Search

Objectives: To determine whether the achieved mandibular central incisor lingual root torque (LRT) changes matched the planned changes after treatment with an initial series of Invisalign aligners when ≥10° of torque change was planned., Materials and Methods: A sample of adult patients who underwent treatment with the Invisalign appliance between 2013 and 2021 were evaluated. The pretreatment, planned, and achieved posttreatment digital models were measured using Geomagic Control X metrology software. The effect of age, number of prescribed aligners, sex, the presence of power ridges (PRs), and differing weekly wear protocols (WPs) in relation to the achieved LRT changes were determined., Results: Seventy mandibular central incisors from 35 patients satisfied inclusion criteria. The accuracy of the achieved lower incisor LRT compared with that planned was 58.2%. Underexpression of planned torque changes was observed in most incisors (N = 66; 94.3%), with a clinically significant shortfall (≥5°) observed in 68.6% (N = 42) teeth. Patient age, sex, the WP, or the presence of PRs did not influence the differences between planned and achieved outcomes (P > .05). The prescribed number of aligners was influential in the difference between the planned and achieved torque outcomes (P < .01)., Conclusions: Underexpression of mandibular central incisor root torque was observed in most incisors in patients when ≥10° change in LRT was planned. Lower incisor LRT was not significantly affected by the presence of PRs or differences in WPs., (© 2024 by The EH Angle Education and Research Foundation, Inc.)

Objective: To compare the accuracy of mandibular incisor intrusion with Invisalign (Align Technology, Santa Clara, Calif) in adolescents to that in adults., Materials and Methods: This prospective clinical study included 58 patients treated with either Invisalign Teen or Invisalign Full. Mandibular central and lateral incisors were measured on digital models created from intraoral scans. Predicted values were determined by superimposing the initial and final ClinCheck models, and achieved values were determined by superimposing the initial ClinCheck models and the digital models from the final scans. Individual teeth were superimposed with a best-fit analysis and measured using Compare software (version 8.1; GeoDigm, Falcon Heights, Minn)., Results: The mean accuracies of mandibular incisor intrusion were 63.5% in adolescents and 45.3% in adults, and this difference was statistically significant. The amounts of achieved intrusion were 1.7 mm in adolescents and 0.9 mm in adults, and this difference was also statistically significant. Overall, there was a weak negative correlation between age and accuracy; as age advanced, the accuracy of mandibular incisor intrusion diminished slightly., Conclusions: Mandibular incisor intrusion with Invisalign is significantly more accurate in adolescents than in adults. Orthodontists could contemplate reducing the degree of overcorrection for mandibular incisor intrusion in adolescents with deep overbites undergoing Invisalign Teen but still implementing the reverse curve of Spee mechanics., (© 2024 by The EH Angle Education and Research Foundation, Inc.)

Objectives: To determine whether achieved outcome regarding overjet and overbite matched the predicted outcome following treatment with Invisalign (Align Technology, San Jose, Calif) aligner appliances., Materials and Methods: Data including pretreatment, predicted and achieved overjet, and overbite measurements provided by Align's digital treatment facility, ClinCheck Pro, were evaluated. Descriptive statistics, Mann-Whitney U-test, and Wilcoxon rank-sum intraclass correlation (ICC) test results were calculated., Results: From an initial sample of 600, 355 adult patients satisfied the inclusion and exclusion criteria. ICC scores for data input were excellent. Median (interquartile range [IQR]) age was 30.14 (23.33, 39.92) years and most (n = 259; 72.95%) were women. Almost one-third (n = 101; 28.45%) had undergone extraction as part of their treatment. More aligners were prescribed in the initial digital treatment plan for patients (median, 44; IQR: 35, 51.5; minimum, 17; maximum, 92) undergoing extractions as part of their orthodontic treatment than those who were not (median, 24; IQR: 18.25, 32; minimum, 13; maximum, 85) (P < .0001). Planned changes in overjet differed significantly from achieved outcomes (P < .001). Planned increases in overbite resulted in up to more than twice (222.72%) as much increase than predicted. Planned reduction of overbite achieved 8.69% of its predicted reduction in extraction cases., Conclusions: Achieved overjet and overbite measurements differed significantly from the predicted outcomes at the end of an initial sequence of aligners. Planned increases in overbite resulted in greater overbite correction than predicted, particularly in extraction cases. Planned overbite reduction was challenging, especially in patients with extractions., (© 2024 by The EH Angle Education and Research Foundation, Inc.)

