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The objective of this study was to assess the relative contribution of genes to shape variation in the permanent dental arches in individuals of Western European descent. The dental casts from 64 monozygotic and 38 dizygotic twins, housed in the Adelaide Dental School's twin record collection, Australia, were assessed. The subjects were of Western European descent, with a mean age of 19.4 ± 5.4 years. Dental casts were scanned using a 3-dimensional scanner (3Shape E4, 3Shape, Copenhagen, Denmark), and landmarks were placed on incisal edges and cusp tips of canines, premolars, and molars. Procrustes superimposition and principal components analysis were applied to examine shape variation. Two-block partial least-squares analysis was used to assess shape covariation between arches. Structural equation modeling was utilized to decompose observed shape variation into genetic and environmental components using the normal assumptions of the twin model. The first 3 principal components (PCs) of the maxillary and mandibular arch were meaningful, accounting for 53% and 50% of the variation in shape space, respectively. The PCs represented shape variability as follows: PC1 - arch depth-width ratio, PC2 - arch taper, canine position (and first premolar rotation for the mandibular arch), and PC3 - incisor displacement and rotation. Genetic modeling indicated that a model incorporating additive genetic and unique environmental factors optimally explained the observed variation for all meaningful PCs. Within shape space, most of the variation in maxillary and mandibular arches exhibited moderate to high heritability (h 2 = 0.61-0.74). Maxillary and mandibular dental arches had strong and significant shape covariation, with high heritability in their reciprocal influences on shape (h 2 = 0.72-0.74; r pls coefficient = 0.87; P <0.05). In this cohort, dental arch shape variation was predominantly influenced by genetic factors. High covariation and heritability were observed between the maxillary and mandibular dental arches. This information may help inform decisions around orthodontic intervention. • The dental arch shape of a sample of twins was analyzed to determine heritability. • The genetic analysis combined structural equation modeling with morphometric analysis. • Dental arch shape variation was predominantly influenced by genetic factors. • High shape covariation and heritability were observed between the dental arches. [ABSTRACT FROM AUTHOR]

Data regarding the efficacy of deep overbite correction with clear aligner therapy in adolescent patients are lacking. This study aimed to investigate the efficacy of deep overbite reduction in adolescent patients treated with Invisalign (Align Technology, San Jose, Calif) aligners. This retrospective study investigated a sample of 102 patients aged 10-17 years from a large database. All patients had completed wear of a prescribed series of Invisalign aligners with planned overbite reduction on a nonextraction basis. The predicted, pretreatment, and posttreatment overbite measurement values were obtained from Align Technology's ClinCheck digital facility. Linear modeling, with Bland-Altman plots, was used to compare the effect of age, the use of bite ramps, and the adoption of the eighth-generational (G8) protocol on the difference between predicted and achieved overbite measurements. A total of 102 patients with a mean ± standard deviation age of 13.94 ± 1.53 years satisfied the selection criteria. A mean ± standard deviation of 41.38 ± 30.43% of the predicted overbite reduction was achieved. There were no differences in the predictability of overbite reduction between patients who were aged <14 years or those aged 14-17 years (P = 0.73), between patients prescribed and not prescribed bite ramps (P = 0.25), or between patients prescribed the G8 protocol and not prescribed the G8 protocol (P = 0.65). The average achieved overbite was less than half of what was planned by the orthodontists via the ClinCheck facility. The age grouping, the provision of bite ramps, and the G8 protocol appear to have little influence on the efficacy of overbite reduction in adolescent patients. • The efficacy of overbite reduction with Invisalign (Align Technology, San Jose, Calif) in adolescents was assessed. • Less than half of the predicted overbite reduction was achieved. • Age, bite ramps, and the eighth-generational protocol appeared not to influence the findings. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the expression of root angulation in canine, premolar, and first molar teeth adjacent to first and second premolar extraction sites in the maxilla after treatment with an initial series of Invisalign aligners (Align Technology, Santa Clara, Calif). Adult patients (aged ≥18 years) with at least 1 first and/or second premolar extraction in the maxilla and satisfying strict selection criteria were evaluated. Digital models representing pretreatment, predicted, and posttreatment were obtained from Align Technology's digital interface, ClinCheck. The Geomagic Control X (version 2017.0.3; 3D systems, Rock Hill, NC) software facility was used to determine and compare the root angulation of adjacent canine, premolar, and first molar teeth at different time points. The predicted angulation of teeth was significantly different (P <0.02) than that achieved in most patients. When adjacent teeth roots were planned to tip away from the extraction site, there was an overexpression of the movement. When teeth roots were planned to tip into the extraction site, underexpression occurred, and movement was in the opposite direction in some instances. There was no difference in root angulation outcomes according to the prescribed number of aligners, 1- or 2-week wear protocols, and sex (P >0.05). Attachments were influential in controlling angulation in first-premolar extractions (P = 0.05), but optimized attachments were not any more effective than conventional attachments (P >0.05). The achieved root angulation in teeth adjacent to premolar extraction sites in the maxilla after treatment with an initial series of Invisalign aligners differed significantly from that predicted. Attachments play a minor role in the predictability of root angulation outcomes. • Root angulation changes after extractions in the maxilla and clear aligner therapy were assessed. • Changes in teeth adjacent to premolar extraction sites differed from those planned. • The roots of some teeth moved in the opposite direction from what was planned. • Attachments play a minor role in controlling root angulation outcomes. [ABSTRACT FROM AUTHOR]

