KidzSonic replacement toothbrush replacement heads are perfectly designed to take care of little teeth and mouths. Ideal for children with mixed baby and adult teeth, or crooked teeth, the unique bi-level flossing bristles help to clean deep down in-between teeth. Short bristles clean the tooth's surface and longer bristles reach between teeth and into the gum line. Suitable from the age of 3, the KidzSonic is designed to grow with your child, offering a selection of replacement brush head sizes. Just replace the brush head to keep using the KidzSonic until they are in their teens!