With mandibular fracture and fracture and dislocation both sides of the condyle, is closed treatment (non-invasive) possible?

Highly unlikely: Open reduction and approximation of the fracture fragments will probably be required to achieve optimal healing & maximum function. Ent/plastic surgeon et al can best determine how to treat once they've reviewed imaging studies. Good luck.

It is possible: Bilateral sub condylar fractures can be managed nonsurgically using inter maxillary fixation in select cases depending on the degree of displacement, overriding of the fracture ends, dentition. Ct of facial bones in all three planes can show fracture best. Best to consult with ENT or other facial surgeon who manages facial fracture.