Prognostic factors, outcomes, and complications for dental autotransplantation: an umbrella review.

BACKGROUND: Dental autotransplantation (DAT) is a biological way of replacing missing or compromised teeth for patients. The techniques often necessitate a multi-disciplinary approach. The prognosis and success of the procedure may be impacted by variable factors in varying degrees. OBJECTIVE: Evaluating outcomes and complications of DAT, including prognostic factors using an umbrella review. SEARCH METHODS: Six databases were searched for all relevant systematic reviews published up to 30 June 2022. No restrictions were applied to language or publication date. SELECTION CRITERIA: Systematic reviews and meta-analyses of DAT studies. DATA COLLECTION AND ANALYSIS: Identification, screening, eligibility, and quality assessment using the AMSTAR 2 tool were performed independently by two authors (M.C. and S.A.). Two studies (20%) scored moderate, six studies (60%) scored low, and two studies (20%) scored critically low. Data were analysed using a random effects meta-analysis, and meta-regression was performed to investigate the effect of open and closed apices on the dependent variables. The results were summarised as relative risk ratios. RESULTS: A total of 310 studies were eligible for inclusion, of which 20 studies were selected for full-text evaluation. Ten systematic reviews were included, 9 of which had a meta-analysis. Overall findings suggest that DAT offers favourable success and survival rates. Meta-regression results indicate that a closed apex increased the proportion of ankylosis and resorption, reduced survival but had no effect on success during the observational period. LIMITATIONS: A varying degree of heterogeneity and bias was present in all systematic reviews. The samples of donor teeth included in the systematic reviews also varied morphologically. CONCLUSIONS: DAT is a technique-sensitive procedure requiring a multidisciplinary team, vigilant case assessment and thorough consideration of the respective prognostic factors involved. Despite methodological limitations reported across studies, DAT shows favourable success and survival rates, with a distinctive advantage of bone induction and soft tissue thickness preservation, and should, therefore, be considered as a viable treatment modality. Standardisation of clinical guidelines and practice are highly recommended. REGISTRATION: CRD42020202484.

Aligning orthodontic education: Investigating the use of a digital app to improve the performance in managing orthodontic problems.

INTRODUCTION: General dentists are qualified to manage orthodontic emergencies within their scope of practice. This may involve advice, hands-on intervention or referral to a specialist orthodontist. This study aimed to assess the effect of an orthodontic app on dental undergraduates' ability to manage common orthodontic issues. In addition, this study aimed to determine the confidence of dental students in finding information related to orthodontic emergencies (CFI) as well as their confidence in managing orthodontic emergencies (CMOE). MATERIALS AND METHODS: Students were randomised into one-of-three groups, an app group, an internet group and a closed-book, exam-style group. All participants self-reported their CFI and CMOE. Following this, all participants were asked to complete a multiple-choice question (MCQ) paper based on clinical orthodontic scenarios. In addition, the app group were instructed to complete an app usability questionnaire (MAUQ). RESULTS: Approximately, 91.40% of students (n = 84) had not received clinical training in managing orthodontic emergencies, and 97.85% (n = 91) had not managed an orthodontic emergency clinically within the last 6 months of their training. The mean score for CFI was 0.10 out of 1.0 (SD 0.11) and CMOE was 0.28 out of 1.0 (SD 0.23). Statistically significant better MCQ scores were found in the app group, and no statistically significant difference was found between the internet and exam-style group. CONCLUSIONS: This study is the first to consider the use of an orthodontic app to aid in the management of orthodontic issues. It has practical implications for how mobile apps can aid in learning and can be incorporated into the wider dental field.

Is there an association between 30-day mortality and adrenaline infusion rates in post-ROSC patients? A retrospective observational analysis.

