I have 2 baby tooth (1cm each) that is hanging very tight onto my bottom jaw. Dentist #1 suggested to extract those 2 baby teeth and put invisialign to help with overcrowding. Dentist #2 advised not to do this, it will cause too much gap between the other teeth and also the teeth around the baby tooth might collapse onto each other. Dentist #3 said I should wait until baby teeth fall off. Since they are healthy and not bothersome. He suggested I should look into bridges when they fall off.