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OCCIPITAL NERVE – Nerve from the back of the neck that supplies motor function and sensation to the forehead; two parts- greater and lesser.
OCCIPUT – The back part of the head. The base of the skull.
OLIGODENDROGLIA – Non-nerve cells, (see glia) forming part of the supporting structure of the central nervous system.
OLIGODENDROGLIOMA – A growth of new cells derived from the oligodendroglia.
OLISTHY – Slipping of bone(s) from normal anatomic site; for example, a slipped disc.
OPHTHALMOPLEGIA – Paralysis of one or more of the eye muscles.
ORTHOPAEDICS (also ORTHOPEDICS) – The medical specialty involved in the preservation and restoration of function of the musculoskeletal system that includes treatment of spinal disorders and peripheral nerve lesions.
ORTHOPAEDIC IMPLANTS – Medical devices used to replace or provide fixation of bone or to replace articulating surfaces of a joint.
ORTHOPEDIC SURGEON – A physician who treats the musculoskeletal system, extremities, and spine by operation or manipulation.
OSTEOINDUCTIVE – A material with the ability to induce bone to grow
OSSIFICATION – The process of forming bone in the body.
OSTEOARTHRITIS – Arthritis characterized by erosion of articular cartilage, either primary or secondary to trauma or other conditions, which becomes soft, frayed, and thinned with eburnation of subchondral bone and outgrowths of marginal osteophytes.
OSTEOMA – A benign tumor of bone.
OSTEOMYELITIS – Inflammation of bone due to infection, which may be localized or generalized.
OSTEOPHYTE – A bony outgrowth or protuberance.
OSTEOPOROSIS – A disorder in which bone is abnormally brittle, less dense, and is the result of a number of different diseases and abnormalities.
OTHER NERVES (twelfth cranial) – Transcervical, supraclavicular, posterior rami, facial, greater auricular, and hypoglossal.
OVERTON – A dowel graft that is applied across facet joints.