## 3 Results
### NASSS Framework
#### 3.2.2 Technology  
The first 3D model was made in 1981 by [PERSON] at the Nagoya Municipal Industrial Research Institute using a photopolymer. Then, in 1984, [PERSON] invented stereolithography, the process of creating three-dimensional models using digital data. This new technology became popular among inventors who could now build and test their prototypes without incurring large costs. Then, in 1992, the first stereolithography (SLA) machine was built, which allowed for the creation of complex parts to be built layer by layer. At roughly the same time, the first selective laser sintering (SLS) machine was invented that could fire a laser at the photopolymer powder instead of the liquid (Table 1) [34]. In 2010, 3D printers were developed around the world for use in oral and maxillofacial surgery. Since then, Iran has made significant progress in using 3D printing technology for oral and maxillofacial surgery. In 2011, the Shahid Sadoughi University of Yazd surgical team used an Iranian-made 3D printer for maxillofacial surgery for the first time in Iran. The printer produced an accurate model of the jaw of a 48-year-old patient with SCC before surgery, which allowed specialists to match the reconstruction plate with the patient's face. This method resulted in a 35-40% reduction in surgery time as well as significant cost savings. Hazare Third Millennium Smart Machines Company, Tehran, Iran. Designed and manufactured the 3D printer, with support from Shinasa Investment Company (Tehran, Iran). By analyzing the patient's 3D CT scan images, the company produced the jaw sample with an error of less than 32 microns [35]. Three-dimensional models have additional uses besides the creation of patient jaw models. Three-dimensional models are also utilized to produce surgical guides and contouring of the osteosynthesis or reconstruction plates in the treatment planning phase of various oral and maxillofacial surgical procedures. The pre-bending of plates on a 3D model can offer higher precision compared to the conventional approach where bending is performed intraoperatively. Furthermore, the physical manipulation of the anatomical structures on a model during planning of the complex surgical procedures permits more control and better comprehension of the different surgical approaches. This allows surgeons to become familiarized with the intraoperative situation beforehand and lead to more predictable intraoperative results (Figure 4) [36]. Figure 3: Iran (Islamic Republic of) Both sexes, All ages, 2019, DALYS. Annual mortality in Iran. Data adapted from [24]. According to this record, road injuries constitute 5.63% of total DALYs (4.83-6.58%), with an annual % change of \(-\)3.27%, and oral disorders constitute 1.31% of total DALYs (0.82-2.05%), with an annual % change of 1.52%. The most common clinical indications of 3D printing in maxillofacial settings include dental implant surgery [37], mandibular reconstruction [38], manufacturing of anatomical models, producing surgical guides/splints, patient-specific implants [37], orthognathic surgeries [39], surgical guides for geniolplasty and osteotomy [21], and prosthesis (Figure 5). Figure 4: Adapted from [34]. A summary of the process of 3D printing in maxillofacial surgery. Figure 5: Applications of 3D printing technology in maxillofacial surgery. Adapted from [39]. For 3D printing technology to avoid pitfalls and complications, proper communication is needed. Specifically, proper communication between the radiologists and the digitized treatment planning team at the 3 DP PoC center is essential to obtain the imaging needed to ensure the accurate design of instruments while avoiding the pitfalls of inaccurate anatomical details. By incorporating the skills of clinicians on site, as well as ensuring dialogue between treating physicians and engineers, the 3 DP PoC can tremendously improve surgical outcomes and meet most of the needs of the surgical team (Figure 6) [39].