When do i go to an oral surgeon versus maxillofacial surgeon?

Oral surgeon: In United States they are the same. Many general dentist perform minor oral surgery procedures but they are not oral surgeons.

No difference : In the U.S. Oral and maxillofacial surgery is one specialty, surgeons differ in their training and degrees, some have dental degrees only, others have both dental and medical degrees, some subspecialize in specific area such as cancer surgery, TMJ surgery, corrective jaw surgey, facial cosmetic surgery, facial reconstruction after trauma or congenital deformity or dental implants.