I bought a Z-Quiet oral appliance (as seen on TV) and shared it with my Sleep Center Physician.  He said to give it a try.  We were traveling in Africa in tented camps without electrical power and did not have many options.  It worked reasonable well.  I also used an ear loop surgical mask that helped to retain the humidity in my nasal passages.  Fortunately we were in humid environments.  
A custom dental appliance ($800+) would certainly perform better, but my $50 option was adequate under the circumstances.