Derotation Kravitz et al. 2008[18] Invisalign *Ellipsoid (16)
*Rectangular (1)
*Ellipsoid and vertical (12)
*Ellipsoid and horizontal (4)
Rectangular and horizontal (1) Group: Interproximal reduction only
Group: neither attachments nor interproximal reduction Movement accuracy Superimposition of The pretreatment and posttreatment virtual models There was no statistically significant difference in rotation accuracy of maxillary and mandibular canines for any of the treatment groups. Simon et al. 2014[12] Invisalign Optimized rotation attachment’ Group (b): No auxiliary Movement accuracy Superimposition of initial and final digital casts of Invisalign treatment The use of attachments had no statistically significant influence on the accuracy of derotation movement. Haouili et al. 2020
[13] Invisalign Optimized attachments No control group Movement accuracy Superimposition of initial and final digital casts of Invisalign treatment The lowest accuracy occurred with rotation (46%). Rotational movement was still difficult for the canines, premolars, and molars even with the use of optimized attachments. Bilello et al. 2022[14] Invisalign Optimized attachments No control group Movement accuracy Superimposition of initial, and final digital casts (real and ideal) The overall accuracy for rotation resulted in 86%, ranging from 96% for the maxillary central incisors to 70.4% for the mandibular first premolars. Karras et al. 2021[15] Invisalign Optimized rotation attachments Conventional rotation attachments Movement accuracy Superimposition of initial, and final digital casts (real and ideal) Conventional attachment types may be just as effective as Invisalign's proprietary optimized attachments for rotations of canines and premolars Castroflorio et al. 2023[16] Invisalign Without attachment Optimized and conventional attachments Movement predictability The superimposition of the post-treatment .stl file (achieved outcome) on the planned final stage .stl file (predicted outcome) Optimized attachments for upper canines and lower premolar rotation seem not working properly.
The lack of correction is reduced in comparison to others studies so attachments should be applied but the design of the used attachments is not sufficient to control the prescribed movement. Stephens 2022
et al.[17] Invisalign Optimized rotation attachment 1 week wear -Optimized attachment 2 week wear
-Conventional rectangular attachments 2 week wear Rotation accuracy Superimposition of initial and final digital casts of Invisalign treatment Vertical rectangular attachments were associated with the least accurate expression of prescribed movement Extrusion Haouili et al. 2020[13] Invisalign Optimized attachment Movement predicted Movement accuracy Superimposition of initial and final digital casts of Invisalign treatment Maxillary incisor extrusion improved with attachments (55%) whereas extrusion of the maxillary and mandibular molars (40%) had the lowest accuracy Karras et al. 2021[15] Invisalign Optimized attachments Conventional attachments Movement accuracy Superimposition of initial, and final digital casts (real and ideal) Differences between mean accuracies of incisor extrusion using Invisalign’s optimized versus conventional attachments were neither statistically nor clinically significant. Groody et al. 2023
[18] Invisalign Optimized (O) attachments. Horizontal attachments:
- Rectangular horizontal non-beveled,
- Rectangular horizontal incisally-
beveled,
- Rectangular horizontal gingivally-
beveled Movement efficacy Digital Models superimposition Horizontal attachments were significantly more effective at achieving prescribed maxillary incisor extrusion (76% of the predicted amount) compared with O attachments (62% of the predicted amount) Burached et al. 2023
[19] Invisalign Optimized attachments Horizontal attachments Openbite correction efficacy Digital Models superimposition Optimized attachments are no more effective than using conventional attachments in incisor extrusion to correct open bite. Intrusion Burached et al. 2023
[23] Invisalign Optimized (O) attachments Attachment conventionals Movement efficacy Digital Models superimposition Movement accuracy: (33–40%)
Optimized attachments are no more effective than using conventional attachments in reducing deep overbite Al-Balaa et al. 2021
[22] Invisalign Passive optimized deepbite attachments No control group Movement accuracy Pre and posttreatment cone-beam computed tomography scans For anterior intrusion>1 mm), the predictability of intrusion for patients treated only with pressure areas and passive OA without bite ramps is 51.19% Haouili et al. 2020
[13] Invisalign G5 attachments No control group Movement accuracy Digital Models superimposition The low accuracy of mandibular incisor intrusion (35%) may be related to the lack of posterior anchorage Incisor torque Simon et al. 2014[12] Invisalign Group (a): “horizontal ellipsoid attachment” Group (b): Power ridges Movement accuracy Superimposition of initial and final digital casts of Invisalign treatment No substantial differences were observed if the upper central incisor torque was supported with a horizontal ellipsoid attachment or with a Power Ridge Molar distalization Simon et al. 2014[12] Invisalign Horizontal beveled gingival attachment No attachments Movement accuracy Superimposition of initial and final digital casts of Invisalign treatment Movement accuracy :
-Without att: 86.9% (SD=0.2)
-With att: 88.4% (SD=0.2)
Bodily tooth movement can be effectively performed using Invisalign, irrespective to attachments Ravera et al. 2016[26] Invisalign 5 Rectangular and vertical attachments on the distalizing teeth (3, 4, 5, 6, 7) No control group Amount of distalization and movement pattern Pre-and post-treatment lateral cephalometric radiographs Distal movement of the 1stand 2ndmolar: 2.25 mm and 2.52 mm respectively without significant tipping and vertical movements Garino et al. 2016[27] Invisalign 5 rectangular attachments (3, 4, 5, 6, 7): group 1 Group 2: 3 rectangular attachments (4, 5, 6)
Group 3: control group (no treatment) Amount of distalization Linear (horizontal, vertical) and angular Measurements on cephalogram - No significant differences in the amount of 2ndmolar movement with or without vertical rectangular attachments.
