clear cheek retractor is the perfect size for most people. Only people with very small mouths would need our smaller size.Cheek retractors are used to keep the mouth open and the lips away from the teeth. This helps to keep the gel concentrated on the teeth as well a protect soft tissue from being irritated by the gel.The cheek retractor material is very smooth, making it very comfortable to wear for an extended period of time.Our cheek retractors come individually packaged and sealed.