Variability of slot size in orthodontic brackets.

Objective: The accuracy of the information incorporated into brackets is a determining factor for the efficacy of torque applied to teeth. The aim of this study was to compare the dimensions of a bracket's slots with the nominal values announced by the manufacturer. Materials and methods: A total of 730 maxillary right central brackets manufactured by seven companies (Dentsply Gac, American Orthodontics, Rocky Mountain Orthodontics, GC Orthodontics, 3M Unitek, and Dentaurum) were studied. The sample included 0.018 × 0.025 and 0.022 × 0.028 in., metal and ceramic, conventional and self-ligating brackets. Images were obtained with an Olympus BX51 optical microscope. Slot dimensions were measured at the base and at the face on both mesial and distal sides using ImageJ software. Data were analyzed using Wilcoxon, sign tests, two- and three-way ANOVA, and Tukey's tests. Intraclass correlation coefficient was employed to assess the intraobserver and interobserver variability. The threshold for statistical significance was p ≤ .05. Results: Statistical analysis showed that the slot dimensions of 90% to 97% of studied brackets were significantly different from nominal values. In general, slot size was oversized, with a face size larger than the base size. Comparison between mesial and distal sides showed that up to 45% of the brackets were significantly asymmetrical. The manufacturer had a significant effect for base and face widths (p = .0001) and for length (p = .003). Conclusion: This study shows that a large proportion of measured brackets displays dimensional inaccuracies when compared with stated values. Clinically, the slot oversize and the divergence of slot walls cause an increase of wire-slot play, inducing a loss of torque control. Practitioners cannot fully trust the precision of used appliances and should be aware that adjustments could be needed in the finishing stages of the treatment.

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.

Differences between active and passive self-ligating brackets for orthodontic treatment : Systematic review and meta-analysis based on randomized clinical trials.

PURPOSE: In orthodontic treatment, the effects of differences in the design between active and passive self-ligating bracket (ASLB and PSLB, respectively) are usually neglected. This study investigated differences in effectiveness and efficiency between ASLBs and PSLBs. METHODS: To identify randomized, controlled clinical trials (RCTs) comparing ASLB with PSLB, the electronic databases Medline, Embase, Cochrane Central Register of Controlled Trials, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, and Chinese Medical Journal Database were searched without language or time limits. Relevant available dental journals and reference lists from included studies were manually searched for applicable reports. Meta-analyses were conducted with the Review Manager program. Two independent reviewers performed all search processes; disagreements were discussed with a third reviewer. RESULTS: Eight studies were included in the systematic review, of which six were included in the meta-analysis due to the data consistency. Three had a low risk of bias, four had an unclear risk of bias, and one had a high risk of bias. With regard to alignment efficiency, meta-analysis favors ASLB [mean difference (MD) -10.24 days, 95% confidence interval (CI) -17.68 to -2.80]. However, the same analysis does not favor either design in terms of width change due to treatment for intercanine (MD -0.49 mm, 95% CI -1.10 to 0.13 mm) interfirst premolar (MD -0.07 mm, 95% CI -0.69, 0.56 mm) intersecond premolar (MD -0.58 mm, 95% CI -1.25 to 0.08 mm) and intermolar (MD 0.10 mm, 95% CI -0.82 to 1.02 mm) width. CONCLUSIONS: Based on current clinical evidence from RCTs, ASLB appears to be more efficient for alignment, while neither design shows an advantage for width change. Further research is needed to confirm present results.

Resistência ao cisalhamento de bráquetes ortodônticos metálicos em dentes submetidos ao clareamento dentário / Orthodontic metal brackets resistance in whitened teeth subjected to shear strength