Introduction: Revised guidelines for the management of cardiac arrest have placed greater emphasis on early defibrillation and closed chest compressions; subsequently there has been a significant rise in the number of patients gaining a return of spontaneous circulation (ROSC). As a consequence, emergency medical services have realised the importance of therapies delivered during this phase of care. In some Trusts this includes the use of inotropic agents to augment the cardiovascular system and maintain adequate cerebral and coronary perfusion pressures to mitigate the effects of post-cardiac arrest syndrome. Currently, limited evidence exists with regards to the efficacy of such treatments in the pre-hospital phase. Methods: Retrospective observational analysis of out-of-hospital cardiac arrest patients who received an adrenaline infusion by critical care paramedics. Infusion rates, time of call (ToC) to ROSC and 30-day mortality were compared. Results: Over a 2-year period, 202 patients were recorded as having an adrenaline infusion commenced. Of these, 25 were excluded as they did not meet criteria or had incomplete data and 22 were excluded as the infusion was stopped at scene; 155 patients were admitted to hospital. There were no survivors in the non-shockable group and three survivors in the shockable group at 30 days. A rare events analysis found no relationship between infusion rate, ToC to ROSC and 30-day mortality (Wald chi2, 1.37). Conclusion: Commencement of adrenaline infusions in post-ROSC was associated with significant 30-day mortality, especially in non-shockable rhythms. Further research is needed to elucidate whether this intervention has any benefit in the post-ROSC patient.

Positional factors affecting the surgical management of impacted permanent mandibular canines.

OBJECTIVE: To assess which positional factors influence the decision to surgically remove or expose an impacted mandibular canine. Clinical and radiographic assessment are important considerations when treatment planning for the management of impacted mandibular canines. DESIGN: A cross-sectional study. SETTING: The Royal Surrey County Hospital, Guildford, UK. METHODS: The clinical notes and orthopantomogram radiographs were assessed for all patients aged 21 years or under who underwent surgical management of impacted mandibular canine teeth between 2017 and 2019. The following variables were recorded: angulation, horizontal position, vertical height, overlap of the adjacent tooth and bucco-lingual position of the canine. RESULTS: From the 67 patients and 77 canines included, surgical extraction was performed for 48 canines (62%) and surgical exposure was performed for 29 canines (38%). Chi-square and multivariable logistic regression revealed canine angulation to the midline, horizontal position of the canine root apex, vertical height of the canine crown and canine overlap of the adjacent tooth to be associated with the decision to remove or expose an impacted permanent mandibular canine (P < 0.001). The bucco-lingual position of the canine did not influence the decision to remove or expose an impacted permanent mandibular canine (P = 0.159). CONCLUSION: The decision to expose or remove an impacted mandibular canine is guided by its angulation, horizontal position and vertical position, and by the degree of overlap of the adjacent tooth. However, the bucco-lingual position is not related to the decision to surgically remove or expose an impacted permanent mandibular canine.

Factors affecting willingness to pay for NHS-based orthodontic treatment.

Objective To assess factors affecting willingness to pay for orthodontic treatment.Methods An online discrete choice experiment and willingness to pay study was conducted on a convenience sample of 250 participants aged 16 and above over a four-month period. Participants completed a series of stated-preference tasks, in which they viewed choice sets with two orthodontic treatment options involving different combinations of attributes: family income; cost to patient; cause of problem; prevention of future problems; age; severity of the problem; and self-esteem/confidence.Results Family income, cost to patient, cause of the problem, age and self-esteem/confidence were the most important attributes influencing participants' decisions to have orthodontic treatment. Participants felt that free NHS-based orthodontic provision should be prioritised for those under 18, regardless of family income, for those with developmental anomalies, particularly where self-esteem and confidence are affected, with younger participants (aged 16-24 years) strongly preferring full NHS funding for those under 18 years old (p = 0.007, 95% CI: 0.57-0.09) who dislike smiling in public, especially where self-esteem and confidence are impaired (p = 0.002, 95% CI: 0.16-0.71). Participants with high annual income had the highest preference for the NHS to fund treatment regardless of income (p = 0.02, 95% CI: 0.13-1.47) and placed an onus on addressing developmental anomalies (p = 0.004, 95% CI: 0.22-1.15). In total, 159 (63.6%) of those who would undergo treatment were willing to pay for it, with the majority (88%) open to paying up to £2,000 and only three participants stating the NHS should not contribute towards the cost of orthodontic treatment.Conclusions Based on this pilot study, key factors influencing the decision to undergo treatment included family income, cost, the aetiology of malocclusion, age and self-esteem/confidence. It was felt that free NHS-based treatment should be given priority where self-esteem and confidence are impaired among young people. Further research to inform the priorities underpinning the provision of dental care and orthodontic treatment within the NHS is required.

