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Objective: To assess the treatment efficacy/efficiency with prefabricated myofunctional appliances (PMA) for children with malocclusion. Data sources: Nine databases searched without limitations till July 2019. Data selection: Randomised trials comparing PMAs to functional appliance treatment or no treatment. Data extraction: Study selection, data extraction and risk of bias assessment were done in duplicate. Data synthesis: Random-effects meta-analyses of mean differences (MDs) or relative risks (RRs) with their 95% confidence intervals (CIs) were conducted on seven publications (three published and one unpublished trials; 232 patients; 53% male; mean age 10.2 years). Compared to no treatment, one trial indicated that PMAs were somewhat effective in reducing overjet (MD −2.4; 95% CI −3.3 to −1.5), reducing overbite (MD −2.5; 95% CI −3.2 to −1.8), reducing mandibular crowding (RR 0.4; 95% CI 0.2–0.8) and establishing Class I canine relationship (RR = 2.3; 95% CI 1.1–4.9). However, compared to custom-made functional appliances, three trials indicated that PMAs were less effective in reducing the ANB angle (MD 0.9; 95% CI 0.5–1.4), increasing mandibular ramus length (MD −2.2; 95% CI −2.9 to −1.51), reducing overjet (MD 1.5; 95% CI 0.9–2.1), establishing a solid Class I molar relationship (RR 0.3; 95% CI 0.2–0.7), reducing the nasolabial angle (MD 5.8; 95% CI 0.8–10.8) and reducing facial convexity (MD −2.6; 95% CI −4.3 to −0.9). Finally, the quality of evidence was moderate to low due to risk of bias. Conclusions: PMAs are more effective in reducing overjet, overbite, mandibular crowding and establishing Class I canine relationship than no treatment. However, compared to custom-made functional appliances, PMAs are less effective in producing dental, skeletal or soft-tissue changes, even though they are less costly.

The aim of this systematic review was to assess qualitative changes induced by fixed appliance orthodontic treatment on the subgingival microbiota. Seven databases were searched up to August 2017 for randomized and nonrandomized clinical studies assessing the effect of orthodontic appliances on the subgingival bacteria in human patients. After elimination of duplicate studies, data extraction and risk of bias assessment according to the Cochrane guidelines, random-effects meta-analyses of relative risks (RR) and their 95% confidence intervals (CIs) were performed. According to controlled studies, the presence of Aggregatibacter actinomycetemcomitans in the subgingival crevicular fluid of orthodontic patients was increased 3-6 months after fixed appliance insertion compared to untreated patients (2 studies; RR = 15.54; 95% CI = 3.19-75.85). There was still increased subgingival prevalence of Aggregatibacter actinomycetemcomitans (3 studies; RR = 3.98; 95% CI = 1.23-12.89) and Tannerella forsythia in orthodontic patients up to 6 months after appliance removal compared to untreated patients. However, caution is warranted due to high risk of bias and imprecision. Insertion of orthodontic fixed appliances seems to be associated with a qualitative change of subgingival microbiota, which reverts to some extent back to normal in the first months after appliance removal. However, there is limited evidence on the timing and extent of these changes.

Background The purpose of the study is to investigate the effect of the bonding procedure on the mechanical properties of human enamel. Methods A total of 20 extracted human premolars were included in this study, with the half of each tooth acting as its own internal control. Embedded and horizontally cut specimens were prepared, and two bucco-orally zones were separated. The first enamel zone of each tooth remained untreated. The opposing zone was subjected to simulated bonding and debonding, including etching with 37% phosphoric acid, bonding with primer and flowable composite resin, and subsequent removal of the composite with an adhesive removal bur. The properties tested were (a) elemental composition by energy-dispersive X-ray analysis, (b) mechanical properties of specimens by instrumented indentation testing (Martens hardness, elastic modulus, and elastic index), (c) enamel morphology by low-vacuum scanning electron microscopy, and (d) molecular composition by Raman microspectroscopy. Statistical analysis was performed by one-way mixed-effects analysis of variance at a = 0.05. Results No significant differences could be found in the mechanical properties (Martens hardness, elastic modulus, and elastic index) and elemental composition of intact and treated enamel, with the possible exception of Si traces, which were found only in the latter. Raman analysis revealed no differences between the two surface states while shallow grooves and parallel lines were found on the surface of treated enamel by SEM analysis. Conclusions Under the limitations of the conditions of the study, there were no mechanical properties’ alterations on enamel subjected to orthodontic bonding.

Objectives: The aim of this research was to assess galvanic behavior of lingual orthodontic brackets coupled with representative types of orthodontic wires. Materials and Methods: Three types of lingual brackets: Incognito (INC), In-Ovation L (IOV), and STb (STB) were combined with a stainless steel (SS) and a nickel-titanium (NiTi) orthodontic archwire. All materials were initially investigated by scanning electron microscopy / x-ray energy dispersive spectroscopy (SEM/EDX) while wires were also tested by x-ray diffraction spectroscopy (XRD). All bracket-wire combinations were immersed in acidic 0.1M NaCl 0.1M lactic acid and neutral NaF 0.3% (wt) electrolyte, and the potential differences were continuously recorded for 48 hours. Results: The SEM/EDX analysis revealed that INC is a single-unit bracket made of a high gold (Au) alloy while IOV and STB are two-piece appliances in which the base and wing are made of SS alloys. The SS wire demonstrated austenite and martensite iron phase, while NiTi wire illustrated an intense austenite crystallographic structure with limited martensite. All bracket wire combinations showed potential differences below the threshold of galvanic corrosion (200 mV) except for INC and STB coupled with NiTi wire in NaF media. Conclusions: The electrochemical results indicate that all brackets tested demonstrated galvanic compatibility with SS wire, but fluoride treatment should be used cautiously with NiTi wires coupled with Au and SS brackets.