This study aimed to investigate whether there was a difference between the planned and achieved lingual root torque of the maxillary central incisors in patients treated with an initial series of Invisalign (Align Technology, Santa Clara, Calif) aligners in which >10° change in the inclination of these teeth was prescribed via the ClinCheck facility. The pretreatment, planned, and the digital models after wear of the initial series of aligners regarding adult patients who satisfied selection criteria and were treated using the Invisalign appliance were measured using the Geomagic Control X software (version 2017.0.3; 3D systems, Rock Hill, SC). A sample of 63 patients with 126 maxillary central incisors satisfied the inclusion criteria. The mean accuracy of the planned torque change of the maxillary central incisors that was achieved was 41.9%. A clinically significant shortfall (≥5°) was detected in 78.6% of the incisors, with the majority showing an underexpression between 10°-15°. Linear regression analyses indicated that weekly or biweekly wear protocols or the presence or absence of power ridges did not influence the accuracy of planned torque expression (P >0.05). The changes in torque expression with an initial series of Invisalign aligners were less than half of what was planned in patients in which at least a 10° change in lingual root torque of these teeth was prescribed. The presence of power ridges and the aligner change protocol did not appear to significantly affect the accuracy of maxillary central incisor torque expression. • Planned moderate-to-severe torque changes with Invisalign treatment were assessed. • The achieved changes in maxillary central incisors were 41.9% of those planned. • The presence or absence of power ridges did not influence torque expression accuracy. • Weekly and biweekly aligner protocols did not differ in torque expression accuracy. [ABSTRACT FROM AUTHOR]

Patients seeking health information on the Internet is commonplace. This scoping review aimed to collate and synthesize the evidence regarding the quality of Web-based orthodontic information. A systematic search and independent screening process was conducted by 2 independent reviewers across 4 databases. The review was conducted in alignment with the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) guidelines. Of 661 records identified, 30 publications satisfied the inclusion criteria. Reviewed studies included those related to the information contained within Web sites regarding dental and orthodontist practices, orthodontic interventions, appliances and auxiliaries, orthodontic conditions commonly requiring orthodontic therapy, issues related to patient experience, and advice during orthodontic treatment. A total of 5 quality of information (QOI) instruments and 3 readability tools were employed, with the University of Oxford, United Kingdom (DISCERN) instrument and the Flesch Reading Ease Score tool being the most frequently used. Most studies determined that the QOI contained within evaluated Web sites was poor and provided suboptimal information related to treatment risks and Web site reliability. Most studies indicated that the information was more difficult to read than recommended by guidelines. The QOI of orthodontic information available on Web sites was low to moderate, with the readability of content at a level that was considered challenging for many readers to understand. A recommendation for greater involvement of the dental and orthodontic specialty in Web site development was commonplace. Research is required for the development of validated tools that can determine the accuracy of information in addition to Web site reliability. • Thirty cross-sectional studies were systematically assessed in this scoping review. • The quality of Web-based orthodontic information was found to be generally low. • Low-quality information is commonly related to treatment risks and Web site reliability. • The content was found to be difficult to read. • Greater input by the orthodontic specialty in Web site development was frequently advised. [ABSTRACT FROM AUTHOR]