Introdução: pacientes adultos estão mais exigentes na busca pela estética oral, com isso, tem-se aumentando o uso de sistemas clareadores. Alguns estudos demonstram que há uma diminuição da resistência dos bráquetes após o clareamento. Objetivo: analisar a resistência as forças de cisalhamento de bráquetes em dentes submetidos ao tratamento clareador com peróxido de hidrogênio (H2O2). Metodologia: foram utilizados 30 dentes pré-molares, divididos aleatoriamente entre os três grupos: Grupo I: colagem direta dos bráquetes em dentes não clareados; Grupo II: colagem direta dos bráquetes em dentes clareados e submetidos ao teste de cisalhamento 15 dias após o clareamento, Grupo III: colagem direta dos bráquetes em dentes 24 horas dias após o clareamento. A colagem foi feita com o sistema Transbond XT. Os resultados obtidos nesse estudo foram registrados em Megapascal (MPa) e submetidos ao teste estatístico de Tukey segunda as normas da ANOVA. Resultados e Discussão: o grupo II não obteve diferença estatística significante em relação ao grupo I (controle), porém houve redução na resistência adesiva entre o grupo I e grupo III clareado com peróxido de hidrogênio à 35% na qual a colagem dos bráquetes foi realizada 24 horas após o clareamento dentário. Conclusão: recomenda-se um período de espera para a colagem dos bráquetes na superfície do esmalte submetido ao clareamento dentário.

Introduction: adult patients are demanding in regard of oral aesthetics. Therefore, there is increasing use of bleaching systems. Some studies show that there is a decrease in resistance of the brackets after dental bleaching. Objective: to analyze the strength of brackets shear strength in teeth submitted to bleaching treatment with hydrogen peroxide (H2O2). Method: a total of 30 premolars were randomly divided among the three groups. Group I: direct bonding of brackets on non-whitened teeth; Group II: direct bonding of brackets on whitened teeth and subjected to shear strength test 15 days after bleaching, Group III: direct bonding of brackets 24 hours days after bleaching. The bonding was performed with Transbond XT system. The results of this study were reported in Megapascal (MPa) and subjected to statistical Tukey test according to the ANOVA guidelines. Results and Discussion: group II did not presented difference statically significant compared to the group control (group I). However, there were reduction on the adhesion resistance between the group I and Group III, in which the brackets bonding was performed 24 hours after the dental bleaching with 35% hydrogen peroxide. There was a reduction in statistically significant bond strength between groups I and III. Conclusion: it is recommended a resting period to be done the placement of brackets on the surface of the enamel whitening submitted.

Oral health-related quality of life after orthodontic treatment for anterior tooth alignment: Association with emotional state and sociodemographic factors.

OBJECTIVES: The aim of this work was to evaluate associations of oral health-related quality of life (OHRQoL) with sociodemographic factors and with emotional state in adults after orthodontic treatment for anterior tooth alignment. Few studies have examined these specific associations in the past, one reason presumably being a lack of specific instruments. PATIENTS AND METHODS: A total of 128 adult patients consecutively treated with multibracket appliances were contacted during the retention period. The response rate was 68 %. They were asked to complete both an emotional well-being test (Zerssen Mood Scale, Bf-S) and a 52-item orthodontic survey of OHRQoL, which we had developed based on the German version of the Oral Health Impact Profile (OHIP-G14). RESULTS: The study demonstrated a high association of self-perceived apperance with OHRQoL and a strong role of the teeth and mouth. Aside from a few exceptions, the patients' responses in the survey did not reveal any significant gender-specific or age-specific differences. By contrast, patients in lower-than-normal spirits were found to also respond with significantly less favorable ratings to the survey items dealing with self-perceived overall attractiveness, facial attractivenss, and course of treatment. CONCLUSION: Dental appearance has a psychosocial impact on private and job-related interactions, which can increase the motivation of those affected to seek treament. Our orthodontic OHRQoL survey proved to be informative and practical. Findings that were especially striking included the patients' high acceptance of the changes induced by treatment and their high willingness to recommend such treatment to other adults.

How orthodontic records can influence torque choice decisions?