Objectives: To compare the failure pattern of four different bracket types and to assess its effect on treatment duration. Materials and Methods: A total of 78 white patients (28 male, 50 female) with a mean age of 12.6 years were included in this retrospective cohort study and treated for a mean period of 30.6 months. The patients were treated in a private practice with stainless steel conventionally ligated brackets, ceramic conventionally ligated brackets, stainless steel self-ligating brackets, or nickel-free self-ligating brackets. The loss of at least one bracket during the course of treatment was analyzed with Cox proportional hazards survival analyses and generalized linear regression. Results: The overall bracket failure rate at the tooth level was 14.1% (217 brackets), with significant differences according to tooth type (between 8.0%–23.4%) and bracket type (between 11.2%–20.0%). After taking confounders into account, patients treated with ceramic brackets lost more brackets (hazard ratio = 1.62; 95% confidence interval = 1.14–2.29; P = .007) than patients with stainless steel brackets. On average, treatment time increased by 0.6 months (95% confidence interval = 0.21–1.05; P = .004) for each additional failed bracket. Conclusions: Bracket failure was more often observed with ceramic brackets and was associated with increased treatment duration.

The following description of a retrospective non-randomized study is given within a publication in a scientific journal: “A total of 54 consecutive patients (24 male / 28 female; mean age: 14.1 years) treated with sequential thermoplastic aligners during the last 12 months were identified from the archive of a private practice. They were compared to 52 consecutive patients treated with conventional fixed appliances during the same period, who were matched for age, sex, and case severity with the patients in the aligner group. The total duration of treatment in months was extracted from the patient files by a third party not involved in any way with their treatment. Initially, descriptive statistics were calculated for all patient characteristics and for the study’s primary outcome (treatment duration), consisting of means and Standard Deviations (SDs). Student’s t-tests for independent samples and chi-square tests were performed on patient age, sex, and case severity to confirm that the two groups were matched. Finally, a t-test for independent samples was performed on treatment duration to assess any differences between the aligner and the fixed appliance group at the 5% level." The authors of the study give the following table (Table 1) in their Results section and conclude that (i) the two groups were adequately matched, since no statistically significant difference was found for any baseline difference and (ii) aligners and braces are equally efficient, since no statistically significant difference was found for treatment duration.

PURPOSE: System-specific scanning strategies have been shown to influence the accuracy of full-arch digital impressions. Special guided scanning procedures have been implemented for specific intraoral scanning systems with special regard to the digital orthodontic workflow. The aim of this study was to evaluate the precision of guided scanning procedures compared to conventional impression techniques in vivo. METHOD: Two intraoral scanning systems with implemented full-arch guided scanning procedures (Cerec Omnicam Ortho; Ormco Lythos) were included along with one conventional impression technique with irreversible hydrocolloid material (alginate). Full-arch impressions were taken three times each from 5 participants (n = 15). Impressions were then compared within the test groups using a point-to-surface distance method after best-fit model matching (OraCheck). Precision was calculated using the (90-10%)/2 quantile and statistical analysis with one-way repeated measures ANOVA and post hoc Bonferroni test was performed. RESULTS: The conventional impression technique with alginate showed the lowest precision for full-arch impressions with 162.2 ± 71.3 µm. Both guided scanning procedures performed statistically significantly better than the conventional impression technique (p < 0.05). Mean values for group Cerec Omnicam Ortho were 74.5 ± 39.2 µm and for group Ormco Lythos 91.4 ± 48.8 µm. CONCLUSIONS: The in vivo precision of guided scanning procedures exceeds conventional impression techniques with the irreversible hydrocolloid material alginate. Guided scanning procedures may be highly promising for clinical applications, especially for digital orthodontic workflows.

Objective: To determine the accuracy (trueness and precision) of two different rapid prototyping (RP) techniques for the physical reproduction of three-dimensional (3D) digital orthodontic study casts, a comparative assessment using two 3D STL files of two different maxillary dentitions (two cases) as a reference was accomplished. Materials and Methods: Five RP replicas per case were fabricated using both stereolithography (SLA) and the PolyJet system. The 20 reproduced casts were digitized with a highly accurate reference scanner, and surface superimpositions were performed. Precision was measured by superimposing the digitized replicas within each case with themselves. Superimposing the digitized replicas with the corresponding STL reference files assessed trueness. Statistical significance between the two tested RP procedures was evaluated with independent-sample t-tests (P < .05). Results: The SLA and PolyJet replicas showed statistically significant differences for trueness and precision. The precision of both tested RP systems was high, with mean deviations in stereolithographic models of 23 (±6) μm and in PolyJet replicas of 46 (±13) μm. The mean deviation for trueness in stereolithographic replicas was 109 (±4) μm, while in PolyJet replicas, it was 66 (±14) μm. Conclusions: Comparing the STL reference files, the PolyJet replicas showed higher trueness than the SLA models. But the precision measurements favored the SLA technique. The dimensional errors observed in this study were a maximum of 127 μm. In the present study, both types of reproduced digital orthodontic models are suitable for diagnostics and treatment planning.

Although several prescriptions and techniques exist for comprehensive fixed appliance treatment, their treatment effects have not yet been adequately assessed in an evidence-based manner. The aim of this systematic review was to assess the therapeutic and adverse effects of various prescriptions or techniques for orthodontic appliances from randomized clinical trials on human patients. Eight databases were searched up to July 2016 for randomized trials assessing any orthodontic prescriptions or techniques in human patients. After elimination of duplicate studies, data extraction, and risk of bias assessment according to the Cochrane guidelines, random effects meta-analyses with mean differences (MD) and their 95% confidence intervals (CIs) were performed. Compared to Roth preadjusted appliances, both Begg and modified Begg appliances were associated with statistically significantly worse occlusal outcome assessed with Peer Assessment Review (PAR) scores (1 trial, MD 3.1 points, 95% CI 1.9–4.3 points and 1 trial, MD 2.4 points, 95% CI 1.2–3.6 points, respectively) with low quality of evidence, due to bias and imprecision. Compared to a partially programmed fixed orthodontic appliance, a fully programmed appliance was associated with a statistically significant, but clinically irrelevant increase in treatment duration (1 trial, MD 2.4 months, 95% CI 0.6–4.2 months), supported by high quality of evidence. However, caution is needed in the interpretation of these results as only a limited number of small trials with methodological issues were available. Based on existing trials, there is limited evidence to support any robust clinical recommendation regarding the prescriptions or techniques for fixed orthodontic appliances. Registration: PROSPERO (CRD42016042727). Funding: None.

