## 4 Discussion
We sought to retrospectively examine whether the preoperative inclination of upper and lower incisors in Cl-III patients just before surgery meets the requirements of proper de-compensation according to accepted cephalometric values. Furthermore, we tried to find whether achieving such an orthodontic position is affected by the severity of the deformity, as reflected by the value of maxilla-mandibular difference according to [PERSON]'s analysis. In our sample, we did not find a correlation between the maxilla-mandibular difference and L1 to MP. This implies that the decompensation of the lower anterior teeth is probably not (or less) influenced by the maxilla-mandibular difference. This finding is in accordance with a previous study that found decompensation to be more adequate in the mandibular arch than in the maxillary arch in Class-III surgical patients. Furthermore, the results showed better surgical correction in cases where the maxillary teeth were adequately decompensated [25]. On the other hand, an interesting finding is that there is a significant positive correlation between maxilla-mandibular difference and immediate preoperative upper incisor proclination, i.e., U1 to FH or PP angle. This means that as the maxilla-mandibular difference increases (the higher the skeletal Class-III severity), the angle of the upper incisors is more pronounced, and the orthodontics could not achieve adequate decompensation as they should have done prior to surgery. The patients in our study were treated by numerous orthodontists in private orthodontic practices. One might argue that treatment modalities and different levels of clinical experience have affected the outcome. However, this study design reflects the real clinical situation that the planning team of surgeons and the orthodontist have to cope with [26]. Patients often get their orthodontics in the community from an orthodontist with limited experience in ortho-surgical preparation. Furthermore, [PERSON] et al. reported no differences in treatment efficiency between experienced and novice clinicians [27]. Therefore, the presented results are relevant to all practicing orthodontists. Possible explanations for the unsatisfactory maxillary decompensation can be found in different studies. One study shows that the longitudinal axis of the root of the upper incisor is not always the same as the axis of the crown according to the cephalometric analysis, and therefore there is an angle between the crown and the root; this angle is more prominent in cases with a more lingually inclined crown. This angle between the crown root of the upper incisor is also more prominent in Class-III patients, a fact that causes great difficulty in identifying the appropriate longitudinal axis of the upper incisor [25]. Another important argument is that decompensation (upright) of the lower incisors during pre-surgical orthodontic treatment increases the risk of periodontal defects, a fact that may be a limiting factor for the orthodontist to achieve optimal decompensation [28]. Furthermore, we demonstrated in a previous work that cephalometric measurements may suffer from significant examiner-based bias, which is correlated to the severity of the dentofacial deformity [29]. These findings should raise the question of whether decompensation is truly compromised as we found in the present study, at least regarding the maxillary incisors in the more severe Cl-III cases, or maybe it is merely misdiagnosed as such because of limited and biased interpretation of the cephalometric imaging. It is very important to mention some of the limitation of our study: first, the technology we used is very dependent on the surgeon or the doctor who performs the cephalometric analysis, and secondly, the technology is very limited because of the 2D limitations.