Outcomes of comprehensive fixed appliance orthodontic treatment: A systematic review with meta-analysis and methodological overview

OBJECTIVE: The aim of this systematic review was to assess the occlusal outcome and duration of fixed orthodontic therapy from clinical trials in humans with the Objective Grading System (OGS) proposed by the American Board of Orthodontics. METHODS: Nine databases were searched up to October 2016 for prospective/retrospective clinical trials assessing the outcomes of orthodontic therapy with fixed appliances. After duplicate study selection, data extraction, and risk of bias assessment according to the Cochrane guidelines, random-effects meta-analyses of the mean OGS score and treatment duration were performed and 95% confidence intervals (CIs) were calculated. RESULTS: A total of 34 relevant clinical trials including 6,207 patients (40% male, 60% female; average age, 18.4 years) were identified. The average OGS score after treatment was 27.9 points (95% CI, 25.3-30.6 points), while the average treatment duration was 24.9 months (95% CI, 24.6-25.1 months). There was no significant association between occlusal outcome and treatment duration, while considerable heterogeneity was identified. In addition, orthodontic treatment involving extraction of four premolars appeared to have an important effect on both outcomes and duration of treatment. Finally, only 10 (39%) of the identified studies matched compared groups by initial malocclusion severity, although meta-epidemiological evidence suggested that matching may have significantly influenced their results. CONCLUSIONS: The findings from this systematic review suggest that the occlusal outcomes of fixed appliance treatment vary considerably, with no significant association between treatment outcomes and duration. Prospective matched clinical studies that use the OGS tool are needed to compare the effectiveness of orthodontic appliances

Evaluation of palatal bone depth, cortical bone, and mucosa thickness for optimal orthodontic miniscrew placement performed according to the third palatal ruga clinical reference

Objectives This retrospective CBCT study aimed to evaluate the palatal anatomical characteristics using the third palatal ruga as a reliable clinical reference for miniscrew placement. Methods Thirty-six subjects (mean age17.1 y.o. +/- 4.1) were randomly selected and their records (CBCT volume and maxillary digital models) were included. BlueSkyPlan CBCT software viewer (BluSkyBio, V4.7) was used to measure the following outcomes at the level of third palatal ruga, 2 mm anteriorly and 2 mm posteriorly: total bone depth, cortical bone thickness, and mucosa thickness. The outcomes were evaluated on lines perpendicular to the palatal mucosa laying on different sagittal planes: the mid-palatal plane, 2 and 4 mm paramedian planes. Results The maximum mean amount of bone depth was registered 2 mm posteriorly to the third ruga and 4 mm paramedian (9.7 mm). No significant difference was observed between the third ruga insertion site and its corresponding 2 mm posterior site. Cortical bone of palatal vault did not change significantly in anteroposterior direction for all the considered sites. Significant differences were found comparing cortical bone at the suture level with cortical bone 2-mm and 4-mm paramedian at all anteroposterior levels. Palatal mucosa increases its thickness in paramedian insertion sites, and it decreases in posterior insertion sites. Conclusions Both third palatal ruga and 2 mm posteriorly to third ruga (4 mm paramedian) could be the optimal insertion site for palatal miniscrew placement, depending on individual anatomic conditions. The thickness of the cortical palatal bone showed, at 4 mm paramedian, optimal characteristics for miniscrew primary stability. Palatal mucosa thickness values suggest miniscrew neck extension of 2.0-2.5 mm for optimal mucosa adaptation

How to Obtain an Orthodontic Virtual Patient through Superimposition of Three-Dimensional Data: A Systematic Review

Background: This systematic review summarizes the current knowledge on the superimposition of three-dimensional (3D) diagnostic records to realize an orthodontic virtual patient. The aim of this study is to analyze the accuracy of the state-of-the-art digital workflow. Methods: The research was carried out by an electronic and manual query eectuated from ISS (Istituto Superiore di Sanit\ue0 in Rome) on three dierent databases (MEDLINE, Cochrane Library and ISI WEB OF SCIENCE) up to 31st January 2020. The search focused on studies that superimposed at least two dierent 3D records to build up a 3D virtual patient\u2014information about the devices used to acquire 3D data, the software used to match data and the superimposition method applied have been summarized. Results: 1374 titles were retrieved from the electronic search. After title-abstract screening, 65 studies were selected. After full-text analysis, 21 studies were included in the review. Dierent 3D datasets were used: facial skeleton (FS), extraoral soft tissues (ST) and dentition (DENT). The information provided by the 3D data was superimposed in four dierent combinations: FS + DENT (13 papers), FS + ST (5 papers), ST + DENT (2 papers) and all the types (FS + ST + DENT) (1 paper). Conclusions: The surface-based method was most frequently used for 3D objects superimposition (11 papers), followed by the point-based method (6 papers), with or without fiducial markers, and the voxel-based method (1 paper). Most of the papers analyzed the accuracy of the superimposition procedure (15 papers), while the remaining were proof-of-principles (10 papers) or compared dierent methods (3 papers). Further studies should focus on the definition of a gold standard. The patient is going to have a huge advantage from complete digital planning when more information about the spatial relationship of anatomical structures are needed: ectopic, impacted and supernumerary teeth, root resorption and angulations, cleft lip and palate (CL/P), alveolar boundary conditions, periodontally compromised patients, temporary anchorage devices (TADs), maxillary transverse deficiency, airway analyses, obstructive sleep apnea (OSAS), TMJ disorders and orthognathic and cranio-facial surgery

