Midpalatal miniscrew insertion: The accuracy of digital planning and surgical placement.

INTRODUCTION: The objective of this study was to investigate the accuracy of palatal miniscrew insertion, evaluating the effect of guide fabrication and surgical placement. METHODS: Guided insertion of bilateral paramedian palatal miniscrews was undertaken using Appliance Designer software (3Shape, Copenhagen, Denmark). A resin surgical guide (P Pro Surgical Guide; Straumann AG, Basel, Switzerland) was used. Superimposition of the miniscrew position relative to the digital design was undertaken using bespoke software (Inspect 3D module, OnyxCeph; Image Instruments GmbH, Chemnitz, Germany) to assess surgical inaccuracy. Miniscrew position relative to the surgical guide was also assessed to isolate the effect of planning inaccuracies. Both horizontal and vertical discrepancies were evaluated at both implant locations. RESULTS: Twenty-seven patients having bilateral palatal insertions were examined. Mean discrepancies were <0.5 mm, both in the horizontal and vertical planes. The mean overall horizontal and vertical discrepancy between the digital design and final miniscrew position on the left side was 0.32 ± 0.15 mm and 0.34 ± 0.17 mm, respectively. The maximum horizontal discrepancy observed was 0.72 mm. No significant differences were observed in relation to the accuracy of mini-implant positioning on the basis of sidedness, either for horizontal (P = 0.29) or vertical (P = 0.86) discrepancy. CONCLUSIONS: High levels of accuracy associated with guided insertion of paramedian palatal implants were recorded with mean discrepancies of less than 0.5 mm both in the horizontal and vertical planes. No difference in accuracy was noted between the left and right sides. Very minor levels of inaccuracy associated both with surgical techniques and surgical guide fabrication were recorded.

An in vitro comparison of the dimensional stability of four 3D-printed models under various storage conditions.

OBJECTIVES: To investigate the dimensional stability of various 3D-printed models derived from resin and plant-based, biodegradable plastics (PLA) under specific storage conditions for a period of up to 21 weeks. MATERIALS AND METHODS: Four different printing materials, including Draft V2, study model 2, and Ortho model OD01 resins as well as PLA mineral, were evaluated over a 21-week period. Eighty 3D-printed models were divided equally into two groups, with one group stored in darkness and the other exposed to daylight. All models were stored at a constant room temperature (20°C). Measurements were taken at 7-week intervals using the Inspect 3D module in OnyxCeph software (Image Instruments GmbH, Chemnitz, Germany). RESULTS: Dimensional change was noted for all of the models with shrinkage of up to 0.26 mm over the study period. Most contraction occured from baseline to T1, although significant further contraction also arose from T1 to T2 (P < .001) and T1 to T3 (P < .001). More shrinkage was observed when exposed to daylight overall and for each resin type (P < .01). The least shrinkage was noted with Ortho model OD01 resin (0.16 mm, SD = 0.06), and the highest level of shrinkage was observed for Draft V2 resin (0.23 mm, SD = 0.06; P < .001). CONCLUSIONS: Shrinkage of 3D-printed models is pervasive, arising regardless of the material used (PLA or resin) and being independent of the brand or storage conditions. Consequently, immediate utilization of 3D printing for orthodontic appliance purposes may be preferable, with prolonged storage risking the manufacture of inaccurate orthodontic retainers and appliances.

Orthodontic retention: Rationale and periodontal implications.

Post-treatment change in the form of true relapse and physiological and maturational effects is common following orthodontics. The unpredictable nature of these manifestations dictates a conservative, near-universal approach to retention. Both fixed and removable forms of retention are popular with the latter constrained by variable levels of adherence particularly in the medium- to long-term. Fixed retention may offer a more predictable means of preservation of orthodontic outcomes; however, this advantage is offset by the requirement for prolonged supervision and the potential for adverse changes including periodontal breakdown. Nevertheless, while examples of severe complications are common, a clear causal relationship between intact, passive retainers and periodontal issues does not appear to exist. Nevertheless, the importance of diligent maintenance and careful supervision during fixed retention, in particular, cannot be disregarded.

