Orthodontics Objective Grading System Research Articles

Knowledge differences between general practitioners and orthodontists about Invisalign clear aligner treatment – a cross-sectional survey-based study

ABSTRACT Purpose This study investigated the knowledge differences between general practitioners and orthodontists about the Invisalign system. Materials and methods A web-based survey regarding 10 Invisalign treatment domains was distributed to 161 orthodontists and 213 general practitioners. The responses were ranked using a Likert-type scale and analysed with the Chi-square test and Bonferroni adjustment. Results The response rate was 52.1% for general practitioners and 63.4% for orthodontists. Comparing Invisalign to conventional fixed appliances, orthodontists agreed/strongly agreed that Invisalign aligners are suitable for all types of cases (p = 0.001). Orthodontists also agreed that it causes less tooth discomfort (p = 0.01) and an increased number of attachments can affect its esthetic perception (p = 0.014) but general practitioners opted for the ‘Do Not Know’ option (p ≤ 0.01). General practitioners also responded ‘Do Not Know’ to whether Invisalign treatment finishes in a shorter duration (p = 0.001), achieves all types of tooth movement (p < 0.001) and results in better periodontal health (p = 0.001). Orthodontists were more likely to disagree/strongly disagree that Invisalign treatment results in less tooth root resorption (p = 0.008), better American Board of Orthodontics Objective Grading System and Peer Assessment Rating scores (p < 0.001) and low risk of relapse (p < 0.001), while general practitioners opted for the ‘Do Not Know’ option (p < 0.0001, p < 0.0001 and p < 0.0001, respectively). Conclusion Regarding Invisalign treatment, this study found that orthodontists were generally evidenced-based but general practitioners lacked such knowledge, suggesting that general practitioners must be provided with relevant evidenced-based information.

Factors influencing treatment outcomes assessed by the American Board of Orthodontics Objective Grading System (ABO-OGS)

BackgroundTreatment outcomes can be influenced by various factors. This study aimed to determine the association between predisposing patient- and treatment-related factors (demographic, cephalometric parameters, skeletal relationships, Discrepancy Index (DI), extractions, treatment type and duration) and treatment outcomes measures according to the American Board of Orthodontics Objective Grading System index (ABO-OGS).MethodsCompleted cases (N = 100) were included in this cross-sectional study. One calibrated examiner assessed DI, pretreatment lateral cephalometric parameters and ABO-OGS. Patient data, including sex, age, types of malocclusion, extractions, treatment type, and duration, were also collected. Intraexaminer reliability for each measurement was evaluated using the intraclass correlation coefficients. Multiple linear regression analysis, using the backward elimination method with a significance level (α) of 0.05, was used to determine which factors significantly influenced the ABO-OGS score.ResultsFrom the study, the overall mean ABO-OGS score was 11.36 points. Factors influencing the ABO-OGS score were pretreatment Wits values (p value = .000), L1-NB (°) (p value = .023) and treatment duration (p value = .019). Subjects with lower negative values of Wits and L1-NB (°) tended to have higher ABO-OGS scores. Additionally, the ABO-OGS score tended to be higher for subjects with longer treatment times.ConclusionsThe majority of treated subjects had satisfactory orthodontic treatment outcomes assessed by the ABO-OGS. The pretreatment severity of skeletal discrepancies determined by the Wits parameter, the degree of retroclined lower incisors and longer treatment duration negatively impacted the treatment outcomes.

Extraction vs nonextraction orthodontic treatment: a systematic review and meta-analysis.

