| Abbreviation | Definition |
|---|---|
| OFS | Oral and Facial Surgery |
| OGBS | Open Gastric Bypass Surgery |
| OHNS | Otolaryngology Head and Neck Surgery |
| OHNS | Otolaryngology – Head and Neck Surgery |
| OHNS | Otolaryngology Head and Neck Surgery |
| OHNS | Otorhinolaryngology Head and Neck Surgery |
| OMS | ORAL and maxillofacial surgeon |
| OMS | Oral and Maxillofacial Surgeons |
| OMS | Oral and Maxillofacial Surgery |
| OMS | Oral Maxillofacial Surgery |
| OMSA | Oral and Maxillofacial Surgery Assistants |
| OMSC | Oral and Maxillofacial Surgery Centers |
| OMSF | Oral and Maxillofacial Surgery Foundation |
| ONAC | One Neurosurgery Advocacy Committee |
| ONDS | Optic Nerve Decompression Surgery |
| OPRS | Ophthalmic Plastic and Reconstructive Surgery |
| ORBS | Oncoplastic Reconstructive Breast Surgery |
| OSC | Outpatient Surgery Center |
| OSCC | Orthopaedic Surgery Center of Clearwater |
| OSCI | Ophthalmology Surgery Center of Illinois |