Assessment of wear characteristics, longevity and stiffness of Essix-type retainers.

OBJECTIVE: To compare four commercially available Essix-type retainers in terms of longevity, wear characteristics, stiffness and their range of rigidity. MATERIALS AND METHODS: An in vitro study was conducted at Queen Mary University of London. Four groups of thermoplastic materials were included: Duran (PETG), Essix C + (Polypropylene), Vivera and Zendura (Polyurethane). A working typodont was fabricated to evaluate surface wear characteristics using a wear machine with a customized jig. Retainers were measured for tensile test, and water absorption was measured at five different time points up to 6 months after initial immersion in two different physical states and two different solutions. Hydrolytic degradation was also evaluated using FTIR spectroscopy. RESULTS: Essix C + was the most flexible retainer with Vivera the stiffest material. Zendura and Essix C + had the most surface wear (413 µm ± 80 and 652 µm ± 12, respectively) with absorption rates of up to 15 wt% in artificial saliva occurring with Zendura. Only Essix C + displayed signs of degradation following water absorption. CONCLUSIONS: All materials had characteristic levels of flexibility and were susceptible to water absorption. Duran 1.5 mm performed similarly to Vivera in relation to stiffness and wear properties. While Zendura and Vivera have similar chemical structures, they exhibited differences concerning wear resistance and water absorption. Further clinical research evaluating the clinical relevance of these laboratory findings is required. CLINICAL RELEVANCE: Characteristic patterns of wear and rigidity of four commercially available Essix-type retainers were observed. This information should help in the tailoring of retainer material on a case-by-case basis considering treatment-related factors and patient characteristics including parafunctional habits.

The effect of vertical skeletal proportions, skeletal maturation, and age on midpalatal suture maturation: a CBCT-based study.

BACKGROUND: Midpalatal suture (MPS) maturation may be influenced by a range of parameters including age, gender, and vertical skeletal pattern. We therefore aimed to evaluate the effect of Frankfurt-mandibular angle (FMA), skeletal maturation, and age on the timing of MPS maturation. METHODS: In this cross-sectional study, cone-beam computed tomography (CBCT) and lateral cephalograms were used to assess the MPS and cervical vertebral maturation (CVM) stage. A proportional odds logistic regression model was used to assess associations between age adjusted for gender and MPS maturation, and a regression analysis was performed to analyze the effect of vertical pattern on these associations. RESULTS: A total of 201 patients (84 male and 117 female) with a mean age of 13.48 (SD 1.94) were included. With increasing age, the odds of belonging to a higher maturation stage increased (OR: 2.14; 95% CI 1.789; 2.567; P < 0.001); however, no association between FMA and MPS maturation was observed (OR: 1.01; 95% CI 0.964; 1.051; P = 0.76). A strong correlation between MPS maturation and CVM stage was not reported. Males had a higher probability of belonging to a lower MPS maturation stage (OR: 0.24; 95% CI 0.136; 0.415; P < 0.001). CONCLUSIONS: Based on this cross-sectional analysis, midpalatal sutural maturation classification is associated with chronological age and occurs later in males. Neither CVM staging nor variation in vertical skeletal proportions were useful predictors of midpalatal maturation stage.

Can ChatGPT identify predatory biomedical and dental journals? A cross-sectional content analysis.