INTRODUCTION: The aim of this study was to investigate whether the addition of records can influence intra- and inter-rated agreement on torque choices made to treat a group of patients with various malocclusions. METHODS: Forty-eight patients were presented to five orthodontic specialists in three different occasions. During the first session, the participants were shown only the models and intraoral photos of the patients; extraoral photos were added during the second session, and cephalometric X-rays were further supplemented during the third session. Mean weighted kappa coefficients were calculated to measure agreement. RESULTS: The inter-observer agreement was low with the mean coefficients measured:κ1 = 0.34 (SD ± 0.09), κ2 = 0.57 (SD ± 0.12), and κ3 = 0.54 (SD ± 0.28) for the three attempts, respectively. The mean kappa coefficients for the intra-rater agreement were also low ranging from 0.18 to 0.66 and the mean coefficients were 0.27 (SD ± 0.11) between first and second, and 0.53 (SD ± 0.11) between second and third attempt, respectively. CONCLUSIONS: This study shows that the addition of extraoral photographs, and subsequently cephalograms to plaster models and intraoral photos, does affect intra-, and inter-rater agreement on torque selection. It seems that the addition of extraoral photos plays a more important role in torque selection decisions than lateral cephalograms. Different clinicians do not have a uniform opinion on the size of torque required to treat cases. Further research is required to define rules on torque choices.

Periodontal health in teenagers treated with removable aligners and fixed orthodontic appliances.

OBJECTIVES: The purpose of this study was to explore the microbiological and periodontal changes occurring in adolescents during 12 months of orthodontic therapy with removable aligners and with fixed appliances. MATERIAL AND METHODS: During the years 2012-2013, 50 teenagers aged 10-18 years with similar initial orthodontic conditions participated in this trial in a university clinic in northern Italy. After receiving professional oral hygiene and instructions on a standardized oral hygiene protocol, the adolescents were randomly assigned to either orthodontic treatment with traditional fixed brackets (n = 25) or to treatment with Invisalign® aligners (n = 25). Subgingival microbiological samples, probing depth (PD), plaque index (PI), and bleeding on probing (BOP) were obtained and documented from the mesiovestibular subgingival sulcus of the upper right first molar and left central incisor at the beginning of treatment and 3, 6, and 12 months later. Compliance with oral hygiene procedures, full mouth plaque score (FMPS), and full mouth bleeding score (FMBS) were assessed at the beginning of treatment and 12 months later. Two sample independent t-tests and the χ(2) test were used to study whether the indices of periodontal health differed in the teenagers due to the experimental conditions. RESULTS: None of the patients was positive for the periodontal anaerobes analyzed. The PI, PD, BOP, FMPS, and FMBS scores were significantly lower and compliance with oral hygiene was significantly higher in the group treated with Invisalign® than in the group treated with fixed brackets. CONCLUSION: Teenagers treated with removable appliances display better compliance with oral hygiene, less plaque, and fewer gingival inflammatory reactions than their peers with fixed appliances.

Comparison of clinical bracket point registration with 3D laser scanner and coordinate measuring machine.

OBJECTIVE: The aim of the present study was to assess the diagnostic value of a laser scanner developed to determine the coordinates of clinical bracket points and to compare with the results of a coordinate measuring machine (CMM). METHODS: This diagnostic experimental study was conducted on maxillary and mandibular orthodontic study casts of 18 adults with normal Class I occlusion. First, the coordinates of the bracket points were measured on all casts by a CMM. Then, the three-dimensional coordinates (X, Y, Z) of the bracket points were measured on the same casts by a 3D laser scanner designed at Shahid Beheshti University, Tehran, Iran. The validity and reliability of each system were assessed by means of intraclass correlation coefficient (ICC) and Dahlberg's formula. RESULTS: The difference between the mean dimension and the actual value for the CMM was 0.0066 mm. (95% CI: 69.98340, 69.99140). The mean difference for the laser scanner was 0.107 ± 0.133 mm (95% CI: -0.002, 0.24). In each method, differences were not significant. The ICC comparing the two methods was 0.998 for the X coordinate, and 0.996 for the Y coordinate; the mean difference for coordinates recorded in the entire arch and for each tooth was 0.616 mm. CONCLUSION: The accuracy of clinical bracket point coordinates measured by the laser scanner was equal to that of CMM. The mean difference in measurements was within the range of operator errors.

Incidence of bracket failure during orthognathic surgery: a comparison of two techniques to establish interim maxillomandibular fixation.