The extraction of second premolars and associated changes in the volume of the airway have not been previously explored. This retrospective study aimed to compare the volumetric changes of the airway preorthodontic and postorthodontic treatment in relevant extraction and control samples and to identify variables that may influence the outcome. Cone-beam computed radiography scans of 54 patients with second premolar extraction and 59 nonextraction patients treated in a private orthodontic practice were matched for crowding. The average age for both samples was 15 years. The images were individually landmarked and measured by applying volumetric, linear, and angular parameters. The results were analyzed using repeated measures, such as variance analysis, correlation testing, and regression statistical analyses. There was a statistically significant increase in the airway volume for both groups (P <0.05). The difference in increase between the groups was not statistically significant. Seven variables demonstrated a collectively significant effect on changes to airway volume (F [7,112] = 38.48; P <0.001; r 2 = 0.701), with 70% of the variation predicted by the variables. Multiple regression analyses indicated that changes to the area of minimum constriction (B = 32.45; t = 11.95; P <0.001) and changes to airway length (B = 94.75; t = 7.79; P <0.001) had a statistically significant effect on airway volume. The volume of the airway increased in both the extraction and nonextraction samples. The biggest contributors to the increase were an increase in airway length and an increase in the area of minimum constriction, which likely occurred as a result of natural growth. • Airway volume changes after orthodontic treatment were assessed in 2 patient groups. • Second premolar extraction treatment was compared with nonextraction treatment. • Airway volume increased in both groups from the beginning to the end of treatment. • The difference in increase between the groups was not statistically significant. • Increases in airway length and the area of minimum constriction were influential. [ABSTRACT FROM AUTHOR]

Interproximal reduction (IPR) is a common adjunct to contemporary orthodontic treatment. This study aimed to carry out a quantitative analysis of IPR prescribed in the refinement phases of clear aligner therapy with the Invisalign appliance (Align Technology, San Jose, Calif). The digital treatment plans (DTPs) of a total of 330 patients treated by 11 orthodontists were evaluated. Relevant data regarding patient age, gender, and prescription of IPR in the initial and refined DTPs were obtained from Align Technology's digital interface, ClinCheck. Computational analyses included descriptive statistics, Mann-Whitney U, and Kruskal-Wallis tests. Most (n = 182; 75.2%) of the 242 patients who satisfied inclusion criteria were females. The median (interquartile range [IQR]) age was 29.2 (22.1-40.2) years. More than 60% of the contact sites prescribed IPR related to the initial DTP (n = 1312; 60.4%), with 39.6% (n = 859) recorded in the refinement DTPs. A median (IQR) of 1.1 (0.6-2.1) mm of IPR was prescribed per patient in the initial DTP compared with a median (IQR) of 0.6 (0.3-1.3) mm in the refinement DTPs. The most common site for prescribed IPR in all DTPs was the mandibular anterior region. Almost half (n = 108; 44.6%) of the patients were prescribed IPR at the same contact point site more than once during treatment. Almost 40% of the contact points that were prescribed IPR were in the patients' refinement DTPs. Most IPR was prescribed for the anterior region of the mandible. Almost half of the patients had IPR repeatedly prescribed at the same sites during treatment. • The prescription of interproximal reduction (IPR) with the Invisalign appliance was evaluated. • Almost 40% of contact points that were prescribed IPR were in the refinement phases. • The most common site for prescribed IPR was in the anterior teeth of the mandible. • Approximately 44.6% were prescribed IPR at the same site more than once during treatment. [ABSTRACT FROM AUTHOR]