To compare four first premolar extraction and nonextraction treatment effects on intra-arch width, profile, treatment duration, occlusal outcomes, smile aesthetics and stability. An electronic search of the literature to June 2, 2023 was conducted using health science databases, with additional search of gray literature, unpublished material, and hand searching, for studies reporting nonsurgical patients with fixed appliances regarding sixteen sub-outcomes. Data extraction used customized forms, quality assessed with ROBINS-I (Risk Of Bias In Non-randomized Studies-of Interventions) and Cochrane RoB 2 (risk-of-bias) tool. GRADE (Grading of Recommendations Assessment, Development and Evaluation) assessed certainty of evidence. Thirty (29 retrospective studies, 1 randomized controlled trial) studies were included. Random-effect meta-analysis (95% CI) demonstrated maxillary (MD: -2.03 mm; [-2.97, -1.09]; P < .0001) and mandibular inter-first molar width decrease (MD: -2.00 mm; [-2.71, -1.30]; P < .00001) with four first premolar extraction; mandibular intercanine width increase (MD: 0.68 mm; [0.36, 0.99]; P < .0001) and shorter treatment duration (MD: 0.36 years; [0.10, 0.62]; P = .007) in the nonextraction group. Narrative synthesis included three and five studies for upper and lower lip-E plane, respectively. For American Board of Orthodontics Objective Grading System and maxillary/mandibular anterior alignment (Little's irregularity index), each included two studies with inconclusive evidence. There were no eligible studies for UK Peer Assessment Rating (PAR) score. Class I subgroup/sensitivity analyses favored the same results. Prediction interval indicated no significant difference for all outcomes. Four first premolar extraction results in maxillary and mandibular inter-first molar width decrease and retraction of upper/lower lips. Nonextraction treatment results in mandibular intercanine width increase and shorter treatment duration. There was no significant difference between the two groups regarding maxillary intercanine width, US PAR score, and posttreatment smile esthetics. Further high-quality focused research is recommended.

Treatment effectiveness of young adults using clear aligners versus buccal fixed appliances in class I malocclusion with first premolar extraction using the ABO-Objective Grading System: A randomized controlled clinical trial

To compare the effectiveness of the clear aligners with the traditional fixed appliances in the treatment of premolars extraction complex cases using the American Board of Orthodontics Objective Grading System (ABO-OGS). A single-centre, 2-parallel groups RCT with two arms. Forty severe crowding patients (14 males, 26 females; mean age: 21.40±2.42) who required four first premolars extraction were included and randomly allocated into two treatment groups: clear aligners therapy group (CAT), and fixed appliances therapy group (FAT). Cases complexities were measured on pre-treatment records using the Discrepancy index (DI). Post-treatment records were evaluated using the American Board of Orthodontics Objective Grading System (ABO-OGS). Two sample t-tests and Fisher's Exact tests were used to test for significant differences between the two groups. The statistical significance was set atP<0.006 using Bonferroni's correction. For the DI, the mean scores were 32.25 (±4.33) in the CAT group and 33 (±7.92) in the FAT group. In the CAT group, the total OGS score ranged between 6-33 points with an average of 17.50(±7.41), whereas the total score in the FAT group went between 4-30 points with an average of 12.89 (±6.31) with no significant differences between the two groups (P=0.05). When comparison of the successful cases between the two groups was made, 11 cases received passing scores, and 9 cases received failing scores in the CAT group. Whereas in the FAT group, 17 cases received passing scores, and 3 received a failing score. No statistically significant differences were found in the passing rates between of the CAT and FAT groups (P=0.421). According to the ABO-OGS total scores, there was no significant difference between the clear aligners and fixed appliances in the treatment of class I severe crowding cases with first premolars extraction in young adults. There were no differences between the two techniques in the OGS components scores except for the occlusal contacts, which were significantly better with the fixed appliances. When comparing the number of successful and failed cases between the two groups, no significant differences were noted, with the fixed appliances having a 30% higher success rate than the clear aligners, which must be considered clinically when choosing between these two techniques in the complex orthodontic cases treatment.

Three-dimensional evaluation of a virtual setup considering the roots and alveolar bone in molar distalization cases

We aimed to evaluate root parallelism and the dehiscence or fenestrations of virtual teeth setup using roots isolated from cone beam computed tomography (CBCT) images. Sixteen patients undergoing non-extraction orthodontic treatment with molar distalization were selected. Composite teeth were created by merging CBCT-isolated roots with intraoral scan-derived crowns. Three setups were performed sequentially: crown setup considering only the crowns, root setup-1 considering root alignment, and root setup-2 considering the roots and surrounding alveolar bone. We evaluated the parallelism and exposure of the roots and compared the American Board of Orthodontics Objective Grading System (ABO-OGS) scores using three-dimensionally printed models among the setups. The mean angulation differences between adjacent teeth in root setups-1 and -2 were significantly smaller than in the crown setup, except for some posterior teeth (p < 0.05). The amount of root exposure was significantly smaller in root setup-2 compared to crown setup and root setup-1 except when the mean exposure was less than 0.6 mm (p < 0.05). There was no significant difference in ABO-OGS scores among the setups. Thus, virtual setup considering the roots and alveolar bone can improve root parallelism and reduce the risk of root exposure without compromising occlusion quality.