PURPOSE: The purpose of this study is to review the frequency of bracket failure using two different techniques for establishing interim fixation during orthognathic surgery. METHODS AND MATERIAL: The first group (standard technique) had a maxillomandibular fixation (MMF) established during surgery by ligating splints to orthodontic appliances. The second group of patients had an interim fixation established using maxillomandibular screws (alternative technique). Preoperative and immediate postoperative panoramic radiographs were examined for loose and or missing brackets in both groups. Intraoperative observations were also recorded in the second group. The type of surgery (one- or two-jaw) and whether or not cemented bands on the molars were present were noted. A Pearson's chi-square analysis was done comparing the two groups. RESULTS: There were 210 patients in the first group and 104 in the second. The overall incidence of missing or loose brackets following surgery in the standard technique group was 16%; 172 of them had a cemented band on either the first or on the first and second molars. There was a higher incident of lost or loose bonded brackets when the patients had no cemented brackets or underwent a two-jaw surgery. In the second group of 104 patients, there was one loose or missing brackets caused by the application of MMF (Pearson's chi-square value = 15.84, p < 0.0001). CONCLUSIONS: When using orthodontic brackets to establish interim fixation, the incidence of missing or loose brackets during orthognathic surgery was dramatically higher in two-jaw cases and in cases where only bonded brackets were placed by the orthodontist. When using maxillomandibular screws to establish interim fixation, the problem has been greatly diminished.

Orthodontics and enamel demineralization: clinical study of risk factors.

UNLABELLED: The appearance of white spots on the vestibular surface of teeth fitted with brackets has been described as one of the potential iatrogenic effects of orthodontic treatment. These enamel demineralizations, more commonly known as "white spot lesions" (WSL), lead in some rare cases to the creation of true cavities, causing both esthetic and functional problems. The aim of our retrospective clinical study was to evaluate the incidence of the appearance of these WSL in a Moroccan orthodontic population and to determine possible associations with a number of risk factors. PATIENTS AND METHODS: The study was based on intraoral photographs of a pool of 69 patients who underwent orthodontic treatment with or without extractions in the DFO unit of the Rabat CCDT (Center for dental consultation and treatment). Patients with prostheses or WSL before the beginning of the study were excluded. Digital start- and end-of-treatment photos for each patient were compared by a single operator looking for the appearance of WSL on the vestibular surfaces of the incisors, canines, premolars and first molars. WSL were classed according to three degrees of severity: slight, severe and cavitation. Data were processed using SPSS 13.0 software. RESULTS: The results of the study showed that the prevalence of WSL in the sample was 66.7%, with a highly significant predominance of localization in the premolar/molar segment and in patients with poor oral hygiene. CONCLUSION: Poor oral and dental hygiene was identified as the most important risk factor for the development of white spots during multibracket orthodontic treatment.

Accidental debondings: Buccal vs fully individualized lingual multibracket appliances.

INTRODUCTION: The aim of this study was to retrospectively assess the frequency and localizations of bond failures (BFs) in patients treated with either lingual (TOP-Service für Lingualtechnik GmbH, a 3M Company, Bad Essen, Germany) or buccal (Mini Diamond brackets/Accent molar tubes; Ormco, Orange, Calif) full multibracket appliances in both dental arches. METHODS: Data were acquired by an independent investigator from the patient records of 3 practitioners. To establish a standardized observation period, the first year of treatment was analyzed for each patient. Statistical analysis comprised the Kruskal-Wallis, Wilcoxon, Mann-Whitney U, and Fisher exact tests. The significance level was set at P <0.05. RESULTS: The mean number of BFs per patient in the first year of treatment did not differ significantly between the lingual group (n = 59; mean age, 31.1 years; mean BFs per patient, 2.63; SD, 2.77; minimum, 0; maximum, 13) and the buccal group (n = 44; mean age, 15.14 years; mean BFs per patient, 2.61; SD, 3.41; minimum, 0; maximum, 14) (P = 0.428) or with respect to sex (lingual group, P = 0.251; buccal group, P = 0.414) or practitioner (lingual group, P = 0.755; buccal group, P = 0.060), but molar attachments were more prone to BFs than were premolar brackets (lingual group, P = 0.015; buccal group, P = 0.049), and premolar brackets were more prone to BF than anterior brackets (lingual group, P = 0.005; buccal group, P = 0.004). CONCLUSIONS: With both appliances, a mean of 2.62 BFs per patient in the first year of treatment can be expected; this benchmark provides a reference for patient briefing, which is very important considering the large interindividual variances and budgeting considerations.

