## 5 Discussion  
The insertion site for orthodontic miniscrews is influenced by several clinical factors, including the direction of intended tooth movement, anchorage requirements, and anatomical limitations. Although the anterior palate is a commonly preferred site due to its favorable bone quality and thickness, several studies have highlighted its high anatomical variability. For this reason, a preliminary evaluation using cone beam computed tomography (CBCT) is strongly recommended to ensure accurate and safe placement, particularly in cases involving impacted teeth or narrow maxillary arches [17, 18, 19, 20]. The use of 3D-printed surgical guides has been proposed to enhance the accuracy and reproducibility of miniscrew insertion. Numerous authors have compared traditional free-hand placement with guided insertion using 3D templates, reporting significantly better outcomes in terms of angular and linear deviations when surgical guides are employed [21, 22, 23]. These guides have proven effective not only in palatal insertions but also in more challenging anatomical regions such as the infrazygomatic crest and interradicular space [21, 24, 25]. Quantitative assessments using pre- and postoperative CBCT scans have confirmed the improved precision of guided insertion techniques, which reduces the risk of iatrogenic damage to adjacent roots or the maxillary sinus [23, 26]. Two different studies conducted on cadavers [27] and phantoms [28] showed that miniscrew-assisted placement with a surgical guide is more accurate than free-hand placement in terms of both angular deviation and mesiodistal deviation in the coronal and apical miniscrew areas [27, 28]. A recent study by [PERSON] et al. [22] analyzed the accuracy of palatal miniscrew placement in a digital workflow, assessing errors at multiple stages, from virtual planning to laboratory model fabrication and clinical insertion. They highlighted how even small deviations during the lab phase (mean angular error \(\sim\)2.12\({}^{\circ}\)) could contribute to cumulative inaccuracies that compromise the final clinical outcome, particularly in protocols requiring high-precision insertion. Figure 8: Distribution of maximum angular deviations (MADs) between planned and actual miniscrew positions. The boxplot (**left**) illustrates the median, interquartile range, and potential outliers, highlighting the variability in insertion angles. The histogram (**right**), with an overlaid density curve, shows the frequency distribution of MAD values across the sample (n = 48), indicating a near-normal distribution with a slight right skew. Discrepancies between planned and achieved miniscrew positions may result from several factors, including patient-specific bone morphology, operator experience, and procedural inconsistencies [29; 30]. Although digital scanners have demonstrated high reliability in the literature [29], operator skill and environmental conditions can still affect scan accuracy. Therefore, standardized protocols and the precise execution of each step in the digital workflow are essential for optimizing outcomes. In the context of single-visit protocols, accurate digital planning followed by predrilling using a surgical guide ensures optimal screw angularation and minimizes undercuts. This facilitates the insertion of TADs and the immediate fit of orthodontic appliances, ultimately reducing chair time and enhancing clinical efficiency [31]. The present study aimed to evaluate the real-world accuracy of 3D-printed surgical guides for palatal miniscrew insertion by comparing the digitally planned position with the actual postoperative outcome. Through the superimposition of STL models from the planning phase and the final clinical scan, discrepancies in the insertion angle and spatial deviation were measured at both the screw head and tip. The results revealed greater horizontal and vertical discrepancies at the tip than at the head, which is consistent with the geometric amplification of angular deviations as distance increases.