Complex sentence: Orthognathic surgery is performed by either an oral and maxillofacial surgeon or a craniofacial surgeon in collaboration with an orthodontist, often including braces before and after surgery, and retainers after the final removal of braces.
Split into simpler sentences: Orthognathic surgery is performed by either an oral and maxillofacial surgeon or a craniofacial surgeon in collaboration with an orthodontist. It often includes braces before and after surgery, and retainers after the final removal of braces.