In summary, in the orthodontic therapy of sufferers with malocclusion, compared with traditional fixed appliances, the clear aligners without brackets can enhance the treatment effects, and could have a good function in improving the periodontal condition such as plaque index, debris index, and gingival bleeding index, and masticatory function, and can reduce the inflammatory factors (CRP, IL-6 and TNF-α), which can make patients feel more comfortable, and improve their psychology, sleep and quality of life. This evidence concerns the gene CRP and Dental malocclusion.