Purpose The aim of this study was to characterize the surface, elemental, and mechanical alterations of orthodontic palatal implants after intraoral aging. Materials and method Nineteen consecutively retrieved implants (RET) after orthodontic treatment and three unused implants used as control (CON) were included in this study. Both groups were characterized non-destructively by Stereomicroscopy, Optical Profilometry (Sa, Sq, Sz, Sc), and SEM/EDX analysis and then destructively after metallogaphic preparation employing instrumented indentation testing (HM, EIT, ηIT, and HV) and SEM/EDX at bone-implant interface. Results All retrieved implants showed a loss of gloss with the formation of bone-like formation on the majority of them. However, no differences in surface roughness parameters were identified between macroscopically intact and retrieved regions of implants. The elements precipitated on the surface were O, C, Ca, and P while traces of Na, K, Al, S, Cl, and Mg were also identified. The surface of control sample is characterized by small pits while only Ti and Al traces were identified by EDX analysis. The presence of all the aforementioned elements apart from Ti and Al on the retrieved implants' surface should be appended to the contact of implant with bone and biological fluids while Interfacial analysis revealed a well-formed bone-implant interface. However, no significant differences were found for all mechanical properties tested between RET and CON groups. Conclusions The results of this study indicate that retrieved palatal implant surface has undergone morphological and elemental alterations probably associated with the osseointegration process during service. Insertion and functional loading did not affect the mechanical properties of implants tested.

Accidental bracket debonding during fixed appliance treatment can lead to prolonged treatment times and additional costs. It is therefore in the interest of both the orthodontist and the patient th...

Objectives: To assess shear bond strength and failure mode (Adhesive Remnant Index, ARI) of orthodontic brackets bonded to polymethylmethacrylate (PMMA) blocks for CAD-CAM fabrication of temporary restorations, following substrate chemical or mechanical treatment. Methods: Two types of PMMA blocks were tested: CAD-Temp® (VITA) and Telio® CAD (Ivoclar-Vivadent). The substrate was roughened with 320-grit sandpaper, simulating a fine-grit diamond bur. Two universal adhesives, Scotchbond Universal Adhesive (3M ESPE, SU) and Assure Plus (Reliance, AP), and a conventional adhesive, Transbond XT Primer (3M Unitek, XTP, control), were used in combination with Transbond XT Paste (3M Unitek) to bond the brackets. Six experimental groups were formed: 1) CAD-Temp®/SU; 2) CAD-Temp®/AP; 3) CAD-Temp®/XTP; 4) Telio® CAD/SU; 5) Telio® CAD/AP; 6) Telio® CAD/XTP. Shear bond strength and ARI were assessed. On 1 extra block for each PMMA-based material surfaces were roughened with 180-grit sandpaper, simulating a normal/medium-grit (100 μm) diamond bur, and brackets were bonded. Shear bond strengths and ARI scores were compared with those of groups 3, 6. Results: On CAD-Temp® significantly higher bracket bond strengths than on Telio® CAD were recorded. With XTP significantly lower levels of adhesion were reached than using SU or AP. Roughening with a more coarse bur resulted in a significant increase in adhesion. Conclusions: Bracket bonding to CAD-CAM PMMA can be promoted by grinding the substrate with a normal/medium-grit bur or by coating the intact surface with universal adhesives. With appropriate pretreatments, bracket adhesion to CAD-CAM PMMA temporary restorations can be enhanced to clinically satisfactory levels.

Summary Objectives The aim of the present study was to investigate the impact of high glucose concentration on the response of human periodontal ligament fibroblasts (PDLFs) to cyclic tensile strain. Materials and Methods Human PDLFs were incubated under normal or high glucose conditions, and then were subjected to cyclic tensile stretching (8 per cent extension, 1 Hz). Gene expression was determined by quantitative real-time polymerase chain reaction. Intracellular reactive oxygen species (ROS) were determined by the 2’,7’-dichlorofluorescein-diacetate assay, activation of mitogen-activated protein kinase (MAPK) was monitored by western analysis and osteoblastic differentiation was estimated with Alizarin Red-S staining. Results Cyclic tensile stretching of PDLF leads to an immediate activation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), as well as to the increased expression of the transcription factor c-fos, known to regulate many osteogenesis-related genes. At later time points, the alkaline phosphatase and osteopontin genes were also upregulated. Hyperglycaemic conditions inhibited these effects. High glucose conditions were unable to increase ROS levels, but they increased the medium’s osmolality. Finally, increase of osmolality mimics the inhibitory effect of hyperglycaemia on MAPK activation, c-fos and osteoblast-specific gene markers’ upregulation, as well as osteogenic differentiation capacity. Conclusion Our findings indicate that under high glucose conditions, human PDLFs fail to adequately respond to mechanical deformation, while their strain-elicited osteoblast differentiation ability is deteriorated. The aforementioned effects are most probably mediated by the increased osmolality under hyperglycaemic conditions.

Background Correction of dentofacial deformities via orthodontics is an integral part of oral health as promotes optimal function, periodontal health, aesthetics and overall oral health-related quality of life. The aim of this study was to examine whether paediatricians refer their patients to orthodontists, whether they have sufficient knowledge in basic orthodontic principles and whether they examine their patients for orthodontic abnormalities. Results We conducted a survey study of paediatricians in Greece. Questionnaires were completed by 96 out of 123 paediatricians (response rate 78%). In the assessment of the examination of the oral cavity, a low frequency of examination of the position of the teeth (54%) and jaws (51%) was found. Reasons paediatricians referred patients to specialists varied from mouth breathing-snoring 24% (23/96) to face or teeth asymmetry 87% (84/96). In the multivariable analyses for the effect of gender, work sector or years of experience in the decision for orthodontic referral, we could not identify any significant predictors. Conclusions The results of this study indicate that there was variability regarding orthodontic knowledge among paediatricians. Although the majority were aware of the importance of examination of the oral cavity, they did not have the appropriate knowledge to perform a full and systematic screening for orthodontic problems. The probability of referral was different for the various orthodontic anomalies.

