## 4 Discussion
Recently, artificial intelligence (AI) systems or fully automatic segmentation have been validated and found to be accurate for the goal of maximizing efficiency and reducing operator variability, and they are capable of improving prediction errors [8]. However, more studies are required prior to determining actual clinical relevance. There were several limitations in this study. First, the small sample size was a major impediment to reaching a definitive conclusion, especially for the one-jaw group. Because the inclusion criteria were quite strict, the number of subjects included was limited. The patients had skeletal type III malocclusion, and they also underwent orthognathic surgery with the same surgeon. To eliminate magnification discrepancies, both preoperative and postoperative CBCTs must be obtained from the same device. An intraoral scan and CBCT must be performed on the same day to reduce tooth movement caused by orthodontic force, which influences the fusion of the dental model to the virtual skull using voxel-based matching methods. Furthermore, only five of the fourteen patients had single-jaw surgeries. Bimaxillary surgery for skeletal type III correction has been on the rise in recent centuries, while mandibular setback surgery has been on the decline [34], which is due to the discovery that mandibular setback surgery may result in increased upper airway resistance and a narrowing of the size and proportion of the pharyngeal airway more than would result from bimaxillary surgery, leading to airway obstruction and contributing to the development of obstructive sleep apnea syndrome [33; 35]. As a result, combined maxillary and mandibular osteotomies are frequently used for patients who have a significant anteroposterior discrepancy, resulting in a limited number of single-jaw samples. A larger study sample size may enable stronger conclusions to be drawn. Second, the sample was not perfectly homogeneous. As previously stated, in addition to the fewer samples in the one-jaw group, some participants in both groups underwent genioplasty. Considering that this procedure only affects pogonion landmarks, we established the results without performing the subset analysis. To eliminate this confounding factor, a future study with definitive homogeneous samples is required. Third, this study only examined midline landmarks and did not evaluate lateral landmarks. Since this study used soft tissue volumes and the postoperative CBCTs were collected at least 4 months after surgery, the fixed appliances remained in place. Metal artifacts from the metal brackets were scattered and had strong impacts on the landmark identifications in the lateral areas, making it difficult to produce reliable results from the lateral areas of the face. The use of a facial scan imported and fused with a virtual model, rather than a soft tissue volume created from a CBCT, can possibly solve this problem and produce a more definitive conclusion. Finally, the time interval between surgery and postoperative CBCT varies between 4 and 13 months. Due to an ethical issue, there is no protocol for taking CBCTs six months after surgery or after completing orthodontic treatment, and this is to be accomplished in a way that does not expose a patient to additional radiation. Therefore, the postoperative CBCTs used in the study were taken when the surgeon needed to check bone healing and remove plate fixations, which occurred approximately 4-6 months after surgery. According to [PERSON] et al. [36], only 20% of the initial edema remained after three months. However, significant reductions in soft tissue swelling continue to occur 6-12 months after surgery. As a result, some participants may have residual soft tissue swelling, which alters the interpretation of the results.