Prioritising NHS dental treatments: a mixed-methods study.

Objectives To determine the priorities of patients and dental professionals concerning NHS dental treatments, the factors influencing prioritisation and the willingness to contribute towards the cost of NHS dental treatments.Methods Focus groups and interviews involving patients and practitioners informed the development of a piloted questionnaire concerning the priorities for NHS dental treatments. Patients attending three purposively selected dental settings in London and Kent, as well as dental professionals working within a large London dental hospital were recruited to participate in this initial qualitative phase. Qualitative interviews were audiotaped, transcribed verbatim and analysed using the framework approach. Subsequently, another sample of patients and dental professionals within the three dental settings and dental hospital completed a questionnaire. Regression models were used to determine the predictors of perceived priorities and willingness to contribute to NHS dental costs based on the questionnaire data.Results Three focus groups (n = 9) and one semi-structured interview with patients and one focus group of dental professionals (four general dental practitioners and two dental nurses) were conducted. Participants prioritised NHS dental treatments that improve quality of life and social wellbeing. Factors influencing the prioritisation of NHS dental treatments included: individual responsibility for oral health care; concerns about self-esteem and confidence; age-related issues; and the role of treatment in prevention of future dental and general health problems, with financial concerns underpinning these themes. Out of the 455 questionnaires completed, 414 (383 patients and 31 general dental practitioners) were included in the analysis. The provision of emergency dental treatment for children was afforded the highest priority among both patients (59%) and dentists (74.2%). Both groups of participants felt that full funding for most NHS dental treatments should be prioritised for children (<18 years old) rather than adults (p <0.05).Conclusion Participants prioritised NHS dental treatments that would improve social wellbeing and quality of life, with an emphasis on full coverage for NHS treatment for children and young people. Policy makers should account for these preferences in the planning of NHS dental services.

Microbial colonisation associated with conventional and self-ligating brackets: a systematic review.

BACKGROUND: Decalcification and gingivitis caused by plaque accumulation around brackets are common iatrogenic effects of fixed appliances. The influence of conventional versus self-ligating bracket design on microbial colonisation is unknown. OBJECTIVE: To assess the levels of microbial colonisation associated with conventional and self-ligating brackets. SEARCH SOURCES: Three databases were searched for publications from 2009 to 2021. DATA SELECTION: Randomised controlled trials comparing levels of microbial colonisation before and during treatment with conventional and self-ligating brackets were assessed independently and in duplicate. DATA EXTRACTION: Data were extracted independently by two authors from the studies that fulfilled the inclusion criteria. Risk of bias assessments were made using the revised Cochrane risk of bias tool for randomized trials. The quality of the included studies was assessed using the Critical Appraisal Skills Programme Checklist. RESULTS: A total of 11 randomised controlled trials were included in this systematic review. Six of the studies were found to be at low risk of bias and five presented with some concerns. The studies were considered moderate to high quality. Five trials reported no statistically significant difference in microbial colonisation between bracket types. The remaining studies showed mixed results, with some reporting increased colonisation of conventional brackets and others increased colonisation of self-ligating brackets. The heterogeneity of study methods and outcomes precluded meta-analysis. CONCLUSION: Of the 11 studies included in this systematic review, five found no differences in colonisation between conventional and self-ligating brackets. The remaining studies showed mixed results. The evidence is inconclusive regarding the association between bracket design and levels of microbial colonisation.

Changes in the Transverse Dimension of the Maxillary Arch of 5-Year-Olds Born With UCLP Since the Introduction of Nationwide Guidance.