Objective: The aim of this study was to explore the methods, reporting and transparency of clinical trials in orthodontics and compare them to the field of periodontics, as a standard within dentistry. Design/setting: Cross-sectional bibliographic study Methods: A total of 300 trials published in 2017–2018 and evenly distributed in orthodontics and periodontics were selected, assessed and analysed statistically to explore key aspects of the conduct and reporting of orthodontic clinical trials compared to trials in periodontics. Results: Several aspects are often neglected in orthodontic and periodontic trials and could be improved upon, including use of statistical expertise (22.3% of assessed trials), blinding of outcome assessors (62.3%), prospective trial registration (12.0%), adequate sample size calculation (35.7%), adherence to CONSORT (14.3%) and open data sharing (4.3%). The prevalence of statistically significant findings among orthodontic and periodontic trials was 62.3%, which was significantly associated with several methodological traits like statistician involvement (odds ratio [OR] = 0.5; 95% confidence interval [CI] = 0.3–0.9), blind outcome assessor (OR = 0.5; 95% CI = 0.2–1.0), lack of prospective trial registration (OR = 2.8; 95% CI = 1.3–5.9) and non-adherence to CONSORT (OR = 4.5; 95% CI = 1.3–15.8). Conclusions: Although trials in orthodontics seem to be significantly worse compared to periodontics in aspects like trial registration, adherence to CONSORT and declaration of competing interests or financial support, their methods do seem to have improved considerably in recent years.

An orthodontist attends the scientific orthodontic congress and passing by the company exhibitions receives a free sample of a novel orthodontic archwire introduced in the market for initial alignment/levelling with favourable performance over conventional superelastic nickel-titanium archwires. This novel archwire should increase according to the manufacturer’s claims alignment efficacy and halve the pain for the patient. After using the free sample wire on a patient and observing that the patient felt little to no pain during the alignment/levelling phase, the orthodontist decides to venture into unknown territory and find out if this holds true for most of her patients by doing a randomised clinical trial in her practice.

Background/Objectives The aim of this study was to identify outcome-related discrepancies between registry trial entries and final published reports in orthodontic randomized controlled trials (RCTs). The percentage of registered orthodontic RCTs was also recorded. Materials/Method Five trial registries, ClinicalTrials.gov (https://clinicaltrials.gov/), International Standard Randomised Controlled Trial Number registry (http://www.isrctn.com/), European Union Clinical Trials Register (https://www.clinicaltrialsregister.eu/), Australia New Zealand Clinical Trials Registry (http://www.anzctr.org.au/) and Clinical Trials Registry of India (www.ctri.nic.in/) were searched up to April 2018 in order to identify completed orthodontic RCTs. The unique trial identifier, the title and authors name were used to search for publications based on entries within Google (https://www.google.com), Google Scholar (https://scholar.google.gr/) and MEDLINE via PubMed (https://www.ncbi.nlm.nih.gov/pubmed/). Outcome reporting discrepancies and a number of other entry/publication characteristics were recorded including timing of registration, type of journal/publication, significance of the primary outcome in the final report. The number of trials registered among the total number of published RCTs in orthodontics was recorded within the time span assessed. Results One hundred and twenty-four entries were identified for completed orthodontic RCTs, whereas 53 of those were related to published final reports. Outcome reporting discrepancies were ascertained for 47 per cent of publications (n = 2 5); discrepancies were more prevalent for non-primary outcomes (n = 21, 40 per cent). Only 16 per cent of the published orthodontic RCTs had been registered. Limitations Only a subset of trial entries were assessed as these were related to publication records. Conclusions/Implications Registration of clinical trials in orthodontics remains far from universal. A significant level of outcome reporting discrepancy was observed within this subset of registered trials.

Why are there so many systematic reviews in orthodontics, and what are the negative consequences of this for our speciality as an academic discipline?

Summary Objective This cross-sectional study aimed to explore the level of knowledge and expectations people deciding on a future orthodontic treatment have about post-orthodontic retention and to investigate the influence of sociocultural characteristics. Material and methods A total of 227 consecutive people involved as legal decision maker (as patient, parent, or legal guardian) for a prospective orthodontic treatment (mean age 37.1 years; 37.3 per cent male) received before their first appointment a questionnaire to assess their knowledge and expectations about post-orthodontic retention. Data were analysed descriptively, whereas predictors were identified with logistic regressions at P value of less than or equal to 0.05. Results Among the 220 responders, 46.3 per cent (n = 99) knew that retention appliances are used after orthodontic treatment and 52.8 per cent (n = 113) believed perfect results can guarantee stability, whereas at the same time, 77.8 per cent (n = 168) knew that teeth can move on their own without any orthodontic appliances. The majority considered stability of the orthodontic result important or extremely important (94.5 per cent; n = 206), preferred bonded over removable retainers (67.2 per cent; n = 133), believed the orthodontist to be primarily responsible for a stable result (73.2 per cent; n = 158), and found it appropriate to charge for recall visits (72.9 per cent; n = 153). Participants’ gender, age, education, nationality, and past orthodontic experiences within the close family significantly influenced answers. Limitations The setting of a single-centred survey conducted in one university moderates the generalizability of the portrayed results. Conclusions Although stability of orthodontic treatment results is very important to people deciding about a prospective orthodontic treatment, knowledge regarding the need for post-orthodontic retention varies and may at times be contradictious. Sociocultural factors seem to influence the level of knowledge and the expectations on post-orthodontic retention.