An assessment of arch dimensional change with self-ligating brackets: systematic review and a randomised controlled trial.

PhDThe purposes of this study were to systematically review the evidence on the clinical use of self-ligating brackets (SLBs) and the validity of digital models, and to compare maxillary arch dimensional change during alignment with conventional brackets (CBs) and active or passive self-ligation in a clinical study. In the systematic reviews, multiple databases were searched, study selection, quality assessment and data extraction were performed, and meta-analyses conducted, where appropriate. In a laboratory study a technique to measure molar inclination change incorporating digital models was developed and validated. A multicentre, 3- arm parallel-group trial was conducted with 96 patients aged 16 and above randomly allocated into 3 equal groups (OvationTM, InOvationCTM or Damon QTM) and undergoing alignment with a DamonTM wire sequence for at least 34 weeks. Meta-analyses demonstrated no difference in arch dimensional changes between SLBs and CBs; however, a greater treatment time was found with self-ligation (2.2 months, 95% CI: 0.4, 3.98). The validity of direct measurement on digital models was confirmed in the other review, although meta-analysis was not possible. Complete data were obtained from 87 subjects in the trial. Bracket type had no significant effect on transverse dimensional changes with no difference in inter-molar width between passive self-ligation and CBs (0.32mm, 95% CI: -0.41, 1.05, p= 0.38) or active selfligation (0.4mm, 95% CI: -0.31, 1.11, p= 0.27). Incisor inclination changes with Damon QTM could not be differentiated from the conventional system (0.44 degrees, 95% CI: - 1.93, 2.8, p=0.71) or InOvationCTM (-0.22 degrees, 95% CI: -2.58, 2.14, p=0.85). Based on the systematic reviews, measurement of digital models is a valid alternative to plaster models, while little evidence to support the use of self-ligation was found. In the clinical trial no differences in arch dimensional changes during alignment between CBs and either active or passive self-ligation was found

Effectiveness and Stability of Treatment with Orthodontics Clear Aligners: What Evidence?

Clear aligners, as a transparent and removable appliance, offer an alternative to conventional fixed appliance to patients with high demands for esthetics and comfort. Only a few investigations have focused on the efficacy of clear aligner therapy in controlling orthodontic tooth movement. Furthermore, the stability after treatment has not been thoroughly investigated. The purpose of this chapter was to update the knowledge of the available evidence about effectiveness and stability of clear aligners in non-growing subjects. Searches was made in different databases from January 2015 to January 2021. Relevant articles that met the inclusion criteria were selected. The level of evidence of the studies was moderate. The vertical movements of tooth were difficult to accomplish. Mesiodistal tipping showed the most predictability (82.5%) followed by vestibulolingual tipping. Molar distalization was also recorded as the highest accuracy. Derotation was difficult to accomplish with aligners especially of rounded teeth. The effectiveness of aligners in achieving the simulated transverse goals was 45%. The stability of clear aligner therapy was assessed by only two studies. Refinements are likely needed in almost all cases and to ensure treatment stability a retention period using a specific protocol is necessary

One Step before 3D Printing\u2014Evaluation of Imaging Software Accuracy for 3-Dimensional Analysis of the Mandible: A Comparative Study Using a Surface-to-Surface Matching Technique