Treatment of skeletal classIII malocclusion using acombined clear aligner and surgery-early approach : Assessment based on the American Board of Orthodontics Objective Grading System.

To evaluate whether clear aligner therapy (CAT) combined with asurgery-early approach can achieve good therapeutic effects in patients with skeletal classIII malocclusion. Thirty consecutive skeletal classIII malocclusion cases treated with clear aligners combined with early surgery were selected. Treatment time, lateral cephalograms and American Board of Orthodontics Objective Grading System (ABO-OGS) scores of the treatment models were measured to evaluate the treatment efficiency, facial profile, and occlusion. The results showed that early surgery was achieved after 7.71months of presurgical orthodontics, on average. ANB decreased by 5.57° (P < 0.001), and STissueN Vert to Pog' decreased by 7.29 mm (P = 0.001), both reaching normal values. The posttreatment ABO-OGS scores were 26.600 on average, meeting its standards. With the assistance of CAT, early surgery can be accomplished in patients with skeletal classIII malocclusion, improving their facial profile and achieving functional occlusion.

Conventional and self-ligating lingual orthodontic treatment outcomes in Class I nonextraction patients: A comparative study with the American Board of Orthodontics Objective Grading System

This study aimed to assess and compare the duration and outcomes of orthodontic treatment with conventional and self-ligating lingual fixed appliances with the American Board of Orthodontics (ABO) Objective Grading System. Thirty consecutive patients with a complete dentition and Angle Class I malocclusion treated with a conventional lingual bracket system (STb; Ormco, Glendora, Calif) or self-ligating lingual bracket system (GC Experience-L; GC Orthodontics, Breckerfeld, Germany) were included. The occlusal outcome was assessed with the ABO instrument. The treatment duration and ABO scores of the 2 groups were recorded. Statistical analyses were evaluated using independent-sample t tests. The conventional group had a mean treatment time of 2.10 ± 0.69 years, and the self-ligating group had a treatment duration of 1.68 ± 0.48 years (P>0.05). The mean posttreatment ABO scores in the conventional group were 20.23 ± 5.13, and the mean posttreatment ABO scores in the self-ligating group were 21.00 ± 5.66. No difference was found between the groups regarding the criteria of ABO (P>0.05). The highest scores were given in the assessment of buccolingual inclinations in both conventional and self-ligating lingual bracket groups. The design of the lingual appliances used in this study did not influence the treatment duration and the total ABO scores in treating patients with a Class I relationship in this sample. Both types of lingual brackets were especially deficient in correcting buccolingual inclinations. The strengths were their ability to close spaces and correct anterior rotations and overjet regardless of the bracket types.

Orthodontic treatment of substituting third molars for missing permanent molars

This study aimed to evaluate the orthodontic effect and efficiency of substituting third molars for missing first or second permanent molars systematically. Forty-six patients (69 third molars total) with missing permanent molars replaced by third molars were selected. The angulation, crown-to-root ratio, and periodontal condition of the third molars before and after treatment were compared. The American Board of Orthodontics Objective Grading System was used to evaluate the alignment and occlusion of third molars after treatment. The duration of orthodontic treatment and third molar replacement therapy were also recorded. The average orthodontic treatment time was 33.9 ± 5.6 months, and the average angulation change of third molars during treatment was 49.8 ± 29.8°. The average height of mesial alveolar bone increased by 4.8 ± 0.5 mm in patients whose third molars were mesially inclined or horizontally impacted. The root length of adult patients decreased by 0.72 ± 0.02 mm on average, and the average gingival recession was 0.10 mm, both of which were not statistically significant. The average score for each third molar evaluated by the American Board of Orthodontics Objective Grading System was 1.8 ± 0.5 points. If the indications and timing of treatment were well-controlled, third molars would be excellent substitutes for missing first or second permanent molars through the orthodontic method.

