Extraction vs nonextraction orthodontic treatment: a systematic review and meta-analysis.

OBJECTIVES: To compare four first premolar extraction and nonextraction treatment effects on intra-arch width, profile, treatment duration, occlusal outcomes, smile aesthetics and stability. MATERIALS AND METHODS: An electronic search of the literature to June 2, 2023 was conducted using health science databases, with additional search of gray literature, unpublished material, and hand searching, for studies reporting nonsurgical patients with fixed appliances regarding sixteen sub-outcomes. Data extraction used customized forms, quality assessed with ROBINS-I (Risk Of Bias In Non-randomized Studies-of Interventions) and Cochrane RoB 2 (risk-of-bias) tool. GRADE (Grading of Recommendations Assessment, Development and Evaluation) assessed certainty of evidence. RESULTS: Thirty (29 retrospective studies, 1 randomized controlled trial) studies were included. Random-effect meta-analysis (95% CI) demonstrated maxillary (MD: -2.03 mm; [-2.97, -1.09]; P < .0001) and mandibular inter-first molar width decrease (MD: -2.00 mm; [-2.71, -1.30]; P < .00001) with four first premolar extraction; mandibular intercanine width increase (MD: 0.68 mm; [0.36, 0.99]; P < .0001) and shorter treatment duration (MD: 0.36 years; [0.10, 0.62]; P = .007) in the nonextraction group. Narrative synthesis included three and five studies for upper and lower lip-E plane, respectively. For American Board of Orthodontics Objective Grading System and maxillary/mandibular anterior alignment (Little's irregularity index), each included two studies with inconclusive evidence. There were no eligible studies for UK Peer Assessment Rating (PAR) score. Class I subgroup/sensitivity analyses favored the same results. Prediction interval indicated no significant difference for all outcomes. CONCLUSIONS: Four first premolar extraction results in maxillary and mandibular inter-first molar width decrease and retraction of upper/lower lips. Nonextraction treatment results in mandibular intercanine width increase and shorter treatment duration. There was no significant difference between the two groups regarding maxillary intercanine width, US PAR score, and posttreatment smile esthetics. Further high-quality focused research is recommended.

Temporary anchorage devices and the forces and effects on the dentition and surrounding structures during orthodontic treatment: a scoping review.

BACKGROUND: Temporary anchorage devices (TADs) offer the clinician an immediate temporary source of skeletal anchorage for a range of orthodontic interventions. It is important to understand forces involved in using TADs and the effects on the dentition and surrounding structures, to improve clinical outcomes. OBJECTIVE: To examine and qualitatively synthesize literature on the forces involved with the use of TADs and the effects on the dentition and surrounding structures in orthodontic tooth movement, to provide better understanding of the complex interactions and the clinical implications. SEARCH METHODS: Electronic databases searched included: Cochrane Library [including Central Register of Controlled Trials (CENTRAL)], Embase via OVID, Pubmed, and Scopus. Study screening and selection were conducted in duplicate. SELECTION CRITERIA: Studies selected were clinical studies, simulation studies (computer or laboratory-based), or animal studies with no restriction over gender, age, study type (excluding case reports), or setting. Studies focusing on the forces involved with the use of TADs in orthodontic treatment and their effects on the dentition and surrounding structures were included. DATA COLLECTION AND ANALYSIS: A data charting form was piloted and refined. Data charting was performed independently and in duplicate. This consisted of key fields with predetermined options and free text. The extracted data were collated, and a narrative synthesis conducted. RESULTS: The results from 203 included studies were grouped into seven TAD based interventions combining the clinical, simulation, and animal studies. They were: En masse retraction of anterior teeth, intrusion, movement of a single tooth, orthopaedic interventions, distalisation, maxillary expansion and other types. The forces involved with the use of TADs, and their effects on the dentition and surrounding structures, were presented in descriptive and tabular formats. LIMITATIONS: This review restricted study language to English. Formal appraisal of the quality of evidence is not a required feature of scoping reviews, as per the PRISMA-ScR guidelines, however it was evident that a proportion of clinical studies were of high risk of bias and low quality and therefore any proposed changes the reader may consider to their clinical practice should be contextualized in light of this. CONCLUSIONS: Across the seven types of TAD based interventions the effects on the dentition and surrounding structures are described providing a better understanding of the complex interactions. A guide to the level and direction of forces in each type of intervention is provided to aid clinicians in achieving high quality outcomes. IMPLICATIONS: There is a need to validate future FEA simulation studies by comparing to clinical data. It is also recommended that future scoping reviews incorporate a formal critical appraisal of studies to facilitate the translation of the results into clinical practice. Development of a standard set of terms for TADs is recommended to facilitate future research. REGISTRATION: Registration of a scoping review is not possible with PROSPERO. FUNDING: None to declare.

Which anchorage device is the best during retraction of anterior teeth? An overview of systematic reviews.

