Table 3.

A descriptive summary of each item selected is presented.

Authors and Years	Study Design	Number of Patient	Average Age (Years)	Aligners Type	Outcomes
Dai et al. (2021) [63]	Randomized clinical trial	17	25 ± 5	Invisalign aligners	Coronal movements of the maxillary and mandibular first molars, canines and central incisors were not fully achieved as expected.
R. Vaid et al. (2022) [64]	Observational study	-	-	Invisalign aligners	CAT has been shown to be biomechanically inadequate for achieving complex orthodontic movements based on aligner use alone, and it is the orthodontist’s knowledge of biomechanics that can make any aligner system succeed or fail.
Taffarel et al. (2022) [65]	Retrospective study	32	35 ± 9	Invisalign aligners	The null hypothesis that distalization of posterior teeth occurs in adult patients using Invisalign aligners was rejected. Treatment of Class II malocclusion with Invisalign aligners did not occur as expected in the virtual planning prepared by ClinCheck according to the occlusal outcome evaluation standards established by the ABO upon completion of use of a set of sequentially distalized aligners.
Sabouni et al. (2023) [66]	Case report	1	25	Invisalign aligners	The combined use of aligners with appropriate position and attachment geometry is an effective means of solving more complex orthodontic problems such as Class II malocclusions in a time frame comparable to, if not shorter than, conventional fixed orthodontics but with excellent aesthetics, oral hygiene and quality of life.
Jia et al. (2023) [67]	Observational study	-	-	CAT	Transparent aligners can effectively control the rotation and tipping of anchor units caused by 3D anchor attachment.
Al-Nadawi et al. (2021) [68]	Prospective study	80	35	Invisalign aligners	Achieving clinically similar accuracy between the 7-day and 14-day protocols in half the treatment time suggests that a 7-day protocol is an acceptable treatment protocol.
X Yan et al. (2023) [2]	Retrospective study	51	25	Invisalign aligners	For Class II division 2 patients, expected incisor proclination (69.8%) and intrusion (53.3%) are partially achieved with CAT. Excessive labial movement (0.7 mm) of the incisors may occur. Incisor movement is influenced by the amount of expected movement, premolar extraction, canine proclination, molar distalization, mini-implants, and age.
Linwei Li et al. (2023) [69]	Retrospective study	43	adults	Invisalign aligners	The efficacy of molar distalization with CAs was significantly affected by anterior teeth retraction, and the arch width significantly increased at premolar and molar levels.
Ravera et al. (2016) [70]	Retrospective study	20 (9 males and 11 females)	29.73	Invisalign aligners	Aligner therapy in association with composite attachments and Class II elastics can distalize maxillary first molar by 2.25 mm without significant tipping and vertical movements of the crown.
Auladell A. et al. (2022) [1]	Case reports	First Case (male) and second case (female)	40 and 28	Mini implants in the first case, CA in the second case	The mini-implant and the CA can be used when a correction of 2 mm or more in the sagittal plane treatment is required.
D’Antò V. et al. (2023) [41]	Prospective study	16 (4 males, 12 females)	25.7 ± 8.8	Ordoline Aligners (UABOrdoline, Vilnius, Lithuania)	The maxillary molar distalization measured at the buccal cusp tips with CAs is effective, although the clinician’s prescription, which is the ideal end-treatment goal, is no likely to be fulfilled. Therefore, refinements are necessary.
Palone et al. (2023) [71]	Retrospective study	150 (80 females, 70 males)	33.7 ± 12.7	CAT	When designing difficult movements like tilt and rotation, around 20% overcorrection should be included in the original planning phase, whereas angulation, intrusion, and extrusion needed little to no correction.
Loberto et al. (2023) [72]	Retrospective study	49 (27 females, 22 males)	14.9 ± 6	CAT	The study found significant distalization of maxillary first permanent molars, slight anchorage loss in premolars, and mesial displacement in upper canines. Transparent aligners successfully caused molar shift, but upper canine anchorage loss occurred.
Palone et al. (2022) [73]	Case report	1 female	22	Hybrid-CAT	A bone appliance was used to achieve rapid skeletal maxillary expansion and bilateral molar distalization in a patient with Class II malocclusion, maxillary skeletal transverse deficiency, and ectopic maxillary left lateral incisor.
De Felice et al. (2020) [74]	Clinical study	40	-	CAT	The study found that the actual interproximal enamel reduction (IPR) space did not match the intended amount, and less IPR was performed than anticipated, which may not be clinically significant.
Feng et al. (2022) [75]	Clinical study	21	adults	CAT	It is possible to avoid unintentional crown tilting into the extraction space during space closure by designing the distal crown tipping of the posterior teeth and the mesial crown tipping of the canines. The preliminary formula that has been provided could serve as a reference for anti-tip designs when using CAs.
Saif et al. (2021) [76]	Clinical study	38	25.4	Invisalign aligners	Invisalign is effective for adult patients requiring 2.6 mm distalization of maxillary molars, but clinicians should be aware of adverse effects, especially if the patient initially had a large overjet.
Laganà et al. (2021) [77]	Clinical study	30 (14 males, 16 females)	24.53 ± 13.41	CAT	During treatment with CAs, there is a discrepancy in the amount of interproximal enamel reduction (IPR) reported by the ClinCheck program and the amount of IPR carried out by the orthodontist.
Greco et al. (2022) [78]	Case report	1 female	25	G-Block: Posterior anchorage device TADs-supported aligners	After distalization of the maxillary molars with aligners, the use of TADs for posterior anchorage may be an efficient way to manage posterior anchorage, requiring less patient cooperation when using elastics and making movements of the posterior teeth simpler by combining the force expressed by the aligners with the force expressed by the auxiliary system.