Dental, skeletal, and soft-tissue changes in adult orthodontic patients treated with premolar extraction and nonextraction: A cross-sectional study

Various treatment modalities exist to improve and correct Class I malocclusion. This study evaluated the dental, skeletal, and soft-tissue changes in patients treated by premolar extraction (PME) and nonextraction. A cross-sectional study was conducted, including subjects ideally planned for PME. Pretreatment and posttreatment lateral cephalograms were compared among the 2 groups. The American Board of Orthodontics Objective Grading System (ABO-OGS) was used to score the posttreatment casts, and soft-tissue profile silhouettes were judged by a panel of orthodontists to evaluate the improvement among the 2 groups. Comparisons between the 2 groups were performed using the Mann-Whitney U test.Spearman correlation was used to study the correlation between the assessment methodologies. Highly significant differences were observed between the 2 groups for ABO-OGS scores (P≤0.001) and profile silhouette assessment (P≤0.001). Compared with posttreatment cephalometric readings, highly significant differences were seen for the dental variables: SN-U1, IMPA, and interincisal angle (P≤0.001). Statistically significant differences were seen for all soft-tissue cephalometric variables. Highly significant moderate to negative correlation (r= -0.410, P≤0.001) was seen between profile silhouettes and ABO-OGS alignment scores. Highly significant strong negative correlation (r= -0.642, P≤0.001) was seen between profile silhouettes and the lower lip. Dental and soft-tissue changes were highly significant and were found to be in the ideal range when treated with PME. However, PME and nonextraction treatment modalities did not significantly affect the skeletal parameters as seen on the lateral cephalogram.

Linear and angular transfer accuracy of labial brackets using three dimensional-printed indirect bonding trays: A systematic review and meta-analysis

To assess the transfer accuracy of three dimensional-printed trays (3D-printed trays) and to compare the accuracy of this approach with the other methods used for the same purpose. An electronic search was performed in PubMed, Scopus, Web of science, Google Scholar and ProQuest (dissertation and theses). Studies were eligible for inclusion if they involved the assessment of transfer errors measured by the superimposition of the original set-up of brackets and the final positions after transfer. Risk of bias was assessed using Cochrane's tools. Seven studies were included. The pooled estimate of the transfer error in the linear dimensions showed an error of 0.095mm in the mesiodistal direction (95%CI: 0.035, 0.155), 0.114mm in the buccolingual direction (95%CI: 0.067, 0.160) and 0.111mm in the vertical direction (95%CI: -0.033, 0.255). Concerning the angular dimensions, the pooled estimate showed a tipping error of 1.3420 (95%CI: 0.444, 2.240), rotational error of 0.9980 (95%CI: 0.323, 1.672), and torque error of 1.9130 (95%CI: 0.922, 2.903). Thus, the maximum transfer error was in the bucco-lingual and torque directions. 3D-printed trays had better control in mesiodistal and vertical directions than vacuum-formed trays. Polyvinyl siloxane trays were more accurate in the vertical direction than 3D-printed trays. The scarcity of randomized clinical trials is the main risk of bias of the included studies. According to the available evidence, 3D-printed trays have an acceptable transfer accuracy, based on the American Board of Orthodontics Objective Grading System (ABO OGS), with maximum linear transfer error in the buccolingual direction and maximum angulation error in the torque. Conducting randomized clinical trials on this topic is highly recommended.

