# Predictability of ClinCheck in Overbite Correction with Aligners: A Systematic Review
## 3 Results  
All the included studies adopted the Invisalign as Clear Aligner System with treatment protocols involving at least \(\geq\)14 aligners.  
Overbite measurements were conducted using Geomagic Control X software (3 DSystem Rock Hill SC) in five studies, while two studies employed the ClinCheck software for this purpose [10, 20, 45, 46, 47, 48, 49].  
Five studies measured the vertical linear distance between the midpoint of the incisal edges of the mandibular left central and lateral incisors and the midpoint of the incisal edge of the maxillary left central incisor to measure overbite, except for one study, which evaluated the vertical distance between the edges of the upper and lower incisors (central or lateral) [10, 20, 45, 46, 49]. Two studies did not specify the overbite measurement by ClinCheck software [47, 48]. The aligners being changed once every two weeks were adopted by four studies, whereas two studies employed a ten-day period, while one study did not specify this parameter [10, 20, 45, 46, 47, 48, 49]. In all studies, second molars were present and no elastics or TADS were employed to implement arch levelling.  
Overall, the studies were grouped into two categories according to the initial overbite to be corrected with Invisalign treatment. The two categories were as follows:  
* Studies analyzing the correction of the open bite [45, 47];
* Studies analyzing the correction of the deep bite [10, 20, 46, 48, 49].  
The overbite data were reported in two tables to appreciate and analyze the differences of the ClinCheck estimation between the open bite group and the deep bite group.  
Overbite values from the included studies were extracted and pooled at three standardized time points: T1 (pre-treatment), T2(CC) (planned outcome as predicted by the software) and T3(R) (post-treatment outcome). The real expression of planned overbite correction was calculated as the difference between the predicted and the achieved values (T2(CC)-T3(R)) (Figures 4 and 5).  
Figure 3: Risk of bias of the included studies [10, 20, 45, 46, 47, 48, 49].  
Two studies analyze open bite correction and one of these evaluates the efficiency of posterior occlusal bite blocks (POBBs) in overbite correction, while one study compares the use of optimized attachments with conventional attachments [45; 49].  
No statistically significant differences were found in overbite correction efficiency among POBBs, optimized attachments and conventional attachments.  
Only one study specified the protocol adopted to correct the open bite and the author revealed a statistically significant difference between the absolute and the relative extrusion demonstrating greater efficiency in the overbite correction through the mechanism of absolute extrusion [47].  
Five studies investigated deep bite correction [10; 20; 46; 48; 49]. One study compared patients treated with EX30 material to those treated with SmartTrack combined with bite ramp material [10]. Two studies focused on overbite correction in patients treated with SmartTrack material, one study analyzed the differences in deep bite correction between patients treated with optimized versus conventional attachments and, in one study, traditional attachments were applied to all patients [20; 46; 48; 49]. None of the included studies reported significant difference or improvements in treatment outcomes associated with the use of the EX30 material, the bite ramp, conventional attachments, or optimized attachments.  
Figure 4: The overbite values in open bite studies [45; 47].  
Figure 5: The overbite values in deep bite studies [10; 20; 46; 48; 49].  
Only two studies described the specific correction mechanism for deep bite [48; 49]. One study adopted the incisor intrusion combined with the incisor intrusion and premolar extrusion [48]. One study recorded anterior intrusion, posterior extrusion, and relative extrusion [49]. Both studies reported no statistically significant differences; however, one study noted greater extrusion in the molar region compared to incisor intrusion.