Abstract:

Clear aligners have unique advantages in the treatment of Class Ⅱ malocclusion at mixed dentition stage， providing a more efficient and comfortable orthodontic option for clinical practice. The authors reported a clinical case of early treatment with clear aligners in a child patient at mixed dentition stage with Angle Class Ⅱ division 1 malocclusion accompanied by deep overbite and large overjet， and analyzed the clinical efficacy of this treatment method， so as to provide a reference for clinical diagnosis and treatment. The patient， a 7-year-old female， presented with parental chief complaint of “protruding teeth and prominent lips”. She was diagnosed as Angle Class Ⅱ division 1 malocclusion， convex facial profile， deep overbite， and large overjet. Imaging examination showed that the angle of long axis of maxillary central incisor to sella-nasion point line （U1-SN） was 114.46°， and the angle of subspinale-nasion-supramentale （ANB） was 5.39°. Clear aligners were used for treatment. After 17 months of treatment， the child patient achieved good dental arch form， tooth alignment and occlusion， facial profile， and soft tissue profile. The treatment effect was stable after 6 months of treatment. The application of clear aligners shows a good therapeutic effect in the child patient at mixed dentition stage with Angle Class Ⅱ division 1 malocclusion.

Key words: Angle Class Ⅱ malocclusion, Clear aligner, Deep overbite, Large overjet, Case report