It is very important to maintain the health of the primary teeth. Neglected cavities can and frequently do lead to problems which affect developing permanent teeth. Primary teeth, or baby-teeth are important for (1) proper chewing and eating, (2) providing space for the permanent teeth and guiding them into the correct position, and (3) permitting normal development of the jaw bones and muscles. Primary teeth also affect the development of speech and add to an attractive appearance. While the front 4 teeth last until 6-7 years of age, the back teeth (cuspids and molars) aren’t replaced until age 10-13.
Information provided by the American Academy of Pediatric Dentistry