# Diagnostic Accuracy and Agreement Between AI and Clinicians in Orthodontic 3D Model Analysis
## 4 Discussion
In radiographic imaging, including lateral cephalograms [40], panoramic radiographs [41], and CBCT [42], AI has supported the automation of landmark identification, segmentation, classification, and analysis tasks, enhancing both speed and diagnostic accuracy [43; 44]. Additionally, tasks such as model segmentation, landmark placement, three-dimensional surface analysis, and virtual tooth movement tracking have also been facilitated through AI technologies [43; 45]. These advancements reduce the need for manual input, alleviate clinical workload, and improve the efficiency and precision of diagnosis and treatment planning [29]. However, to ensure clinical reliability, AI systems must undergo continuous training, testing, and validation. Therefore, assessing the agreement between AI-generated analyses and manual measurements on digital models is crucial. In this context, the findings of our study provide valuable insight into the diagnostic reliability of AI in orthodontics. There was an almost perfect agreement between the orthodontist and the Titan AI system in the classification of malocclusion on both the right and left sides, with [PERSON]'s kappa values of 0.955 (right) and 0.900 (left), respectively (\(p<0.001\)). Similarly, no statistically significant differences were observed among the three groups in the evaluation of anterior and overall Bolton analyses when the location of the tooth size discrepancy (maximilary or mandibular excess) was consistent (anterior: \(p=0.226\); overall: \(p=0.795\)). This inconsistency may be attributed to errors in measuring mesiodistal dimensions, as illustrated in Figure 4, particularly in tooth 15. On the other hand, statistically significant differences were observed between the Orthodontist group and the Titan group (AI) in the measurements of overjet, overbite, and space analysis (\(p<0.001\)). Previous studies have primarily focused on comparing manual measurements performed on traditional dental casts with those obtained from digital intraoral scans. [PERSON] et al. [46] reported statistically significant differences between digital and manual measurements in parameters such as mesiodistal tooth width and overbite (\(p<0.001\)), with values ranging from 0.16 to 0.49 mm. However, these differences were considered clinically negligible. In contrast, [PERSON] et al. [25] found no statistically significant differences between digital and plaster models across all evaluated parameters, including tooth width, arch length, and overjet (\(p>0.05\)). Similarly, [PERSON] et al. [47] concluded that any differences observed between digital and traditional model measurements remained below clinically relevant thresholds and could be considered negligible in clinical practice. Notably, greater deviations have been reported in larger and more complex measurements, such as arch length and arch perimeter [27]. Furthermore, some studies have considered differences up to 0.2 mm to be clinically acceptable in repeated measurements, while others have reported that discrepancies up to 0.3 mm in digital models remain within tolerable limits [27; 48]. The observed discrepancies in space analysis are believed to arise not only from potential inaccuracies in mesiodistal tooth width measurements but also from the method used to calculate the required arch length based on the defined arch form. In particular, in cases of crowding, the software may interpret the dental arch as a sequence of angular segments rather than as a smooth, continuous curve, which can lead to an overestimation of the space required (Figure 3). As for the differences observed in overjet and overbite measurements, these are likely due to variations in reference points used during measurement. While orthodontists typically measure from the midpoint of the incisal edge of the upper incisors to the buccal surface of the lower incisors, Titan Dental Design appears to follow this pattern in simple cases. However, in more complex cases, it tends to take measurements from the central portion of the teeth instead.