Patients were selected based on being adults and having mild Class I malocclusion. They were randomly allocated into either the aligner group and the traditiona (clear braces group).. The aligner group was treated with invisalign, with up to two adjustments at the end of treatment. The traditional group had clear braces placed on their teeth. The outcome variables including the following: 1) pain and discomfort related to treatment, 2) posttreatment occlusal status, and 3) postretention occlusal status.
