## 5 Results  
The 3D inspection results shown in Figure 12 illustrated that the majority of the surface was mapped green in the cavity-filled approach, suggesting a high degree of precision between reference (R) and test (T) models. A 2D analysis was also conducted to determine the variance around a specific cross-section. A 2D comparison is useful for matching the cross-section of the test object to the cross-section of the reference component. The section plane, shown in Figure 13, was taken across the middle of the mandible to divide the part into top and bottom halves. Figure 13a implies that the top half of the mandible in the test portion was not precisely aligned with the reference artifact. This could be due to either inaccurate  
Figure 11: Data acquisition from FDM-reconstructed models using a FARO arm laser scanner. Figure 12: Three-dimensional (3D) inspection results of the resected original mandible model with (a) mirror reconstruction model and (b) cavity-filled reconstruction model. symmetrical measurement of the plane or differences on both sides of the mandible of the patient. Indeed, the 2D analysis in Figure 13b demonstrated the higher precision of the cavity-filled approach as compared to the mirror-reconstructed mandible. The findings of the STL file comparison were further assisted by examining the FDM-produced physical prototype scans using the Faro arm laser scanner. The 3D color map, shown in Figure 14a, further determined that the cavity-filled reconstruction technique resulted in higher accuracy. The Geomagics program produced the statistical information, including the RMS and AD (positive and negative sides), upon alignment of the two models. There was a positive deviation when the test model was outside the reference model and conversely for a negative deviation. A series of five measurements was conducted for each mode under study to validate the consistency of the method, as shown in Table 1. The placement and positioning of the specimen or mandible was altered at each measurement run. A comparative analysis of the mirror and cavity-filled techniques with respect to their accuracy (RMS and AD) was made using the two sample \(t\)-test. As the \(p\)-value was less than the significance level (\(\alpha\)) of 0.05, the null hypothesis was discarded, and it could be inferred that the two reconstruction techniques differed significantly. Furthermore, the one-way ANOVA test also verified that the \(p\)-values for the RMS and AD between mirror and cavity-filled groups were less than 0.05. This finding substantiated yet again that both techniques (mirror and cavity-filled) varied considerably. The outcomes of both the sample \(t\)-test  
Figure 14: The 3D comparison results for physical prototypes with (a) Cavity-filled with resected comparison (b) Mirror with resected comparison. Figure 13: Two-dimensional (2D) comparison results of the cross-sectional plane of resected mandible with (a) mirror mandible model and (b) cavity-filled model. and the one-way ANOVA led to the rejection of the null hypothesis and concluded that the population means from two reconstruction techniques were not equal. The mean RMS values observed for mirroring and cavity-filled techniques in the physical prototype evaluation were 1.2683 and 1.1019 mm, respectively. This implied an error decline of nearly 13% in 3D-printed mandibles restored using a cavity-filled approach, as depicted in Figure 15. Similarly, when the STL files from the mirror and the cavity-filled rehabilitated virtual variants were assessed, the RMS error value decreased from 1.8018 to 1.5048 mm, resulting in an approximately 16% drop. The significant decrease in AD (both positive and negative in Table 1) can also be noted in the cavity-filled procedure relative to the mirror reconstruction solutions. This provided mean values of 0.5194/\(-\)0.5392 mm (AD) for the cavity-filled approach as compared to the mirroring technique, which resulted in corresponding higher values of 0.7441/\(-\)0.8682 mm (see Table 1).