American Board of Orthodontics (ABO) Discrepancy Index and peer assessment rating (PAR) index with models versus photographs

BackgroundThe objectives of this study were to determine whether rating systems, such as the Peer Assessment Rating (PAR) and the American Board of Orthodontics Objective Grading System (ABO-OGS) can be applied to intraoral photographs. MethodsModels and photographs of 50 cases were graded by 4 raters, and a 20% repeat of randomized cases was completed 2 weeks later. Intraclass correlation coefficients (ICCs) were used to assess inter- and intra-rater agreements, as well as the level of agreement between the ratings on models and photographs. ResultsThe intra- and inter-rater agreements were considered good to excellent. The paired mean difference (model minus photo) for the PAR index and the ABO Discrepancy Index as a total was 2.405 and 1.156, respectively. Overjet was the subdomain that produced the highest differences between photos and models. The ABO- Discrepancy Index method on photographs was more reliable than the PAR index when grading pre-treatment and more-severe malocclusions. ConclusionsBoth methods can be used, but the choice depends on the purpose of the evaluation, and on consideration of the weaknesses and strengths of each relating to its use on photographs.

Measuring orthodontic treatment impact: Description or judgment, challenge or result

Determination of improvement in orthodontic treatment may depend on the measurement method used and the purpose. Improvement after orthodontic treatment (from T1 to T2 [beginning to end of treatment]) was assessed 3 ways from a set of 98 patient records: (1) calculated by subtracting judges' assessments at T2 from T1 for records presented in random order, (2) judged as a holistic impression viewing T1 and T2 records side by side, and (3) determined from proxies (American Board of Orthodontics Discrepancy Index, the American Board of Orthodontics Objective Grading System, and the Peer Assessment Rating index). High levels of intramethod consistencywere observed, with intraclass correlation coefficient clustering around an intraclass correlation coefficient of 0.900, and distributions were normal. Calculated and judged improvements correlated at r=0.606. Calculated or judged improvements were correlated at a lower level with proxies. Calculated improvement was significantly associated with "challenge" (T1) scores and judged improvement associated with "results" (T2) scores. Common method bias was observed, with higher correlations among similar indexes than among indexes at the same time that used various methods. Relative to differences in Peer Assessment Rating scores, calculated improvement overestimated low scores and underestimated high ones. The same effect, but statistically greater, was observed using direct judgment of improvement. These findings are consistent with decision science and measurement theory. In some circumstances, such as third-party reimbursement and research, operationally defined measures of occlusion are appropriate. In practice, the determination of occlusion and improvement are best performed by judgment that naturally corrects for biases in proxies and incorporates background information.

The Herbst appliance combined with a completely customized lingual appliance: A retrospective cohort study of clinical outcomes using the American Board of Orthodontics Objective Grading System

In this retrospective study we aimed to evaluate the quality of treatment outcomes using the American Board of Orthodontics (ABO) scoring system with a completely customized lingual appliance used in combination with a Herbst appliance for Class II correction. Patient selection criteria for this study were Class II division 1, II/2 or subdivision treated with a WIN® lingual appliance combined with an L-pin Herbst device. Thirty-two consecutively debonded cases were included in this retrospective case series. Pre- and post- treatment dental casts, dental set-ups, panoramic X-rays, cephalometric analysis, photographs and clinical files were available for data collection. The primary outcome was the ABO score based on the Discrepancy Index (ABO DI) including: overjet, overbite, anterior open bite, lateral open bite, crowding, occlusion (Angle class), lingual posterior crossbite, buccal posterior crossbite, ANB, IMPA and SN-GoGN angles and the Cast-Radiograph Evaluation (ABO CR-Eval) comprising of alignment/rotations, marginal ridges, buccolingual inclination, overjet, occlusal contacts, occlusal relationship (Angle class), interproximal contacts and root angulation. In addition, overjet, overbite and Class II correction were also evaluated on pre- and post-treatment models. The secondary outcome was bracket failure and complications related to the Herbst device. The study cohort included 18 female and 12 male patients with a mean age of 15.8 (range 12, 6- 18, 5). Twenty patients were Class II division 1 and ten were Class II division 2. The mean pre-treatment value of ABO DI was 20.8 (range 10-39); more than two-thirds of the sample were rated as being either of moderate difficulty (ABO DI: 16-24) or severe (ABO DI: over 25). The average post-treatment ABO Cast-Radiograph Evaluation score was 15.0 (SD=4.4), which is considered a passing score. Twenty-six patients had a score equal or lower than 20 (undisputed passing score). The Class II discrepancy was effectively corrected from a score of 16.83 penalty points (SD: 3.65) pre-treatment to a score of 1.57 (SD: 1.70) post-treatment. No association was found between initial and final Class II occlusal relationships (P=0.42), indicating that regardless of the initial discrepancy, no difference in the success of Class II correction was observed. The mean bracket failure rate was 3.8 per patient. Herbst related complications were few: 1.6 per patient, with the majority of complications being of little consequence and with 43% of the patients having no breakages. The completely customized lingual appliance assessed in this study combined with an L-pin Herbst led to effective Class II correction regardless of the initial severity of the sagittal discrepancy. The average ABO CR-Eval score for this sample was well below the undisputed passing score indicating a high quality of treatment outcomes.

