Clinical Efficacy of Clear Aligners in Class II Malocclusion: From Pediatric to Adult Cases—A Narrative Review

Background: Class II malocclusion is one of the most common and challenging orthodontic problems, often requiring complex, lengthy treatment and sometimes involving extractions or surgery. While conventional fixed appliances have been the gold standard, the increasing demand for aesthetic and comfortable treatment alternatives has made clear aligners a prevalent choice. Understanding the specific biomechanics, limitations, and successful clinical strategies for using aligners—especially in managing vertical dimension and achieving skeletal correction (mandibular advancement)—is crucial for expanding non-invasive treatment options and improving outcomes for a broad range of Class II patients. Objective: The objective of this review is to examine the effectiveness and clinical approaches of clear aligners in Class II correction across different age groups, with particular attention to vertical control, mandibular advancement methods, and the predictability of tooth movements in both growing and fully mature patients. Materials and Methods: This review narratively discusses the most relevant clinical findings and practical strategies for managing Class II malocclusions with clear aligners. Particular attention is given to the integration of auxiliary devices, such as elastics, attachments, and temporary anchorage devices (TADs), which can enhance biomechanical control. Results: The combination of aligners with mini-implants and attachments resulted in a consequent decrease in excessive overjet, improvement in facial profile, and long-term stability supported by fixed retention. In growing patients, correction benefited from mandibular advancement protocols and control of molar extrusion, allowing for preservation of the mandibular plane angle. Movement predictability showed higher reliability in anterior torque movements, whereas maxillary incisor intrusion remained less predictable. Conclusions: Clear aligners, especially when supported by auxiliary device, such as mini-implants and attachments, offer a reliable and aesthetic alternative to conventional orthodontic treatment for Class II malocclusions. However, certain tooth movements may still be less predictable, highlighting the need for careful planning, individualized biomechanics, and ongoing technological improvements.