Survival analysis of brackets and tubes: A twelve-month assessment.

OBJECTIVE: To compare the clinical performance of brackets bonded to anterior and posterior teeth, including second molars. MATERIALS AND METHODS: One operator, using the straight-wire technique, bonded metallic brackets to the teeth of 127 consecutive patients. All patients were observed for 12 months during their regular orthodontic appointments. Bracket failures were recorded and summarized for statistical analysis. The Cox proportional hazards regression analysis was performed to evaluate bracket failure rates. RESULTS: Statistically significant differences in survival rates were observed between molar tubes and anterior brackets (P < .05). Twelve-month failure rates of incisor, canine, premolar, and molar brackets were 3.6, 1.6, 4.8, and 11.6%, respectively. The first and second molar did not show significant difference in bond failure. Young patients (age <18 years) showed a higher failure rate than old patients (≥18 years). CONCLUSIONS: Brackets directly bonded to the buccal surfaces of molars failed significantly more often than those directly bonded to anterior teeth or premolars, but showed acceptable failure rate especially in adult patients. Bonding on second molars seems to be as reliable as bonding on the first molars.

Long-term evaluation of clinical performance of direct-bonded brackets: an epidemiologic survey.

AIM: The objective of the current epidemiologic study was to investigate characteristics associated with bracket failure in bonded brackets. MATERIALS AND METHODS: A retrospective study on data of 144 patients treated during 2009 to 2012 was done. Baseline data including age, gender, malocclusion, bite type and debonding incidences per teeth were retrieved. ANOVA analysis and t-test were used to evaluate the data. RESULTS: Second premolar teeth had significantly higher debonding incidences. Patients' age was negatively correlated with debonding incidences. No difference was observed for various types of malocclusion (class I, II and III), arch side (right or left) or arch location (upper or lower). However, deep bite patients had significantly higher failure incidents. CONCLUSION: For a total of 144 patients with 2,524 bonded brackets, the overall failure rate was 7.8%. Deep bite was the only factor that was associated with higher bracket failure. The bracket failure incidents tend to decrease as patients age increase. CLINICAL SIGNIFICANCE: Deep bite patients and also second premolar teeth seem to be especially prone to debonding incidents. Care must be taken to avoid premature contacts in deep bite patients. Also strict adherence to moisture control protocols when bonding second premolar teeth is recommended since these teeth are at increased risk for debonding.

Reproducibility of bracket positioning in the indirect bonding technique.

INTRODUCTION: Current studies have compared indirect bonding with direct placement of orthodontic brackets; many of these have shown that indirect bonding is generally a more accurate technique. However, the reproducibility of an indirect bonding setup by an orthodontist has yet to be described in the literature. Using cone-beam computed tomography and computer-assisted modeling software, we evaluated the consistency of orthodontists in placing orthodontic brackets at different times. METHODS: Five orthodontists with experience in indirect bonding were selected to place brackets on 10 different casts at 3 time periods (n = 30 per orthodontist). Each participant completed an initial indirect bonding setup on each cast; subsequent bracket placements were completed twice at monthly intervals for comparison with the initial setup. The casts were scanned using an iCAT cone-beam computed tomography scanner (Imaging Sciences International, Hatfield, Pa) and imported into Geomagic Studio software (Geomagic, Research Triangle Park, NC) for superimposition and analysis. The scans for each time period were superimposed on the initial setup in the imaging software, and differences between bracket positions were calculated. For each superimposition, the measurements recorded were the greatest discrepancies between individual brackets as well as the mean discrepancies and standard deviations between all brackets on each cast. RESULTS: Single-factor and repeated-measure analysis of variance showed no statistically significant differences between time points of each orthodontist, or among the orthodontists for the parameters measured. The mean discrepancy was 0.1 mm for each 10-bracket indirect bonding setup. CONCLUSIONS: Orthodontists are consistent in selecting bracket positions for an indirect bonding setup at various time periods.