OBJECTIVES: To assess whether ChatGPT can help to identify predatory biomedical and dental journals, analyze the content of its responses and compare the frequency of positive and negative indicators provided by ChatGPT concerning predatory and legitimate journals. METHODS: Four-hundred predatory and legitimate biomedical and dental journals were selected from four sources: Beall's list, unsolicited emails, the Web of Science (WOS) journal list and the Directory of Open Access Journals (DOAJ). ChatGPT was asked to determine journal legitimacy. Journals were classified into legitimate or predatory. Pearson's Chi-squared test and logistic regression were conducted. Two machine learning algorithms determined the most influential criteria on the correct classification of journals. RESULTS: The data were categorized under 10 criteria with the most frequently coded criteria being the transparency of processes and policies. ChatGPT correctly classified predatory and legitimate journals in 92.5 % and 71 % of the sample, respectively. The accuracy of ChatGPT responses was 0.82. ChatGPT also demonstrated a high level of sensitivity (0.93). Additionally, the model exhibited a specificity of 0.71, accurately identifying true negatives. A highly significant association between ChatGPT verdicts and the classification based on known sources was observed (P <0.001). ChatGPT was 30.2 times more likely to correctly classify a predatory journal (95 % confidence interval: 16.9-57.43, p-value: <0.001). CONCLUSIONS: ChatGPT can accurately distinguish predatory and legitimate journals with a high level of accuracy. While some false positive (29 %) and false negative (7.5 %) results were observed, it may be reasonable to harness ChatGPT to assist with the identification of predatory journals. CLINICAL SIGNIFICANCE STATEMENT: ChatGPT may effectively distinguish between predatory and legitimate journals, with accuracy rates of 92.5 % and 71 %, respectively. The potential utility of large-scale language models in exposing predatory publications is worthy of further consideration.

The effect of vertical skeletal proportions on overbite changes in untreated adolescents: a longitudinal evaluation.

OBJECTIVES: To evaluate the change in overbite within an untreated cohort from 9 to 18 years of age and to compare age-related changes in overbite depth based on vertical skeletal proportion. MATERIALS AND METHODS: Lateral cephalograms were obtained from the American Association of Orthodontists Foundation (AAOF) Craniofacial Growth Legacy Collection Project. All cephalometric outcome measures were assessed at ages 9-11 (T1), 13-15 (T2), and 17-19 (T3) years. Generalized estimating equation (GEE) regression models were fit to examine the effect of MP-SN on overbite adjusted for age and gender. RESULTS: A total of 130 subjects from the Denver, Bolton Brush, and Oregon Growth Studies were included. Overbite was relatively constant from T1 to T3 irrespective of facial type, with a minor decrease (0.15 mm) being observed overall. There was a transient increase between T1 and T2 (0.31 mm) that was canceled out by changes during later adolescence. Based on the GEE regression model adjusted for time and gender, a minor but statistically significantly greater reduction in overbite arose as MP-SN increased (coefficient = -0.080; 95% confidence interval -0.12, -0.04; P < .01). CONCLUSIONS: In hyperdivergent subjects, a marginal decrease in overbite was observed from 9 to 18 years of age, with a transient increase from the period spanning 9-11 years to 13-15 years, which was negated in later adolescence. There are limited data to suggest that observation of vertical growth is required in most patients with marginally increased vertical facial proportions in the juvenile and pubertal phases.

The skeletal and dental effects of Hanks Herbst versus twin block appliances for class II correction in growing patients: a randomized clinical trial.

BACKGROUND: Despite the popularity of the Twin Block (TB) and the Hanks Herbst (HH) functional appliances, there is limited prospective research comparing these removable and fixed designs, respectively. OBJECTIVES: To evaluate and compare the skeletal and dental effects associated with TB and HH functional appliances as well as to detect factors that might influence the success or failure of treatment in adolescents with Class II malocclusion. DESIGN AND SETTING: A parallel-group randomized controlled trial was undertaken in a single-centre hospital in the United Kingdom. METHODS: A total of 80 participants (aged 10-14 years) with overjet of 7 mm or more were randomized to receive either the HH or TB appliance. Cephalometric radiographs were collected at the start of the study and immediately after the withdrawal of the functional appliances and measured using Pancherz analysis. Participants were allocated to the TB or HH group, based on an electronic randomization, stratified for gender and allocation concealed. Blinding to the allocated arm was not possible. However, all data were coded and anonymized to ensure that assessors were blinded to the group allocation. The main outcome was the anterior-posterior skeletal and dento-alveolar changes at the end of the functional phase. RESULTS: Fifteen (37.5%) participants from the TB group and 7 (15.5%) from HH failed to achieve full overjet reduction (<4 mm) after 12 months of treatment. Overjet reduction was 2 mm greater with HH compared to TB (P = .05; 95% CI: 0.2, 3.2). No significant differences regarding skeletal and dental changes were reported, with the exception that participants in HH group experienced greater lower molar protraction (P = .002; 95% CI: -2.8, -0.8) and mandibular incisors advancement (P = .001; 95% CI: -2.9, -1), indicating greater dental than skeletal effects. CONCLUSION: The TB appliance was associated with a higher rate of treatment discontinuation. No significant clinical differences were observed in the skeletal and dental effects, although the HH may be associated with more pronounced effects on the mandibular dentition. CLINICAL TRIAL REGISTRATION: The protocol was registered online before the start of the trial (ISRCTN11717011).