OBJECTIVE: To determine whether the transverse dimensions of the maxillary arch of 5-year-old children with unilateral cleft lip and palate (UCLP) have changed following centralization of cleft services in the United Kingdom. DESIGN: Retrospective cross-sectional study. SETTING: Digital analysis of UCLP maxillary dental casts. PARTICIPANTS: All available maxillary dental casts from 5-year-old participants of the Clinical Standards Advisory Group (CSAG, N = 114) and Cleft Care UK (CCUK, N = 175) studies. INTERVENTIONS: Quantitative measurements of the intercanine width (ICW), intermolar width (IMW), and the distance from the midline to the greater and lesser side canine (GC/LC) and greater side and lesser side second primary molar (GE/LE). Degree measurements of the greater and lesser arch form angles, arch length, anterior palatal depth (APD), and posterior palatal depth were also measured. MAIN OUTCOME: Differences between the transverse dimensions of the maxillary arch for the CSAG and CCUK cohorts. RESULTS: In 5 (ICW, IMW, LC, LE, and APD) of the 11 measurements, there was a statistically significant difference between the CSAG and CCUK cohorts. In all of these, the CCUK values were greater than CSAG. CONCLUSIONS: There have been small but positive improvements for the transverse maxillary dimensions since centralization of the UK cleft service.

Patient reported experiences and treatment outcomes of orthodontic patients treated within secondary care settings in the South West of England during the COVID-19 pandemic.

OBJECTIVE: To assess the impact of the temporary cessation of orthodontic services on patients undergoing treatment during the COVID-19 pandemic. DESIGN: Two-phase multicentre service evaluation. SETTING: Secondary care orthodontic departments in the South West of England. MATERIALS AND METHODS: Phase 1 - Patient-Reported Experience Measure questionnaire (PREM). The questionnaire was distributed to patients who had undergone orthodontic treatment during the COVID-19 pandemic once services had resumed. Phase 2 - assessment of treatment outcomes, specifically with the Peer Assessment Rating (PAR) Index. A total of 280 PAR scores were obtained from a cohort of patients treated before and during the pandemic. RESULTS: A total of 711 PREM questionnaires were completed. Participants generally felt relaxed when visiting secondary care settings, orthodontic departments and whilst wearing orthodontic appliances during the pandemic. Nearly 40% of participants were concerned that the pandemic would impact on their treatment, particularly treatment length. Treatment outcomes revealed that patients treated before and during the pandemic experienced percentage PAR score reductions of 83.9% and 80.6%, respectively. Patients receiving treatment during the pandemic experienced longer treatment durations of 126 days. CONCLUSION: During the pandemic, low levels of anxiety were reported with respect to receiving orthodontic treatment in secondary care settings. Irrespective of the pandemic, a high standard of orthodontic treatment was provided. However, patient concerns regarding treatment length were justified.

Quantitative and qualitative analysis of operator inhaled aerosols during routine motorised equine dental treatment.

BACKGROUND: Routine equine odontoplasty is performed by both Veterinary Surgeons and Equine Dental Technicians. The production of aerosolised particulates from motorised equipment has been well documented in human orthodontics but has yet to be investigated in the veterinary industry. OBJECTIVES: To assess the size, quantity and composition of particulates produced during routine motorised odontoplasty and to model their deposition in the human respiratory tree. STUDY DESIGN: Analytic observational study. METHODS: Fifteen-minute routine motorised odontoplasties were performed on cadaver heads with monitoring equipment placed 30 cm away from the oral cavity to simulate the position of the operator's face. For quantitative analysis, an active air sampling photometric monitor was used to detect the concentration of fully respirable (<4.25 µm) particles produced. The use of water and non-water-cooled equipment and 2 different types of face mask (standard surgical and FFP3) were compared. An 8-stage Marple Personal Cascade Impactor modelled the deposition of the particulates in relation to the human respiratory tree. Qualitative analysis of these particulates was performed using scanning electron microscopy and energy dispersive x-ray spectroscopy. RESULTS: Motorised odontoplasty created aerosolised particulates that could reach all levels of the human respiratory tree. These particulates were composed mostly of calcium and phosphate, although traces of metals were found. The concentration of fully respirable particulates exceeded the recommended exposure limits set by the Health and Safety Executive. The use of an FFP-3 face mask significantly reduced the level of inhaled particulates. MAIN LIMITATIONS: This was a simulated experiment. It does not take into account the variety of environments in which routine treatment takes place. CONCLUSIONS: There are possible health risks in performing a large amount of routine motorised dentistry due to inhalation of aerosolised particulates. The use of an adequate face mask lowers exposure levels to within acceptable limits and, therefore, should be worn.

