Effects of Mandibular Advancement with Clear Aligners on Class II Patients and Their Comparison with Traditional Functional Appliances: A Scoping Review

Clear aligners are increasingly used for various orthodontic treatments, including mandibular advancement in patients with skeletal Class II. Mandibular advancement with clear aligners (MA) aims to achieve skeletal effects by promoting mandibular growth. This scoping review aims to evaluate the dental and skeletal effects of mandibular advancement with clear aligners and to compare it with traditional functional appliances. A literature search was conducted in PubMed, Scopus, Web of Science, and Google Scholar for studies published between 2017 and February 2025. The search identified 53 articles, of which 10 studies meeting the eligibility criteria were included. The quality of the studies was examined using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist. Most studies reported a reduction in A point–Nasion–B point (ANB) angle and Wits appraisal after MA treatment. Comparisons with Twin Block (TB) showed similar skeletal outcomes, although MA caused less lower incisor protrusion. Studies comparing MA and Herbst appliance found greater lower molar mesialization with the Herbst appliance, while Sella–Nasion–A point (SNA), Sella–Nasion–B point (SNB), and ANB values were similar. It is important to note that the effects of the Herbst appliance reported in the included studies were evaluated in patients at the pubertal growth peak, although the appliance can also be used in the post-peak period. The included studies show that mandibular advancement with clear aligners can induce forward mandibular growth and achieve skeletal improvement. Reported advantages in these studies include simultaneous dental alignment during advancement, improved aesthetics, and potentially higher patient compliance compared to conventional appliances. Additionally, clear aligners may allow better control of lower incisor inclination during mandibular advancement. However, the findings should be interpreted with caution due to the limited number of high-quality studies and heterogeneity in study designs.

Keywords: Clear aligners, functional appliances, Herbst appliance, mandibular advancement, skeletal class II, twin block.