Objectives: To investigate whether the predicted changes in overbite (OB) and overjet (OJ) in Align Technology's (Santa Jose, Calif) digital treatment plan for the prescribed course of treatment with the Invisalign appliance were consistent with those same changes in OB and OJ measured with the Geomagic Control X (Geomagic US, Research, Triangle Park, NC) metrology software system., Materials and Methods: Geomagic Control X software was used to determine OB and OJ differences between the pretreatment and predicted outcome. STL files for patients satisfying inclusion criteria and undergoing nonextraction orthodontic treatment with the Invisalign appliance. The differences were compared, using the Bland-Altman analysis, to the corresponding data provided by Align Technology's digital treatment-planning interface, ClinCheck., Results: Data regarding 76 adult patients who satisfied strict inclusion criteria were assessed. The Shapiro-Wilks test indicated normality (P > .05). The Bland-Altman analysis showed high levels of agreement between the two measurements, with a bias range of -0.131 to 0.111 for OB and -0.393 to 0.03 for OJ recorded., Conclusions: Clinicians and researchers can be confident that measurement data provided by Invisalign's ClinCheck digital treatment-planning facility concerning OB and OJ changes from the initial to the predicted treatment outcome are valid., (© 2024 by The EH Angle Education and Research Foundation, Inc.)

Objectives: To evaluate the predictability of the Invisalign appliance (Align Technology, Santa Clara, Calif) in leveling the maxillary curve of Spee (COS)., Materials and Methods: A retrospective sample of adult subjects treated with the Invisalign appliance between 2013 and 2019 were selected. Patients were treated nonextraction in the maxillary arch and had either Angle Class I or II malocclusions with a minimum of 14 aligners with no bite ramps. Initial, predicted, and actual outcomes were analyzed with Geomagic Control X software (version 2017.0.3; 3D Systems, Cary, NC)., Results: A sample of 53 cases satisfied inclusion/exclusion criteria. Paired t-tests demonstrated a significant difference between mean predicted and actual maxillary COS leveling with a shortfall of 0.11 mm (SD = 0.37; P = .033). Planned intrusion tended to be more accurate posteriorly with an overexpression of 117% for the first molars. Planned extrusion was the least accurate, with the mid-arch demonstrating expressions of -14% to -48%. These teeth intruded despite a prescribed extrusive movement., Conclusions: The Invisalign appliance did not accurately predict maxillary COS leveling. Planned intrusive movements were overcorrected, and planned extrusive movements were either undercorrected or resulted in intrusion. This effect was most apparent for the upper first molar, which expressed 117% and -48% of planned intrusion and extrusion, respectively., (© 2023 by The EH Angle Education and Research Foundation, Inc.)

Objectives: To investigate the changes made by orthodontists to the initial digital treatment plan (DTP) regarding the Invisalign appliance provided by Align Technology until acceptance of the plan by the orthodontist., Materials and Methods: The DTPs of subjects who underwent treatment with the Invisalign appliance and satisfied inclusion criteria were assessed to determine the number of DTPs and changes regarding prescription of aligners, composite resin (CR) attachments, and interproximal reduction (IPR) between the initial DTP and the accepted plan. Statistical analyses were calculated via GraphPad Prism 9.0 (GraphPad Software Inc., La Jolla, Calif)., Results: Most of the 431 subjects who satisfied inclusion/exclusion criteria were female (72.85%). More DTPs were required for subjects who had orthodontic extractions (median [interquartile range; IQR]: 4 [3, 5]) compared with those who did not (median [IQR]: 3 [2, 4], P < .0001). The median (IQR) overall number of aligners prescribed in the accepted DTP (30 [20, 39]) was greater than the initial DTP (30 [22,41], P < .001). The number of teeth used for CR attachments increased from the initial to the accepted DTP (P < .001). More CR attachments were observed in extraction treatment DTPs with a prescribed 2-week aligner change protocol compared with nonextraction treatment (P < .0001). The number of contact points with prescribed IPR increased between initial and accepted DTPs (P < .0001)., Conclusions: Significant changes regarding DTP protocols were observed between the initial and accepted DTPs and between nonextraction and extraction-based CAT., (© 2023 by the EH Angle Education and Research Foundation, Inc.)

