Personalized Straightening Up Toddler Long Sleeve T-Shirt. Orthodontist, straightening up, one tooth at a time text with a row of teeth is a humorous dental design for birthdays and holidays. A classic for Fall, Winter and Spring, these long sleeve toddler t-shirts are sure to be a staple in your child's wardrobe. Whether layered or alone, this t-shirt is soft yet durable enough to stand up to your toddler's playtime demands.