The American Academy of Pediatrics recommends children be weaned from the sippy cup by age 2 (keep in mind, this means a traditional sippy cup, with a soft or hard spout, not a straw cup). Prolonged use of traditional sippy cups can contribute to speech delays, changes in facial appearance, increased need for orthodontia, and tooth decay and cavities. Yet another reason why it's nice to go straight from bottle to a straw or open cup - once less product to transition away from as your toddler gets older (and more opinionated!).