This retrospective investigation aimed to determine whether the achieved changes in the treatment of Class II malocclusion were the same as those planned after the prescribed wear of an initial phase of Invisalign treatment with the mandibular advancement appliance (MAA) (Align Technology, Santa Jose, Calif). All patients treated with the MAA and who satisfied inclusion/exclusion criteria were selected from a database of 16,500 patients treated with clear aligners by 16 orthodontists. The pretreatment, planned, and achieved overjet measurements were documented from data provided in Align Technology's software facility, ClinCheck. Changes in intermaxillary anteroposterior (AP) first permanent molar (FPM) relationships were evaluated using Geomagic Control X (3D systems, Rock Hill, SC) metrology software. Most of the 195 patients who satisfied the inclusion criteria were females (n = 104; 53.3%). The mean age was 12.62 ± 2.20 years. The pretreatment overjet was reduced from 6.49 ± 2.86 mm to 4.61 ± 2.22 mm after prescribed MAA wear, which was 42.5% of the planned outcome. The pretreatment AP FPM reduced from 3.14 ± 1.95 mm to 2.24 ± 2.51 mm, which was 31.3% of that planned. Thirty-eight (19.5%) patients experienced an increase in overjet where a reduction was planned. Less than half of the planned overjet reduction and less than a third of the planned AP FPM correction were achieved with the MAA. Almost 20% of patients completed the MAA phase of treatment with an increased overjet despite a reduction being planned. • We studied the efficacy of Invisalign's mandibular advancement appliance. • The mean achieved overjet reduction with the appliance was less than that planned. • Just 31% of the planned anteroposterior first permanent molar changes occurred. • Almost 20% experienced an increase in overjet after prescribed wear of the appliance. [ABSTRACT FROM AUTHOR]

Patients with one or more developmentally absent teeth are routinely encountered in dental practice. Tooth agenesis can be associated with significant functional, aesthetic and psycho-social problems. The present article provides an overview of the prevalence and aetiology of tooth agenesis, as well as the condition's clinical characteristics and management options with reference to the evidence base. A timely diagnosis can facilitate the appropriate planning and management which might not be straightforward, and patient care will likely require multi- and inter-disciplinary input. It is critical that dental care practitioners are aware of the clinical characteristics and management options for tooth agenesis. [ABSTRACT FROM AUTHOR]

The use of social media has increased significantly, which enables the sharing of patient experiences of healthcare interventions. Evaluation of the available data regarding patient experiences of their own orthodontic treatment is lacking. The present registered scoping review aimed to collate and evaluate the current evidence to enable a greater understanding of the experiences of patients, undergoing orthodontic treatment, conveyed via social media platforms regarding their treatment. Studies with patients reporting their orthodontic experiences through social media platforms regarding orthodontic treatment were considered for evaluation. Four electronic databases (PubMed, Web of Science, Embase and Scopus) were searched up until January 29th, 2023. A total of 379 records were screened, of which 47 potentially pertinent articles were obtained in full. Twelve studies satisfied the inclusion and exclusion criteria following screening and were assessed in the present scoping review. Most studies evaluated patient experiences conveyed via Twitter. The findings indicated that patient experiences regarding orthodontic treatment were generally positive and those regarding orthodontic retention were generally negative. Positive experiences included satisfaction associated with treatment outcome, removal of fixed appliances and the aesthetic appearance of clear aligners. Negative experiences related to pain/discomfort, impact on speech and eating, dislike of retainers and the need to comply with retainer wear protocols. Instagram appears to be the social media platform through which patients are more likely to express positive sentiments. Research is required to develop validated methodological processes to enable future systematic review and meta-analysis of relevant studies, and to develop strategies for the orthodontic profession to minimise the negative experiences borne by their patients. In addition, guidance on the appropriate ethical management of data in future similar studies is required. [ABSTRACT FROM AUTHOR]