Aim of this systematic review was to assess the efficacy of preventive interventions against the development of white spot lesions (WSLs) during fixed appliance orthodontic treatment. Nine databases were searched without limitations in September 2018 for randomized trials. Study selection, data extraction and risk of bias assessment were done independently in duplicate. 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 24 papers (23 trials) were included, assessing preventive measures applied either around orthodontic brackets (21 trials; 1427 patients; mean age 14.4 years) or molar bands (2 trials; 46 patients; age/sex not reported). Active patient reminders were associated with reduced WSL incidence on patient level compared to no reminder (3 trials; 190 patients; RR: 0.4; 95% CI: 0.31-0.64; Number Needed to Treat [NNT]: 3 patients), flat surface sealants were associated with reduced WSL incidence on tooth level than no sealant (5 trials; 2784 teeth; RR: 0.8; 95% CI: 0.63-0.95; NNT: 33 teeth), and fluoride varnish was associated with reduced WSL severity on tooth level (2 trials; 1160 teeth; MD: -0.32 points; 95% CI: -0.44 to -0.21 points). However, the quality of evidence was low according to GRADE, due to risk of bias. Some evidence indicates that active patient reminders and flat surface sealants or fluoride varnish around orthodontic brackets might be associated with reduced WSL burden, but further research is needed. Keywords: adverse effects; clinical trials; dental caries; evidence-based medicine; fixed appliances; systematic review.

Aim: The validity of meta-analysis is dependent upon the quality of included studies. Here, we investigated whether the design of untreated control groups (i.e. source and timing of data collection) influences the results of clinical trials in orthodontic research. Materials and methods: This meta-epidemiological study used unrestricted literature searching for meta-analyses in orthodontics including clinical trials with untreated control groups. Differences in standardized mean differences (ΔSMD) and their 95% confidence intervals (CIs) were calculated according to the untreated control group through multivariable random-effects meta-regression controlling for nature of the interventional group and study sample size. Effects were pooled with random-effects synthesis, followed by mixed-effect subgroup and sensitivity analyses. Results: Studies with historical control groups reported deflated treatment effects compared to studies with concurrent control groups (13 meta-analyses; ΔSMD = −0.31; 95% CI = −0.53, −0.10; P = 0.004). Significant differences were found according to the type of historical control group (based either on growth study or clinical archive; 11 meta-analyses; ΔSMD = 0.40; 95% CI = 0.21, 0.59; P < 0.001). Conclusions: The use of historical control groups in orthodontic clinical research was associated with deflation of treatment effects, which was independent from whether the interventional group was prospective or retrospective and from the study’s sample size. Caution is warranted when interpreting clinical studies with historical untreated control groups or when interpreting systematic reviews that include such studies. Registration: PROSPERO (CRD42015024179). Conflict of interest: None.

Objectives: To investigate, using a split-mouth randomized clinical design, the effect of micro-osteoperforation (MOP) on mini-implant supported canine retraction using fixed appliances. Materials and Methods: Thirty subjects (seven males and 23 females) with a mean age of 22.2 (3.72) years were randomized into three canine retraction groups: Group 1 (MOP 4-weekly maxilla/8-weekly mandible; n = 10); Group 2 (MOP 8-weekly maxilla/12-weekly mandible; n = 10) and Group 3 (MOP 12-weekly maxilla/4-weekly mandible; n = 10) measured at 4-week intervals over 16 weeks. Subjects also completed pain (5-point Likert scale) and pain impact (Visual Analogue Scale) questionnaires. The primary outcome was the amount of canine retraction over 16 weeks at MOP (experimental) and non-MOP (control) sites. Results: Mean overall canine retraction was 4.16 (1.62) mm with MOP and 3.06 (1.64) mm without. After adjusting for differences between jaws, all MOP groups exhibited significantly higher canine distalization than the control group: 0.89 mm more (95% confidence interval [CI] = 0.19 to 1.59 mm; P = .01) in the MOP-4 group, 1.08 mm more (95% CI = 0.49 to 1.68 mm; P = .001) in the MOP-8 group and 1.33 mm more (95% CI = 0.55 to 2.10 mm; P = .002) in the MOP-12 group. All subjects reported pain associated with MOP with 60% classifying it as moderate and 15% severe. The main impact of this reported pain was related to chewing and speech. Conclusions: MOP can increase overall mini-implant supported canine retraction over a 16-week period of observation but this difference is unlikely to be clinically significant.

The publication of the three-paper series on the effects of two slot sizes on treatment parameters in this issue, targets a topic, which has attracted a lot of discussion based primarily on anecdotal evidence. The conclusive evidence contribute to the lack of variation of treatment variables with slot size selection, clarifies one of the traditional beliefs on this issue; several others still hold strong however. This commentary has the objective of highlighting some points, which could be taken into consideration in interpreting the results of this three-part trial.

Background Fixed orthodontic appliances might be associated with intraoral adverse effects on enamel, due to plaque accumulation and their colonization by oral microbes. At the same time, the demand for esthetic alternatives to orthodontic treatment, like thermoplastic aligners, is growing. However, thermoplastic aligners may behave differently intraorally than fixed appliances in terms of bacterial colonization and biofilm formation. Therefore, the aim of this prospective cohort study was to assess the salivary prevalence of the cariogenic bacteria Streptococcus mutans, Lactobacillus acidophilus, and Streptococcus sanguinis among adolescents treated orthodontically with thermoplastic aligners or fixed appliances. Methods Thirty adolescent patients (17 girls/13 boys; mean age 13.8 years old) were assigned to treatment with either (i) self-ligating fixed appliances with nickel-titanium archwires or (ii) aligners constructed from clear transparent polyethylenterephthalat-glycol copolyester (PET-G) thermoplastic sheets. Whole stimulated saliva was collected from each patient at three time points: at baseline (before bonding and initiation of orthodontic therapy or before insertion of the thermoplastic aligners), after 2 weeks, and after 1 month. A simplified plaque index, a simplified gingival index, and the decayed, missing, and filled teeth (DMFT) index were assessed from the clinical examination of the patients. Microbiological analysis of salivary bacteria was performed by quantitative polymerase chain reaction, followed by descriptive and inferential statistics at the 5% level. Results Although patients treated with aligners had significantly lower plaque and gingivitis scores throughout treatment compared to patients treated with fixed appliances, no significant difference could be found between the S. mutans counts of the two groups at any time through treatment (P > 0.05). On the other hand, patients treated with aligners had significantly lower salivary S. sanguinis counts at all time points than patients treated with fixed appliances (P