National British Orthodontic Society (BOS) Orthognathic Audit 2017-2018.

OBJECTIVE: To carry out a UK national clinical audit of orthognathic acceptance criteria and information provided to orthognathic patients before treatment. DESIGN: National clinical audit. SETTING: Data collected using Bristol Online Surveys. PARTICIPANTS: Sixty-nine UK hospital orthodontic departments submitted data. METHODS: Data were collected at two time points using Bristol Online Surveys over a period of 12 months. These were before treatment at the first multidisciplinary clinic (MDT) and immediately after surgery. The data collected included: Index of Orthognathic Functional Treatment Need (IOFTN); Index of Orthodontic Treatment Need (IOTN); age; previous orthodontic treatment; attendance at an MDT; treatment times; and information provision. RESULTS: Eighty-five units agreed to take part in the audit with 69 submitting data, giving a response rate of 81%. The data from 3404 patients were uploaded, 2263 before treatment and 1141 immediately after surgery. Of patients, 91.07% had an IOFTN score of 4 or 5 and 88.73% had an IOTN score of 4 or 5. The mean age at the first MDT was 22 years in the first cohort and 21 years and 4 months in the second immediate post-surgery cohort. Of patients, 37.93% had undergone some form of previous orthodontic treatment, but only 0.28% had undergone previous orthognathic treatment; 96.93% had an MDT confirm that orthodontic treatment by itself was insufficient to adequately correct their functional symptoms. The average treatment time from bond up to surgery was 2 years and 6 months. With respect to information provision, patients received information from a number of sources, principally the British Orthodontic Society (BOS) patient information leaflets and the BOS website Your Jaw Surgery. CONCLUSIONS: In the UK, the majority of orthognathic cases fulfil the criteria for acceptance for NHS-funded orthognathic treatment, as outlined by the Chief Dental Officer's interim guidance on orthognathic treatment. This suggests any prior approval process would not be a good use of NHS resources in the commissioning of orthognathic treatment.

Particulate production during debonding of fixed appliances: Laboratory investigation and randomized clinical trial to assess the effect of using flash-free ceramic brackets.

INTRODUCTION: The aim of this laboratory and randomized clinical trial was to investigate particulate production at debonding and enamel clean-up following the use of flash-free ceramic brackets and to compare them with non-flash-free metal and ceramic brackets. METHODS: In the laboratory study, brackets were bonded to bovine teeth. After 24 hours of immersion in water, the brackets were debonded, the adhesive remnant scores noted, and the enamel cleaned with the use of rotary instruments. Four bracket-adhesive combinations and 2 different enamel pretreatment regimens were tested, including metal and ceramic brackets (conventional, adhesive precoat [APC], and APC flash-free) and conventional acid etch and self-etching primer. Quantitative (mg/m3) and qualitative analysis of particulate production was made in each case. In the clinical trial, 18 patients treated with the use of fixed appliances were recruited into this 3-arm parallel-design randomized controlled trial. They were randomly allocated to 1 of 3 groups: experimental flash-free ceramic bracket or non-flash-free ceramic or metal bracket group. Eligibility criteria included patients undergoing nonextraction maxillary and mandibular fixed appliance therapy. At completion of treatment, the brackets were debonded, and the primary outcome measure was particulate concentration (mg/m3). Randomization was by means of sealed envelopes. Data were analyzed with the use of quantile plots and linear mixed models. The effect of etch, bracket, and stage of debonding of clean-up on particle composition was analyzed with the use of mixed-effects regression. RESULTS: In the laboratory study, the APC brackets produced the highest particulate concentration. Although statistically significantly higher than the metal and conventional ceramic brackets, it was not significantly higher than the ceramic flash-free brackets. In the clinical study, there was no statistically significant effect of bracket type on particulate concentration (P = 0.29). This was despite 3 patients with APC flash-free and 1 patient with conventional Clarity (with 1 bracket) having 1 or more ceramic bracket fracture at debonding requiring removal. No adverse events reported. CONCLUSIONS: Particulates in the inhalable, thoracic, and respirable fractions were produced at enamel clean-up with all bracket types. Although APC and APC flash-free brackets produced the highest concentrations in the laboratory study, there was no difference between any of the brackets in the clinical trial. REGISTRATION: The trial was not registered. FUNDING: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Efficiency and effectiveness of orthodontic treatment within United Kingdom secondary care: a service evaluation.

