In the last five years, Pratyusha Yalamanchi, 18, has helped provide treatment to more than 290,000 dental patients in Andhra Pradesh.A high school graduate from the International Academy in Bloomfield Hills, Michigan, she founded Dental HygIndia, partnering with Dr Kadiyala Rajendra, a dentist in Andhra Pradesh, at the age of 13, after she saw the sorry state of dental hygiene among villagers in India during a trip.