Objective: To evaluate the available evidence regarding the clinical effectiveness of different types of anchorage devices. Methods: A comprehensive literature search of different electronic databases was conducted for systematic reviews investigating different anchorage methods published up to April 15, 2021. Any ongoing systematic reviews were searched using PROSPERO, and a grey literature search was undertaken using Google Scholar and OpenGrey. No language restriction was applied. Screening, quality assessment, and data extraction were performed independently by two authors. Information was categorized and narratively synthesized for the key findings from moderate- and high-quality reviews. Results: Fourteen systematic reviews were included (11 were of moderate/high quality). Skeletal anchorage with miniscrews was associated with less anchorage loss (and sometimes with anchorage gain). Similarly, skeletal anchorage was more effective in retracting anterior teeth and intruding incisors and molars, resulting in minor vertical skeletal changes and improvements in the soft tissue profile. However, insufficient evidence was obtained for the preference of any anchorage method in terms of the duration of treatment, number of appointments, quality of treatment, patient perception, or adverse effects. The effectiveness of skeletal anchorage can be enhanced when: directly loaded, used in the mandible rather than the maxilla, used buccally rather than palatally, using dual rather than single miniscrews, used for en-masse retraction, and in adults. Conclusions: The level of evidence regarding anchorage effectiveness is moderate. Nevertheless, compared to conventional anchorage, skeletal anchorage can be used with more anchorage preservation. Further high-quality randomized clinical trials are required to confirm these findings.

Clinical effectiveness of clear aligner treatment compared to fixed appliance treatment: an overview of systematic reviews.

OBJECTIVE: To evaluate the available evidence regarding clinical effectiveness of clear aligner treatment (CAT). MATERIALS AND METHODS: A comprehensive literature search was conducted for systematic reviews investigating effectiveness of CAT published up to July 15, 2021. This was accomplished using different electronic databases. No language restriction was applied. Screening, quality assessment, and data extraction were performed by two authors independently. Information was categorized and narratively synthesized for the key findings from moderate and high-quality reviews. RESULTS: A total of 361 potentially eligible reviews were identified. After excluding the non-relevant/low-quality reviews, 18 systematic reviews were included. CAT was found to be effective for mild to moderate malocclusions, and was associated with inferior outcomes when treating severe cases or with achieving specific tooth movements. There were conflicting results regarding treatment duration; however, CAT may be associated with shorter treatment in mild to moderate cases. Relapse was greater with CAT, while periodontal health was better. The risk of root resorption tended to be lower with CAT. Regarding pain, the results were unclear, although CAT was found to be more comfortable and associated with a reduced impact on eating and chewing. CONCLUSIONS: The level of evidence regarding CAT is moderate; hence, further high-quality randomized clinical trials are required. Evidence supports use of aligners as an alternate to fixed appliances in patients with mild-to-moderate malocclusion but not in severe cases. Advancement in technology could enhance the accuracy of CAT in delivering planned outcomes. CLINICAL RELEVANCE: CAT can be used effectively for selected cases with mild to moderate malocclusion. REGISTRATION: PROSPERO registration number: CRD42021246855.

Development of patient information leaflets for fixed, removable, and functional appliances for Arabic-speaking orthodontic patients.

OBJECTIVE: To develop Orthodontic Patient Information Leaflets (PILs) in Arabic. MATERIAL & METHOD: This study included five phases starting with Arabic translation of existing British Orthodontic Society leaflets; initial face validation with three orthodontists; content validation with ten orthodontists; final face validation with ten orthodontists, five postgraduate students, and ten patients; and re-translation to English prior to comparing the new documents with the original PILs to verify that all the necessary information were included. The content validity index (CVI) assessed item level (I-CVI) and scale level (S-CVI). RESULTS: The three Arabic PILs were face validated with inclusion of mini-screws, rapid maxillary expansion, and interproximal reduction. Content validity was perfect with no item I-CVI < 0.80. The S-CVI/Ave for PIL Fixed Appliances = 0.98, PIL Removable Appliances = 0.98 and PIL Functional Appliances = 0.97. In the final face validation, the three leaflets received 100% agreement from all observers for consistency of leaflet format and style, clarity, readability and use of adequate phrases. Finally, the leaflets were re-translated and the information was checked by native English speakers to ensure the completeness of information. There were no discrepancies and face validity was excellent. CONCLUSION: Valid PILs for Arabic-speaking patients undergoing orthodontic treatment with fixed, removable, and functional appliances have been developed.

Orthodontic treatment and root resorption: an overview of systematic reviews.

BACKGROUND: Root resorption can be considered the most unfortunate complication of orthodontic treatment. OBJECTIVE: To evaluate the available evidence regarding orthodontically induced inflammatory root resorption (OIIRR). SEARCH METHODS: A comprehensive literature search was conducted for the systematic reviews investigating OIIRR published up to 24 May 2020. This was accomplished using electronic databases: MEDLINE via OVID, EMBASE, AMED (Allied and Complementary Medicine Database), PubMed, and Web of Science. Any ongoing systematic reviews were searched using Prospero and a grey literature search was undertaken using Google Scholar and OpenGrey (www.opengrey.eu/). No language restriction was applied. SELECTION CRITERIA: Only studies investigating OIIRR were included. DATA COLLECTION AND ANALYSIS: Screening, quality assessment [using the AMSTAR 2 tool (A Measurement Tool to Assess Systematic Reviews)], and data extraction were performed by two authors independently. Information was categorized and narratively synthesized for the key findings from moderate and high-quality reviews. RESULTS: A total of 2033 potentially eligible studies were identified. After excluding the non-relevant studies, 28 systematic reviews were included. Of which, 20 systematic reviews (71.5%) were of moderate and high-quality level of evidence. The incidence and severity of OIIRR increase with the fixed appliance, especially with heavy force, intrusion, torqueing movements, increased treatment duration, and treatment with extractions or with long apical displacement (particularly for maxillary incisors). There was insufficient evidence regarding most other treatment- and patient-related factors on OIIRR. Following all precautionary measures, pausing treatment and regular monitoring benefits patients with OIIRR. CONCLUSIONS AND IMPLICATIONS: There is a limited number of high-quality studies in terms of OIIRR. The influence of fixed appliance on root resorption was noted; however, the cause and effect relationship between OIIRR and orthodontic biomechanics has not been confirmed. Avoiding heavy, continuous forces and a greater amount of apical displacement over a long duration of treatment is recommended. Precautionary measures should be carefully considered when treating patients with a high risk of OIIRR. REGISTRATION: CRD42020166629.