Objectives: To compare mandibular relative anchorage loss (RAL) under reciprocal anchorage between first and second premolar extraction cases in bimaxillary protrusion mild crowding cases treated using clear aligner therapy (CAT)., Materials and Methods: Adult patients who met the following criteria were included: treated using CAT with bilateral mandibular premolar extractions and space closure using intra-arch reciprocal anchorage. RAL was defined as the percent molar mesial movement relative to the sum of molar mesial plus canine distal movement. Movements of the mandibular central incisor (L1), canine (L3), and first molar (L6) were measured based on superimposition of the pre- and post-treatment dentition and jaw models., Results: Among the 60 mandibular extraction quadrants, 38 had lower first premolar (L4) and 22 had lower second premolar (L5) extracted. L6 mesial movement was 2.01 ± 1.11 mm with RAL of 25% in the L4 extraction group vs 3.25 ± 1.19 mm with RAL of 40% in the L5 extraction group (P < .001). Tooth movement efficacy was 43% for L1 occlusogingival movement, 75% for L1 buccolingual inclination, 60% for L3 occlusogingival movement, and 53% for L3 mesiodistal angulation. L1 had unwanted extrusion and lingual crown torquing whereas L3 had unwanted extrusion and distal crown tipping, on which the power ridges or attachments had little preventive effect., Conclusions: The average mandibular reciprocal RAL is 25% or 40% for extraction of L4 or L5, respectively, in CAT cases. A RAL-based treatment planning workflow is proposed for CAT extraction cases., (© 2023 by the EH Angle Education and Research Foundation, Inc.)

Objectives: To quantify the predicted occlusal contact outcomes compared with the clinically achieved occlusal contacts following treatment using the Invisalign aligner appliance., Materials and Methods: The occlusal contacts of 33 adult patients presenting with a Class I mild-to-moderate malocclusion (spacing <4 mm or crowding of <6 mm) and treated using the Invisalign appliance were measured at the initial, predicted, and achieved stages of treatment by the metrology software Geomagic Control X. Assessed measurements were related to individual teeth and anterior, posterior, and overall contacts., Results: The mean (standard deviation) difference between the achieved occlusal contact was significantly less than that predicted for overall occlusal contact and posterior occlusal contact (P < .0025). The achieved posterior occlusal contact was also less than pretreatment initial posterior occlusal contact. There was no difference in anterior occlusal contact between the predicted and achieved outcomes (P > .05). The central and lateral incisors displayed no statistically significant difference between the predicted and achieved occlusal contact. The patients with prescribed overcorrection demonstrated a statistically significant difference in predicted occlusal contact compared with those with nonprescribed overcorrection (P ≤ .0025), but no statistically significant difference in achieved occlusal contact., Conclusions: Treatment by the Invisalign appliance in Class I mild-to-moderate malocclusion resulted in a decrease in posterior occlusal contact. Further research is required to account for the deficiencies between the predicted and achieved clinical outcome related to occlusal contact and to determine the corrective changes required in the treatment protocols., (© 0000 by The EH Angle Education and Research Foundation, Inc.)

Objectives: To identify predictors regarding the type and severity of malocclusion that affect total Invisalign treatment duration based on an intraoral digital scan., Materials and Methods: The subjects of this retrospective clinical cohort were 116 patients treated with Invisalign. A deep learning method was used for automated tooth segmentation and landmark identification of the initial and final digital models. The changes in the six degrees of freedom (DOF), representing types of malalignment, were measured. Linear regression was performed to find the contributing factors associated with treatment time. In addition, the Peer Assessment Rating (PAR) score and a composite score combining 6 DOF were correlated separately to the treatment time., Results: The number of trays differed between sexes (P = .0015). The absolute maximum torque was marginally associated with the total number of trays (P = .0518), while the rest of the orthodontic tooth movement showed no correlation. The composite score showed a higher correlation with the total number of trays (P = .0045) than did individual tooth movement. Pretreatment upper and lower anterior segment PAR scores were positively associated with the treatment time (P < .001)., Conclusions: There is not enough evidence to conclude that certain types of tooth movement affect the total aligner treatment time. A composite score seems to be a better predictor for total treatment time than do individual malalignment factors in aligner treatment. Upper and lower anterior malalignment factors have a significant effect on the treatment duration., (© 0000 by The EH Angle Education and Research Foundation, Inc.)

