ORIGINAL ARTICLE Predicted and actual outcome of anterior intrusion with Invisalign assessed with cone-beam computed tomography Maher Al-balaa,a Hanyue Li,a Abdelrahman MA Mohamed,b Lulu Xia,a Wei Liu,a Yaosen Chen,b Tamer Omran,c Shufang Li,a and Xianming Huaa Wuhan and Chengdu, China Introduction: The purpose of this study was to compare predicted anterior teeth intrusion measurements with the actual clinical intrusion measurements using cone-beam computed tomography Understanding the precision of the software in anticipating changes may help practitioners predict the need for overcorrection Methods: Twenty-two patients, with a mean age of 23.74 years, who underwent Invisalign (Align Technology, Santa Clara, Calif) clear aligners treatment for both arches only after having completed treatment with an initial series of aligners were included in this study The pretreatment and posttreatment cone-beam computed tomography scans after the initial series were acquired by a single orthodontist practitioner ClinCheck measurements were recorded with Align Technology The long axis of the anterior tooth intrusion movement was measured in 142 teeth A comparison between the predicted and actual measurements of anterior intrusion of the teeth was performed, and the intraclass correlation coefficients showed an almost perfect agreement in the linear measurements Results: A statistically notable difference between the predicted and actual measurements of anterior intrusion The predicted intrusion movement of the maxillary canines (P 0.001), maxillary lateral incisors (P \0.0001), and maxillary central incisors (P \0.0001) significantly differed from the actual values Similarly, the intrusion movement in the mandibular teeth seemed to be inaccurate, with significant differences in the mandibular canines (P \0.0001) and mandibular lateral and central incisors (P \0.0001) Conclusions: The mean precision of true anterior intrusion with Invisalign clear aligners was 51.19%, and the mean amount of correction was 48.81% The use of other supplementary methods of anterior teeth intrusion may be helpful to reduce the rate of midcourse corrections and refinements (Am J Orthod Dentofacial Orthop 2021;159:e275-e280) T he treatment of misaligned teeth with Invisalign (Align Technology, Santa Clara, Calif) involves the sequential use of software-fabricated, clear plastic aligners that fits over the buccal, palatal a Department of Orthodontics, The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China b Department of Stomatology, Zhongnan Hospital, Wuhan University, Wuhan, China c Department of Orthodontics, State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest, and none were reported Address correspondence to: Xianming Hua, Department of Orthodontics, The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan 430079, China; e-mail, hxm@whu edu.cn Submitted, February 2020; revised, September 2020; accepted, October 2020 0889-5406/$36.00 Ó 2020 by the American Association of Orthodontists All rights reserved https://doi.org/10.1016/j.ajodo.2020.10.018 (lingual), and occlusal surfaces of the teeth and move specific teeth to their appropriate positions The appliances are removable and made of 0.75 mm dense polyurethane Patients are instructed to wear the aligners for a minimum of 20 hours per day on a 1-2 week basis before progressing to the next step Every aligner is designed to adjust specific teeth by approximately 0.25-0.3 mm.1,2 The Invisalign technique is used to manufacture tailored aligners from a very accurate impression or an intraoral 3-dimensional (3D) image scanned in the dental office.3 This process allows the replication of a patient's teeth as a 3D model, which can be operated on and practically amended by an orthodontist using advanced propriety software; the treatment designed by the orthodontist is then implemented by Invisalign clear aligners appliances The ClinCheck (Align Technology) online software program allows clinicians to view virtual models showing a range of conditions from malocclusion to correction in small increments e275 Al-balaa et al e276 The Invisalign clear aligners were initially proposed to treat orthodontic patients of moderate severity.1,4 However, intricate orthodontic case reports of patients who are effectively managed with Invisalign clear aligners treatment are still being published in the literature.5 The Invisalign clear aligners appliance was recently modified to include the latest treatment alternatives comprising calculated attachments and virtual bite ramps to specifically control movement in the vertical dimension and reduce deep overbites.6 Align Technology has developed numerous techniques over the past 17 years