Spacing between the maxillary anterior teeth is a common concern for young patients and their parents. Patients often consider a diastema to be an annoying but minor problem; they might consult their general dentists for help, or try to address the issue themselves by applying elastic "gap bands." Moreover, parents, without any informed consent, sometimes accept this erroneous method as an easy and inexpensive treatment approach. A 9-year-old boy had severe acute periodontitis involving the maxillary central incisors caused by the placement of an elastic band and its apical migration. Despite periodontal and surgical interventions, the maxillary central incisors were finally extracted, and the patient started orthodontic treatment. The orthodontic treatment plan included maxillary lateral incisor substitution to replace the lost central incisors and mesialization of the maxillary posterior dentition. An interdisciplinary approach with excellent cooperation among the orthodontist, general dentist, and other dental specialists obtained an esthetically pleasing and optimized functional result. Treating the diastema between the anterior teeth with elastic gap bands and without fixed orthodontic appliances should be avoided. Patients should seek proper orthodontic advice for even small-scale orthodontic problems to prevent catastrophic outcomes, as exhibited in this case report.

Clinical trials using categorical outcomes often express their results as risk, which is the probability with which a health outcome (usually an adverse event) will occur. For this article, two sce...

Background/objectives To assess the prevalence of within-group comparisons from baseline to follow-up in published orthodontic articles and to identify potential associations between this statistical problem and a number of study characteristics. Materials/method The most recent 24 issues of four leading orthodontic journals with highest impact factor (American Journal of Orthodontics and Dentofacial Orthopedics; AJODO, European Journal of Orthodontics; EJO, Angle Orthodontist; ANGLE, Orthodontics and Craniofacial Research; OCR) were electronically searched until December 31st 2017. The proportion of articles using comparisons against baseline and interpretation of findings according to within-group comparisons were recorded. The association of this practice with journal, year of publication, study design, continent of authorship, number of centres and researchers, statistical significance of results, and statistical analysis was tested. Univariable and multivariable modified Poisson regression were used to identify significant predictors. Results Overall, 339 articles were eligible for inclusion with the majority published in ANGLE (n = 157, 46%), followed by AJODO (n = 75, 22%), and EJO (n = 75, 22%). A total of 60 studies (18%) presented interpretation of their findings based on within-group comparisons against baseline in isolation. Statistical significance of the primary outcome was a very strong predictor of the prevalence of this flawed approach (RR: 2.33, 95% CIs: 1.22, 4.43; P = 0.01). Limitations The effect of time since publication was not addressed. Conclusions/implications Statistical testing and interpretation within groups is prevalent in orthodontic research. Endorsement of accurate conduct and reporting of statistical analyses and interpretation of research findings is important in order to promote optimal inferences to support clinical decision-making.

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.

Aim To assess the in vivo colour alterations of two different clear thermoplastic retainers. Methods Thirty patients were randomly allocated into two Groups (N = 15) following the completion of active orthodontic treatment. Group 1 received Vivera® and Group 2 Essix® C+ thermoplastic retainers. Each patient was provided with two fabricated retainers (one for use and the other to serve as a control). The CIELAB parameters of the patients’ upper central incisors were measured with a SpectroShade™ spectrophotometer immediately after retainer placement (T0) and again after 15 days (T1), one month (T2) and three months (T3). The measurements were also performed on teeth without the retainer in place. ΔE differences were calculated. Methods ΔE changes from T0 to Tp T2 or T3 showed no statistically significant differences between Groups 1 and 2 within any combination of measurements or teeth. ΔEļŢ3-Ţ0ļ changes for used retainers were 1.55 times higher than control appliances (p = 0.002) and 1.44 times higher than for teeth-only (p = 0.004). For used retainers, changes between T3 and T0 were 1.56 times higher than between T and T0 and 1.47 higher than between T2 and T0 (p < 0.001). There were no statistically significant differences in ΔE between teeth 11 and 21. Results Used retainers exhibited greater colour change than control appliances or teeth-only readings, and increased commensurate with the duration of use. Vivera® and Essix® retainers exhibited similar colour stability. All differences observed were considered clinically acceptable (ΔE < 3.7), although prolonged use could cause clinically significant colour changes.

Introduction A multicenter parallel 3-arm randomized clinical trial was carried out in 3 university hospitals in the United Kingdom to investigate the effect of supplemental vibratory force on space closure and treatment outcome with fixed appliances. Methods Eighty-one subjects less than 20 years of age with mandibular incisor irregularity undergoing extraction-based fixed appliance treatment were randomly allocated to supplementary (20 minutes/day) use of an intraoral vibrational device (AcceleDent; OrthoAccel Technologies, Houston, Tex) (n = 29), an identical nonfunctional (sham) device (n = 25), or fixed-appliance only (n = 27). Space closure in the mandibular arch was measured from dental study casts taken at the start of space closure, at the next appointment, and at completion of space closure. Final records were taken at completion of treatment. Data were analyzed blindly on a per-protocol basis with descriptive statistics, 1-way analysis of variance, and linear regression modeling with 95% confidence intervals. Results Sixty-one subjects remained in the trial at start of space closure, with all 3 groups comparable for baseline characteristics. The overall median rate of initial mandibular arch space closure (primary outcome) was 0.89 mm per month with no difference for either the AcceleDent group (difference, −0.09 mm/month; 95% CI, −0.39 to 0.22 mm/month; P = 0.57) or the sham group (difference, −0.02 mm/month; 95% CI, −0.32 to 0.29 mm/month; P = 0.91) compared with the fixed only group. Similarly, no significant differences were identified between groups for secondary outcomes, including overall treatment duration (median, 18.6 months; P >0.05), number of visits (median, 12; P >0.05), and percentage of improvement in the Peer Assessment Rating (median, 90.0%; P >0.05). Conclusions Supplemental vibratory force during orthodontic treatment with fixed appliances does not affect space closure, treatment duration, total number of visits, or final occlusal outcome. Registration NCT02314975. Protocol The protocol was not published before trial commencement. Funding AcceleDent units were donated by OrthoAccel Technologies; no contribution to the conduct or the writing of this study was made by the manufacturer.