The impact of labial fixed appliance orthodontic treatment on patient expectation, experience, and satisfaction: an overview of systematic reviews.

BACKGROUND: Patient perception with fixed appliance orthodontic treatment is important to improve oral health-related quality of life. OBJECTIVE: The main objective of this study was to evaluate the impact of labial fixed appliance orthodontic care on patient perception before, during, and after the treatment. SEARCH METHODS: Relevant systematic reviews investigating patient perception with fixed appliance orthodontic treatment were identified by searching electronic databases: MEDLINE via OVID (1946 to 31 December 2018), EMBASE (1974 to 31 December 2018), AMED (Allied and Complementary Medicine Database; 1985 to November 2018), PubMed (inception to 31 December 2018), Web of Science (1900 to 2018), and PsychINFO (1806 to 31 December 2018). Ongoing systematic reviews were searched using Prospero and a grey literature search was undertaken using Google Scholar and OpenGrey (www.opengrey.eu/). No language restriction was applied. SELECTION CRITERIA: Only studies investigating patient perception of fixed appliance orthodontic treatment were included. DATA COLLECTION AND ANALYSIS: Screening, quality assessment [using the AMSTAR 2 tool (A Measurement Tool to Assess Systematic Reviews)], and data extraction were performed by two authors independently. Information was categorized and narratively synthesized for the key findings. RESULTS: A total of 163 articles investigating patient expectation, experience, and satisfaction with conventional ligation labial fixed orthodontic appliances were obtained. Of these, 152 observational or interventional studies were excluded, resulting in 11 eligible systematic reviews. Two were excluded as earlier reports of a Cochrane review. The quality of the reviews was variable (critically low, low, and moderate). The findings were as follows: aesthetics represents a primary motive for orthodontic treatment; a temporary deterioration in the quality of life occurs during the initial phases of treatment; gender and ethnicity factors do not have an impact on patient perception of treatment; and a positive relationship between orthodontist-patient-parent is important to achieve patient compliance and satisfaction. CONCLUSIONS: There is a lack of high-quality studies in terms of systematic reviews and meta-analyses for assessing patient perception with fixed appliance orthodontic treatment. The aesthetic impact of malocclusion is the main motive for seeking orthodontic treatment. Quality of life reduces during the initial stages of orthodontic treatment but improves in the later stages of treatment. Assessment before, during, and after orthodontic treatment is necessary to comprehensively assess patient perception at all stages of care. TRIAL REGISTRATION: CRD42019122653. CONFLICT OF INTEREST: None to declare.

Effectiveness of miniscrew-supported maxillary incisor intrusion in deep-bite correction: A systematic review and meta-analysis.

OBJECTIVES: To evaluate systematically the effectiveness of miniscrew-supported maxillary incisor intrusion compared with other nonsurgical intrusive mechanics for deep-bite correction. MATERIALS AND METHODS: Unrestricted electronic searches in Embase, Web of Science, MEDLINE, LILACS, and Cochrane's CENTRAL as well as manual searches were conducted up to August 2019. Only randomized clinical trials (RCTs) were included. Study selection, data extraction, and bias assessment were done by two independent reviewers. The Cochrane risk-of-bias tool was used, and the quality of evidence was graded using the GRADE approach. A random-effects meta-analysis of continuous data, with its 95% confidence intervals (CIs), was used. RESULTS: Seven RCTs were included in the quantitative synthesis, and the overall quality of evidence was very low to low. When compared with intrusion arches, miniscrews resulted in a more efficient deep-bite reduction with a standardized mean difference (SMD) of -0.48 (95% CI, -0.89 to -0.07). When miniscrews were used, a statistically significant difference was observed favoring less maxillary molar extrusion (SMD, -0.86; 95% CI, -1.46 to -0.27) and more incisor intrusion as measured from centroid to palatal plane (SMD, -0.95; 95% CI, -1.41 to -0.49). Results also showed a statistically nonsignificant difference regarding the amount of resultant root resorption between miniscrews and intrusion arches. CONCLUSIONS: There is weak evidence indicating efficient deep-bite correction using miniscrews. Root resorption seems to be an associated adverse effect that occurs regardless of the intrusive mechanics used. These conclusions should be viewed with great caution as further well-designed long-term research is recommended.

