Skeletal, Dentoalveolar, and Soft Tissue Effects of Conventional and Digitally Designed Functional Appliances in Class II Malocclusion: A Retrospective Pilot Study

Functional appliances constitute a common treatment approach for skeletal Class II malocclusion. However, evidence regarding the effects of appliance design and manufacturing workflows on treatment outcomes remains limited. This study aimed to compare the skeletal, dentoalveolar, and soft tissue effects of conventionally fabricated, prefabricated, and digitally designed functional appliances. A total of 28 growing patients with skeletal Class II malocclusion were retrospectively assessed and evenly assigned to four treatment groups: Twin Block, PowerScope, Invisalign Mandibular Advancement, and digitally designed Herbst. Skeletal, dentoalveolar, and soft tissue parameters were evaluated using lateral cephalometric radiographs obtained before (T0) and after treatment (T1). Statistical analyses included one-way ANOVA, repeated-measures ANOVA, and the Kruskal–Wallis test. All treatment modalities demonstrated significant sagittal improvement, characterized by reductions in ANB and Wits values and increases in SNB angle and mandibular length (Co–Gn). The Twin Block appliance showed a significantly greater increase in mandibular length compared with the other groups (p = 0.037). Dentoalveolar adaptations were more pronounced in the PowerScope and Invisalign Mandibular Advancement groups. In conclusion, within the limitations of this retrospective pilot study, functional appliances with different design and manufacturing characteristics appear to produce distinct skeletal and dentoalveolar response patterns, and digitally designed systems may represent clinically effective alternatives for the treatment of skeletal Class II malocclusion; however, these findings should be considered preliminary and interpreted with caution.