Abstract: The accuracy of 3D reconstructions of the craniomaxillofacial region using cone beam computed tomography (CBCT) is important for the morphological evaluation of specific anatomical structures. Moreover, an accurate segmentation process is fundamental for the physical reconstruction of the anatomy (3D printing) when a preliminary simulation of the therapy is required. In this regard, the objective of this study is to evaluate the accuracy of four dierent types of software for the semiautomatic segmentation of the mandibular jaw compared to manual segmentation, used as a gold standard. Twenty cone beam computed tomography (CBCT) with a manual approach (Mimics) and a semi-automatic approach (Invesalius, ITK-Snap, Dolphin 3D, Slicer 3D) were selected for the segmentation of the mandible in the present study. The accuracy of semi-automatic segmentation was evaluated: (1) by comparing the mandibular volumes obtained with semi-automatic 3D rendering and manual segmentation and (2) by deviation analysis between the two mandibular models. An analysis of variance (ANOVA) was used to evaluate dierences in mandibular volumetric recordings and for a deviation analysis among the dierent software types used. Linear regression was also performed between manual and semi-automatic methods. No significant dierences were found in the total volumes among the obtained 3D mandibular models (Mimics = 40.85 cm3, ITK-Snap = 40.81 cm3, Invesalius = 40.04 cm3, Dolphin 3D = 42.03 cm3, Slicer 3D = 40.58 cm3). High correlations were found between the semi-automatic segmentation and manual segmentation approach, with R coecients ranging from 0,960 to 0,992. According to the deviation analysis, the mandibular models obtained with ITK-Snap showed the highest matching percentage (Tolerance A = 88.44%, Tolerance B = 97.30%), while those obtained with Dolphin 3D showed the lowest matching percentage (Tolerance A = 60.01%, Tolerance B = 87.76%) (p < 0.05). Colour-coded maps showed that the area of greatest mismatch between semi-automatic and manual segmentation was the condylar region and the region proximate to the dental roots. Despite the fact that the semi-automatic segmentation of the mandible showed, in general, high reliability and high correlation with the manual segmentation, caution should be taken when evaluating the morphological and dimensional characteristics of the condyles either on CBCT-derived digital models or physical models (3D printing)

Evaluation of orthodontically induced external root resorption following orthodontic treatment using cone beam computed tomography (CBCT): a systematic review and meta-analysis

Background: Orthodontically induced external root resorption (OIRR) is a pathologic consequence of orthodontic tooth movement. However, the limitations of two-dimensional radiography suggest that cone beam computed tomography (CBCT) with its three-dimensional capabilities might be more suitable to assess OIRR. Objective: The aim of this study was to assess in an evidence-based manner data on linear or volumetric OIRR measurements of permanent teeth by means of CBCT, during and/or after the end of orthodontic treatment. Search methods: Unrestricted electronic and hand searches were performed up to January 2017 in 15 databases. Selection criteria methods: Randomized clinical trials, prospective, and retrospective non-randomized studies assessing OIRR during and/or after orthodontic treatment using CBCT in human patients were included. Data collection and analysis: After duplicate study selection, data extraction, and risk-of-bias assessment according to the Cochrane guidelines, random-effects meta-analyses, followed by subgroup, meta-regression, and sensitivity analyses were also performed in order to evaluate factors that affect OIRR. Results: A total of 33 studies (30 datasets) were included in the qualitative analysis while data from 27 of them were included in the quantitative analysis. Direct comparisons from randomized trials found little to no influence of appliance-related factors on OIRR. Explorative analyses including non-randomized studies found a pooled OIRR of 0.79 mm based on all included studies and 0.86 mm when OIRR was assessed at the end of orthodontic treatment. Statistically significant differences in OIRR were found according to tooth type or jaw, inclusion of extractions, treatment duration, and diagnostic accuracy of the CBCT. Conclusions: Based on the results of this study, CBCT seems to be a reliable tool to examine OIRR during or at the end of orthodontic treatment. Although the average OIRR measured with CBCT seems to lack clinical relevance, there are certain factors that may affect OIRR following orthodontic treatment. Nevertheless, due to data heterogeneity and low quality of the included studies, the corresponding results should be interpreted with some caution

Digital Assessment of Dental Parameters in Italian and Mozambican Subjects with Ideal Occlusion and Permanent Dentition

Objective: To obtain reference values for tip, torque and in-out from digital models of Italian and Mozambican subjects in ideal occlusion using a repeatable and validated method and to compare these measurements with previously reported values. Material and Methods: Dental parameters were acquired from digital models of each subject, categorized to one of two groups: Italians (23 males, 27 females; mean age 28.3 years, ±5.7 years) and Mozambicans (14 males, 15 females; mean age, 23.4 years, ±5.9), using VAM software. All subjects had ideal occlusion, permanent dentition and no previous orthodontic treatment, fillings or prostheses. After normality of data was assumed (p<0.05), a paired t-test was performed to detect any statistical differences between the two groups (p<0.05). Then, classical inference (t-test and power analysis) was used to compare our data to those reported by other authors. Results: Mozambicans’ incisors were more proclined, while their upper molars appeared to be more prominent regarding Italians’. Italians shown greater tip values, especially at the upper first premolars and lower first molars. In-out values were comparable between the two groups, except for the upper molars (more prominent in Mozambicans) and lower first molar (more prominent in Italians). Unlike other reports, upper second molars displayed negative tip in our samples. Conclusion: Pre-adjusted appliances with standard prescription should not be expected to guarantee optimal outcomes. Prescriptions specific for ethnicities are recommended and reference values should be reconsidered