• Content regarding orthodontic retention and retainers on Reddit was assessed. • Most initial posts were negative, and most responding posts were positive. • Eight main themes regarding relevant patient concerns were identified. • More negative sentiments about orthodontists were expressed than positive. Social media can provide insight into patient experiences with health care. The aim of this study was to evaluate the content regarding orthodontic retention and retainers on the social media website, Reddit. A systematic search for relevant content submitted over a 12-month period on the Reddit forum, r/braces, was conducted. Qualitative analysis of the initial posts for themes and subthemes was conducted by two investigators. Responding comments to the initial posts were assessed for supportiveness for each initial poster and alignment with the evidence-base. Quantitative assessment was via descriptive statistics. A total of 271 initial posts and 984 comments satisfied the inclusion/exclusion criteria. All initial posts were by patients. Just 1.12% (n = 11) of the comments appeared to be provided by oral health professionals. Most initial posts were negative (50.18%; n = 136), and most comments were positive (70.42%; n = 693). Alignment with the evidence-base was high among the comments (67.89%; n = 668). Eight main themes were identified with concerns regarding the negative impact of retention and retainers on quality of life, compliance with retention protocols and relapse commonly expressed. Concern regarding fear of relapse when waiting for the initial or renewal of retainers was a novel finding. More negative sentiments about orthodontists were expressed than positive. Reddit is a supportive and reliable environment for patients regarding orthodontic retention and retainers. The content evaluation suggested deficiencies in communication processes between clinicians and patients. Greater engagement of the orthodontic profession in the provision of supportive and evidence-based information on an individual patient basis and through appropriate information channels is required. [ABSTRACT FROM AUTHOR]

• Average maxillary curve of Wilson increased more than the prescribed outcome using Invisalign. • Inclination of maxillary posterior teeth demonstrated an unintended buccal crown tip. • Except for the second molars, arch width expansion was consistently underexpressed. • Second molars overexpressed expansion mostly because of an unintended buccal crown tip. This retrospective study aims to evaluate the predictability of the Invisalign appliance (Align Technology, Santa Clara, CA) in leveling the maxillary curve of Wilson (COW). 53 adult subjects treated by orthodontists who are experienced Invisalign providers, between 2013 and 2019 were selected. All patients had either Angle Class I or II malocclusions and were treated by non-extraction in the maxillary arch with a minimum of 14 Invisalign aligners with no bite ramps or auxiliaries. Initial, predicted, and actual outcomes were analyzed with Geomagic Control X software (3D systems, Rock Hill, SC; Version 2017.0.3). Despite planning mean (SD) COW leveling of 0.25 mm (1.91), the curve became significantly more pronounced by 1.15 mm (0.85) (P <.001). There was a significant overexpression of buccal inclinations between mean prescribed versus actual values from 0.10 mm (0.39) (P =.007) to 0.29 mm (0.47) (P <.001) from the first premolars to the second molars, respectively. These differences were more pronounced posteriorly. The differences between the predicted and actual arch width values were underexpressed for all teeth except the second molars; a mean underexpression between 0.28 mm (0.92) and 0.60 mm (1.14). The second molars were the only teeth to overexpress with a mean of 0.42 mm (1.02). Overall mean maxillary COW was not predictably controlled with Invisalign. The appliance tends to overexpress the buccal crown tip regardless of prescribed direction, especially posteriorly. Arch expansion was underexpressed at all levels of the arch except for second molars which overexpressed by almost four times. [ABSTRACT FROM AUTHOR]

Research regarding orthodontic changes using the superimposition of digital study models (DSMs) is commonplace. Information regarding the accuracy of data processing by superimposition software is limited. The study aimed to compare different methods of superimposing DSMs using implant-supported crowns (ISC) as a stable reference structure. DSMs containing ISCs were sourced from a database of patients treated with clear aligner therapy. The DSM representing the planned treatment outcome was superimposed on the pretreatment DSM. Three tooth points were selected for comparison on the contralateral side of each ISC. Differences in Cartesian coordinates for each tooth point for each arch superimposition method, used by the Geomagic Control X (3D systems, Rock Hill, NC) software system, were recorded. Paired t tests for the reference standard superimposition method best-fit high-resolution using the entire dental arch compared with initial, best-fit low-resolution, and best-fit high-resolution using the ISC only were calculated. The DSMs of 54 dental arches containing ISCs were evaluated. All mean differences for displacements of selected points on the contralateral side to the ISC in the 3 Cartesian planes were <0.05 mm (P <0.05) and below the threshold of clinical significance. In addition, the standard superimposition techniques (initial, best-fit low-resolution, and best-fit high-resolution) resulted in nonstatistically significant and nonclinically significant differences in the position of the ISC. Researchers can be confident that the described superimposition methodologies, with and without ISCs as a stable reference structure, are a valid method for accurately assessing most intraarch dental changes. • Four methods of superimposing digital models via Geomagic Control X (3D systems, Rock Hill, NC) were assessed. • Implant crowns were used as a framework for the appraisal of superimposition algorithms. • The 4 methods were found to be valid for accurately assessing most dental changes. [ABSTRACT FROM AUTHOR]