Three-dimensional deformation comparison of self-ligating brackets.

INTRODUCTION: Archwire rotation is used in orthodontic treatment to alter the labiolingual orientation of a tooth. Measurement of the 3-dimensional (3D) motion of the orthodontic brackets requires a new configuration of the orthodontic torque simulator. METHODS: The orthodontic torque simulator was coupled with a stereo microscope and 2 cameras to allow for the 3D bracket motion to be determined during wire twisting. The stereo camera images were processed with a 3D digital image correlation technique to determine the 3D deformation of the orthodontic brackets. Three self-ligating brackets (Damon Q, Ormco, Orange, Calif; In-Ovation R, GAC, Bohemia, NY; and Speed, Strite Industries, Cambridge, Ontario, Canada) were compared by using the 3D digital image correlation method to demonstrate the difference in 3D motion of self-ligating brackets components. RESULTS: Contour plots of the 3 brackets demonstrate the 3D motion of the bracket tie-wings and the archwire retentive component. The 3D motion of the bracket tie-wings and archwire retentive component were quantified. The displacement values of the archwire retentive component measured with the 3D orthodontic torque simulator were found to be 2.0 and 3.5 times less for the In-Ovation and Damon Q brackets than the values in previous studies that examined the compliance of the archwire retentive component. CONCLUSIONS: The 3D digital image correlation method used to quantify bracket deformation showed the 3D motion of the bracket tie-wings and the motion of the archwire retentive component. The use of a 3D optical measurement system is useful to understand the motion of the archwire retentive component but is not necessary to quantify bracket tie-wing motion. This measurement technique can be used to evaluate brackets of varying designs.

Soportes de autoligado en ortodoncia / Orthodontic brackets

Fundamento: el sistema de ligado del arco al soporte debe ser seguro, fuerte, rápido, confortable para el paciente, fácil de usar y producir poca fricción. Objetivo: argumentar el manejo de las técnicas fijas con el uso de los soportes de autoligado. Conclusiones: los soportes de autoligado constituyen una opción novedosa en ortodoncia, pero en Cuba se han utilizado poco. Se clasifican en pasivos y activos. El sistema Damon, Vision LP y Time son los más utilizados entre los pasivos y el Speed e In Ovation entre los activos. Se describen cuatro fases de tratamiento para usar la técnica con este tipo de soportes y a pesar de su alto costo, es más ventajosa que las técnicas precedentes.

Background: the system bound to the orthodontic bracket arch must be safe, strong, rapid and comfortable for the patient, easy to use and must provoke little friction. Objective: to argue about the management of fixed techniques with the use of brackets. Conclusions: brackets constitute a newfangled option in orthodontics, but in Cuba it has been rarely used. They are classified into passive and active. Damon system, Vision LP and Time are the mostly used among the passive ones and the Speed and In Ovation among the active ones. Four phases of treatment are described to use the technique of these orthodontic brackets and in spite of its high cost; it is more advantageous than the previous techniques.

Systematic review on self-ligating vs. conventional brackets: initial pain, number of visits, treatment time.

OBJECTIVE: Meta-analysis of differences between conventional and self-ligating brackets concerning pain during tooth movement, number of patient visits, total treatment duration, and ligation times. MATERIALS AND METHODS: Online search in Medline, Embase, and Central focused on randomized clinical trials and controlled clinical studies published between 1996 and 2012. RESULTS: Four studies on pain met our inclusion criteria, two on the number of appointments, two on overall treatment time but none on ligation times. Pain levels did not differ significantly between patients treated with conventional or self-ligating brackets after 4 h, 24 h, 3 and 7 days. The number of appointments and total treatment times revealed no significant differences between self-ligating and conventional brackets. CONCLUSION: The lack of significant overall effects apparent in this meta-analysis contradicts evidence-based statements on the advantages of self-ligating brackets over conventional ones regarding discomfort during initial orthodontic therapy, number of appointments, and total treatment time. Due to the limited number of studies included, further randomized controlled clinical trials are required to deliver more data and to substantiate evidence-based conclusions on differences between the two bracket types considering orthodontic pain, number of visits, treatment, and ligation times.