"Over-reviewing" of research? An analysis of orthodontic reviews.

INTRODUCTION: Research overviews may be undertaken to identify gaps in the literature, evaluate existing systematic reviews (SRs), and summarize evidence. This paper aims to profile overviews that have been conducted in orthodontics and related interventions since 2012 and to evaluate the degree of overlap among these overviews. METHODS: Overviews published between January 1, 2012 and June 20, 2023 were identified using an electronic search involving Google Scholar and PubMed. A descriptive summary was produced, and citation matrices were used to evaluate the percentage of overlap between overviews using corrected covered area and covered area. This was classified as slight, moderate, high, or very high. RESULTS: A total of 35 overviews were identified across a wide range of topics. Eight overviews included <10 SRs; 21 had 10-20 SRs; and 6 included >20 SRs (median no. of SRs per overview, 15; range, 3-62). Meta-analysis was conducted in only 5 overviews. Overlap between overviews on the same topic ranged from slight (2.7%) to very high (53.8%). CONCLUSIONS: Almost all overview topics address treatments and their effects, with a wide variation in the number and quality of SRs included. There is considerable overlap in some orthodontic overviews, suggesting unnecessary duplication and research waste. Researchers should be encouraged to focus on primary data collection to add more high-quality data to SRs, which will ultimately enhance the yield from secondary and tertiary orthodontic research.

Clear aligner therapy practice among orthodontists in the United Kingdom and the Republic of Ireland: A cross-sectional survey of the British Orthodontic Society membership.

OBJECTIVE: To investigate clear aligner therapy (CAT) practice among orthodontists in the British Orthodontic Society (BOS). DESIGN: A cross-sectional online survey. METHODS: An electronic survey was distributed to members of the BOS in 2022. The survey comprised questions regarding respondent demographics, general use of CAT, the choice of proprietary CAT appliances, CAT planning, case selection, treatment protocols and orthodontist-reported CAT problems. RESULTS: Overall, 233 (19.5%) responses were received with the majority (n = 121, 53.1%) being female. Most respondents reported practising in England (n = 171, 74.7%). The majority (n = 177, 77.3%) indicated that they used CAT in their practice, with 48.1% (n = 81) treating 1-20 patients with CAT annually. The most frequently prescribed CAT system was Invisalign (n = 138, 81.2%). One to three changes to the initial digital treatment plan were made by 72.9% (n = 121) with final tooth positions being the most common reason for adjustment (64.4%). Most (n = 97, 60.3%) rarely or never performed premolar extractions with CAT. Of the respondents, 23 12.7%) reported that they always or mostly used a remote monitoring system in conjunction with CAT, with a wide range of aligner change protocols reported. The median number of months required to complete non-extraction CAT reported by the respondents was 12. Most respondents (n = 77, 51.7%) did not feel that CAT provides superior outcomes compared with fixed appliance therapy. CONCLUSION: CAT practice varied widely among the surveyed orthodontists. A predilection for the use of Invisalign and utility in less severe cases was noted.

Postgraduate orthodontic education: An international perspective on content and satisfaction levels.

