My 3 year old son, Aaron, HATED me brushing his teeth. He would throw a fit every single time he saw the toothbrush coming.
During one of our parent trainings with his ABA therapist, she taught us "First-Then." One way to get Aaron to comply was to tell him he had to do something first, then he would get what he wanted. For example, if he wanted to eat candy, we would tell him, "FIRST you have to eat your broccoli, THEN you can have some candy."
I figured this idea was a great way to get him to let me brush his teeth. He likes having a bottle of milk in the morning and another one at night. So I always tell him, "FIRST brush, THEN milk." He still fights me and whines a little bit, but it has gotten much, much better.