I agree with everything BFord23 said. Know your application well, and let that guide you into applying intelligently.
You should definitely apply this cycle. Make sure to apply to appropriate schools, and you definitely have a shot. I would suggest that, in addition to the advice given above, you apply widely. Remember and 4 or 6 yr programs both graduate oral surgeons, don't limit yourself and apply broadly to both. Be choosy if you get a ton of interviews, but if you match at a 4yr you hardly knew about it, you wont be complaining.
At my school, 12 of us applied to OMFS this cycle. 11 of the 12 got interviews, and 9 of the 11 interviewed matched. One of the two unmatched was top 10, and several of the accepted were prob top third, and without stellar boards.
Apply intelligently, be hopeful, and cross your fingers
If you are from UM, I think I am the unmatched person you're talking about.
I would say the most important thing is to apply to lots of programs, and definitely do some research about the programs before the interviews. I did not... I applied to 11 (2 of them after the deadline, so probably didn't count), and I went into interviews completely blind. I thought that I should be able to answer any questions on the spot since I planned on being completely honest, which probably came across badly.
For 6 year programs, some have complete say in the matter, while others are restricted by the medical schools in whom they can accept. Med schools pay more attention on your undergrad grades and your boards, while OMS mainly focus on your personality (once you get an interview). Every program is different in what they are looking for. The ones I applied to are programs with cancer component, and they tend to emphasize research as well.
Objectively speaking, as a candidate I was far from ideal. The only thing I had was good grades. I did research but had no publications, some volunteers but they were non-dental community volunteers, 3 externships but not at the famous programs, and my board score was only 88. I was very lucky that I end up getting post-matched, but if I had to do it all over again, I would definitely apply to 30+ programs. Every single program asked how many and where I applied to, and how I made my decisions. My answer for them was that I wanted to be educated in treating and managing cancer patients, regardless of whether I'd end up doing the cancer fellowship or not, so I only applied to cancer programs, and I made my decision based on what the OMS faculty at my school recommended. Most likely, the small numbers made me look arrogant, and the fact that I made my decision so lightly just killed any chance I had. Anyways, my point is that you should definitely give it a shot, because there are programs out there that want you, you just have to apply to give them a chance and give yourself a chance, and everything will work out in the end.