## 4 Discussion
Additive manufacturing offers a notable advantage in presurgical planning for cancer cases and reconstruction planning of mandible fractures, which are the second-most prevalent facial fractures in children. By utilizing a 3D-printed mandible model, the placement of titanium plates becomes more challenging due to the presence of tooth germs in growing patients. Additionally, this approach significantly reduces surgical time under general anesthesia [57; 58; 59; 60; 61]. The application of 3D-printing technology also contributes to the enhanced success rate of autotransplantation. This is achieved by reducing the extraoral time interval between the tooth extraction and the transplantation through recipient bone site modification and the preparation of the tooth for a temporary crown prior to extraction [62]. Furthermore, 3D printing finds utility in the creation of space maintainers and various orthodontic appliances, including Hawley retainers, brackets, and clear aligners. These applications of 3D printing significantly benefit the fields of preventive and corrective orthodontics [57; 58; 59; 60; 61]. Remarkably, the number of studies investigating the utilization of CAD/CAM and 3D-printing technology in the manufacturing of space maintainers (SMs) is limited. Among the existing studies, a variety of methodologies, materials, and technologies have been reported. While the more advanced and advantageous 4D printing technology has been introduced, which is capable of creating self-folding structures that reshape over time or space, it has not been applied in the field of pediatric dentistry, and therefore, no scientific reports on its implementation were found [43; 63]. * _Manufacturing technologies_ In clinical dental practices, the choice of additive materials and their corresponding applications determine the manufacturing technology that is employed. Various technologies including stereolithography, digital light processing, photopolymer, material, and binder jetting, alongside selective laser sintering/melting, and fused filament fabrication can be utilized depending on the specific requirements [64]. * _Laser sintering_ Approximately 21 years ago, laser sintering technology emerged as a groundbreaking advancement in the dental field, ultimately, revolutionizing the processing of non-precious alloys. This technology was initially utilized for printing metallic structures, such as crowns, bridges, or clasp-retained cast-metal frameworks [65; 66]. Laser sintering operates on a powder-based layer-additive manufacturing technique, thereby employing a continuous or pulse mode laser beam as a heat source to scan and fuse powders together [67]. The first documented case of fabricating 3D-printed band-loop space maintainers was reported by [PERSON] et al. [27]. They digitally designed a space maintainer using a 3D model and utilized titanium powder metallurgy with micro laser sintering technology for manufacturing. The authors discovered that incorporating innovative digital technology into the design and production process of space maintainers made it more convenient and time-efficient compared to conventional methods. This signifies the promising potential of 3D printing technology in the field of pediatric dentistry [27]. This finding aligns with another study where researchers utilized micro laser sintering technology and titanium powder metallurgy to manufacture a 3D-printed space maintainer for an uncooperative patient. They observed a notable improvement in the child's cooperation following the placement of the 3D-printed space maintainer. Additionally, during the 6-month follow-up visit, the 3D-printed space maintainer remained intact without any signs of plaque accumulation or gingival inflammation. The authors attributed the resilience of the 3D-printed space maintainer to its single-unit fabrication, which eliminated the need for soldering, and its precise adaptation that did not disrupt occlusion. They also noted that the 3D-printed space maintainer featured a more complex structure with finer details.