Brushing teeth is a good habit which is common to people all over the world. This habit has been developing since 3000 B.C., when people used twigs for brushing their teeth. Modern toothbrushing dates back to 1770, when a modern tooth brush was invented by William Addis. William Addis lived in England and was in prison for causing a riot when he made his invention. He was watching a guard sweep the floor with a broom and wondered if the same principle could be used for brushing teeth. He kept a small lamb bone from his lunch, drilled some holes in it and pulled some pig bristles through them. When William Addis was released, he started a toothbrush business and became rich. After his death, his business remained in his family for almost 200 years. The company still exists in the UK and produces 70 million toothbrushes per year!