There was significantly more distal movement of the first molar and central incisor when vertical rectangular attachments were placed on all five distalized teeth D’Anto et al. 2023[28] Invisalign Horizontal rectangular attachments on both 1M and 2M No control group Movement accuracy Superimposition of initial and final digital casts Clear aligners can be regarded as a valuable option for the distalization of first and second molars.
Mean accuracy: 2M 75.2%/1M 69.4% Tipping movement Smith et al. 2022[31] Invisalign 45: No attachments 21: Vertical attachments Lower incisor tip accuracy Superimposition of initial, and final digital casts (real and ideal) Vertical rectangular attachments are recommended when large amounts of root movement are planned, and their presence improves the ability to translate the root apex Molar anchorage Linghuan et al. 2022[36] Invisalign G6 optimized attachments 25 (43.9%) Conventional attachments
Horizontal attachment
13 (22.8%)
Vertical attachment
19 (33.3%) Movement predictability Superimposing the actual and virtual post-treatment models mesial movement and extrusion did not differ among different types of attachments, but mesial tipping decreases with Invisalign G6 attachments Dai et al. 2021[37] Invisalign G6 Optimized[22]
-5mm horizontal rectangular attachments (14)
-4mm horizontal rectangular attachments (16)
-3mm horizontal rectangular attachments (6)
-3mm vertical rectangular attachments (10) No control group 3 Dimensional crown movement Superimposition of pretreatment, predicted posttreatment and actual posttreatment maxillary and mandibulary dental models Relative to predicted changes, first molars achieved greater mesial displacement, mesial tipping, and buccal inclination in both the maxilla and mandible, greater intrusion in the maxilla, and greater mesial-lingual rotation and less constriction in the mandible. Dai et al. 2019[35] Invisalign Attachment G6-optimized[23] -3mm vertical attachment (8)
-3mm horizontal attachment (15)
-5mm horizontal attachment (14) Differences between predicted and achieved tooth movement Superimposition of pretreatment, predicted posttreatment and actual posttreatment maxillary and mandibulary dental
models First molar anchorage control was not fully achieved as predicted even with the use of attachments. Canine retraction Linghuan et al. 2022[36] Invisalign Canine attachment
Vertical attachment Optimized attachment Movement predictability Superimposing the actual and virtual post-treatment models - Significant decrease in distal movement by 1.3 mm was achieved, with a significant increase in distal tipping, lingual inclination, and distal rotation than
predicted
- Distal tipping was associated with optimized attachments
- Vertical rectangular attachments on canines are superior to optimized attachments on canine root control among extraction
cases. Tang et al. 2023[38] Clear aligner Rectangular
att (22)
Optimized
att (38) Rectangular
att (22)
Optimized
att (38) First and second PM extraction Relative anchorage loss Unwanted extrusion and distal crown tipping during anterior retraction; attachments had little effect on preventing this from occurring. Dai et al. 2021[37] Invisalign G6 Optimized (51)
-3mm vertical rectangular attachment (1)
-4mm vertical rectangular attachment (16) 3 Dimensional crown movement Superimposition of pretreatment, predicted posttreatment and actual posttreatment maxillary and mandibulary dental models Both the maxillary and mandibular canines achieved notably more distal
tipping than predicted
Limited benefit in using optimized attachments to control canine angulation Incisor retraction Ren et al. 2022[36] Invisalign Power ridge 23 (37.1%) used on central incisors; associated with different canine attachments (optimized or Vertical) no power ridge on central incisors; associated with different canine attachments (optimized or Vertical) Movement predictability Superimposing the actual and virtual post-treatment models The power ridge did not influence the lingual tipping, extrusion, and retraction of central incisors
When power ridges are prescribed on incisors, lingual root-torquing and intrusion of incisors are more predictable with vertical rectangular attachments than with optimized attachments on canines Dai et al. 2021[37] Invisalign Optimized att (2)
Power ridge (12) No auxillary used (54) Crown movement Superimposition of pretreatment and predicted post-treatment models Both maxillary and mandibular central incisors achieved notably more lingual inclination than predicted Dai et al. 2019[35] Invisalign Power ridge (11) None (49) Differences between predicted and achieved tooth movement Superimposition of pretreatment and predicted post-treatment models Central incisors tipped more lingually, retracted less and extruded more than predicted