Best invisalign aligners in 200 feet radial road Teenagers or Young Adults ? Younger people are great candidates for Invisalign because their bodies aren’t fully developed yet, including the mouth. The teeth in young adults or teenagers can still move more easily because they aren’t fully set yet. Because Invisalign uses durable aligners and doesn’t rely on metal to shift the teeth, it is better for the patient to be younger so that the teeth can move fast and efficiently. While Invisalign will work for adults, the treatment process may take longer to achieve desired results. For example, your perfect smile may take longer to show if adults or people who have fully developed use clear aligners compared to teenagers. However, this isn’t to say that the aligners wouldn’t work. Just prepare yourself for a longer process.