OBJECTIVES: To evaluate the efficiency and effectiveness of Orthodontic treatment in the National Health Service (NHS) hospitals in England and to identify factors that may be predictive of the duration of Orthodontic treatment and number of patients' visits. DESIGN: Retrospective service evaluation. SETTING: The orthodontic departments of two NHS hospitals. METHODS: The data were collected from the clinical notes, the hospital data base and the pre- and post-treatment study models of 70 patients who were treated with fixed appliances. The pre- and post-treatment models were assessed using the Index of Orthodontic Treatment Need (IOTN) and the Peer Assessment Rating (PAR) index. RESULTS: (1) 98.5% of the patients treated with fixed appliances in both hospitals were in definite need for treatment, (2) The mean percentage PAR score reduction was 81.5%, (3) The mean treatment duration was 27 months with an average of 21 appointments, (4) Factors increasing treatment duration included being a female patient, class I malocclusion, IOTN 5, extractions, prescribing headgear wear, using functional appliances or quadhelixes and increased number of missed appointments, (5) Factors reducing the treatment time were male patients, class II or class III malocclusions and an increased number of emergency appointments. CONCLUSIONS: The hospitals demonstrated a high standard of orthodontic treatment.

Color stability of nonpigmented and pigmented maxillofacial silicone elastomer exposed to 3 different environments.

STATEMENT OF PROBLEM: The color degradation of maxillofacial prostheses in clinical service requires their frequent renewal. How different materials compare is unclear. PURPOSE: The purpose of this in vitro study was to investigate the color stability of a nonpigmented and pigmented maxillofacial silicone when stored in darkness and exposed to accelerated aging in a weathering chamber and natural outdoor weathering. MATERIAL AND METHODS: M511 elastomer was colored with Spectromatch Pro colorants, stored in darkness, and exposed to accelerated aging and natural outdoor weathering for 1500 hours. Test groups included nonpigmented specimens (n=18), individually pigmented specimens (n=90), and Caucasian skin tone-colored specimens (n=18). The CIELab values of the test specimens were measured using the CM-2600d spectrophotometer (Konica Minolta Sensing) at base line (0 hours) and then every 100 hours up to 1500 hours of aging. Color changes (ΔE) were calculated based on the recorded CIELab values. All data were analyzed by using linear mixed models and the Sídák multiple comparison of means test (α=.05). RESULTS: A significant effect of time was found on the ΔE of all test specimens in all environments (P=.001). All pigmented M511 specimens demonstrated good color stability with maximum ΔE below the acceptability threshold of 2 ΔE when stored in darkness and exposed to outdoor weathering. However, nonpigmented specimens crossed this acceptability threshold when exposed to outdoor weathering with maximum ΔE values of 3.65. The greatest color changes were observed for all specimens when exposed to accelerated aging and most exceeded the acceptability threshold. Nonpigmented (ΔE, 4.86) and Indian yellow (ΔE, 5.20) demonstrated the highest color changes after 1500 hours. CONCLUSIONS: All environments resulted in visible color changes of nonpigmented and pigmented M511 elastomer. The lowest ΔE values were observed for specimens stored in darkness and the greatest for specimens exposed to accelerated aging. The organic pigment Logwood maroon demonstrated the best color stability with maximum ΔE values below the perceptibility threshold (PT) of 1 ΔE.

Association between severity of hypodontia and cephalometric skeletal patterns: a retrospective study.