Stability of occlusal outcome during long-term retention: the time-dependent variation of the American Board of Orthodontics index.

The aim of this retrospective cohort study was to assess long-term occlusal changes at debond and a median of 8 years afterwards (in retention) with the American Board of Orthodontics (ABO) objective grading system and identify risk factors. Fifty patients (median age: 14.3 years at debond; 60% female) treated with fixed appliances (25 with and 25 without premolar extractions) were included. The occlusal outcome was assessed with the ABO tool and analyzed statistically at 5%. Extraction treatment was associated with better occlusal outcome than non-extraction treatment (34.2 versus 40.9 points; P = 0.009). In retention, ABO scores improved by 7.4 points, while patients with worse debond finishing improved more afterwards (P = 0.001). Alignment/rotations deteriorated in 58% of the cases and occlusal relationships in 38% of the cases. Marginal ridges improved more for extraction than non-extraction patients (28% versus 0%; P = 0.001). Occlusal relationships improved more for cases that 'passed' the ABO requirements at debond than failed cases (64% versus 28%; P = 0.02). Furthermore, patients with worse debond ABO scores were more likely to deteriorate at alignment/rotations in retention. Finally, the proportion of cases passing the ABO requirements improved considerably between debond (28%) and in retention (54%) as half (47%) of the cases that had failed the ABO requirements at debond passed them in retention. Considerable long-term occlusal changes are seen post-debond, which mostly favour improved settling. Extraction treatment and higher finishing quality at debond significantly influenced the chance for improvement. However, setting a cut-off score to denote treatment excellence showed considerable instability through time.

Comment on: Treatment outcome with orthodontic aligners and fixed appliances: a systematic review with meta-analyses.

Background: The use of orthodontic aligners to treat a variety of malocclusions has seen considerable increase in the last years, yet evidence about their efficacy and adverse effects relative to conventional fixed orthodontic appliances remains unclear. Objective: This systematic review assesses the efficacy of aligners and fixed appliances for comprehensive orthodontic treatment. Search methods: Eight databases were searched without limitations in April 2019. Selection criteria: Randomized or matched non-randomized studies. Data collection and analysis: Study selection, data extraction, and risk of bias assessment was done independently in triplicate. Random-effects meta-analyses of mean differences (MDs) or relative risks (RRs) with their 95% confidence intervals (CIs) were conducted, followed by sensitivity analyses, and the GRADE analysis of the evidence quality.Results: A total of 11 studies (4 randomized/7 non-randomized) were included comparing aligners with braces (887 patients; mean age 28.0 years; 33% male). Moderate quality evidence indicated that treatment with orthodontic aligners is associated with worse occlusal outcome with the American Board of Orthodontics Objective Grading System (3 studies; MD = 9.9; 95% CI = 3.6-16.2) and more patients with unacceptable results (3 studies; RR = 1.6; 95% CI = 1.2-2.0). No significant differences were seen for treatment duration. The main limitations of existing evidence pertained to risk of bias, inconsistency, and imprecision of included studies. Conclusions: Orthodontic treatment with aligners is associated with worse treatment outcome compared to fixed appliances in adult patients. Current evidence does not support the clinical use of aligners as a treatment modality that is equally effective to the gold standard of braces.

Treatment outcome with orthodontic aligners and fixed appliances: a systematic review with meta-analyses.