to control deep overbites better Passive optimized deepbite attachments are usually placed on the buccal surface of the first or second premolar to increase retention and provide anchorage for the intrusion of the anterior teeth, whereas active optimized deepbite attachments deliver extrusive forces to the premolars to achieve posterior extrusion and level the curve of Spee Precision bite ramps operate similarly to anterior bite planes or bite turbos These bite ramps are placed onto the palatal surface of the maxillary incisors and make contact with the mandibular incisors to separate the posterior teeth as a patient brings his or her teeth together.6 In recent years, numerous methods, including the American Board of Orthodontics objective grading system, peer assessment rating systems, and other objective occlusal criteria, have been used by scholars to evaluate the quality of orthodontic treatment with Invisalign clear aligners.7-13 The conclusions were that Invisalign clear aligners are not an effective removable appliance for managing overbites, occlusal contacts, occlusal relationship.14 Although they have some limitations, and they not explain the etiology of unsatisfactory results in depth There are limited studies on the level of inconsistency between the predicted and actual measurements of the movement achieved with Invisalign clear aligners.11 The average precision of tooth movement in the anterior region was 41% with Invisalign clear aligners.15 An inhouse study from Align Technology found that approximately 80% of the desired tooth movement is achieved, as measured by ClinCheck.6 To comprehend how the Invisalign clear aligners appliance manages the intrusion of anterior teeth, studies with various sample sizes and sophisticated designs are required Most of the studies performed before Invisalign clear aligners launched their SmartTrack material and deep overbite protocol used different methods to evaluate the accuracy of Invisalign clear aligners, such as 2dimensional (2D) cephalometric and 3D models The major limitations of these methods are that the contours and shapes change, and a stable anatomic structure is March 2021 Vol 159 Issue missing Furthermore, the etiology of unsatisfactory results cannot be determined with these methods Studies with 3D images can provide valuable information for efficient treatment planning with ClinCheck For instance, if the precision percentage of a specific tooth movement is known, overcorrecting it by the appropriate amount may result in the desired outcome Cone-beam computed tomography (CBCT) allows an orthodontist to rapidly and accurately create patient-specific 3D software models that can be used for diagnoses, treatment planning, and evaluations Accurate measurements can be made for any part of the anatomy, and the tooth sizes can be measured Therefore, the true anatomic measurements for each patient can be determined.16 Studying treatment results using CBCT can be useful because CBCT scans provide authentic quantitative data permitting images to be compared with accuracy and precision and without magnification Furthermore, these scans enable volumetric measurements of an object and the assessment of changes in the contours and shapes of objects, which are often limited in 2D cephalometry In addition, these scans provide more information than 2D images.17,18 This study aimed to compare predicted anterior teeth intrusion measurements with the actual clinical intrusion measurements using CBCT Understanding the precision of the software in anticipating changes may help practitioners predict the need for overcorrection, thereby reducing the need for midcourse modifications and the treatment time MATERIAL AND METHODS An endorsement certificate was issued by the Wuhan University Hospital of Stomatology Ethics committee at Wuhan University (no B20) for this retrospective study Patients being treated in the Department of Orthodontics in Wuhan University Hospital of Stomatology, Wuhan, China, under the guidance of an experienced orthodontist who certified in Invisalign treatment, were included in this study The patient's identification, age, sex, treatment duration, crowding, overbite, and molar relationships, as well as the files required to determine the predicted treatment and achieved treatment (the difference from before and after treatment), were recorded The study population was composed of 22 patients, including 142 teeth, 12 females and 10 males with a mean age of 23.74 years (range from 16 years to 46 years months) All patients had both arches treated with Invisalign clear aligners only The average treatment period was 19.27 months (range from 11 months to 29 months) Mild crowding ranged