Secure bonding of orthodontic appliances during fixed appliance treatment is closely related to treatment efficiency, as bond failures lead to increased costs in terms of time and money. Additional...

Background Torque of the maxillary incisors is crucial to occlusal relationship and esthetics and can be influenced by many factors. The aim of this study was to assess the relative influence of the material of the orthodontic appliance (adhesive, bracket, ligature, and wire) on tooth displacements and developed stresses/strains after torque application. Methods A three-dimensional upper right central incisor with its periodontal ligament (PDL) and alveolus was modeled. A 0.018-in. slot discovery® (Dentaurum, Ispringen, Germany) bracket with a rectangular 0.018 x 0.025-in. wire was generated. The orthodontic appliance varied in the material of its components: adhesive (composite resin or resin-modified glass ionomer cement), bracket (titanium, steel, or ceramic), wire (beta-titanium or steel), and ligature (elastomeric or steel). A total of 24 models were generated, and a palatal root torque of 5° was applied. Afterwards, crown and apex displacement, strains in the PDL, and stresses in the bracket were calculated and analyzed. Results The labial crown displacement and the palatal root displacement of the tooth were mainly influenced by the material of the wire (up to 150% variation), followed by the material of the bracket (up to 19% variation). The magnitude of strains developed in the PDL was primarily influenced by the material of the wire (up to 127% variation), followed by the material of the bracket (up to 30% variation) and the ligature (up to 13% variation). Finally, stresses developed at the bracket were mainly influenced by the material of the wire (up to 118% variation) and the bracket (up to 59% variation). Conclusions The material properties of the orthodontic appliance and all its components should be considered during torque application. However, these in silico results need to be validated in vivo before they can be clinically extrapolated. Electronic supplementary material The online version of this article (doi:10.1186/s40510-017-0161-5) contains supplementary material, which is available to authorized users.

The advances in the field of materials as they relate to orthodontics can be divided into the actual evolution of materials applied to daily practice and the changes in research methods to study the performance and the biologic properties of the materials. Although it is evident that new materials have saturated the market during the past century, the basic concepts of attaching one appliance to the enamel to use as a grip and inserting wires into that to control the spatial orientation of a tooth are identical to the original concepts. In contrast to that, the numbers of treatises about those subjects and the complexity of instrumentation and analytic tools used in published research have advanced tremendously and at a frenetic pace. This highly specialized pattern of research may effectively raise boundaries across research areas, since the complexity of the issues allows researchers to comprehend the content of journal articles in a narrow spectrum of disciplines. The purposes of this article were to review the advances in the research methods for investigating the various properties of orthodontic materials and to assist the reader in navigating this topic. A synopsis of the materials is also provided, listing future applications that already exist at the experimental stage or are yet unavailable but with the relevant technology already presented in broader scientific disciplines.

Background: Condylar and somatic growth have similar growth curves. The aim of this study was to compare both growth curves in untreated subjects at different ages and investigate if a correlation factor (CF) could be established. Material and methods: Semi-longitudinal records (cephalograms and body height) of 418 untreated, healthy children (193 girls and 225 boys) from a craniofacial growth study were analyzed. Incremental changes of three mandibular measurements from articulare and three from condylion were compared to statural growth changes separately. Based on the assumption that mandibular and somatic growth both follow a parallel line, a CF was postulated and checked for validity and reliability. Results: Mandibular growth spurt could be observed in all six different mandibular measurements, but distances from condylion were more informative. Gonial measurements were not as indicative as symphyseal distances. Mandibular growth did not coincide with somatic growth precisely, and condylar peak velocity preceded statural peak velocity in boys and was slightly delayed in girls. CF was close to the value of 0.4, and its validity could be ascertained when using the condylion–gnathion distance for all ages in girls and up to the age of 12 in boys. Reliability, however, proved to be poor owing to heterogeneity of the sample. Conclusions: Although the relationship between mandibular and statural growth increments can be expressed as a CF with some degree of adequacy, the variance rendered CF unreliable. When evaluating growth-related changes, condylion should be preferred as condylar reference, and symphyseal landmarks should be favoured over gonion.

Aim of this systematic review was to assess the effect of orthodontic treatment with fixed appliances on the tooth color of patients. Nine databases were searched up to May 2017 for clinical cohort studies on the effect of fixed appliance treatment on tooth color. After elimination of duplicate studies, data extraction, and risk of bias assessment according to the Cochrane guidelines, random effects meta-analyses of mean differences (MD) or means and their 95% confidence intervals (CIs) were performed, followed by GRADE (Grading of Recommendations Assessment, Development and Evaluation) assessment of the quality of evidence. Three nonrandomized and one randomized study with a total of 138 patients (46% male, 54% female) with average age of 15.7 years were included. Tooth color of treated patients was significantly altered during or after orthodontic treatment (4 studies; average of 3.2 ∆E units; 95% CI = 2.0–4.4 ∆E units), which was more than the variation among controls (1 study; MD = 1.9 ∆E units; 95% CI = 1.7–2.2 ∆E units). However, the quality of evidence was very low, due to the inclusion of nonrandomized studies, bias, and imprecision. Re-analysis of raw study data indicated that significant differences in clinically discernable treatment-induced color changes were seen between chemically and light-cured adhesives and among the various tooth categories. Existing evidence of very low quality indicates that orthodontic treatment might be associated with alterations of tooth color, which are however not consistently clinically discernible. Treatment-induced color alterations might be dependent on bonding material and tooth type, but evidence supporting this is weak.