The use of orthodontic aligners to treat a variety of malocclusions has seen considerable increase in the last years, yet evidence about their efficacy and adverse effects relative to conventional fixed orthodontic appliances remains unclear. This systematic review assesses the efficacy of aligners and fixed appliances for comprehensive orthodontic treatment. Eight databases were searched without limitations in April 2019. Randomized or matched non-randomized studies. Study selection, data extraction, and risk of bias assessment was done independently in triplicate. Random-effects meta-analyses of mean differences (MDs) or relative risks (RRs) with their 95% confidence intervals (CIs) were conducted, followed by sensitivity analyses, and the GRADE analysis of the evidence quality. A total of 11 studies (4 randomized/7 non-randomized) were included comparing aligners with braces (887 patients; mean age 28.0 years; 33% male). Moderate quality evidence indicated that treatment with orthodontic aligners is associated with worse occlusal outcome with the American Board of Orthodontics Objective Grading System (3 studies; MD = 9.9; 95% CI = 3.6-16.2) and more patients with unacceptable results (3 studies; RR = 1.6; 95% CI = 1.2-2.0). No significant differences were seen for treatment duration. The main limitations of existing evidence pertained to risk of bias, inconsistency, and imprecision of included studies. Orthodontic treatment with aligners is associated with worse treatment outcome compared to fixed appliances in adult patients. Current evidence does not support the clinical use of aligners as a treatment modality that is equally effective to the gold standard of braces. PROSPERO (CRD42019131589).

Comparison of Stability of the Results of Orthodontic Treatment and Gingival Health between Hawley and Vacuum-formed Retainers

Aim: Retention is one of the stages of orthodontic treatment, which is an attempt to retain teeth in their corrected positions after active treatment with the use of fixed orthodontic appliances. The aim of the present study was to compare the stability of the results of orthodontic treatment and the gingival health between Hawley retainer (HR) and vacuum-formed retainer (VFR) with two different thicknesses. Materials and methods: In this randomized clinical trial, 66 patients undergoing comprehensive orthodontic treatment in a private office were evaluated after completion of treatment. The subjects were randomly assigned to three groups. At the end of orthodontic treatment, the subjects in all the groups received a fixed bonded retainer in the mandible; in the maxilla, group I received an HR, group II received a VFR with a thickness of 1.5 mm, and group III received a VFR with a thickness of 1 mm. The American Board of Orthodontics objective grading system (ABO-OGS) index was used at the end of treatment (before the delivery of the retainers) and 6 months after the use of retainers to evaluate the stability of the results of orthodontic treatment. Gingival index (GI) was used at the two above-mentioned intervals to evaluate gingival health. The ABO-OGS measurements were carried out on dental casts by a clinician who was blinded to the types of retainers the patients wore. Data were analyzed with Statistical Package for the Social Sciences (SPSS) version 20, using proper statistical analyses. Results: Six months after the delivery of retainers, ABO-OGS and GI scores with the 1.5 mm VFR were higher than those in the two other groups, with no significant differences between the three groups. There were no significant differences between the ABO-OGS scores before the delivery of retainers and 6 months after the use of retainers in any of the study groups. In the HR and 1.5 mm VFR groups, there were significant differences in GI scores between the period before the delivery of the retainers and 6 months after their delivery; however, in the 1 mm VFR group, no significant differences were observed in GI scores between the two time intervals. Conclusion: Hawley retainer and 1 mm thick and 1.5 mm thick VFRs were equally effective in preserving and stabilizing the results of orthodontic treatment during the 6-month interval after the completion of orthodontic treatment. In addition, there were no significant differences between the three retainers in relation to gingival health. Clinical significance: The VFR might be a good alternative for HR due to its better esthetic appearance and greater popularity with orthodontic patients. Keywords: American Board of Orthodontics model grading system, American Board of Orthodontics objective frading system, Gingival index, Hawley retainers, Vacuum-formed retainers.

Computerized occlusal analysis: correlation with occlusal indexes to assess the outcome of orthodontic treatment or the severity of malocculusion.