Variation in bracket slot sizes, ligation methods and prescriptions: UK national survey.

OBJECTIVE: This study designed to investigate the use of fixed bracket slot sizes, ligation method and prescriptions in the UK using an online survey/questionnaire comprised of seven questions. MATERIAL AND METHODS: The questionnaire link along with an explanation of its nature was circulated via the British Orthodontic Society (BOS) to all 978-email addresses of the Consultant Orthodontists Group (COG) and Orthodontic Specialists Group (OSG) (registered on the UK Specialist List for Orthodontics) members inviting them to participate. Two email reminders were sent to increase the response rate. Chi2 analyses determined the statistical differences in the use of bracket slots and prescriptions according to the regions and years of experience. RESULTS: The respondents represented 31.2% of the BOS specialist orthodontic members. Most of the respondents practised in the South of England with experience between 11-30years. The vast majority of the respondents routinely used brackets with the multibracket appliance treatment (MBT) prescription (81.6%) and 0.022-inch slot size (98.7%), which was statistically significantly higher in all geographical regions and experience levels (P<0.001). The majority of the respondents reported either 100% or 90% use of conventional brackets when compared to self-ligating brackets. CONCLUSION: The vast majority of UK specialist orthodontists use conventional ligating MBT prescription brackets with the 0.022-inch slot size. This was mainly because they perceive that this combination provides better treatment outcomes, whilst many respondents also indicated that they were taught and trained using this combination and that there was not enough evidence to support a change in their clinical practice.

Quantification of maxillary dental midline deviation in 2D photographs: Methodology trial.

INTRODUCTION: Discrepancy of the upper dental midline to the facial midline plays an important role in smile aesthetic assessment. This study presents different reference points to quantify the deviation of upper dental midline to the facial midline in 2D frontal photographs. The aim was to find the most accurate, precise, and practical reference points to measure dental midline discrepancy in 2D photographs. METHODOLOGY: A modified headset with a protractor was developed in order to achieve photographs in nine standardised head positions. Six reference points were used to detect the facial midline in the 2D photographs (eyebrows "EB", inner-canthus of the eyes "ICE", alae of the nose "AN", columella "C", nasolabial folds "NLF", and the philtrum "PH"). The deviation of the maxillary dental midline from the facial midline was measured and compared with clinical measurements. STATISTICAL ANALYSIS: Standard deviations (SD), Root Mean Square Error (RMSE), Method of Moments' Estimator (MME), 2-way repeated measures ANOVA, and multi-level linear model were used to estimate the true errors. RESULTS: The different reference points responded significantly differently to changes in head position and all showed measurement errors, which increased with greater head rotation. Alae of the nose showed the least measurement error and the greatest precision in all head positions. CONCLUSION: The alae of the nose are the recommended reference points to identify the facial midline in order to quantify dental midline deviation from frontal photographs.

Does anchorage loss differ with 0.018-inch and 0.022-inch slot bracket systems?

OBJECTIVES: To compare maxillary first molar anchorage loss between 0.018-inch and 0.022-inch slot fixed appliance systems. MATERIALS AND METHODS: Patients requiring bilateral maxillary premolar extractions (n = 74) within a randomized clinical trial comparing the effectiveness of 0.018-inch and 0.022-inch slot MBT bracket systems (3M-Unitek, Monrovia, Calif) were included. Three-dimensional pre- and posttreatment digital models were landmarked and measured (R700 scanner and OrthoAnalyzer software, 3Shape, Copenhagen, Denmark). Anteroposterior position of the first molars was measured using the third medial rugae point as a reference. Anchorage loss (AL) represented the subtraction of the posttreatment distance from the pretreatment distance for both anchorage loss right (ALR) and left (ALL) sides. The values were then compared using a two-way analysis of variance. RESULTS: There were 41 and 33 cases for the 0.018-inch and 0.022-inch bracket slot systems, respectively. The baseline characteristics were similar between groups, except for the presence or absence of anchorage devices (P = .050). For the total sample: 0.018-inch ALR = 3.86 mm, ALL = 3.30 mm and 0.022-inch ALR = 3.73 mm, ALL = 3.47 mm (P = .970). There was also no significant difference between the 0.018-inch and 0.022-inch groups when subjects with anchorage devices were excluded (P = .383). CONCLUSIONS: Bracket slot size does not influence maxillary molar anchorage loss during orthodontic treatment.

A randomized clinical trial of the effectiveness of 0.018-inch and 0.022-inch slot orthodontic bracket systems: part 1-duration of treatment.