American Journal of Orthodontics and Dentofacial Orthopedics Al-balaa et al from 0.00 to 3.00 mm in subjects, moderate crowding ranged from 3.00 to 5.49 mm in 14 subjects, and subjects had spacing (3.92-4.76 mm) The overbite status was normal in patients (ranged from 1.80 to \4.00 mm), and 14 patients had a deep overbite with a mean of 4.18 mm (standard deviation, 1.51 mm; range, 4.00-8.50 mm) The Angle classifications of malocclusion were as follows: 19 patients had Angle Class I malocclusion, patients had Class II malocclusion, and patient had a Class III malocclusion The patients had to wear each aligner for 14 days Each patient in this study started treatment in 2016 or later after Align Technology introduced the SmartTrack material and launched their deepbite protocol This protocol was developed to improve the predictability of deepbite correction with clear aligner treatment via several innovations, including specific pressure areas and optimized deepbite attachments In this study, we used passive optimized deepbite attachments The study focused only on the initial series of aligners No refinement was included We defined the inclusion criteria as follows: (1) the patient underwent treatment in both arches, (2) the patient successfully completed treatment with an initial series of aligners, (3) the patient attended their appointments and had good compliance with consistent aligner wear, (4) the patient had a minimum of mm or more of intrusion of the anterior teeth, (5) the patient started treatment in 2016 or later, (6) the treatment plan was nonextraction, and (7) the patient had good-quality pretreatment and posttreatment CBCT scans after the initial series We defined the exclusion criteria as follows: (1) an initial series of aligners unsuccessfully completed, (2) the absence from appointments or poor compliance, (3) extraction cases or arch extraction, (4) bite ramps or the extrusion of posterior teeth, and (5) missing before or after CBCT scans The CBCT scans were obtained by NewTom VGI (Quantitative Radiology, Verona, Italy) The volume data were exported in the DICOM format for Dolphin Imaging software (version 11.95 premium; Dolphin Imaging and Management Systems, Chatsworth, Calif) to perform 3D analysis with reference lines and landmarks for evaluation In the axial view, each tooth was adjusted from the midpoint of the crown in the buccolingual and mesiodistal directions (Fig 1) In addition, reference planes in the sagittal view on each CBCT scan were used to determine the maxillary anterior teeth palatal plane from the right side to the left side shows the Video 1, available at www.ajodo.org (plane constructed by projecting a line through points ANS and PNS) (Fig 2) and the mandibular anterior teeth mandibular plane Me-Go from the right side to the left side shows the e277 Fig The midpoint of each tooth adjusted from the midpoint of the crown in the buccolingual and mesiodistal directions in the axial view Fig The blue line corresponds to the maxillary palatal plane (ANS to PNS): A, upper tip of the anterior tooth; B, the apex of the maxillary anterior tooth; C, intersection line between the palatal plane and point A Fig The blue line corresponds to the mandibular plane (GoMe): A, the lower tip of the anterior tooth; B, apex of the mandibular anterior tooth; C, intersection line between the mandibular plane and point A American Journal of Orthodontics and Dentofacial Orthopedics March 2021 Vol 159 Issue Al-balaa et al e278 Video 2, available at www.ajodo.org (plane between the left gonion, right gonion and menton) (Fig 3).19,20 The CBCT scans taken before and after the treatment were superimposed to assess the reference planes and landmarks positions.20 The linear measurements included the UT-PP, expressed as the distance in millimeters from the intersection point between the palatal plane and tip of the maxillary anterior teeth (Fig 2) The LTMP was defined as the distance in millimeters from the intersection point between the mandibular plane and tip of the mandibular anterior teeth (Fig 3).21 These measurements were taken because Align Technology developed pressure areas to intrude the maxillary and mandibular anterior teeth, and these pressure areas allowed for an intrusive force to be directed along the long axis of the tooth.22,23 Predicted (Clincheck) Tooth Maxillary canines (mm) Maxillary lateral incisors (mm) Maxillary central incisors (mm) Mandibular canines (mm) Mandibular incisors (mm) Actual n Mean Median SD Mean Median SD 1.74 1.8 0.48 0.83 0.8 0.46 19 1.97 1.8 1.02 1.1 0.9 0.82 22 2.4 2.25 1.06 1.16 1.2 0.84 18 1.52 1.5 0.41 0.72 0.7 0.25 74 1.85 1.8 0.64 0.82 0.7 0.52 SD, Standard deviation Table II Paired-samples t test