Objective: To assess if severity of hypodontia is related to a specific skeletal pattern. Study design: Lateral cephalometric radiographs and dental panoramic tomographs of 182 hypodontia patients were analysed. The severity of hypodontia was recorded and the sample was divided into groups with mild (n = 71), moderate (n = 56) and severe (n = 55) hypodontia. According to ethnicity, the sample was further subdivided into White Caucasians, African-British, and Arabian/Indian subgroups. Cephalometric measurements were used to quantify the skeletal discrepancy and vertical facial dimensions. Mean and standard deviation for each group were obtained for comparison and an analysis of variance (ANOVA) was carried out to assess the level of significance between the means of the readings in different severity groups. Results: In the white Caucasian group, increased severity of hypodontia, was related to a retrusive maxilla with concomitant reduction of A point, Nasion, B point (ANB), reduced mandibular plane angle and anterior lower facial height (P value: 0.0935-0.9371). For the Black-British and Arabian/Indian groups' findings were inconsistent, with no specific pattern as the number of missing teeth increased. Conclusion: The white Caucasian group followed a pattern that has previously been reported in other studies. For Black-British and Arabian/Indian groups' findings were inconsistent and no specific pattern emerged for different degrees of hypodontia.

Development of a 3D printable maxillofacial silicone: Part II. Optimization of moderator and thixotropic agent.

STATEMENT OF PROBLEM: Conventionally, maxillofacial prostheses are fabricated by hand carving the missing anatomic defect in wax and creating a mold into which pigmented silicone elastomer is placed. Digital technologies such as computer numerical control milling and 3-dimensional (3D) printing have been used to prepare molds, directly or indirectly, into which a biocompatible pigmented silicone elastomer can be placed. PURPOSE: The purpose of this in vitro study was to develop a silicone elastomer that could be 3D printed directly without a mold to create facial or body prostheses by varying its composition. MATERIAL AND METHODS: The room temperature vulcanizing silicone composition was divided into 2 components which were mixed 1:1 to initiate polymerization in the printer before printing began. Different types of moderators and thixotropic agents were used, and the base composition was varied to obtain 11 formulations. The specimens were printed and polymerized from these formulations and tested for tear and tensile strength and hardness. Ten readings of the specimens were recorded for tear and tensile strength and 6 for hardness. Results were analyzed using ANOVA (α=.05). Visual assessment of uncured printed specimens was undertaken for 5 formulations to assess any differences in their ability to hold their shape after printing. RESULTS: The tear and tensile strength of the 11 formulations with varying moderators, thixotropic agents, and base compositions were statistically similar to each other (P>.05). Five of 11 formulations were chosen for the visual assessment as they had sufficient thixotropic agent to avoid slumping while printing. The specimens showed varied slumping behavior until they polymerized. The filler content was increased in the selected formulation, and the tear and tensile strength of the formulation was increased to 6.138 kNm-1 and 3.836 MPa; these increases were comparable to those of commercial silicones currently used for the fabrication of facial prostheses. CONCLUSIONS: The optimum combination of mechanical properties implies the use of one of the formulations as a suitable material for the 3D printing of facial prostheses.

Alignment efficiency and esthetic performance of 4 coated nickel-titanium archwires in orthodontic patients over 8 weeks: A multicenter randomized clinical trial.