BACKGROUND: There is significant international variation in the postgraduate orthodontic training. The aim of this study was to obtain information relating to the design, content, and delivery of formal postgraduate orthodontic training internationally. Moreover, we aimed to evaluate the perception of orthodontists towards their training as well as identifying factors associated with an improved level of satisfaction. METHODS: A 42-question survey was sent to orthodontists worldwide via SurveyMonkey. The survey was circulated on orthodontic Facebook groups and through other digital channels including Instagram. RESULTS: A total of 168 respondents completed all sections of the questionnaire. The vast majority believed programme length was appropriate (n = 150; 89%). Most respondents were confident with their research skills and in their ability to diagnose and treatment plan. Social media was frequently accessed by the respondents for the purposes of orthodontic education (n = 83; 49%). A high proportion (n = 70; 42%) did not treat any clear aligner cases during postgraduate training with many having experience using InvisalignTM only. The majority of respondents across the regions had training in buccal miniscrew insertions. Exposure to three-dimensional printing during residency was limited. CONCLUSIONS: The study offers an overview of the structure, content, and modes of delivery in orthodontic postgraduate training internationally. While satisfaction levels are good, there is a disparity in terms of exposure to certain techniques internationally. Further training in the modern diagnostic approaches and mechanics may improve satisfaction with postgraduate training.

Knowledge assessment on cleft lip and palate among recently graduated dentists: a cross-sectional study.

BACKGROUND: The complex presentation, associated co-morbidities and multi-disciplinary requirements dictate the requirement for in-depth knowledge in order to effectively manage patients with cleft lip and palate (CLP). We aimed to develop a validated questionnaire for cleft lip and palate knowledge assessment and to evaluate the knowledge of cleft lip and palate among a group of recently-graduated dentists. MATERIALS AND METHODS: A multiple-site, cross-sectional questionnaire-based study was conducted. The study population included recently graduated dentists involved in a dental internship program. A bespoke questionnaire was developed and validated, with internal consistency assessed using Cronbach's alpha and factor analysis performed. A 47-item prototype was distilled into a 15-item questionnaire. This was distributed to the participants with a response rate of 67% obtained. RESULTS: The overall proportion of correct responses among dental interns was moderate (73%). The best results were found in relation to CLP treatment including the effect of unfavorable surgical outcomes on speech (89.5%) and the impact of CLP on the occlusion (87.6%). The lowest rate of correct responses (26.7%) was identified in relation to the association between CLP and smoking. CONCLUSION: A validated CLP questionnaire was developed, permitting evaluation of the knowledge of cleft lip and palate and its management among recently graduated dentists. There is limited appreciation among dental interns of the risk factors for CLP as well as post-surgical complications. Given that general dentists are often the gatekeepers for the management of patients with cleft lip and palate, it is important that the findings of this survey are used to inform the curriculum and teaching of cleft lip and palate.

The scientific evidence for pre-adjusted edgewise attachments and mechanics.

Introduction Fixed orthodontic appliance systems continue to evolve with a wealth of evidence emerging to underpin these refinements.Aims To present the evidence from comparative prospective research informing the selection of fixed appliance design and mechanics.Design Detailed literature review.Materials and methods An electronic search to identify randomised controlled trials and clinical controlled trials was undertaken using pre-defined search terms.Results Based on high-level evidence, no one bracket system has been proven superior in terms of efficiency or outcome. Similarly, a clear advantage associated with one wire type or dimension has not been shown. The effect of lacebacks in terms of anchorage management appears to be limited, while elastomeric chain and nickel titanium closing coils are associated with similar rates of space closure.Discussion A wealth of high-quality recent evidence to support the selection of fixed appliance attachments, archwires and auxiliaries, including lacebacks and space closing mechanics, was identified.Conclusions There has been a considerable increase in the amount of high-quality evidence informing the choice of pre-adjusted edgewise mechanics in recent years. This information can be used to make evidence-based decisions in the selection and manipulation of fixed appliances during daily practice.

The use of the Hanks Herbst vs Twin-block in Class II malocclusion: A randomized controlled trial.

