关键词: 无托槽隐形矫治, Andrews六要素, 数字化正畸, 骨性Ⅱ类错牙合畸形, 临时支抗装置

Abstract: Objective: This case reports an adolescent patient with skeletal ClassⅡ deep overbite underwent clear aligner orthodontic treatment with tooth extraction, involving Andrews' six elements and jaw growth characteristics. Diagnosis and treatment: The patient received clear aligner orthodontic treatment supported by temporary anchorage devices (TADs), with the design of the occlusal final position based on Andrews' six elements, involving the extraction of teeth$\begin{array}{l|l} 4 & 4 \\ \hline 5 & 5 \end{array}$. Results: The treatment achieved the goals of retraction of the anterior teeth, adjustment of deep bite, and correction of deep overbite, significantly improving the skeletal ClassⅡ malocclusion and convex facial profile. Conclusions: Guided by Andrews' six elements and the developmental characteristics of adolescent jaw bones, this approach enables precise three-dimensional target positioning. Through a single extraction and orthodontic treatment followed by a refined adjustment (45 units + 35 units) plan, it achieves anterior tooth retraction, posterior tooth occlusal cusp-to-fossa interlocking, and vertical control, effectively improving facial aesthetics.

Key words: clear aligners, Andrews' six elements, digital orthodontics, skeletal ClassⅡ malocclusion, temporary anchorage devices