INTRODUCTION: The objective of this 4-arm parallel study was to evaluate the alignment efficiency and esthetic performance of 4 coated nickel-titanium archwires over an 8-week period. METHODS: Patients in the permanent dentition requiring maxillary and mandibular fixed orthodontic treatment with a preadjusted edgewise appliance were eligible for inclusion. Patients attending 4 hospital departments (United Kingdom and Italy) were randomly allocated to 1 of 4 treatment interventions: (1) BioCosmetic (Forestadent, Pforzheim, Germany), 0.017 in; (2) Titanol (Forestadent), 0.016 in; (3) TP Aesthetic (TP Orthodontics, La Porte, Ind), 0.014 in; and (4) Tooth Tone (Ortho Organizers, Calsbad, Calif) 0.016 in. Block randomization with block sizes of 4 and 8 was used to ensure an allocation ratio of 1:1:1:1. The primary outcome was alignment efficiency determined by the reduction in Little's irregularity index (mm). Secondary outcomes were color change using the Commission Internationale de L'Eclairage L*a*b* system and percentage of coating loss. Blinding was only applicable to outcome assessment of alignment efficiency. Regression models with Sidak's multiple comparison of means were used to analyze the data. RESULTS: One hundred fifty patients (300 dental arches) were allocated to the treatment interventions, including 61 male and 89 female subjects with a mean age of 16.60 years. The average duration of follow-up was 63.65 days. Baseline characteristics for the archwire groups were similar. One patient was lost to follow-up. Five percent (n = 15) of the archwires fractured: BioCosmetic, 5.3% (n = 4); Titanol, 6.8% (n = 5); TP Aesthetic, 5.3% (n = 4); and Tooth Tone, 2.7% (n = 2). We analyzed 283 dental arches for alignment efficiency. There was no statistically significant difference for mean reduction in irregularity between the archwire groups (P = 0.627): BioCosmetic (n = 71), 3.86 mm (95% CI, 3.31-4.41); Titanol (n = 69), 4.51 mm (95% CI, 4.00-5.02); TP Aesthetic (n = 71), 4.13 mm (95% CI, 3.49-4.78); and Tooth Tone (n = 72), 4.21 mm (95% CI, 3.89-4.46). There was a statistically significant difference between archwire groups for color change (P = 0.001) and percentage of coating loss (P = 0.001), with BioCosmetic performing best in both parameters. CONCLUSIONS: There was no difference between the archwires for alignment efficiency. BioCosmetic performed statistically significantly better than did the other groups for both color change and coating loss. REGISTRATION: This trial was registered with the East Midlands NHS Research Ethics Committee (12/EM/0190). PROTOCOL: The protocol was not published before trial commencement.

YouTube™ as an information resource for orthognathic surgery.

OBJECTIVE: To investigate video content on YouTube™ related to orthognathic surgery. MATERIALS AND METHODS: YouTube™ was searched using the terms: orthognathic surgery; orthodontic surgery; jaw surgery; jaw corrective surgery. Inclusion criteria included English language; primary content orthognathic surgery and acceptable audio-visual quality. Videos were sorted into the top 50 for each search term by view-count and into an overall top 60 from the four searches. The following parameters were recorded for each video: number of views; likes; dislikes; source; primary intention. Each was classified according to information content as 'excellent', 'moderate' or 'poor'. A pre-determined list of orthognathic surgery-related information domains was also evaluated. RESULTS: The top 60 videos had a combined total of 6,986,141 views. Videos predominantly involved patients describing their personal experience (41.67%) with the majority positively biased (61.67%). Only 9.17% of videos were classified as having excellent general information content and 55.83% were rated as poor. Surgical procedures were described in 45% whilst the need for pre- and post-surgical orthodontics was discussed in 33% and 16%, respectively. Post-operative paraesthesia was discussed in 17.5% of videos outcome. CONCLUSIONS: Video content on YouTube™ relating to orthognathic surgery is substandard and patients should be advised to view it with caution.

Bond strength of stainless steel orthodontic brackets bonded to prefabricated acrylic teeth.

OBJECTIVES: The purpose of this in-vitro study was to evaluate the force to debond stainless steel orthodontic brackets bonded to acrylic teeth using different combinations of adhesive and surface treatments. MATERIALS AND METHODS: One hundred prefabricated upper lateral incisor acrylic teeth were divided into 4 equal groups: Transbond XT® adhesive only (Group 1, control), Transbond XT® adhesive with sandblasting (Group 2), Transbond XT® adhesive with abrasion / + methyl methacrylate (MMA) (Group 3) and Triad® Gel only (Group 4). The force in Newtons (N) to debond the brackets was measured. One-way analysis of variance (ANOVA) and pairwise multi-comparison of means (Sidak's adjustment) were undertaken. RESULTS: The highest force to debond was recorded for Group 2 (275.7 N; SD 89.0) followed by Group 3 (241.9 N; SD 76.0), Group 1 (142.7 N; SD 36.7) and Group 4 (67.9 N; SD 21.1). Significant differences in bond strength measurements between the experimental groups were detected. Mean force values for the groups revealed no significant differences between Group 2 and Group 3 (p>0.05). CONCLUSIONS: Both sandblasting and surface abrasion/+ application of methyl methacrylate (MMA) in combination with Transbond XT® adhesive are recommended for bonding stainless orthodontic brackets to acrylic teeth.