Introduction: The purpose of this cross-sectional study was to survey orthodontic clear aligner therapy (CAT) practices among orthodontists in Australia.Methods: A pilot-tested electronic questionnaire was distributed to 434 full members of the Australian Society of Orthodontists. Questions were related to demographics, use and choice of aligners, digital treatment planning, patient selection, treatment protocols, refinements/finishing, retention, and patient-reported aligner issues. Factors regarding the decision not to provide CAT were also surveyed.Results: The response rate was 54.6%. Most orthodontists (93.13%) provided CAT, which made up 24.17% of their annual orthodontic caseload. The median percentage of initial digital treatment plans (DTP) approved without changes was 0, with 4-6 changes reported by 24.14%. Orthodontists reported a mean of 2.02 ± 1.76 refinements per patient. Orthodontists were least comfortable treating patients with bilateral crossbite (71.28%) and deep overbite (62.56%). DTP challenges regarding tooth attachments and tooth positions and issues regarding patient compliance with CAT wear protocols were commonly reported. More than 1 CAT system was used by most (63.92%), with in-house systems used by 21.63%. Orthodontists rarely or never (63.68%) performed premolar extraction treatment with CAT. Adjunctive interproximal reduction was reportedly mostly carried out to relieve crowding and reduce open gingival embrasures. The view that fixed appliances provide better outcomes was a major influence (71.43%) on the decision for those who did not provide any CAT.Conclusions: CAT practices among orthodontists varied. Further research is required to investigate the challenges in effective CAT provision highlighted in this survey. [ABSTRACT FROM AUTHOR]

• TikTok videos regarding orthodontic retention and retainers were assessed. • Most videos were uploaded by dental professionals. • The overall content, reliability, and quality of the videos was poor. • The effects of retainers on the quality of life were infrequently addressed by orthodontists. • Dissatisfaction with indefinite retainer wear was commonly reported by laypersons. To analyze the content, reliability, and quality of relevant TikTok videos regarding orthodontic retention. Six relevant terms were searched on the TikTok social media Web site. Uploaded videos satisfying inclusion/exclusion criteria were assessed for the presence of nine predetermined content domains and categorized as "high-content" (≥5) or "low-content" (<5). Reliability was determined using the DISCERN instrument and quality by the Global Quality Score (GQS). Layperson videos were evaluated for themes using discourse analysis. Intraclass coefficients for content, DISCERN scores, and GQS were calculated for intrarater reliability. Statistical analysis was via IBM SPSS Statistics (version 27.0.0.0; SPSS Inc. Chicago, IL). Orthodontists uploaded 37.8% and laypersons 34% of the 209 assessed videos. Just 22.1% of videos were considered to be 'high-content.' Quality of life issues related to retainer wear was the domain that was present least often in the videos provided by orthodontists (13.9%) and most often in those uploaded by laypersons (53.5%). High-content videos recorded greater mean GQS and DISCERN scores compared with low-content videos (P < 0.001). Strong positive associations existed between the number of domains present and DISCERN scores (rho = 0.808; P < 0.01) and between GQS and DISCERN scores (rho = 0.67; P < 0.01). Intraclass coefficient scores ranged between 0.92 and 0.98. Dissatisfaction with the need for long-term retainer wear was a prevalent negative theme in layperson videos. The content, reliability, and quality of TikTok videos regarding orthodontic retention were poor. The orthodontic profession must use TikTok effectively to ensure it delivers high-quality information relevant to laypersons' concerns. [ABSTRACT FROM AUTHOR]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jimonfin.2010.02.008 Byline: Michael J. Moore (a), Maurice J. Roche (b) Abstract: We present a simple framework in which both the exchange rates disconnect and forward bias puzzles are simultaneously resolved. The flexible-price two-country monetary model is extended to include a consumption externality with habit persistence. Habit persistence is modeled using Campbell Cochrane preferences with 'deep' habits along the lines of the work of Ravn, Schmitt-Grohe and Uribe. By deep habits, we mean habits defined over goods rather than countries. The model is simulated using the artificial economy methodology. It offers a neo-classical explanation of the Meese-Rogoff puzzle and mimics the failure of fundamentals to explain nominal exchange rates in a linear setting. Finally, the model naturally generates the negative slope in the standard forward market regression. Author Affiliation: (a) School of Management and Economics, Queen's University Belfast, Lanyon Building, Belfast BT7 1NN, Northern Ireland, UK (b) Ryerson University, Toronto, ON M5B 2K3, Canada

