occiput posterior.

OP - OP operation.

OP - OP opponens pollicis.

OP - OP out patient.

OPC - OPC oculopalatocerebral (syndrome).

OPC - OPC outpatient clinic.

OPCA - OPCA olivopontocerebellar atrophy.

OPCD - OPCD olivopontocerebellar degeneration.

OPCOS - OPCOS oligomenorrheic polycystic ovary syndrome.

OPD - OPD obstetric prediabetic.

OPD - OPD optical path difference.

OPD - OPD otopalatodigital (syndrome).

OPD - OPD outpatient department.

OPD - OPD outpatient dispensary.

OPD - OPD p-phetiylenediamine.

OpDent - OpDent operative dentistry.

OPDG - OPDG ocular plethysmodynamography.

OPG - OPG ocular pneumoplethysmography.

opg - opg opening.

OPG - OPG orthopantomograin.

OPG - OPG osteoprotegerin.

OPG - OPG oxypolygelatin.

OPH - OPH obliterative pulmonary hypertension; ophthalmia.

OPH - OPH Oph ophthalmology; ophthalmoscopy ophthalmoscope.

OPHC - OPHC Office of Prepaid Health Care.

OphD - OphD Doctor of Ophthalmology.

Ophth - Ophth ophthalmology.

OPI - OPI obliteration prediction index.

OPI - OPI oculoparalytic illusion; Omnibus Personality Inventory.

OPI - OPI opiates.

OPI - OPI osteoblastic proliferation index.

OPI - OPI overproduction inhibition.

OPIDN - OPIDN organophosphorus-induced delayed neuropathy.

OPK - OPK optokinetic.

OPL - OPL other party liability; outer plexiform layer; ovine placental lactogen.

OPLL - OPLL ossification of posterior longitudinal ligament.

OPM - OPM occult primary malignancy; Office of Personnel Management; ophthalmoplegic migraine.

OPN - OPN ophthalmic nurse; osteopontin.

OPO - OPO Organ Procurement Organization.

opp - opp opposite.

OPP - OPP opposite.

OPP - OPP osmotic pressure of plasma; oxygen partial pressure.

OPPA - OPPA vincristine procarbazine prednisone Adriamycin.

OPPG - OPPG oculopneumoplethysmography.

OPRD - OPRD opiate receptor delta.

OPRK - OPRK opiate receptor kappa.

OPRR - OPRR Office of Protection from Research Risks.

OPRT - OPRT orotate.. pbosphoribosyltransferase.

OPRTase - OPRTase orotate phosphoribosyltransferase.

OPS - OPS operations; optical position sensor; osteoporosis-pseudolipoma syndrome; outpatient service; outpatient surgery.

OPSA - OPSA ovarian papillary serous adenocarcinoma.

OpScan - OpScan optical scanning.

OPSI - OPSI overwhelming postsplenectomy infection.

OPSR - OPSR Office of Professional Standards Review.

opt - opt best (Lat. Optimus); optics optician.

OPT - OPT outpatient treatment.

OPT - OPT outpatient; outpatient treatment.

OPTHD - OPTHD optimal hemodialysis.

OPV - OPV oral polio vaccine.

OPV - OPV oral poliovirus vaccine.

OPWL - OPWL opiate withdrawal.

OR - OR (o)estrogen receptor; odds ratio; oil retention (enema]; open reduction; operating room; optic radiation; oral rehydration; orosomucoid; orthopedic; orthopedic research.

OR - OR open reduction.

OR - OR operating room.

Or - Or orbitale.

OR - OR oriented.

OR - OR rate of outflow.

OR&F - OR&F open reduction and fixation; open reading frame.

ORA - ORA opiate receptor agonist.

ORA - ORA Orthopaedic Rehabilitation Association (AAOS Specialty Societies).

ORALABX - ORALABX oral antibiotics.

ORANS - ORANS Oak Ridge Analytical System.

ORBC - ORBC ox red blood cell.

ORBD-NRC - ORBD-NRC Osteoporosis and Related Bone Diseases - National Resource Center.

ORC - ORC oculo-reno-cerebellar [syndrome].

Orcb - Orcb orchitis.

ORD - ORD optical rotatory dispersion; oral radiation death.

ORDS - ORDS Office of Research Demonstration and Statistics.

ORE - ORE oil retention enema.

OREF - OREF Orthopaedic Research and Education Foundation.

ORF - ORF open reading frame.

ORF - ORF open reading frames.

Org - Org org organic.

Organizations). - Organizations).

ORIF - ORIF open reduction with internal fixation (sample operative report).

OrJ - OrJ orange juice.

ORJF - ORJF open reduction jaw fracture.

ORL - ORL otorhinolaryngology.

ORM - ORM orosomucoid; other regulated material; oxygen ratio monitor.

ORMC - ORMC oxygen ratio monitor controller.

ORN - ORN operating room nurse; orthopedic nurse.