INTRODUCTION: This 2-arm parallel study aimed to compare and evaluate the efficiency of Hanks Herbst (HH) and Twin-block (TB) functional appliances in treating adolescents with Class II malocclusion. METHODS: A parallel-group randomized controlled trial was undertaken in a single United Kingdom hospital. Eighty participants were recruited and randomized in a 1:1 ratio to receive either the HH or TB appliance. Eligibility criteria included children aged 10-14 years with an overjet of ≥7 mm without dental anomalies. The primary outcome was the time (in months) required to reduce overjet to normal limits (<4 mm). Secondary outcomes included treatment failure rates, complications and their impact on oral health-related quality of life (OHRQOL). Randomization was accomplished using electronic software with allocation concealed using sequentially numbered, opaque, and sealed envelopes. Blinding was only applicable for outcome assessment. Data were analyzed using descriptive statistics and regression analyses to detect between-group differences, including Cox regression for time to treatment success. RESULTS: HH was significantly faster than TB in reducing the overjet to within normal limits (95% confidence interval [CI], -3.00 to -0.03; P = 0.046). Mean overjet reduction was more efficient with the HH than the TB appliance (ß = 1.3; 95% CI, 0.04-2.40; P = 0.04). Fifteen (37.5%) of the participants in the TB group and 7 (17.5%) in the HH group failed to complete the treatment (hazard ratio = 0.54; 95% CI, 0.32-0.91, P = 0.02). However, TB was associated with fewer routine (incidence rate ratio = 0.81; 95% CI, 0.7-0.9; P = 0.004) and emergency (incidence rate ratio = 0.1; 95% CI, 0.1-0.3; P = 0.001) visits. Chairside time was greater with the HH (ß = 2.7; 95% CI, 1.8-3.6, P = 0.001). Participants in both groups experienced complications with similar frequency. A greater deterioration in OHRQOL was found during treatment with the TB. CONCLUSIONS: Treatment with HH resulted in more efficient and predictable overjet reduction than TB. More treatment discontinuation and greater deterioration in OHRQOL were observed with the TB. However, HH was associated with more routine and emergency visits. REGISTRATION: ISRCTN11717011. PROTOCOL: The protocol was not published before trial commencement. FUNDING: No specific external or internal funding was provided. Treatment for participants was provided as part of routine orthodontic treatment in the hospital.

Non-surgical adjunctive interventions for accelerating tooth movement in patients undergoing orthodontic treatment.

