The Airway and Oxygen Connection

You can't once the cartilage in the mandible is fixed. Once the maxilla has expanded to whatever its maximum capacity, then it fills in through what's known as cancels,. You can't make it bigger except by surgery. But you know, people have jaw expanding surgeries. If you get to kids before puberty, you can use appliances like Crozats to try to grow the width of the palatal vault.