Background Insertion of orthodontic fixed appliances has been known to induce a mostly transient qualitative and quantitative alteration of the intraoral microbiota. However, the extent to which treatment with fixed appliances might have a lasting adverse effect on the periodontal attachment of the teeth has not yet been investigated in an evidence-based manner. Objectives Aim of this systematic review was to assess the effect of comprehensive treatment with fixed orthodontic appliances on clinical attachment levels of adolescent and adult periodontally healthy patients. Search methods Seven databases were searched from inception to February 2017. Selection criteria Prospective non-randomized longitudinal clinical studies. Data collection and analysis After duplicate study selection, data extraction, and risk of bias assessment according to the Cochrane guidelines, Paule-Mandel random-effects meta-analyses of the clinical attachment loss and its 95 per cent confidence intervals (CIs) were calculated. Results A total of 9 trials were identified that included 335 treated patients (at least 34 per cent male / 66 per cent female) with an average age of 22.6 years. The average pooled clinical attachment loss was 0.11 mm (9 studies; 335 patients; 95 per cent CI = 0.12 mm gain to 0.34 mm loss; P = 0.338) with high heterogeneity. Furthermore, one study hinted that a small amount of clinical attachment might be gained by intrusion of upper incisors. Additional analyses indicated that the results were robust to addition of untreated patient groups, while patient age and timing of outcome measurement might play an important role. Conclusions According to existing evidence from longitudinal clinical studies orthodontic treatment with fixed appliances has little to no clinically relevant effect on periodontal clinical attachment levels.

Background Permanent canines are amongst the teeth most affected by impaction and ectopic eruption. Although impacted canines are often subjected to surgical exposure and alignment with either the open or the closed technique for many decades, their treatment effects have not yet been systematically asssessed. Objectives The aim of this systematic review was to critically assess whether significant differences exist in the outcomes of the open or closed surgical exposure of impacted canines. Search methods An unrestricted electronic search of nine databases from inception to December 2016 was performed. Selection criteria methods Included were randomized or prospective non-randomized studies comparing open versus closed exposure of impacted canines in human patients. Data collection and analysis After duplicate study selection, data extraction, and risk of bias assessment according to the Cochrane guidelines, random-effects meta-analyses of mean differences (MDs) and odds ratios (ORs), including their 95 per cent confidence intervals (CIs) were performed, followed by subgroup and sensitivity analyses. Results A total of eight unique studies and a total of 433 (30.1% male/59.9% female) patients were included, with an average age of 15.2 years and a total of 453 impacted canines (48.6% and 51.4% in the open and closed exposure, respectively). Open exposure of impacted canines was associated with reduced duration of canine alignment (two studies; MD = -2.14 months; 95% CI = -4.23 to -0.05 months; P < 0.05; moderate heterogeneity and moderate quality) and lower odds of tooth ankylosis (one study; OR = 0.15; 95% CI = 0.03-0.83; P < 0.05; low quality) compared to closed exposure; both findings being independent of canine localization. However, initial alignment of palatally impacted canines took overall significantly longer than labially impacted canines (8.87 versus 4.17 months). Conclusions Based on existing evidence, open surgical exposure seems to be superior in treatment duration and ankylosis risk over the closed technique. Due to the limited number of small included trials, further research is needed for robust clinical recommendations. Registration PROSPERO (CRD42016051916).

Background In the long-lasting debate of extraction versus non-extraction treatment, the impact of extractions on the skeletal vertical dimension remains rather unclear. The aim of this retrospective research study was to obtain a bias-free sample of morphologically similar borderline patients treated with or without extraction of the four first premolars and to retrospectively evaluate the vertical changes that occurred. Methods A borderline sample of 83 patients, 41 treated with four first premolar extractions and 42 treated without, was obtained by means of discriminant analysis applied to a previously investigated parent sample of 542 class I patients. The pretreatment and posttreatment cephalometric radiographs were analyzed digitally, and seven measurements were assessed for vertical skeletal changes. Also, average tracings between the two treatment groups were evaluated using the Procrustes superimposition method. Results The variables of SN to Go-Gn and Y-axis showed adjusted intergroup differences of − 0.91° and − 1.11° (P = 0.04). Comparing the mean intra-group differences of all the variables simultaneously, a significant difference was found between the two treatment groups (overall P value = 0.04). In the extraction group, only the gonial angle showed a significant decrease (P = 0.01) while the overall P value evaluating the intra-group differences between pre- and posttreatment was significant (overall P value

A private orthodontic practitioner wants to make his private practice more clinically efficient in terms of patient output. To this end he looks for ways to reduce the average treatment duration of...

Aim: To systematically search the literature and assess the available evidence for the influence of chin-cup therapy on the temporomandibular joint regarding morphological adaptations and appearance of temporomandibular disorders (TMD). Materials and methods: Electronic database searches of published and unpublished literature were performed. The following electronic databases with no language and publication date restrictions were searched: MEDLINE (via Ovid and PubMed), EMBASE (via Ovid), the Cochrane Oral Health Group’s Trials Register, and CENTRAL. Unpublished literature was searched on [ClinicalTrials.gov][1], the National Research Register, and Pro-Quest Dissertation Abstracts and Thesis database. The reference lists of all eligible studies were checked for additional studies. Two review authors performed data extraction independently and in duplicate using data collection forms. Disagreements were resolved by discussion or the involvement of an arbiter. Results: From the 209 articles identified, 55 papers were considered eligible for inclusion in the review. Following the full text reading stage, 12 studies qualified for the final review analysis. No randomized clinical trial was identified. Eight of the included studies were of prospective and four of retrospective design. All studies were assessed for their quality and graded eventually from low to medium level of evidence. Based on the reported evidence, chin-cup therapy affects the condylar growth pattern, even though two studies reported no significance changes in disc position and arthrosis configuration. Concerning the incidence of TMD, it can be concluded from the available evidence that chin-cup therapy constitutes no risk factor for TMD. Conclusion: Based on the available evidence, chin-cup therapy for Class III orthodontic anomaly seems to induce craniofacial adaptations. Nevertheless, there are insufficient or low-quality data in the orthodontic literature to allow the formulation of clear statements regarding the influence of chin-cup treatment on the temporomandibular joint. [1]: http://ClinicalTrials.gov