At 2 years old, the mother gives her child the first toothbrush, it is already late when the first tooth appeared around 6 months old. Children were just too hyperactive to clean their own teeth and still needed parents' help at that moment. People like what they are used to. I remember, I had been using manual toothbrush until the age of 25. And I was happy. Until a day in the second year of my orthodontics residency training program, Oral B, during one lecture, gave out ev