## 2 Case Report  
### Diagnosis and Treatment Plan  
A 21-year-old female presented with the chief complaints of a gummy smile and mandibular deficiency with difficulty maintaining lip closure (Figure 1). During her adolescence, she refused orthodontic treatment several times and declined to wear braces for aesthetic reasons. Figure 1: Pre-treatment facial records of a 21-year-old female presenting asymmetric gummy smile, mandibular deficiency and lips incompetence. Clinical examination confirmed a gummy smile which deeply compromised her facial and smile aesthetics. She was found to have a convex soft-tissue facial profile with a retrognathic mandible, retrusive chin, and 6 mm of lip incompetence at rest. Harmonic nose-labial and mental folds were present at rest, with stretching and compromise during forced closure of the lips. The upper dental midline was coincident with the facial midline and the mandibular midline was deviated 3 mm to the right, with the result that it centred on the chin and the mandibular midline. Furthermore, a slight upper jaw canting was noted relative to the bipupillar line and the frontal plane. Intraoral evaluation and analysis showed an asymmetric occlusion with a full-cusp Class II molar and canine relationship on the right side and a Class I molar and end-on canine relationship on the left side. The overjet was 9 mm with a slight open bite on the lateral incisors and 1 mm overbite on the central incisors (Figure 2). Evaluation of X-rays (Dentsply Sirona, York, PA, USA) revealed the presence of an impacted upper third molar; the lower third molars were already erupted. Cephalometric analysis confirmed a normodivergent skeletal pattern with wide symphysis and optimal position and inclination of lower incisors. The upper incisors were proclined and protruded with respect to the anterior nasal spine. The patient did not present any signs or symptoms of temporomandibular disorders (TMD) according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) [14] and all the relative anamnestic data were negative for TMD involvement. No functional shifts or discrepancies between centric relation and centric occlusion were found. Intraoral scans were collected prior to surgery using a true definition scanner (3M, Saint Paul, MN, USA) in order to plan aligner treatment. Aligner therapy was considered the best choice for the specific patient given her total refusal to wear braces or visible orthodontics and her fear of possible tongue and speech problems with lingual braces. Invisalign aligners (Align Technology, Tempe, AZ, USA) were selected for the patient due to the greater availability of clinical and scientific studies on this specific aligner. The computer-generated ClinCheck setup displayed the type and placement of attachments. Because surgery was planned, we asked the ClinCheck technician not to correct the anteroposterior relationship between the maxillary and mandibular arches but to virtually simulate the surgical 'jump' to a bilateral molar Class I relationship and to align and level  
Figure 2: Pre-treatment intraoral records and X-rays showing full-cusp Class II molar and canine relationship on the right side, Class I molar and end-on canine relationship on the left side, with increased overjet and slight open-bite on the lateral incisors. the teeth starting from this position. According to the ClinCheck software, 17 maxillary and 17 mandibular trays would be required to treat the case  
Dolphin 3D Surgery TM (Dolphin Imaging & Management Solutions, Chatsworth, CA, USA) was used to virtually plan treatment using a Le Fort I osteotomy, a bilateral sagittal split osteotomy, and genioplasty (Figure 3). A CAD-CAM 3D surgical splint was used to guide maxilla and mandible positioning during orthognathic surgery. We planned an asymmetric maxillary impaction of 5 mm on the right side and 7 mm on the left side in order to simultaneously correct the gummy smile and the canted upper jaw.