OBJECTIVE: To compare treatment duration between 0.018-inch and 0.022-inch slot systems and determine factors influencing treatment duration. SUBJECTS AND METHODS: Eligible participants aged 12 years or over were allocated to the 0.018-inch or 0.022-inch slot MBT appliance (3M-Unitek, Monrovia, California, USA) using block randomization in groups of 10. Outcome measures included duration of: 1. overall treatment, 2. levelling and alignment, 3. working and finishing, and 4. appointment numbers and other treatment-related factors. Parametric tests (independent samples t-test) and non-parametric tests (chi-square with Fisher's exact tests and Mann-Whitney U-test) assessed differences between groups. A multiple linear regression analysis identified factors influencing treatment duration (P < 0.05). RESULTS: Of the 187 participants randomized (1:1 ratio), 34 withdrew or were excluded (protocol deviations or poor cooperation). There were 77 patients in the 0.018-inch slot group and 76 patients in the 0.022-inch slot group (overall mean age: 19.1 years). Baseline characteristics were similar between groups (P > 0.05). The mean duration of treatment for the 0.018-inch and 0.022-inch slot groups was 29.3 and 31.2 months, respectively. There were no statistically significant differences between the two treatment groups in terms of treatment duration, duration of the key stages of treatment, and number of appointments (P > 0.05). The regression analysis revealed 33.0 per cent of variance in treatment duration was explained by age at bonding, Class II division 2 malocclusion, number of failed appointments, number of emergency appointments, and transfer to another clinician. There were no adverse events. LIMITATIONS: It was impossible to blind clinicians or patients to allocation and oral hygiene and periodontal outcomes were not assessed. CONCLUSIONS: There was no statistically or clinically significant difference in treatment duration between 0.018-inch and 0.022-inch slot bracket systems. Increasing patient age, Class II division 2 malocclusion, number of failed and emergency appointments, and multi-operator treatment all increase orthodontic treatment duration. REGISTRATION: The trial was registered with ClinicalTrials.gov on 5 March 2014, registration number: NCT02080338. PROTOCOL: The protocol was published at DOI: 10.1186/1745-6215-15-389.

A randomized clinical trial of the effectiveness of 0.018-inch and 0.022-inch slot orthodontic bracket systems: part 3-biological side-effects of treatment.

OBJECTIVE: To compare orthodontically induced inflammatory root resorption (OIIRR) and patient perception of pain during orthodontic treatment between 0.018-inch and 0.022-inch slot bracket systems. SUBJECTS AND METHODS: Eligible participants aged 12 years or above were allocated to treatment with the 0.018-inch or 0.022-inch slot MBT appliance (3M Unitek, Monrovia, California, USA) using block randomization in groups of 10. OIIRR was assessed radiographically using standardized periapical radiographs before and after 9 months from the start of treatment. Patient perception of pain was assessed using a validated patient questionnaire at 6 months from the start of treatment. Parametric tests (t-test) and non-parametric tests (chi-square with Fisher's exact tests and Kruskal-Wallis test) assessed differences between the groups (P < 0.05). The correlation between severity of OIIRR and abnormal root morphology, history of dental trauma, and pain during treatment was assessed. RESULTS: Of the 187 participants randomized (1:1 ratio), 34 withdrew or were excluded (protocol deviations or poor cooperation). There were 77 patients in the 0.018-inch slot group and 76 patients in the 0.022-inch slot group (overall mean age: 19.1 years). Baseline characteristics were similar between groups (P > 0.05). There was no significant difference in the severity of the OIIRR nor patient perception of pain between the two study groups (P = 0.115 and P = 0.08 respectively). The correlation between the severity of OIIRR and abnormal root morphology or history of dental trauma was not statistically significant (P = 0.086 and P = 0.313). Moreover, there was no significant correlation between the severity of OIIRR and pain during treatment (R = 0.045, P = 0.617). LIMITATIONS: It was impossible to blind clinicians or patients to allocation, and oral hygiene and periodontal outcomes were not assessed. CONCLUSIONS: The effect of bracket slot size on the severity of OIIRR and patient perception of pain are not significant. TRIAL REGISTRATION: The trial was registered with ClinicalTrials.gov on 5 March 2014, registration number: NCT02080338.

A randomized clinical trial of the effectiveness of 0.018-inch and 0.022-inch slot orthodontic bracket systems: part 2-quality of treatment.

OBJECTIVE: To compare the quality of orthodontic treatment between 0.018-inch and 0.022-inch slot bracket systems. SUBJECTS AND METHODS: Eligible participants aged 12 years or over were allocated to the 0.018-inch or 0.022-inch slot MBT appliance (3M-Unitek, Monrovia, California, USA) using block randomization in groups of 10. Outcome measures included: 1. ABO cast-radiograph evaluation (CR-EVAL), 2. peer assessment rating (PAR) scores, 3. incisor inclination, and 4. patient perception using the Index of Orthodontic Treatment Need aesthetic component (IOTN AC) and three validated questionnaires before, during and after treatment. Parametric tests [independent samples t-test and two-way analysis of variance (ANOVA)] and non-parametric tests (chi-square with Fisher's exact tests and Mann-Whitney U-test) assessed differences between groups (P < 0.05). RESULTS: Of the 187 participants randomized (1:1 ratio), 34 withdrew or were excluded (protocol deviations or poor cooperation). There were 77 patients in the 0.018-inch slot group and 76 patients in the 0.022-inch slot group (overall mean age: 19.1 years). Baseline characteristics were similar between groups (P > 0.05). The mean total ABO CR-EVAL scores were 34.7 and 34.5; mean percentage PAR score reduction 74.1 per cent and 77.1 per cent; mean change for maxillary incisor inclination 2.9 degrees and 1.6 degrees and for mandibular incisor inclination 2.7 degrees and 1.4 degrees for the 0.018-inch and 0.022-inch groups, respectively. Improvement in patient perception of aesthetics after treatment was statistically significant for both groups (P < 0.05). However, there were no statistically significant differences between the two treatment groups for ABO CR-EVAL, percentage PAR score reduction, incisor inclination, and patient perception of treatment (P > 0.05). No adverse events were observed during treatment. LIMITATIONS: It was impossible to blind clinicians or patients to allocation and oral hygiene and periodontal outcomes were not assessed. CONCLUSIONS: There were no statistically or clinically significant differences in the quality of occlusal outcomes, incisor inclination and patient perception of treatment between 0.018-inch and 0.022-inch slot bracket systems. REGISTRATION: The trial was registered with ClinicalTrials.gov on 5 March 2014, registration number: NCT02080338. PROTOCOL: The protocol was published at DOI: 10.1186/1745-6215-15-389.