Objectives: To analyze adaptational changes in clear aligner fit after intraoral usage at different sets of time., Materials and Methods: Eight Invisalign appliances (Align Technology, San Jose, California, USA) were collected after intraoral usage. Acrylic imprints of the lower incisor region were constructed for each appliance at T0 (unused appliance). Two appliances were then used intra-orally for each of the following defined periods of time: 3 days, 7 days, 10 days, or 15 days. Used aligners were adapted on its T0 imprint and both were sectioned buccolingually from the distal surfaces of each incisor at the attachment area. Eight surfaces were collected for each set of time (n = 32 surfaces). Microphotographs of obtained sections and micrometric measurements of aligner fit were recorded at five different levels using scanning electron microscopy (SEM). Mean values of the fit changes (gap width) and group comparisons were statistically analyzed using analysis of variance and Tukey's post hoc tests. Significance level was set at P < .05., Results: Highly significant differences in aligner fit were found at the different time points assessed (P < .001) with the least mean gap width at 15 days (176 ± 98 μm) and the highest at 7 days (269 ± 145 μm). Significant differences in aligner fit at different attachment levels were also found (P < .01) with the least mean gap width at the middle of the labial surface of the attachment (187 ± 118 μm)., Conclusions: The 15-day period of intraoral aligner wear might still be recommended as it showed the best adaptation and least gap width between the aligner and the attachment., (© 2022 by The EH Angle Education and Research Foundation, Inc.)

Objectives: To compare the treatment and posttreatment effects of Invisalign aligners that incorporated SmartForce features and attachments to traditional fixed appliances., Materials and Methods: This randomized controlled trial included 66 patients, 32 aligners, and 34 fixed-appliance patients. The median ages of the aligner and braces patients were 26.7 (interquartile range [IQR]: 9.8) and 25.9 (IQR: 16.6) years, respectively. Pretreatment occlusion was assessed using the ABO Discrepancy Index. Posttreatment (T1) and 6-month retention (T2) occlusions were quantified using the ABO Objective Grading System (OGS) scores., Results: The braces group finished treatment significantly (P < .001) earlier (0.4 years) than the aligner group. The median DI scores for the aligner and braces groups were 4.5 and 7.0, respectively, which was a statistically significant (P = .015), but clinically insignificant, difference. There were no statistically significant between-group differences for the total OGS scores or any of the individual component scores at debond (T1) or after 6 months of retention (T2). During the posttreatment period, alignment and overjet worsened significantly in the aligner group, while buccolingual inclinations and occlusal relations improved. Over the same period, alignment worsened in the braces group and buccolingual inclinations improved. There was no statistically significant between-group difference in posttreatment changes of the total OGS scores., Conclusions: While patients with simple malocclusions require 4.8 months longer treatment times with aligners than traditional braces, the treatment and 6-month posttreatment occlusal outcomes are similar., (© 2022 by The EH Angle Education and Research Foundation, Inc.)

Objectives: To assess speech performance of adult patients undergoing orthodontic treatment with Invisalign., Materials and Methods: Twenty-four adult patients with Invisalign (Invisalign group: 6 men, 18 women; average age; 34.88 years) and 20 adult patients with fixed labial appliances (fixed group: 5 men, 15 women; average age; 38.85 years) were evaluated. Speech was recorded immediately before delivery of the first set of clear aligners or bonding of labial appliances (T0), immediately after delivery or bonding (T1), and 2 months after delivery or bonding (T2). Speech was evaluated via a combination of three auditory analyses: (1) objective acoustic analysis through digital sonography, (2) semiobjective assessment by six speech and language pathologists, and (3) subjective assessment patient questionnaire., Results: The objective acoustic analysis showed a statistically significant difference over time from T0 to T1, T1 to T2, and T0 to T2 for Invisalign patients. The semiobjective analysis revealed a significant speech alteration from T0 to T1 and T1 to T2 for both groups, and from T0 to T2 in the Invisalign group. The subjective analysis showed a significant difference between means of Invisalign and fixed group patient perception at both T1 and T2., Conclusions: Invisalign treatment significantly affected speech, and although patients experience some level of adaptation, speech does not return to normal after 2 months of treatment., (© 2022 by The EH Angle Education and Research Foundation, Inc.)