Statistical analysis SPSS software was used for the statistical analyses (version 22; IBM Corp, Armonk, NY) The intrusion movement for each tooth was calculated independently Every tooth was measured individually times by the same examiner (MA) The methodological error was calculated using intraclass correlation coefficients, which showed nearly perfect agreement and interrater reliability from 0.961 to 1.000 for the linear measurements To minimize the number of variables assessed, the teeth were grouped together as follows: teeth contralateral to the maxillary canines, maxillary lateral incisors, maxillary central incisors, mandibular canines, and mandibular central and lateral incisors Descriptive statistics were calculated for the anterior teeth in terms of the predicted and actual movement The data were normally distributed according to the Shapiro-Wilk test, and the paired-samples t test was used as appropriate RESULTS The mean, median, and standard deviation of the ClinCheck and actual intrusion movements are presented in Table I The paired-sample t test was used to compare the predicted and actual quantities and assess the accuracy of each tooth movement The outcomes of the paired-sample t test, the mean of the achieved values, and the mean difference between the achieved and predicted values are given in Table II The predicted intrusion movement of the maxillary canines (P 0.001), maxillary lateral incisors (P \0.0001), and maxillary central incisors (P \0.0001) significantly differed from the actual values Similarly, the intrusion movements of the mandibular teeth seemed to be inaccurate, with significant differences in the mandibular March 2021 Vol 159 Issue Table I Descriptive statistics Intrusion Maxillary canines (mm) Maxillary lateral incisors (mm) Maxillary central incisors (mm) Mandibular canines (mm) Mandibular incisors (mm) Mean actual 0.83 1.1 Mean difference (actualClinCheck) P value À0.91 0.001* À0.87 \0.0001y 1.16 À1.24 \0.0001y 0.72 0.82 À0.79 À1.02 \0.0001y \0.0001y *Statistically significant difference (P #0.001); yStatistically significant difference (P #0.0001) canines (P \0.0001) and lateral and central incisors (P \0.0001) DISCUSSION In 1946, invisible orthodontic treatment was first introduced by Kesling, and it involved the use of a sequence of aligners to correct the alignment of teeth gradually In the 1970s, Ponitz24 incrementally corrected the alignment of teeth with clear aligner treatment In 1999, Align Technology introduced this idea to the United States The Invisalign system manufactured by Align Technology uses aligners to correct the alignment of misaligned teeth.25 The Invisalign system has significantly developed over the last 17 years Nevertheless, our understanding of the device is primarily restricted to the information provided by Align Technology and the limited number of studies in the orthodontic literature.26 A systematic review on the efficiency of clear aligners in managing various tooth movements was conducted in 2015 and American Journal of Orthodontics and Dentofacial Orthopedics Al-balaa et al included 11 studies from January 2000 to June 2014.26 Unclear risk of bias was found in several studies, whereas a mild risk of bias was found in studies The most recurrent sources of bias were associated with the study design and sample size Therefore, studies with enormous sample sizes and rigorous research designs are required to comprehend better how Invisalign clear aligners correct malocclusion, including in the vertical dimension To this end, we report the predicted and actual outcomes of anterior intrusion with Invisalign using CBCT in consecutively treated patients at Wuhan University Hospital of Stomatology Our investigation aimed to compare the predicted (ClinCheck) anterior intrusion measurements with the actual clinical outcomes To the best of our knowledge, no studies have evaluated the precision of anterior intrusion adjustments with the Invisalign system using CBCT In this study, the patients had pressure areas on the lingual cingulum area of the incisors, and these patients were treated without the bite ramps, which may increase the aligner efficacy To interpret the results accurately, the specific limitations of this study should be discussed The risk of selection bias could not be avoided because retrospective studies have been argued to have limited ability to control patient cooperation.15 However, on the termination of the initial series, confirmation of whether patients switched their aligners at the period we prescribed and attended their appointments seemed to be as effective as the compliance measures used in other studies An orthodontist who has a high level of experience