| OET | oral endotracheal tube; oral esophageal tube |
|---|---|
| OHI | Occupational Health Institute; operative hypertension indicator; oral hygiene index; Oral Hygiene In... |
| ALL | Acute Lymphocytic Leukemia 형태학적 분류 L1; Small, Homogenous(... |
| A-C | acromioclavicular; adult-versus-child; aortocoronary bypass |
| ACA | abnormal coronary artery; acrodermatitis chronica atrophicans; acute cerebellar ataxia; adenocarcino... |