The video discusses the importance of retainers after phase one intervention in orthodontic treatment, emphasizing their role in maintaining the achieved position of teeth and bone. It also covers the purpose of phase one intervention, which involves guiding the growth and development of a child's jaws, as well as providing instructions for teeth and bone until permanent teeth come in. The process of fabrication, initial wearing schedule, transition to nighttime wear, and monitoring progress every six months for retainers are highlighted. Additionally, the video addresses the importance of communication and teamwork in maintaining orthodontic progress, as well as the actions to take if retainers break, are lost, or don't fit, including the costs of new retainers and procedures for adjustments if the retainer causes discomfort.