Perhaps it is hard to imagine that a bad tooth could be deadly. But doctors in the Washington area say a twelveyearold boy died last month of a tooth infection that spread to his brain. They say it might have been prevented if the boy had received the dental care he needed. Experts at the National Institutes of Health say good dental care should start at birth. They say breast milk is the best food for the healthy development of teeth. Breast milk can help slow bacterial growth and acid production in the mouth. When baby's teeth begin to appear,you can clean them with a wet toothbrush. Dentists say it is important to find soft toothbrushes made especially for babies,and use them very gently. The use of fluoride   to protect teeth is common in many parts of the world. This natural element is often added to drinking water supplies. The fluoride mixes with enamel ,the hard surface on teeth,to help prevent holes,or cavities from forming. But the American Academy of Pediatric Dentistry points out that young children often swallow toothpaste when they brush their teeth. The group notes that swallowing fluoridated toothpaste can cause problems. So young children should be carefully supervised when they brush their teeth. And only a small amount of fluoridated toothpaste,the size of a green pea,should be used. Parents often wonder what effects sucking a thumb or sucking on a pacifier might have on their baby's teeth. Dental experts generally agree that this is fine early in life. The American Academy of Family Physicians says most kids stop sucking their thumbs by the age of four. If it continues,the group advises parents to talk to their child's dentist or doctor. It could influence the correct development of permanent teeth. The best title of this passage is   _  .
The reason of a twelveyearold boy's death Baby teeth should be cared for from birth Breast milk and fluoride are important How to help young children form good habits