| ORS | olfactory reference syndrome; oral rehydration solution; oral surgery, oral surgeon; Orthopaedic Res... |
|---|---|
| OSI | open systems interconnection [reference model] |
| PDR | pediatric radiology; peripheral diabetic retinopathy; Physicians' Desk Reference; postdelivery room;... |
| QMR | quick medical reference |
| RE | radium emanation; readmission; rectal examination; reference emitter; reflux esophagitis; regional e... |