decided that the participants could be treated with Invisalign effectively Nevertheless, all the patients in this study underwent refinement after completing the initial series, indicating that the treatment objectives to promote intrusion of the anterior teeth were not fully achieved with the first series of aligners; therefore, these outcomes should not be generalized to all patients who underwent treatment with Invisalign clear aligners The accuracy of the tooth movement may be influenced by interproximal reduction, but the evidence is unclear.27-29 The supervising orthodontist for this study was presumed to have had sufficient experience to prescribe them appropriately, and no restrictions were applied In our findings, the mean efficacy was 51.19% The highest precision of intrusion was achieved by the maxillary lateral incisors (58.12%) The lowest accuracy of intrusion was achieved by the mandibular incisors (44.71%) The accuracy for the maxillary central incisors (51.83%), the maxillary canines (48.95%), and the e279 mandibular canines (52.34%) were moderate The mean aggregate of true intrusion achieved was 0.90 mm In a study by Kravitz et al,15 in which the virtual models of the predicted tooth positions were superimposed over the actual models for 189 intruded teeth, the mean accuracy of intrusion in the anterior region was reported to be 41.3%; the maxillary teeth and mandibular central incisors had the precision of intrusion of 45% and 47%, respectively The maxillary lateral incisors had the lowest precision of intrusion, which was 33% The average aggregate of true intrusion attempted was 0.72 mm Krieger et al8 measured the initial and final models by using an electronic digital caliper (ie, ClinCheck using the measurement tool ToothMeasure in Invisalign clear aligners software) and reported that the degree of concordance between the predicted and actual measures for anterior intrusion was 14.3%, and they found that correction in the vertical direction was the most difficult to achieve Charalampakis et al30 and Buschang et al12 reported that intrusion of the anterior region is difficult to achieve and unpredictable with Invisalign clear aligners However, Boyd and Waskalic31 observed that intrusion is highly predictable with Invisalign clear aligners Furthermore, an internal study from Align Technology showed that the average precision of anterior intrusion was 80%.6 Most of the previous studies have used initial and final models for measurement and lateral cephalometry Future studies should include volumetric 3D CBCT scans to assess tooth intrusion movement with Invisalign clear aligners Other auxiliary means of anterior intrusion may be helpful to reduce the need for midcourse adjustments and improvements CONCLUSIONS In this retrospective study, the predicted magnitude of anterior intrusion was compared with the actual clinical outcome For anterior intrusion (.1 mm), the predictability of intrusion for patients treated only with pressure areas without bite ramps and programming in posterior extrusion is 51.19% The maxillary lateral incisors had the most precise tooth movement (58.12%) The least precise tooth movement was observed with the mandibular incisors (44.71%) Therefore, the mean amount of correction observed in this study was 48.81% SUPPLEMENTARY DATA Supplementary data associated with this article can be found, in the online version, at https://doi.org/10 1016/j.ajodo.2020.10.018 American Journal of Orthodontics and Dentofacial Orthopedics March 2021 Vol 159 Issue Al-balaa et al e280 REFERENCES Joffe L Invisalign: early experiences J Orthod 2003;30:348-52 Ali SA, Miethke HR Invisalign, an innovative invisible orthodontic appliance to correct malocclusions: advantages and limitations Dent Update 2012;39(254-6):258-60 Malik OH, McMullin A, Waring DT Invisible orthodontics part 1: Invisalign Dent Update 2013;40:203-4: 207-10, 213-5 Bollen AM, Huang G, King G, Hujoel P, Ma T Activation time and material stiffness of sequential removable orthodontic appliances Part 1: ability to complete treatment Am J Orthod Dentofacial Orthop 2003;124:496-501 Boyd RL Complex orthodontic treatment using a new protocol for the Invisalign appliance J Clin Orthod 2007;41:525-47: quiz 523 Nguyen C, Chen J, Tuncay O The Invisalign System Chicago: Quintessence Publishing; 2006 Jie RLK Treating bimaxillary protrusion and crowding with the Invisalign G6 first premolar extraction solution and Invisalign aligners APOS Trends Orthod 2018;8:219-24 Krieger E, Seiferth J, Saric I, Jung BA, Wehrbein H Accuracy of InvisalignÒ treatments in the anterior tooth region First results J Orofac Orthop 2011;72:141-9 Clements KM, Bollen AM, Huang G, King G, Hujoel P, Ma T