Objectives: To investigate adolescent orthodontic patient experiences and quality of life with fixed appliances compared to Invisalign., Materials and Methods: Adolescent patients in active treatment with Invisalign or fixed appliances for a minimum of 6 months were provided with the Child Oral Health Impact Profile-Short Form 19 questionnaire, along with additional items of interest that were assessed separately. Pearson's χ2 test was used to compare responses (P < .05), and unpaired t-tests (P < .05) were used to test for differences in mean satisfaction, quality of life, and domain scores., Results: In total, 74 patients (37 in each treatment group) participated. Overall, no significant differences were noted in the mean quality of life, satisfaction, or domain scores between the two groups. A significant difference was noted in the time taken to adjust to appliances, with the Invisalign group demonstrating faster adaptation. Additionally, the fixed appliance group was 3.8 times more likely to report missing school because of their appliance (95% confidence interval [CI]: 1.2, 12.5) and 2.7 times more likely to report having difficulty eating certain foods (95% CI: 1.1, 7.1). When the sample of females between the ages of 14 and 18 was analyzed, the Invisalign group reported feeling attractive more often than the fixed appliance group., Conclusions: Both treatment groups were generally very satisfied with their treatment modality. The overall quality of life of adolescent orthodontic patients undergoing treatment with fixed appliances and Invisalign for a minimum of 6 months was similar., (© 2021 by The EH Angle Education and Research Foundation, Inc.)

Objectives: To compare the efficacy of orthodontic tooth movement with three aligner wear protocols: 7 day, 10 day, and 14 day., Materials and Methods: Eighty patients were randomly allocated into three groups: group A (7-day changes), group B (10-day changes), and group C (14-day changes). The posttreatment scans were compared with the final virtual treatment simulations through digital superimposition. The differences between predicted and actual achieved treatment outcomes were computed in six angular and six linear dimensions. Differences >0.5 mm for linear measurements and >2° for angular measurements were considered clinically relevant., Results: Within groups, and irrespective of wear protocol, all linear discrepancies in both jaws were deemed clinically insignificant (<0.5 mm) while nearly all angular discrepancies were considered clinically significant (>2.0°). When the three groups were compared, group C (14-day changes) showed significantly greater accuracy in the posterior segment for maxillary intrusion, distal-crown tip and buccal-crown torque, and mandibular intrusion and extrusion. The mean treatment duration in the 7-day aligner change group was nearly half that of the 14-day aligner change group (5 months vs 9 months)., Conclusions: Fourteen-day changes were statistically significantly more accurate in some posterior movements. However, this difference in accuracy did not exceed the threshold for clinical significance (>0.5 mm/>2.0°). Achieving a clinically similar accuracy between the 7-day protocol and 14-day protocol in half the treatment time suggests a 7-day protocol as an acceptable treatment protocol. Clinicians may consider slowing down to a 14-day protocol if challenging posterior movements are desired., (© 2021 by The EH Angle Education and Research Foundation, Inc.)

Objectives: To investigate the correspondence between programmed interproximal reduction (p-IPR) and implemented interproximal reduction (i-IPR) in an everyday-practice scenario. The secondary objective was to estimate factors that might influence i-IPR to make the process more efficient., Materials and Methods: Fifty patients treated with aligner therapy by six orthodontists were included in this prospective observational study. Impressions were taken at the beginning of treatment and after the first set of aligners. Data on p-IPR, i-IPR and technical aspects of IPR were gathered for 464 teeth. Statistical analyses included the Wilcoxon signed-rank test, Kruskal-Wallis, and multilevel mixed regression., Results: Mean difference between p-IPR and i-IPR was 0.15 mm (SD: 0.14 mm; P = .0001), with lower canines showing the highest discrepancy. Use of burs and measuring gauges resulted in a smaller difference (respectively: coeff.: 0.09, P = .029; coeff.: -0.06, P = .013). IPR was performed more accurately on the mesial surface of teeth than on the distal surface. Round tripping before IPR resulted in a slightly more precise i-IPR compared to the previous alignment (coeff.: -0.021, P = .041)., Conclusions: Implemented IPR tends to be less than p-IPR, especially for lower canines and distal surfaces of teeth. Burs tend to provide more precise i-IPR, especially compared to manual strips; however, there is variation between the techniques. Using a measuring gauge tends to increase the precision of i-iPR. As several factors influence the implementation of IPR, particular attention must be paid during the procedure to maximize its precision., (© 2021 by the EH Angle Education and Research Foundation, Inc.)

