OASASNew York Office of Addiction Services and Supports
OAToral appliance therapy
OATPorganic anion transporting polypeptide
OATSosteochondral allograft transplantation surgery
OCDobsessive-compulsive disorder
OCPoral contraceptive pill
OCToptical coherence tomography
OCT3organic cation transporter 3
OCTAoptical coherence tomography angiography
ODDoppositional defiant disorder
ODGOfficial Disability Guidelines
ODIOswestry Disability Index
ODTorally disintegrating tablet
OGTToral glucose tolerance test
OHCAout-of-hospital cardiac arrest
OHSSovarian hyperstimulation syndrome
OM1obtuse marginal branch 1
OM2obtuse marginal branch 2
OM3obtuse marginal branch 3
OMDoligometastatic disease
OMSOral & Maxillofacial Surgery
ONLSOverall Neuropathy Limitation Scale
OOM-SCorbicularis oculi muscle stem cell
OPLLossification of the posterior longitudinal ligament
OPTNOrgan Procurement and Transplantation Network
OPUSOral Passage Understanding Scale
ORIFopen reduction internal fixation
ORRobjective response rate
ORSoral rehydration solution
OS12overall survival at 12 months
OSAobstructive sleep apnea
OSASObstructive Sleep Apnea Syndrome
OSCOperative Status Criteria
OSCCoropharyngeal squamous cell carcinoma
OSDocular surface disease
OVBoral viscous budesonide
