The treatment of midfacial hypoplasia is of great significance in adolescents, with the goal of correcting midfacial deformities, improving appearance, articulation and breathing disorders, and regaining self-confidence 2. Traditional orthognathic surgery, osteotomy, and traction surgery often require the use of Lefort osteotomy techniques, which are traumatic and highly risky 4. Hence, they are gradually discontinued in clinical practice for correcting facial hypoplasia in adolescents. Meanwhile, TSDO is a minimally invasive, non-osteotomy procedure that has become the procedure of choice for children with midfacial hypoplasia 18; 19; however, a minimally invasive incision is often required to expose the maxilla and define the surgical path to allow observation of the situation related to the roots and nerves in the maxilla, which may damage the roots and nerves in complicated cases.
Artificial intelligence can be used to assist surgery in other parts of the body to achieve better results 20–22. For example, traditional craniofacial intelligent navigation often requires a positioning device in the head, which can interfere with the placement of the head frame in TSDO and readjustment of the site after intraoperative head position changes. However, this device cannot be sufficiently adjusted at any time, thereby greatly limiting its use in TSDO.
Currently the OSNS is a surgically assisted navigation device that has gained widespread interest owing to its enhanced ability to visualize surgery-related dynamics in real time 23. In this study, we present the application of an OSNS developed by the authors in TSDO. It has the following advantages: first, it is based on an optical navigation system, which was successfully applied for the first time in TSDO; second, by perfecting the modeling in advance and producing visualized images, it can guide the surgical approach dynamically in real time, which is more minimally invasive and achieves precise medical treatment; third, by combining the use of preoperative data, it allows observation of the situation related to the roots in the maxilla in real time, which minimizes the damage to the roots and teeth; fourth, the OSNS, which no longer requires a frontal fixed signal receiver, can greatly increase the scope of plastic surgery through the positioning kit out of the braces, and can control plastic surgery more precisely; fifth, the 3D Mimics 20.0 software can be used to determine the clinical effect before and after traction, and precisely define the traction site to provide more precise guidance for subsequent research 23; 24.
In this group of six patients, TSDO was performed with the assistance of optical surgery. The operation was successfully performed in all the patients, avoiding incisions through the mucosa and the nasal base of the oral cavity, realizing true "minimally invasiveness,” reducing bleeding, and maximizing the protection of the patient's roots and nerves, especially in difficult patients. Preliminary clinical applications have shown that TSDO combined with an OSNS can precisely correct midfacial hypoplasia.
Regarding application, according to different individuals, the design can be tailored to choose the most suitable surgical access. For the surgeon, this combination breaks the dilemma that traditional TSDO is unable to observe the surgical approach dynamically in real time without incision; for the patient, the surgical design is more reasonable, more effective in avoiding other structures in the maxilla, and precise placement of the traction hook can achieve the best traction effect, allowing the patient to obtain the best surgical results with minimal trauma. Therefore, combination with the OSNS accelerates the promotion and application of TSDO-related surgery and further shortens the learning curve 25; 26, which is another milestone in the field of treatment related to midfacial hypoplasia correction.
The application of an OSNS in TSDO can provide surgeons with better control over surgery, which can effectively improve the efficiency and safety of surgery and reduce patient trauma. However, this study had some limitations. First, surgery time in the early stage of learning combined with artificial intelligence may be slightly longer, although the surgery time can be shortened after improving surgery skills, which is also in line with the traditional learning curve. Second, the sample size was small because the combination of the OSNS and TSDO is the first of its kind. Nevertheless, we intend to expand the sample size and combine it with prospective longitudinal clinical studies in the future to obtain more effective results and explore the advantages of TSDO combined with the OSNS.
In conclusion, the OSNS can effectively guide the application of TSDO in correcting midfacial dysplasia. The procedure is non-invasive, improves surgical precision, reduces bleeding, and obtains better clinical results.