Role of anatomical sites and correlated risk factors on the survival of orthodontic miniscrew implants: a systematic review and meta-analysis.

OBJECTIVES: The aim of this review was to systematically evaluate the failure rates of miniscrews related to their specific insertion site and explore the insertion site dependent risk factors contributing to their failure. SEARCH METHODS: An electronic search was conducted in the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Knowledge, Scopus, MEDLINE and PubMed up to October 2017. A comprehensive manual search was also performed. ELIGIBILITY CRITERIA: Randomised clinical trials and prospective non-randomised studies, reporting a minimum of 20 inserted miniscrews in a specific insertion site and reporting the miniscrews' failure rate in that insertion site, were included. DATA COLLECTION AND ANALYSIS: Study selection, data extraction and quality assessment were performed independently by two reviewers. Studies were sub-grouped according to the insertion site, and the failure rates for every individual insertion site were analysed using a random-effects model with corresponding 95% confidence interval. Sensitivity analyses were performed in order to test the robustness of the reported results. RESULTS: Overall, 61 studies were included in the quantitative synthesis. Palatal sites had failure rates of 1.3% (95% CI 0.3-6), 4.8% (95% CI 1.6-13.4) and 5.5% (95% CI 2.8-10.7) for the midpalatal, paramedian and parapalatal insertion sites, respectively. The failure rates for the maxillary buccal sites were 9.2% (95% CI 7.4-11.4), 9.7% (95% CI 5.1-17.6) and 16.4% (95% CI 4.9-42.5) for the interradicular miniscrews inserted between maxillary first molars and second premolars and between maxillary canines and lateral incisors, and those inserted in the zygomatic buttress respectively. The failure rates for the mandibular buccal insertion sites were 13.5% (95% CI 7.3-23.6) and 9.9% (95% CI 4.9-19.1) for the interradicular miniscrews inserted between mandibular first molars and second premolars and between mandibular canines and first premolars, respectively. The risk of failure increased when the miniscrews contacted the roots, with a risk ratio of 8.7 (95% CI 5.1-14.7). CONCLUSIONS: Orthodontic miniscrew implants provide acceptable success rates that vary among the explored insertion sites. Very low to low quality of evidence suggests that miniscrews inserted in midpalatal locations have a failure rate of 1.3% and those inserted in the zygomatic buttress have a failure rate of 16.4%. Moderate quality of evidence indicates that root contact significantly contributes to the failure of interradicular miniscrews placed between the first molars and second premolars. Results should be interpreted with caution due to methodological drawbacks in some of the included studies.

Effectiveness of en masse versus two-step retraction: a systematic review and meta-analysis.

BACKGROUND: This review aims to compare the effectiveness of en masse and two-step retraction methods during orthodontic space closure regarding anchorage preservation and anterior segment retraction and to assess their effect on the duration of treatment and root resorption. METHODS: An electronic search for potentially eligible randomized controlled trials and prospective controlled trials was performed in five electronic databases up to July 2017. The process of study selection, data extraction, and quality assessment was performed by two reviewers independently. A narrative review is presented in addition to a quantitative synthesis of the pooled results where possible. The Cochrane risk of bias tool and the Newcastle-Ottawa Scale were used for the methodological quality assessment of the included studies. RESULTS: Eight studies were included in the qualitative synthesis in this review. Four studies were included in the quantitative synthesis. En masse/miniscrew combination showed a statistically significant standard mean difference regarding anchorage preservation - 2.55 mm (95% CI - 2.99 to - 2.11) and the amount of upper incisor retraction - 0.38 mm (95% CI - 0.70 to - 0.06) when compared to a two-step/conventional anchorage combination. Qualitative synthesis suggested that en masse retraction requires less time than two-step retraction with no difference in the amount of root resorption. CONCLUSIONS: Both en masse and two-step retraction methods are effective during the space closure phase. The en masse/miniscrew combination is superior to the two-step/conventional anchorage combination with regard to anchorage preservation and amount of retraction. Limited evidence suggests that anchorage reinforcement with a headgear produces similar results with both retraction methods. Limited evidence also suggests that en masse retraction may require less time and that no significant differences exist in the amount of root resorption between the two methods.

Three questionnaires to assess the perception of fixed orthodontic therapy before, during and after treatment: validity and reliability.