ObjectiveThe aims of our study were to verify the validity of the T-Scan III system (Tekscan) as an objective occlusal evaluation tool, and to assess the differences between two occlusal indexes-the peer assessment rating (PAR) index and the American Board of Orthodontics objective grading system (OGS)-by comparing the scores derived from the T-Scan III system with the two occlusal indexes and analyzing the correlations between them.MethodsThe final study sample included 48 adult volunteers (39 men and 9 women, mean age 24.14 ± 3.16 years), after excluding 29 volunteers whose occlusion could not be evaluated by the T-Scan III system due to severe skeletal or occlusal problems. PAR index and OGS scores were assessed using dental study models, and measurements of centric occlusion, protrusive movement, and lateral excursion movement were obtained via the T-Scan III system. The results were analyzed to determine correlations.ResultsOcclusal analysis by the T-Scan III system was clinically reliable (p < 0.05), and the PAR index and OGS scores were significantly correlated with several measurements obtained with the T-Scan III system (p < 0.05).ConclusionsThe T-Scan III system is a quantitative and reliable method for occlusal evaluation, and represents a potential substitute for occlusal indexes. Compared to the PAR index, the OGS scores of more variables were significantly correlated with the T-Scan measurements.

Assessment of the Knowledge of General Dentists Practicing in Tehran about Timing of Orthodontic Treatment

Objective: The ideal time to commence orthodontic treatment is very important. In Iran, due to the widely distributed population and low number and uneven distribution of orthodontists, general dental practitioners (GDPs) play an important role in proper treatment of occlusal and functional disorders and referring orthodontic patients to orthodontists. The purpose of this study was to assess the knowledge of GDPs about the proper timing of orthodontic treatment in comparison with orthodontists practicing in Tehran.Methods: This cross-sectional analytical study was conducted on GDPs and orthodontists practicing in Tehran, who were selected by random sampling. The questionnaire used in this survey asked for demographic information including age, sex, academic degree, work place and work experience and contained questions concerning the knowledge of clinicians regarding the proper time to commence treatment for the most common types of occlusal disorders, functional disorders, temporomandibular joint (TMJ) disorders and other orthodontic problems. The answers of both groups of participants were assessed based on the American Board of Orthodontics objective grading system (ABO OGS). Results: The results of ANOVA showed that the two groups were significantly different in terms of age (p<0.05), sex, academic degree (p<0.001), and place of work (private office, private clinic, governmental clinic) (p<0.05). The results of comparison of GDPs and orthodontists for the proper time of initiation of orthodontic treatment for occlusal, functional and TMJ disorders showed that the GDPs had significantly less knowledge in this regard.Conclusion: Because of low level of knowledge of GDPs about the ideal time to commence orthodontic treatment, further training regarding diagnosis of malocclusion in primary and mixed dentition periods, etiology of malocclusion, recognition of normal occlusion and normal dental relationships as well as the proper time to start orthodontic treatment for each type of disorder seems necessary

A comparison of orthodontic treatment outcomes using the Objective Grading System (OGS) and the Peer Assessment Rating (PAR) index

Abstract Introduction The use of objective criteria is essential to uniformly quantify and measure the severity of malocclusions and the efficacy of different treatment modalities. The Peer Assessment Rating (PAR) index and, more recently, the American Board of Orthodontics Objective Grading System (OGS) were developed to fulfill this need. Aim The aim of this retrospective study was to assess and compare treatment outcomes using the UK and US weighted PAR and the OGS. Materials and methods The sample consisted of randomly selected records of 50 patients treated by residents in one postgraduate orthodontic clinic. UK and US weightings for the PAR index were applied and compared with OGS. Results There was no statistically significant association between the OGS and the PAR index grading systems. Neither the UK nor the US PAR weightings showed statistically significant correlation with the OGS. All cases were ‘greatly improved’ or ‘improved’ according to the PAR index, while most cases (62%) failed according to OGS. There was a statistically significant correlation between the unweighted PAR index and the OGS (r = −0.32, p = 0.024). The US and the UK weightings for the PAR were highly correlated (r = 0.90, p &lt; 0.001). Both weighting systems were also highly correlated with the unweighted PAR (p &lt; 0.001). There were no gender differences found in any of the scoring systems. Conclusions The current PAR index cannot replace the OGS for evaluating treatment outcomes. The current OGS cannot detect the improvement achieved in a treated case.