Orn - Orn ornithine.

ORNL - ORNL Oak Ridge National Laboratoiy.

ORO - ORO oil red 0.

OROS - OROS oral osmotic.

ORP - ORP operating room personnel.

ORP - ORP oxidation-reduction potential.

ORPM - ORPM orthorhythniic pacemaker.

ORS - ORS olfactory reference syndrome.

ORS - ORS oral rehydration solution.

ORS - ORS oral surgery oral surgeon.

ORS - ORS Orthopaedic Research Society (also: AAOS Specialty Societies).

ORS - ORS orthopedic surgeon orthopedic surgery.

ORS - ORS oxygen radical scavengers.

ORS-ROC - ORS-ROC Orthopedic Research Society Republic of China.

ORSA - ORSA osteoclast resorption stimulating activity.

ORT - ORT object relations technique; operating room technician; oral rehydration therapy.

ORT - ORT operating room technician.

orth - orth ortho orthopedics orthopedic.

Ortho - Ortho ORTH orthopedics.

ORV - ORV Orthopaedic Research of Virginia.

ORW - ORW Osler-Rendu-Weber (syndrome).

OS - OS (oculus sinister) left eye.

OS - OS bone.

Os - Os occipitosacral.

Os - Os occupational safety.

Os - Os office surgery.

Os - Os Omenn syndrome.

Os - Os opening snap.

Os - Os operating system.

Os - Os oral surgery.

OS - OS oral surgery.

Os - Os organ specific.

OS - OS oris mouth or other opening.

Os - Os orthopedic surgeon orthopedic surgery.

Os - Os Osgood-Schlatter [disease].

Os - Os osmium.

OS - OS osteogenic sarcoma (context bone tumors).

Os - Os osteogenic sarcoma.

Os - Os osteosarcoma.

Os - Os osteosclerosis.

Os - Os oubain sensitivity.

Os - Os overall survival.

OS - OS overall survival.

Os - Os oxygen saturation.

OS - OS ozone safe.

OSA - OSA obstructive sleep apnea.

OSA - OSA Office of Services to the Aging.

OSA - OSA Optical Society of America.

OSA - OSA ovarian sectional area.

OSAE - OSAE Orthopaedic Special Assessment Examination (for AAOS members: Medical Education Section).

OSAS - OSAS obstructive sleep apnea syndrome.

osc - osc oscillation.

OSCAR - OSCAR on-line survey certification and reporting system.

OSCC - OSCC oral squamous cell carcinoma.

OSCE - OSCE objective structured clinical examination.

OSF - OSF organ system failure; osteoclast-stimulating factor; outer spiral fiber; overgrowth stimulating factor.

OSH - OSH Act Occupational Safety and Health Act of 1970.

OSHA - OSHA Occupational Safety and Health Adminstration.

OSI - OSI open systems interconnection [reference model].

osm - osm osmole; osmosis osmotic.

OSM - OSM ovine submaxillary mucin; oxygen saturation meter.

Osm/kg - Osm/kg osmoles per kilogram.

Osm/l - Osm/l osmoles per liter.

OSMED - OSMED otospondylometaphyseal dysplasia.

osmol - osmol osmole.

OSR - OSR oilseed rape.

OSRD - OSRD Office of Scientific Research and Development.

oss - oss osseous.

OSS - OSS over-the-shoulder strap.

OST - OST object sorting test; Office of Science and Technology.

osteo - osteo osteoarthritis; osteomyelitis; osteopathy.

OSTOP - OSTOP Osteoporosis Society of British Columbia.

OSUK - OSUK Ophthalmological Society of the United Kingdom.

OSV - OSV Orbis Sigma Valves Type I.

OT - OT objective test; oblique talus; occlusion time; occupational therapist occupational therapy; ocular tension; office therapy; old term (in anatomy).

OT - OT objective test; occupational therapy.

OT - OT occupational therapy old tuberculin.

OT - OT old tuberculin (Koch's old tuberculin) or Koch's original tuberculin.

OT - OT olfactory threshold; optic tract; orientation test ; original tuberculin; ornithine transcarbamylase; orotracheal; orthopedic treatment; otolaryngology; otology; oxytocin; oxytryptamine.

Ot - Ot otolaryngology.

OTA - OTA occupational therapy assistant.

OTA - OTA Office of Technology Assessment.

OTA - OTA ornithine transaminase.

OTA - OTA Orthopaedic Trauma Association (Newsletter) (also: AAOS Specialty Societies).

OTA - OTA orthotoluidine arsenite.

OTC - OTC over the counter (a drug that can be obtained without a prescription).

OTM - OTM os tibiale mediale.

Oto - Oto otology.

OTRPC - OTRPC osm TRPC.

OU - OU (oculus uterque) each eye.

OV - OV office visit.

OWL - OWL Orthopaedic Web Links.

OXT - OXT oxytocin.

oz - oz ounce.