BACKGROUND/OBJECTIVE: To assess the validity and reliability of a series of three questionnaires for the quantification of patient perception of fixed appliance orthodontic treatment. SUBJECTS AND METHODS: The study was carried out at the University of Dundee with content and face validity being assessed using proformas. Initially ten experts (Orthodontic Specialists) assessed content validity with 11 professionals (seven Orthodontic Specialists and four Postgraduates) and 20 patients assessing face validity. Content validity was determined according to the values of item-level content validity index (I-CVI) and scale-level CVI (S-CVI/Ave), while specially designed feedback forms were used for face validation. Internal consistency determined the reliability of the questionnaires according to the value of Cronbach alpha correlation coefficient test. The three questionnaires were then modified according to the recommendations of professionals and patients with seven experts reassessing content validity and ten newly selected patients assessing face validity. RESULTS: The first round of content validity revealed that around half of the items in the questionnaires were not valid. Therefore, the questionnaires were not valid as a whole (S-CVI/Ave = 0.60). After modifying the questionnaires and removing the non-valid items, the new versions of the Pre-treatment, Orthodontic Experience, and Post-treatment Questionnaires showed high levels of face validity, content validity (S-CVI/Ave: 0.99, 0.97, and 0.99, respectively) and good levels of internal consistency (α = 0.86, 0.78, and 0.88, respectively). LIMITATION: The patient sample was collected from a single university clinic and from one city within the UK and this could affect the generalizability of the results. CONCLUSION: Three content valid and reliable questionnaires have been developed and validated for the evaluation of patient perception of fixed appliance orthodontic treatment. IMPLICATIONS: Unlike other tools that assess oral health-related quality of life, this series of three questionnaires assess the perception of fixed appliance orthodontic treatment before, during and after treatment.

Retention procedures for stabilising tooth position after treatment with orthodontic braces.

BACKGROUND: Retention is the phase of orthodontic treatment that attempts to keep teeth in the corrected positions after treatment with orthodontic braces. Without a phase of retention, there is a tendency for teeth to return to their initial position (relapse). To prevent relapse, almost every person who has orthodontic treatment will require some type of retention. OBJECTIVES: To evaluate the effects of different retention strategies used to stabilise tooth position after orthodontic braces. SEARCH METHODS: We searched the following databases: the Cochrane Oral Health Group's Trials Register (to 26 January 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 12), MEDLINE via Ovid (1946 to 26 January 2016) and EMBASE via Ovid (1980 to 26 January 2016). We searched for ongoing trials in the US National Institutes of Health Trials Register (ClinicalTrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform. We applied no language or date restrictions in the searches of the electronic databases. We contacted authors of randomised controlled trials (RCTs) to help identify any unpublished trials. SELECTION CRITERIA: RCTs involving children and adults who had had retainers fitted or adjunctive procedures undertaken to prevent relapse following orthodontic treatment with braces. DATA COLLECTION AND ANALYSIS: Two review authors independently screened eligible studies, assessed the risk of bias in the trials and extracted data. The outcomes of interest were: how well the teeth were stabilised, failure of retainers, adverse effects on oral health and participant satisfaction. We calculated mean differences (MD) with 95% confidence intervals (CI) for continuous data and risk ratios (RR) with 95% CI for dichotomous outcomes. We conducted meta-analyses when studies with similar methodology reported the same outcome. We prioritised reporting of Little's Irregularity Index to measure relapse. MAIN RESULTS: We included 15 studies (1722 participants) in the review. There are also four ongoing studies and four studies await classification. The 15 included studies evaluated four comparisons: removable retainers versus fixed retainers (three studies); different types of fixed retainers (four studies); different types of removable retainers (eight studies); and one study compared a combination of upper thermoplastic and lower bonded versus upper thermoplastic with lower adjunctive procedures versus positioner. Four studies had a low risk of bias, four studies had an unclear risk of bias and seven studies had a high risk of bias. Removable versus fixed retainers Thermoplastic removable retainers provided slightly poorer stability in the lower arch than multistrand fixed retainers: MD (Little's Irregularity Index, 0 mm is stable) 0.6 mm (95% CI 0.17 to 1.03). This was based on one trial with 84 participants that was at high risk of bias; it was low quality evidence. Results on retainer failure were inconsistent. There was evidence of less gingival bleeding with removable retainers: RR 0.53 (95% CI 0.31 to 0.88; one trial, 84 participants, high risk of bias, low quality evidence), but participants found fixed retainers more acceptable to wear, with a mean difference on a visual analogue scale (VAS; 0 to 100; 100 being very satisfied) of -12.84 (95% CI -7.09 to -18.60). Fixed versus fixed retainersThe studies did not report stability, adverse effects or participant satisfaction. It was possible to pool the data on retention failure from three trials that compared polyethylene ribbon bonded retainer versus multistrand retainer in the lower arch with an RR of 1.10 (95% CI 0.77 to 1.57; moderate heterogeneity; three trials, 228 participants, low quality evidence). There was no evidence of a difference in failure rates. It was also possible to pool the data from two trials that compared the same types of upper fixed retainers, with a similar finding: RR 1.25 (95% CI 0.87 to 1.78; low heterogeneity; two trials, 174 participants, low quality evidence). Removable versus removable retainersOne study at low risk of bias comparing upper and lower part-time thermoplastic versus full-time thermoplastic retainer showed no evidence of a difference in relapse (graded moderate quality evidence). Another study, comparing part-time and full-time wear of lower Hawley retainers, found no evidence of any difference in relapse (low quality evidence). Two studies at high risk of bias suggested that stability was better in the lower arch for thermoplastic retainers versus Hawley, and for thermoplastic full-time versus Begg (full-time) (both low quality evidence).In one study, participants wearing Hawley retainers reported more embarrassment more often than participants wearing thermoplastic retainers: RR 2.42 (95% CI 1.30 to 4.49; one trial, 348 participants, high risk of bias, low quality evidence). They also found Hawley retainers harder to wear. There was conflicting evidence about survival rates of Hawley and thermoplastic retainers. Other retainer comparisonsAnother study with a low risk of bias looked at three different approaches to retention for people with crowding, but normal jaw relationships. The study found that there was no evidence of a difference in relapse between the combination of an upper thermoplastic and lower canine to canine bonded retainer and the combination of an upper thermoplastic retainer and lower interproximal stripping, without a lower retainer. Both these approaches are better than using a positioner as a retainer. AUTHORS' CONCLUSIONS: We did not find any evidence that wearing thermoplastic retainers full-time provides greater stability than wearing them part-time, but this was assessed in only a small number of participants.Overall, there is insufficient high quality evidence to make recommendations on retention procedures for stabilising tooth position after treatment with orthodontic braces. Further high quality RCTs are needed.

