Abstract: Objective: An adult case of skeletal ClassⅢ with mandibular deviation was treated by invisible orthodontic combined with orthognathic surgery. Diagnosis and Treatment: The patient received combined invisible orthodontic and orthognathic treatment after a clear diagnosis and the patient’s informed consent. In the preoperative orthodontic stage, $\begin{array}{l|l}65 & 58 \\ \hline 6 & 8 \end{array}$ extraction was performed. The extraction space was used for decompensation of maxillary anterior teeth, and using$\left. \frac{87}{87} \right|$ to replace$\left. \frac{76}{76} \right|$. The orthognathic operation was performed with maxillary LefortⅠosteotomy and bilateral mandibular sagittal split osteotomy. After operation, orthodontics further adjusted for the anterior deep overbite, mandibular midline deviation and posterior occlusion. Results: At the end of treatment, the patient’s profile was straight, the facial deviation was corrected, overbite and overjet were normal, the teeth were arranged neatly, the bilateral canine and molar were both neutral, and the upper and lower midline was aligned with the midline of the face. Conclusions: Clear aligner combined with orthognathic surgery can effectively treat the patients with skeletal Class Ⅲ with mandibular deviation.

Key words: clear aligner, orthodontic-orthognathic combined treatment, skeletal classⅢ malocclusion;, deviation deformity of mandible, preoperative orthodontics