BACKGROUND: Deviation from a normal bite can be defined as malocclusion. Orthodontic treatment takes 20 months on average to correct malocclusion. Accelerating the rate of tooth movement may help to reduce the duration of orthodontic treatment and associated unwanted effects including orthodontically induced inflammatory root resorption (OIIRR), demineralisation and reduced patient motivation and compliance. Several non-surgical adjuncts have been advocated with the aim of accelerating the rate of orthodontic tooth movement (OTM).         OBJECTIVES: To assess the effect of non-surgical adjunctive interventions on the rate of orthodontic tooth movement and the overall duration of treatment. SEARCH METHODS: An information specialist searched five bibliographic databases up to 6 September 2022 and used additional search methods to identify published, unpublished and ongoing studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) of people receiving orthodontic treatment using fixed or removable appliances along with non-surgical adjunctive interventions to accelerate tooth movement. We excluded split-mouth studies and studies that involved people who were treated with orthognathic surgery, or who had cleft lip or palate, or other craniofacial syndromes or deformities. DATA COLLECTION AND ANALYSIS: Two review authors were responsible for study selection, risk of bias assessment and data extraction; they carried out these tasks independently. Disagreements were resolved by discussion amongst the review team to reach consensus.  MAIN RESULTS: We included 23 studies, none of which were rated as low risk of bias overall. We categorised the included studies as testing light vibrational forces or photobiomodulation, the latter including low level laser therapy and light emitting diode. The studies assessed non-surgical interventions added to fixed or removable orthodontic appliances compared to treatment without the adjunct. A total of 1027 participants (children and adults) were recruited with loss to follow-up ranging from 0% to 27% of the original samples.  Certainty of the evidence For all comparisons and outcomes presented below, the certainty of the evidence is low to very low. Light vibrational forces  Eleven studies assessed how applying light vibrational forces (LVF) affected orthodontic tooth movement (OTM). There was no evidence of a difference between the intervention and control groups for duration of orthodontic treatment (MD -0.61 months, 95% confidence interval (CI) -2.44 to 1.22; 2 studies, 77 participants); total number of orthodontic appliance adjustment visits (MD -0.32 visits, 95% CI -1.69 to 1.05; 2 studies, 77 participants); orthodontic tooth movement during the early alignment stage (reduction of lower incisor irregularity (LII)) at 4-6 weeks (MD 0.12 mm, 95% CI -1.77 to 2.01; 3 studies, 144 participants), or 10-16 weeks (MD -0.18 mm, 95% CI -1.20 to 0.83; 4 studies, 175 participants); rate of canine distalisation (MD -0.01 mm/month, 95% CI -0.20 to 0.18; 2 studies, 40 participants); or rate of OTM during en masse space closure (MD 0.10 mm per month, 95% CI -0.08 to 0.29; 2 studies, 81 participants). No evidence of a difference was found between LVF and control groups in rate of OTM when using removable orthodontic aligners. Nor did the studies show evidence of a difference between groups for our secondary outcomes, including patient perception of pain, patient-reported need for analgesics at different stages of treatment and harms or side effects.  Photobiomodulation Ten studies assessed the effect of applying low level laser therapy (LLLT) on rate of OTM. We found that participants in the LLLT group had a statistically significantly shorter length of time for the teeth to align in the early stages of treatment (MD -50 days, 95% CI -58 to -42; 2 studies, 62 participants) and required fewer appointments (-2.3, 95% CI -2.5 to -2.0; 2 studies, 125 participants). There was no evidence of a difference between the LLLT and control groups in OTM when assessed as percentage reduction in LII in the first month of alignment (1.63%, 95% CI -2.60 to 5.86; 2 studies, 56 participants) or in the second month (percentage reduction MD 3.75%, 95% CI -1.74 to 9.24; 2 studies, 56 participants). However, LLLT resulted in an increase in OTM during the space closure stage in the maxillary arch (MD 0.18 mm/month, 95% CI 0.05 to 0.33; 1 study; 65 participants; very low level of certainty) and the mandibular arch (right side MD 0.16 mm/month, 95% CI 0.12 to 0.19; 1 study; 65 participants). In addition, LLLT resulted in an increased  rate of OTM during maxillary canine retraction (MD 0.01 mm/month, 95% CI 0 to 0.02; 1 study, 37 participants). These  findings were not clinically significant. The studies showed no evidence of a difference between groups for our secondary outcomes, including OIIRR, periodontal health and patient perception of pain at early stages of treatment. Two studies assessed the influence of applying light-emitting diode (LED) on OTM. Participants in the LED group required a significantly shorter time to align the mandibular arch compared to the control group (MD -24.50 days, 95% CI -42.45 to -6.55, 1 study, 34 participants). There is no evidence that LED application increased the rate of OTM during maxillary canine retraction (MD 0.01 mm/month, 95% CI 0 to 0.02; P = 0.28; 1 study, 39 participants ). In terms of secondary outcomes, one study assessed patient perception of pain and found no evidence of a difference between groups.   AUTHORS' CONCLUSIONS: The evidence from randomised controlled trials concerning the effectiveness of non-surgical interventions to accelerate orthodontic treatment is of low to very low certainty. It suggests that there is no additional benefit of light vibrational forces or photobiomodulation for reducing the duration of orthodontic treatment. Although there may be a limited benefit from photobiomodulation application for accelerating discrete treatment phases, these results have to be interpreted with caution due to their questionable clinical significance. Further well-designed, rigorous RCTs with longer follow-up periods spanning from start to completion of orthodontic treatment are required to determine whether non-surgical interventions may reduce the duration of orthodontic treatment by a clinically significant amount, with minimal adverse effects.

An assessment of the impact of adhesive coverage and wire type on fixed retainer failures and force propagation along two types of orthodontic retainer wires: an in vitro study.

