A Neurosurgeon is a type of surgeon who specializes in the diagnosis and treatment of disorders of the nervous system, which includes the brain, spinal cord, and peripheral nerves. An ORAL Surgeon is a type of surgeon who specializes in the diagnosis and treatment of diseases and conditions of the mouth, jaws, teeth, and facial structures. A Tree Surgeon is a type of surgeon who specializes in the care and maintenance of trees, including pruning, trimming, and removal of dead or diseased branches.