## 3 3D Printing in Orthognathic and Oral Maxillofacial Surgery
The application of reconstruction plates following tumor removal for the purpose of reconnecting mandibular segments has been associated with the potential complications of plate exposure and the formation of oro-cutaneous fistulas [42]. Major contributors to the condition include postoperative radiotherapy and compromised soft tissue atrophy [43]. The patient having multiple previous surgeries frequently shows severe wound shrinkage and fibrosis [31]. The design for the customized implant should be made considering the individual situation of patient. According to the research of [PERSON] et al. [31], the mandible, a component of the human jaw, can be fitted with a custom-designed implant that incorporates a plate, which extends to the lingual side (Figure 2). The plate utilized for securing screws extended from the implant body and was adjusted to the lingual surface of the mandible [31]. By utilizing this lingual plate, it was possible to decrease the buccal volume of the implant, thereby mitigating the risk of plate exposure [31]. In a previous study, the lingual application of a reconstruction implant plate was conducted successfully, yielding favorable outcomes without any complications [44]. It was observed that the customized implant did not necessitate the filling of the bone defect area [44]. Furthermore, through previous mechanical tests, it was established that the EBM titanium implant exhibited sufficient strength to effectively support mandibular jaw movement and withstand bite force [45]. The porous structure of the EBM implant serves multiple functions in facilitating successful bone integration and implantation. Firstly, its porous nature allows for the reduction of device weight, thereby minimizing stress on the bone [46]. Additionally, this porous structure creates a favorable microenvironment that promotes the migration of osteogenic cells and facilitates bone ingrowth [41]. Specifically, the upper, medial, and distal surfaces of the implant faced with the residual bone segment feature a porous structure [31]. This design enables the ingrowth of alveolar bone and facilitates osseogeintegration with the surrounding bone, as illustrated in Figure 2. This customization effectively surrounds the residual bone and enhances its integration with the implant [38]. The efficacy of the  
Figure 2: The research investigates the utilization of 3D printing and virtual surgical planning in addressing mandibular defects. (**a**) The initial examination revealed a broken mesh and defect in the right mandibular body region. (**b**) To gain better insights, a 3D-simulated image was produced to visualize the extent of the defect. (**c**) Subsequently, a prosthesis was designed using computer-aided design/computer-aided manufacturing (CAD/CAM) technology, with a lingual plate being incorporated and applied to the lingual surface of the mandible. (**d**) To create the actual implant, a 3D-printed titanium version was applied to a 3D model of the patient. Notably, the upper surface of the implant was intentionally designed with a porous structure to improve integration. (**e**) Following the surgical procedure, the 3D-printed implant was seen to integrate successfully into the bony defect. customized 3D implant has been demonstrated in the successful treatment of maxillofacial bone defects [47; 48]. Moreover, efforts have been made to extend its application to the repair of alveolar bone, thereby improving tooth rehabilitation outcomes [49]. In such cases, a customized titanium tray, augmented with an iliac bone graft, is employed to restore the bone defect, and facilitate tooth implantation [50]. Another noteworthy application of the implant's specific design is found in hemi-mandible reconstruction for patients with hemifacial microsomia [51]. This design incorporates vital components such as the mandibular condyle, ramus, body, and tooth prosthesis, resulting in a comprehensive and tailored solution for the specific anatomical requirements of these individuals [51].