Objectives: To evaluate the content, reliability, and quality of videos about orthodontic clear aligners on YouTube., Materials and Methods: Researchers used the Google Trends website to determine that the most frequently used search term for orthodontic clear aligners on the Internet was: "Invisalign." A search was then conducted on YouTube using the key word "Invisalign." From the first 140 results, 100 videos were selected for analysis. A 13-point content score was used to classify poor-content and rich-content videos, and the global quality scale (GQS) was used to examine quality of the videos. To evaluate reliability of the information, a five-question scale was used. The Mann-Whitney U-test, χ2 test, and Pearson correlation coefficients were used for statistical evaluations., Results: Of the YouTube videos, 33 were classified as rich content and 67 as poor content. Most videos (73%) were uploaded by laypeople, and most uploaders (71%) were women. The most commonly discussed content was instructions (65%), followed by procedure (57%) and pain (52%). Regarding the GQS, most of the videos were evaluated as moderate quality (51%). Compared with the poor-content video group, the rich-content video group had a significantly higher GQS score (P = .004). There was no significant difference between the poor-content and rich-content groups regarding information reliability (P > .05)., Conclusions: Video content on YouTube relating to aligner orthodontics was generally insufficient. The quality of videos was moderate, but the reliability of information was generally poor. Specialists should refer patients to reliable sources of information., (© 2020 by The EH Angle Education and Research Foundation, Inc.)

Objectives: To compare achieved and predicted tooth movements of maxillary first molars and central incisors in first premolar extraction cases treated with Invisalign., Materials and Methods: The present study included 30 patients who received maxillary first premolar extraction treatment with Invisalign. The actual posttreatment model was registered with the pretreatment model on the palatal stable region and superimposed with the virtual posttreatment model. Achieved and predicted tooth movements of maxillary first molars and central incisors were compared using paired t -test. Linear mixed-effect model analyses were used to explore the influence of age (adolescents vs adults), attachment (G6-optimized vs 3-mm vertical, 3-mm horizontal, and 5-mm horizontal), and initial crowding on the differences between predicted and achieved tooth movement (DPATM)., Results: First molars achieved greater mesial tipping, mesial translation, and intrusion than predicted. Central incisors achieved less retraction and greater lingual crown torque and extrusion than predicted. Adolescents showed greater DPATM in the mesiodistal translation of first molars and labiolingual translation of central incisors and smaller DPATM in the occlusogingival translation of the first molars and crown torque of the central incisors than adults. The 3-mm vertical attachment group showed greater DPATM in the mesiodistal translation of the first molars vs the G6-optimized attachment group. Initial crowding had an inverse correlation with DPATM in angulation and mesiodistal translation of the first molars., Conclusions: First molar anchorage control and central incisor retraction were not fully achieved as predicted in first premolar extraction treatment with Invisalign. Age, attachment, and initial crowding affected the differences between predicted and achieved tooth movement.

Objectives: The fitting of aligners on anchorage teeth is a crucial factor in clear aligner orthodontics. The purpose of this experimental study was to evaluate the fitting of two aligner systems, Invisalign and CA-Clear Aligner, using scanning electron microscopy (SEM)., Materials and Methods: Passive aligners (Invisalign and CA-Clear Aligner) were adapted on resin casts obtained by stereolithography (STL) files of a patient, and then sectioned buccolingually. Upper and lower central incisors, upper and lower first premolars, and upper and lower first molars were the regions analyzed. Representative microphotographs of sections were taken with a scanning electron microscope (SEM); a total of 160 micrometric measurements were obtained and analyzed with ANOVA tests., Results: Invisalign provided an overall better fit on lower incisors ( F = 11.48, P = .0095) and on lower molars ( F = 19.93, P = .0012). Considering the different regions, Invisalign provided better fit at the gingival edge of the buccal aspect on lower incisors ( F = 11.33, P = 0.0056) and at the gingival edge of the lingual aspect on upper premolars ( F =5.34, P = 0.0047). On the upper molars, Invisalign provided better fit at the gingival edge of the buccal aspect, while CA-Clear Aligner provided better fit at the buccal maximum convexity, on the buccal cusp, on the occlusal groove and at the palatal cusp. On lower molars, Invisalign showed a more accurate fit at the buccal aspect points., Conclusions: Invisalign and CA-Clear Aligner exhibited comparable fit on anchorage teeth. Invisalign provided better fit at the gingival edges of aligners, while the CA-Clear Aligner provided better fit on complex occlusal surfaces.

