Yes absolutely. Working anywhere, especially fast-food places, restaurants, or even at the mall is always important. The customer service and interpersonal skills developed at these types of jobs are invaluable. Many employers, in general, value people who've had jobs at fast-food places, restaurants, or a mall job because you've learned the value of a dollar. I'm sure at McD's you've learned to be quick, interact with customers (especially rude ones), keeping the store clean, money-handling skills, etc. All of that is valuable for any future job, especially dentistry..so yes include that!