## 1 Introduction  
Mandibular reconstruction in oral and maxillofacial surgery remains one of the most challenging procedures due to the anatomical complexity and functional significance of the mandible [1]. Mandibular defects can arise from various causes, including benign and malignant tumor resection, severe trauma, congenital deformities, infections [2], and failed previous reconstruction attempts. The mandible plays a crucial role in forming the lower facial structure and is essential for fundamental functions such as mastication, speech, breathing, and swallowing. Therefore, mandibular reconstruction must consider the restoration of these functions while ensuring sufficient resistance to repetitive physical forces generated during various functional activities. Furthermore, since the mandible significantly influences facial aesthetics, the aesthetic outcome must also be carefully considered. Due to this functional and aesthetic importance, mandibular reconstruction surgery is essential for restoring patients' quality of life [3]. The optimal approach to restoring both the functional and aesthetic elements of the mandible is to reconstruct it as close as possible to its original or normal anatomical structure. Traditionally, this has been accomplished using autogenous bone and flap transplantation along with mandibular reconstruction plates [4]. However, a major limitation of these conventional reconstruction methods is the inherent difficulty in achieving a perfect mandibular alignment and contour when relying solely on intraoperative assessment [5]. This challenge particularly arises from the mandible's complex anatomical structure, which includes two temporomandibular joints capable of rotational and sliding movements connecting it to the maxilla, allowing free movement, along with its three-dimensional curved form following the dental arch, and its intricate interactions with various masticatory and deglutition muscles [6]. These methods heavily depend on the expertise of the oral and maxillofacial surgeon and the intraoperative decision making [7]. Surgical outcomes can vary significantly based on the surgeon's skill level, and discrepancies between preoperative plans and actual surgical results are common. Such discrepancies can lead to various complications, including malocclusion, facial asymmetry, plate fatigue fracture, screw loosening, and the non-union of transplanted autogenous bone. Additional surgeries may be required to address these issues, prolonging the recovery period and impacting the patient's quality of life. Recent advances in medical technology, particularly computer-aided patient-specific surgical simulation and 3D-printing technology, have transformed the approach to mandibular reconstruction surgery [8; 9; 10; 11; 12; 13]. Computer-aided surgical simulation enables not only precise lesion resection but also planning for ideal anatomical structure restoration. Based on this, patient-specific surgical guides and fixation plates can be manufactured using 3D-printing technology, offering the potential to significantly enhance the surgical precision. The use of these patient-specific devices allows surgeons to plan and execute reconstruction more accurately, reducing the uncertainties inherent in conventional approaches and achieving more predictable results [14]. This surgical approach has shown particularly promising results in mandibular reconstruction using fibular free flaps [15; 16; 17]. Recent studies have demonstrated reduced operation times and predictable outcomes through accurate bone harvesting using cutting guides and precise positioning with customized plates [18; 19; 20]. The Deep Circumflex Iliac Artery (DCIA) flap with internal oblique muscle, which can provide sufficient bone comparable to the original mandibular contour and restore the natural mandibular morphology with minimal or no osteotomy, is also frequently used as a donor site for mandibular reconstruction [21].