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

BACKGROUND: Accelerating the rate of tooth movement may help to reduce the duration of orthodontic treatment and associated unwanted effects including root resorption and enamel demineralisation. Several methods, including surgical and non-surgical adjuncts, have been advocated to accelerate the rate of tooth movement. Non-surgical techniques include low-intensity laser irradiation, resonance vibration, pulsed electromagnetic fields, electrical currents and pharmacological approaches. 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: We searched the following databases on 25 November 2014: the Cochrane Oral Health Group's Trials Register (November 2014), the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library 2014, Issue 10), MEDLINE via OVID (1946 to November 2014), EMBASE via OVID (1980 to November 2014), LILACS via BIREME (1980 to November 2014), metaRegister of Controlled Trials (November 2014), the US National Institutes of Health Trials Register (ClinicalTrials.gov; November 2014) and the WHO International Clinical Trials Registry Platform (November 2014). We checked the reference lists of all trials identified for further studies. There were no restrictions regarding language or date of publication in the searches of the electronic databases. SELECTION CRITERIA: We included randomised controlled trials (RCTs) of people receiving orthodontic treatment using fixed appliances along with non-surgical adjunctive interventions to accelerate tooth movement. We excluded non-parallel design studies (for example, split-mouth) as we regarded them as inappropriate for assessment of the effects of this type of intervention. 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. Any disagreements were resolved by discussion amongst the review team to reach consensus. The review authors contacted the corresponding authors of trials to obtain missing information and data to allow calculation of mean differences (MD), 95% confidence intervals (CI) or risk ratios (RR) when these were not reported. MAIN RESULTS: We included two studies in this review, which were both assessed as being at high risk of bias. The two studies, involving a total of 111 participants, compared the use of Tooth Masseuse and OrthoAccel with conventional treatment mechanics during orthodontic alignment and canine retraction phases, respectively. Both studies included objective assessment of the amount or rate of tooth movement, but we were not able to meta-analyse this data as they used different outcome measurements at different stages of the orthodontic treatment process. One study measured subjective evaluation of pain and discomfort and the other evaluated adverse effects. The studies did not directly report either the duration of orthodontic treatment or the number of visits during active treatment.Using the Tooth Masseuse with 111 Hz at 0.06 Newtons (N) for 20 minutes daily resulted in greater reduction in irregularity in the lower incisor region over 10 weeks, assessed using Little's Irregularity Index (LII) with a mean difference (MD) of 0.6 mm (95% confidence interval (CI) -0.94 to 2.34) when compared to the control group. Pain and discomfort increased at six to eight hours after arch wire placement and after seven days, with minimal difference between the intervention and control groups. No statistical tests were provided for either variable and the differences between the two groups were not clinically important.Using OrthoAccel with 30 Hz at 0.25 N for 20 minutes daily produced a higher rate of maxillary canine distalisation in comparison to the control group (MD 0.37 mm/month; 95% CI -0.07 to 0.81; P = 0.05). Whilst this difference suggested 50% faster tooth movement using the vibrational appliance, the absolute differences were marginal and deemed clinically unimportant. Similar levels of non-serious adverse effects were reported in the intervention and control groups with a risk ratio of 0.96 (95% CI 0.32 to 2.85).Overall, the quality of the evidence was very low and therefore we cannot rely on the findings. AUTHORS' CONCLUSIONS: There is very little clinical research concerning the effectiveness of non-surgical interventions to accelerate orthodontic treatment. The available evidence is of very low quality and so it is not possible to determine if there is a positive effect of non-surgical adjunctive interventions to accelerate tooth movement. Although there have been claims that there may be a positive effect of light vibrational forces, results of the current studies do not reach either statistical or clinical significance. Further well-designed and rigorous RCTs with longer follow-up periods are required to determine whether non-surgical interventions may result in a clinically important reduction in the duration of orthodontic treatment, without any adverse effects.