See Their Smile Grow. The Oral-B Kid’s Manual Toothbrushes featuring Marvel’s Avengers is the perfect kid’s toothbrush for your own little Super Hero . As their oral health evolves, children ages 5-7 will lose some baby teeth as their permanent teeth start to grow. This manual kid’s toothbrush is the ideal size to surround and clean pearly whites and help reach tricky back teeth while helping to protect tender gums. Best of all, this toothbrush is compatible with the interactive Disney MagicTimer App by Oral-B to help your kids brush for a dentist-recommended 2 minutes.