## 1 Introduction  
Functional and aesthetic defects in the maxillofacial region occur primarily due to various ailments, such as tumor excision, trauma, malformation, jaw atrophy, and benign or malignant neoplasm [1; 2]. Immediate reconstruction is the most effective way to achieve improved and long-term functional outcomes [3]. Recent advances in technology and innovations in the patient-specific implants and their treatment led to the minimization of surgical time and cost. Precise design and production of patient-specific implants are essential in the surgical outcome. One of the biggest challenges, even for experienced surgeons, is to precisely fit the implant onto the bone contours and eliminate postoperative revisions. The success rate of any reconstructive implant surgery depends on several factors, such as medical evaluation, implant design, and the surgeon's skill [4]. The majority of conventionally manufactured reconstructive implants are of standard size and form. Such implants must be adjusted by manual bending or twisting according to the bone contour of the patient, resulting in poor adaptation and prolonged operating time [5]. Most patients undergo secondary surgical reconstruction to refine the cosmetic and functional outcomes that result in psychological stress and social implications [6; 7]. The pre-operative preparation and three-dimensional (3D) printed patient-specific implant assessment are crucial to mitigate these instances. In addition, accurate patient-specific implants and their evaluation will result in reduced operating time, predictability of surgical outcome, and increased implant accuracy [8; 9]. Virtual pre-operative planning and 3D-printed polymer models help minimize revision, as well as errors, eventually providing better aesthetic and functional results [10]. The technique of 3D printing developed in the mid-1980s laid the foundation for the efficient manufacturing of complex anatomical models, whereby anatomical defects can be measured and pre-planned by surgeons, and surgeries can be simulated [11]. The anatomical curvature of the skull and its facial bone is extremely complex, and it is often a demanding process for skilled surgeons to accurately align and rebuild the implant [12]. In the past, several computer-assisted design (CAD) and 3D planning strategies were proposed for the reconstruction of mandibular and dental implants [13; 14]. These concepts utilized a preoperative virtual simulation of the proposed mandibular defect, and they could easily modify the 3D file multiple times, rather than relying heavily on the traditional intraoperative manual assessment [15]. In addition, 3D reconstruction planning improved the surgical precision, reduced the operating time, and ultimately enhanced the structural and functional outcomes [16]. [PERSON] et al. [17] demonstrated that a 3D reconstruction technique maintained the symmetrical accuracy, as well as improved the functional and aesthetic outcomes, in mandibular reconstruction when compared to traditional freehand technique. [PERSON] et al. [18] and [PERSON] et al. [19] also developed a patient-specific mandibular reconstruction plate using a CAD procedure and proved that it was more effective and satisfying for accurate mandibular reconstruction. According to [PERSON] et al. [20], the segmental mirroring technique could be exploited satisfactorily for creating reasonably accurate 3D models to enable mandibular reconstruction in instances where preoperative adjustment of a reconstruction plate was constrained by the complexity of the mandibular defect. This strategy was rather less effective when the complicated mandibular condyle anatomy was involved. Similarly, [PERSON] et al. [21] advocated the application of CAD/computer-aided manufacturing (CAM) technology and 3D-printed cutting guides to accomplish realistic and cosmetic performance in patients seeking mandibular reconstruction with a free fibula flap.