Hi-- I will be starting as a D1 at the Univ of MN School of Dentistry next fall... When I applied, I wondered the same thing so I asked the UoM adcomm. They replied by saying that it would never negatively affect my application so long as I was content with my GPA, etc. They also said that if anything, it might work in my favor financially speaking.
I went ahead and graduated in December and I don't regret it at all. The adcomm was definitely right--it HAS helped financially. I have now had this entire spring semester and will have the summer to do nothing but work and save money for school. Sometimes I worry that it will be harder for me to get back into the swing of school and studying again when d-school starts in August, but I'm sure it won't be a problem. I'd also state that your graduating in December on your application--it shows that you have worked hard and are highly motivated at what you do! It also shows that you have considered your future thoughtfully. Why hide that?
My advice: graduate early--you've obviously earned it! use the time to work and save money for school (while also saving yourself a semester's tuition!) 👍