Objective: To evaluate the accuracy of Invisalign technology in achieving predicted tooth positions with respect to tooth type and direction of tooth movement., Materials and Methods: The posttreatment models of 30 patients who had nonextraction Invisalign treatment were digitally superimposed on their corresponding virtual treatment plan models using best-fit surface-based registration. The differences between actual treatment outcome and predicted outcome were computed and tested for statistical significance for each tooth type in mesial-distal, facial-lingual, and occlusal-gingival directions, as well as for tip, torque, and rotation. Differences larger than 0.5 mm for linear measurements and 2° for angular measurements were considered clinically relevant., Results: Statistically significant differences (P < .05) between predicted and achieved tooth positions were found for all teeth except maxillary lateral incisors, canines, and first premolars. In general, anterior teeth were positioned more occlusally than predicted, rotation of rounded teeth was incomplete, and movement of posterior teeth in all dimensions was not fully achieved. However, except for excess posttreatment facial crown torque of maxillary second molars, these differences were not large enough to be clinically relevant., Conclusions: Although Invisalign is generally able to achieve predicted tooth positions with high accuracy in nonextraction cases, some of the actual outcomes may differ from the predicted outcomes. Knowledge of dimensions in which the final tooth position is less consistent with the predicted position enables clinicians to build necessary compensations into the virtual treatment plan.

Objective: To evaluate differences in discomfort levels between patients treated with aligners and traditional fixed orthodontic appliances., Materials and Methods: This blinded, prospective, randomized equivalence two-arm parallel trial allocated 41 adult Class I nonextraction patients to either traditional fixed appliance (6 males and 12 females) or aligner (11 males and 12 females) treatment. Patients completed daily discomfort diaries following their initial treatment appointment, after 1 month and after 2 months. They recorded their levels of discomfort at rest, while chewing, and while biting, as well as their analgesic consumption and sleep disturbances., Results: Both treatment modalities demonstrated similar levels of initial discomfort. There were no significant sex differences. Patients in the traditional fixed appliances group reported significantly (P < .05) greater discomfort than patients in the aligner group during the first week of active treatment. There was significantly more discomfort while chewing than when at rest. Traditional patients also reported significantly more discomfort than aligner patients after the first and second monthly adjustment appointments. Discomfort after the subsequent adjustments was consistently lower than after the initial bonding or aligner delivery appointments. A higher percentage of patients in the fixed-appliance group reported taking analgesics during the first week for dental pain, but only the difference on day 2 was statistically significant., Conclusions: Patients treated with traditional fixed appliances reported greater discomfort and consumed more analgesics than patients treated with aligners. This trial was not registered.

Objective: To examine the orthodontic patient experience having braces compared with Invisalign by means of a large-scale Twitter sentiment analysis., Materials and Methods: A custom data collection program was created that collected tweets containing the words "braces" or "Invisalign" for a period of 5 months. A hierarchal Naïve Bayes sentiment analysis classifier was developed to sort the tweets into five categories: positive, negative, neutral, advertisement, or not applicable. Each category was then analyzed for specific content., Results: A total of 419,363 tweets applicable to orthodontics were collected. Users posted significantly more positive tweets (61%) than they did negative tweets (39%; P ≤ .0001). There was no significant difference in the distribution of positive and negative sentiment between braces and Invisalign tweets (P = .4189). Positive orthodontics-related tweets often highlighted gratitude for a great smile accompanied with selfies. Negative orthodontic tweets frequently focused on pain., Conclusion: Twitter users expressed more positive than negative sentiment about orthodontic treatment with no significant difference in sentiment between braces and Invisalign tweets.

Objective: To investigate differences in case selection, treatment management, and aligner treatment expertise between orthodontists and general practitioners., Materials and Methods: A parallel pair of original surveys with three sections (case selection, treatment management, and demographics) was sent to orthodontists (N = 1000) and general dentists (N = 1000) who were providers of aligner treatment., Results: Orthodontists had treated significantly more patients with aligners, had treated more patients with aligners in the previous 12 months, and had received more aligner training than general dentists (P < .0001). In general, case confidence increased with increasing experience for both orthodontists and general dentists. After adjusting for experience, there was a significant difference in aligner case confidence between orthodontists and general dentists for several malocclusions. General dentists were more confident than orthodontists in treating deep bite, severe crowding, and Class II malocclusions with aligners (P ≤ .0001). Significant differences were also found for all treatment management techniques except interproximal reduction., Conclusion: There was a significant difference in case selection, treatment management, and aligner expertise between orthodontists and general dentists, although the differences in case selection were small. Overall, it was shown that orthodontists and general dentists elected to treat a variety of moderate to severe malocclusions with aligners but with different utilization of recommended auxiliaries, perhaps demonstrating a difference in treatment goals.