OBJECTIVES: To evaluate the force required to promote the failure of fixed orthodontic retainers with different adhesive (composite) coverage and to assess the presence and extent of force propagation with two different orthodontic retainer wires. MATERIALS AND METHODS: Ortho-FlexTech and Ortho-Care Perform (0.0175 inches), each of 15-cm length, were bonded on acrylic blocks with different adhesive surface diameters (2 mm, 3 mm, 4 mm, and 5 mm). The samples (n = 160) were subjected to a tensile pull-out test, and debonding force was recorded. Fixed retainers using two different wires and 4-mm adhesive diameter were bonded on acrylic bases resembling a maxillary dental arch (n = 72). The retainers were loaded occluso-apically until the first sign of failure while being video recorded. Individual frames of the recordings were extracted and compared. A force propagation scoring index was developed to quantify the extent of force transmission under load. RESULTS: A 4-mm adhesive surface diameter required the highest debonding force for both retainer wires with significant differences compared with 2 mm (P < .001; 95% confidence interval [CI]: 8.69, 21.69) and 3 mm (P = .026; 95% CI: 0.60, 13.59). Force propagation scores were significantly higher for Ortho-Care Perform. CONCLUSIONS: Based on this laboratory-based assessment, consideration should be given to the fabrication of maxillary fixed retainers using a minimum of 4-mm diameter composite coverage on each tooth. Force appeared to propagate more readily with Ortho-Care Perform than with a flexible chain alternative. This may risk stress accumulation at the terminal ends with potential for associated unwanted tooth movement in the presence of intact fixed retainers.

The influence of nasal deviation on the perception of maxillary dental centreline and smile aesthetics.

OBJECTIVE: To assess the impact of nasal deviation on the perception of the maxillary dental centreline position as judged by orthodontists, dentists and laypersons. DESIGN: Cross-sectional study. SETTING: Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK. PARTICIPANTS: Three groups of raters comprising 30 orthodontists, 30 dentists and 30 laypersons. METHODS: A frontal photograph of a smiling white woman was captured and digitally manipulated with varying degrees of nasal deviation and dental centreline (DC) position in increments of 1.5 mm and 3 mm to the right and left. Three rater groups assessed the attractiveness of images using a visual analogue scale (VAS). Multiple regression analysis was undertaken, and images were compared using the Tukey HSD method. RESULTS: Using a mixed linear model, the intraclass correlation coefficient (ICC) was estimated in the range of 69%-86%, indicating good inter-rater reliability. The interaction between image rating and nasal position (P < 0.001), DC position (P < 0.001) and the relationship between nose and DC position (P < 0.001) were found to be statistically significant with symmetrical upper midline and nasal tip position, both considered to be most aesthetically pleasing. Image rating was not influenced by rater group type (P = 0.995), age (P = 0.983) or sex (P = 0.476). CONCLUSION: There was a preference for a central and coincident nose and maxillary DC position uniformly across the rater groups. Deviations of the nose, DC and their interactions negatively impacted on perceived smile aesthetics with increasing extent and opposing direction of deviations rated progressively more unaesthetic. No differences were observed between orthodontists, general dental practitioners and lay people with respect to perceived impact on smile aesthetics.

An analysis of dental articles in predatory journals and associated online engagement.

OBJECTIVE: We aimed to assess the extent of social media sharing of presumed predatory (PP) dental journals and to compare level of engagement, type of accounts and characteristics of the articles published in presumed legitimate (PL) and PP journals. METHODS: Six hashtags were searched across three social media platforms (Instagram, Facebook and Twitter). Data extraction was performed and journals were classified into PP or PL in a multistep approach using MEDLINE, Beall's list and Directory of Open Access Journals (DOAJ). A checklist was created and used for studies not found in the aforementioned recognized databases. RESULTS: A total of 1742 posts were identified, with the majority (94%) found on Instagram. Of the identified journals, 15.6% were PP. Over one-third of articles from PP journals (35.42%) were indexed on PubMed. The majority of presumed legitimate publications were published in dental specialty only journals (56.44%), compared to 24% in the PP group. The majority of accounts were those of healthcare professionals with most publications related to prosthodontics and implantology (26.3%) and restorative and esthetic dentistry (14.4%), in PL and PP groups, respectively. Similar median number of followers/friends and comments were found among the PL and PP groups. CONCLUSION: Our findings highlight that presumed predatory publications have comparable reach to PL journals on social media risking the sharing of unreliable and misleading information. CLINICAL SIGNIFICANCE: Researchers, students and social media users should be capable of identifying presumed predatory dental publications. Means of moderating the influence of these publications should be explored.