When we went through this we were told that all of the line items add up to generate the tuition of the first semester and then that x2 gives the cost of the 2nd semester. There is additional COL and summer tuition factored into the third semester. I believe that the online number does not incorporate any cost of living or traval/misc costs. So JUST tuition and fees is $45,786. That's the amount due to the university. The additional cost comes from housing, food, etc. I know you get that, just wanted to clarify
The difference between the tuition/fees and the total cost is, as you pointed out, 27k. That's about the cost of living for 1 year in Salt Lake PLUS books/supplies. The ADEA estimates a 22k cost of living, some random website I used estimated 13k, and I've been doing some legwork to figure out my loans and my numbers suggest about a 16k cost of living for an "I'm a student but I don't want to live like I'm homeless" lifestyle. I had forgot about books/supplies (I thought that would be included in fees) so just tack on 6k.
I believe they have either miscalculated or misrepresented their totals since there is that 14k that is unaccounted for- likely they didn't list everything out. Their room and board is way low, even for the cheapest university housing options. I can only assume the rest of the money is going towards things like groceries, personal expenses, medical expenses, etc. I would email the financial aide office and the dental school representative, she can probably give you more information too.