Objective: To evaluate the expression of receptor activator of nuclear factor-kappa ligand (RANKL), osteoprotegerin (OPG), osteopontin (OPN), interleukin 1β (IL-1β), and transforming growth factor ß1 (TGF-ß1) in the gingival crevicular fluid (GCF) of teeth subjected to orthodontic forces released by aligners., Materials and Methods: A total of 10 healthy, adult patients were selected to participate in this split-mouth study. The treatment plan was designed to obtain only one movement with the first aligner: distalization of a second molar. GCF samples were obtained from pressure and tension sites of the test tooth and from the mesiobuccal and distobuccal sites of the control tooth. The GCF sample volumes were measured using a Periotron 8000. Levels of TGF-β, IL-1β, RANKL, OPG, and OPN were measured by enzyme-linked immunosorbent assay., Results: IL-1β showed a significant increase at the pressure sites after 1 week and 3 weeks with respect to baseline (P < .05) compared with control sites. The kinetics of TGF-1β and OPN were characterized by a significant increase at the tension sites of the test teeth (P < .05) after 3 weeks from the application of orthodontic force. The RANKL level was significantly increased at pressure and tension sites after 1 hour and after 1 week from the application of the orthodontic forces (P = .023 and P = .043, respectively)., Conclusions: An increased concentration of bone modeling and remodeling mediators at the pressure sites (IL-1β, RANKL) and tension sites (TGF-1β, OPN) was observed. These scenarios are compatible with previous in vivo and in vitro studies investigating the biological effects of orthodontic tooth movement.

Objectives: To investigate the predictability of arch expansion using Invisalign., Materials and Methods: Sixty-four adult white patients were selected to be part of this retrospective study. Pre- and posttreatment digital models created from an iTero scan were obtained from a single orthodontist practitioner. Digital models from Clincheck were also obtained from Align Technology. Linear values of upper and lower arch widths were measured for canines, premolars, and first molars at two different points: lingual gingival margins and cusp tips. A paired t-test was used to compare expansion planned on Clincheck with the posttreatment measurements. Variance ratio tests were used to determine if a larger change planned was associated with larger error., Results: For every maxillary measurement, there was a statistically significant difference between Clincheck and final outcome (P < .05), with prediction worsening toward the posterior region of the arch. For the lower arch measurements at the gingival margin, there was a statistically significant difference between the Clincheck planned expansion and the final outcome (P < .05). Points measured at the cusp tips of the lower arch teeth showed nonstatistically significant differences between Clincheck prediction and the final outcome (P > .05). Variance ratios for upper and lower arches were significant (P < .05)., Conclusions: The mean accuracy of expansion planned with Invisalign for the maxilla was 72.8%. The lower arch presented an overall accuracy of 87.7%. Clincheck overestimates expansion by body movement; more tipping is observed. Overcorrection of expansion in the posterior region of the maxillary arch seems appropriate.

Objective: To investigate changes in mandibular incisor position resulting from Invisalign correction of the crowded dentition without extraction., Materials and Methods: A retrospective chart review was completed on 61 adult White patients. Patients were categorized into three groups based on the value of pretreatment crowding of the lower dentition: 20 mild (2.0-3.9 mm), 22 moderate (4.0-5.9 mm), and 19 severe (>6.0 mm). Cephalometric radiographs were measured to determine lower incisor changes. Interproximal reduction and changes in arch width were also measured. Statistical evaluation of T0 and T1 values using paired t-tests and analysis of covariance were applied to evaluate mean value changes., Results: Lower incisor position and angulation changes were statistically significant in the severe crowding group. There were no statistically significant differences in lower incisor position between the mild and moderate crowding groups. There was a statistically significant increase in buccal expansion in each of the three groups., Conclusions: Invisalign(®) treatment can successfully resolve mandibular arch crowding using a combination of buccal arch expansion, interproximal reduction, and lower incisor proclination. When there is <6 mm of crowding, lower incisor position remained relatively stable. The lower incisors proclined and protruded in the more severely crowded dentitions (>6 mm).