Activation time and material stiffness of sequential removable orthodontic appliances Part 2: dental improvements Am J Orthod Dentofacial Orthop 2003;124:502-8 10 Kuncio D, Maganzini A, Shelton C, Freeman K Invisalign and traditional orthodontic treatment postretention outcomes compared using the American Board of Orthodontics objective grading system Angle Orthod 2007;77:864-9 11 Krieger E, Seiferth J, Marinello I, Jung BA, Wriedt S, Jacobs C, et al InvisalignÒ treatment in the anterior region: were the predicted tooth movements achieved? J Orofac Orthop 2012;73:365-76 12 Buschang PH, Ross M, Shaw SG, Crosby D, Campbell PM Predicted and actual end-of-treatment occlusion produced with aligner therapy Angle Orthod 2015;85:723-7 13 Pavoni C, Lione R, Lagana G, Cozza P Self-ligating versus Invisalign: analysis of dento-alveolar effects Ann Stomatol (Roma) 2011;2:23-7 14 Djeu G, Shelton C, Maganzini A Outcome assessment of Invisalign and traditional orthodontic treatment compared with the American Board of Orthodontics objective grading system Am J Orthod Dentofacial Orthop 2005;128:292-8: discussion 298 15 Kravitz ND, Kusnoto B, BeGole E, Obrez A, Agran B How well does Invisalign work? A prospective clinical study evaluating the efficacy of tooth movement with Invisalign Am J Orthod Dentofacial Orthop 2009;135:27-35 16 Jacobson A, Jacobson RL Radiographic Cephalometry: From Basics to 3-D Imaging Chicago: Quintessence Publishing; 2006 March 2021 Vol 159 Issue 17 Cha JY, Mah J, Sinclair P Incidental findings in the maxillofacial area with 3-dimensional cone-beam imaging Am J Orthod Dentofacial Orthop 2007;132:7-14 18 Hilgers ML, Scarfe WC, Scheetz JP, Farman AG Accuracy of linear temporomandibular joint measurements with cone beam computed tomography and digital cephalometric radiography Am J Orthod Dentofacial Orthop 2005;128:803-11 19 Sendyk M, de Paiva JB, Abr~ao J, Rino Neto J Correlation between buccolingual tooth inclination and alveolar bone thickness in subjects with Class III dentofacial deformities Am J Orthod Dentofacial Orthop 2017;152:66-79 20 Ruellas AC, Yatabe MS, Souki BQ, Benavides E, Nguyen T, Luiz RR, et al 3D mandibular superimposition: comparison of regions of reference for voxel-based registration PLoS One 2016;11: e0157625 21 Moshiri S, Ara ujo EA, McCray JF, Thiesen G, Kim KB Cephalometric evaluation of adult anterior open bite non-extraction treatment with Invisalign Dental Press J Orthod 2017;22:30-8 22 Tai S Clear Aligner Technique Hanover Park: Quintessence Publishing Co, Inc; 2018 23 Glaser BJ Insider’s Guide to Invisalign Treatment: A Step-by-Step Guide to Assist You with Your ClinCheck Treatment Plans Sacramento: 3L Publishing; 2017 24 Ponitz RJ Invisible retainers Am J Orthod 1971;59:266-72 25 Chishti M, Lerios A, Freyburger B, Wirth K, Ridgley R System for Incrementally Moving Teeth Santa Clara: Align Technology; 1998 26 Rossini G, Parrini S, Castroflorio T, Deregibus A, Debernardi CL Efficacy of clear aligners in controlling orthodontic tooth movement: a systematic review Angle Orthod 2015;85:881-9 27 Simon M, Keilig L, Schwarze J, Jung BA, Bourauel C Forces and moments generated by removable thermoplastic aligners: incisor torque, premolar derotation, and molar distalization Am J Orthod Dentofacial Orthop 2014;145:728-36 28 Kravitz ND, Kusnoto B, Agran B, Viana G Influence of attachments and interproximal reduction on the accuracy of canine rotation with Invisalign A prospective clinical study Angle Orthod 2008; 78:682-7 29 Simon M, Keilig L, Schwarze J, Jung BA, Bourauel C Treatment outcome and efficacy of an aligner technique–regarding incisor torque, premolar derotation and molar distalization BMC Oral Health 2014;14:68 30 Charalampakis O, Iliadi A, Ueno H, Oliver DR, Kim KB Accuracy of clear aligners: a retrospective study of patients who needed refinement Am J Orthod Dentofacial Orthop 2018;154:47-54 31 Boyd RL, Waskalic V Three-dimensional diagnosis and orthodontic treatment of complex malocclusions with the Invisalign appliance Semin Orthod 2001;7:274-93 American Journal of Orthodontics and Dentofacial Orthopedics ... this end, we report the predicted and actual outcomes of anterior intrusion with Invisalign using CBCT in consecutively treated patients at Wuhan University Hospital of Stomatology Our investigation... compare the predicted (ClinCheck) anterior intrusion measurements with the actual clinical outcomes To the best of our knowledge, no studies have evaluated the precision of anterior intrusion adjustments... tool ToothMeasure in Invisalign clear aligners software) and reported that the degree of concordance between the predicted and actual measures for anterior intrusion was 14.3%, and they found that