# Predictability of ClinCheck in Overbite Correction with Aligners: A Systematic Review
## 3 Results
### Quantitative Assessment of Overbite Correction
According to [PERSON] et al., there is no scientific evidence confirming the efficacy of posterior occlusal bite blocks (POBBs) in promoting posterior dental intrusion [55]. Deep bite correction, on the other hand, is less predictable and there is a lack of consensus regarding clinical strategies involving posterior extrusion and anterior intrusion. Consequently, this systematic review is intended to investigate the reliability of the bite opening mechanism. The results revealed a low concordance between T2(CC) and T3(R). Only two authors clearly outlined the specific role of each mechanism; however, a comprehensive description of the intrusion and extrusion movements was not provided. Only [PERSON] et al. reported greater accuracy in the extrusion of lower molars compared to the anterior intrusion, although this difference was not statistically significant [49]. Similar findings have been reported by other studies, with a mean intrusion accuracy of 45%. Furthermore, [PERSON] et al. also concluded that the anterior intrusion predicted by the aligner treatment plan was not fully realized in clinical outcomes [19; 25; 56]. The relative intrusion is evaluated in only one study, which confirmed that the overbite correction accuracy improves when incisor proclination is planned. The use of bite ramps did not improve the overbite correction, a finding that contrasts with the overbite correction of 1.3 mm achieved by [PERSON] et al. [13]. For both open bite and deep bite correction, current evidence does not demonstrate the superior effectiveness of either optimized or traditional attachments. Only two studies specify the type, the sizes and the position of attachments on teeth whereas one study merely stated the use of traditional attachments without further detail [47; 48; 49]. Two studies found no significant differences between conventional and optimized attachments [47; 48]. [PERSON] et al. reported that most orthodontists prefer traditional attachments and, as previously documented, the use of attachments may enhance vertical tooth movement [57; 58]. A recent systematic review concluded that the attachments could improve aligner biomechanics, and they should therefore be considered important auxiliary elements of aligner therapy [59]. No study has investigated the influence of skeletal pattern, although the literature suggests that brachyfacial patients are more resistant to deep bite correction, just as dolicofacial patients are in open bite cases [60]. Additionally, various biomechanical strategies can impact treatment efficiency. One such method, commonly referred to as \"frog staging\", involves sequencing the intrusion of anterior teeth to enhance predictability. In this protocol, the intrusion is performed in alternating phases, initially targeting the lower canines, followed by the incisors, then returning to the canines and incisors in a staggered manner depending on the clinical scenario. While this approach increases the total number of aligners and prolongs treatment duration, it enhances control by allowing one group of teeth to serve as anchorage while the other undergoes movement. Several clinicians recommend using 4-mm rectangular horizontal attachments at the premolar level and 5 mm attachments at the canine level. When extrusion is planned at the premolar level, the attachments are beveled gingivally [61; 62]. Similarly, factors such as proclination, class II elastics or anchorage design and overengineering the final set up might influence predictability [63; 64]. To our knowledge, this is the first systematic review and meta-analysis providing a quantitative assessment of ClinCheck software accuracy in overbite correction, stratified by open and deep bite groups. These results may offer valuable insights for clinicians in planning and adjusting aligner treatments for improved overbite control.