CSP is often carried out manually; thus, errors and distortions often occur. For example, the impression accuracy may vary depending on the impression material mixing time, the mixing temperature, and the work time during impression, and the accuracy of the facebow transfer may vary depending on the skill of the operator and the degree of patient cooperation [11, 12]. VSP is emerging as a way of reducing errors and improving the accuracy of the surgical planning process. It is much more accurate than CSP because it involves virtual surgery and surgical stent fabrication using CBCT [5, 6, 13,14,15,16]. Due to the high accuracy of VSP, OMS surgeons use it more often than CSP when performing maxillofacial reconstruction as well as orthognathic surgery (Fig. 3). Some studies have pointed out, however, that the cost of VSP is higher than that of CSP [17,18,19].
This study was conducted to compare the time and cost investments in CSP and VSP in planning orthognathic surgery in South Korea. Wrozosek et al. and Resnick et al. hypothesized that VSP is more time- and cost-efficient than CSP [7, 9]. These authors aimed to categorize each step of the surgical plan between the two groups and to measure and compare the times of CSP and VSP.
In terms of the total time, that of VSP was much shorter than that of CSP in both groups in this study, and the time reduction rate was larger in group I than in group II (Table 2). This is because the processes of CSP and VSP are similar in group II, and the process of CSP in group I is largely omitted in VSP. In the office workup category in group I, the time reduction rate was negative. The difference, however, was statistically insignificant, and it can thus be concluded that CSP and VSP are similar in terms of the time to the office workup. This is similar to the results of the study of Steinhuber et al., where the time for analyzing the patients and that for planning the surgery were similar regardless of the type of program used by the OMS residents [8], as the planning is done by the patient’s characteristic and knowledge of surgeons rather than the method used.
Since the total cost of VSP was much higher than CSP in both groups, it seems likely to consider VSP was not effective in both groups (Table 4). The reason why the cost of VSP was higher than CSP was that the stent was fabricated in an outsourced laboratory instead of fabricating the stent in a dental hospital. However, when the labor cost of resident and intern was considered, the cost of VSP was much lower than CSP. Therefore, from the OMS surgeon’s point of view, when comparing all of these factors, VSP is more cost-effective than CSP.
It was found that relatively complex surgery was more time-effective than relatively simple surgery in group I; as such, it is concluded that the more complex the surgery is, the more time-effective VSP is. Otherwise, in the case of relatively simple surgery, it can be concluded that CSP is more cost-effective than VSP.
A law for the improvement of the residents’ training environment and status was recently established in South Korea. The law ensures that residents do not work for more than 80 h a week and have at least 1 day off per week. VSP does not significantly reduce the office workup time, but it saves on the resident work time by significantly reducing the laboratory work time. The transition from CSP to VSP in surgery planning can be said to be in accordance with the above trend. Many studies have shown that VSP has high accuracy, and it was also shown in this study that it is more time-effective than CSP in South Korea.
Even if VSP is more effective compared to CSP, it still has cost disadvantage due to the high cost of processing its software and hardware. However, when the number of surgeon and hospital using VSP for their surgery increases, there will be more outsourced laboratories and systems available with lower cost. Therefore, VSP will eventually be available in more effective way, and it will also increase accuracy of orthognathic surgery in South Korea.
In this study, each step of VSP and CSP was not performed in the same place. Since it was performed separately, it is possible that its accuracy and cost-effectiveness decreased when it was processed in different laboratories. As a result, if the hospital is well equipped with software and hardware, each step of VSP and CSP can be performed in the same hospital and it will increase the cost-effectiveness and accuracy of the process by reducing errors and extra charges from the outsourced laboratory.