Introduction: This study aimed to survey retention protocols and retainer characteristics among orthodontists practicing in Canada.Methods: An online questionnaire was distributed to 576 orthodontists registered with the Canadian Association of Orthodontists. It included respondents' demographic details, preferred orthodontic retainers and prescribed wear protocol, adjunctive retention procedures, the timing of retention follow-ups, retainer choice in specific situations, and retainer characteristics. Chi-square tests and Fisher's exact tests were used to test the associations between variables.Results: An 18% response rate was recorded (n = 101). Vacuum-formed retainers were the most commonly used retainers in the maxilla (50.5%), whereas bonded retainers were preferred in the mandible (54.5%). An initial full-time removable retainer wear period was commonly prescribed (63.0%-67.0%). Retainer checks were carried out by 85.1%-89.1% of orthodontists for 1 or 2 years after the end of active orthodontic treatment. Only 44.6%-56.4% were comfortable with general dentists continuing retainer checks. Most (72.5%-84.1%) retainers were fabricated in the orthodontists' office laboratory. Indefinite retainer wear was commonly suggested and was significantly influenced by the number of years in practice.Conclusions: Most orthodontists' preferred retainer was the vacuum-formed retainers in the maxilla and the bonded retainers in the mandible. A variety of retention protocols and retainer characteristics was evident among orthodontists that reflect the considerable variation in malocclusion traits we face day-to-day. There seems to be a potential dichotomy between orthodontists being uncomfortable about allowing general dental practitioners to manage retention and orthodontists unwilling to provide retention care indefinitely. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to evaluate the quality of information and readability of online content regarding medication-related osteonecrosis of the jaw (MRONJ).Study Design: Three search engines were used to identify websites containing information regarding MRONJ. The content was assessed with 5 quality of information and readability tools. Statistical analyses were performed via GraphPad Software (GraphPad Software Inc., La Jolla, Calif, United States).Results: The Health on the Net (HONcode) seal was present in 2 of the 21 websites that satisfied inclusion/exclusion criteria. The mean JAMA (Journal of the American Medical Association) benchmark satisfied per website was 1.619 out of 4 (standard deviation [SD] = 1.2; 95% confidence interval [CI], 1.07-2.17). The mean overall Quality Evaluation Scoring Tool score was 15.29 out of a maximum 28 (SD = 6.174; 95% CI, 12.48-18.1). The Quality Evaluation Scoring Tool scores of those websites that satisfied ≥3 JAMA criteria were significantly higher than those that did not (P = .01; 95% CI, -11.41 to -1.79). The readability levels of all content ranged from fairly difficult to very difficult.Conclusions: The information related to MRONJ on the Internet is unreliable and too difficult for the general public to read. Authors of online MRONJ information should consider use of quality of information and readability tools to ensure that reliable information is understood by those with poor health literacy skills. [ABSTRACT FROM AUTHOR]

The study of three populations of larvae of Chrysopa quadripunctata, a generalist predator, show individual repeatability and geographical variation. Identically reared larval population show differences in the feeding and defense strategies. There is geographical variation in Larval response to camouflaging material, evidence of the behavioural plasticity of the larvae.