Passive Self-ligating Brackets Research Articles

Correlation between Pain Perception and CGRP Expression during Initial Tooth Alignment Using either a Self-ligating or a Pre-adjusted Bracket System

Orthodontic tooth movement (OTM) occurs when the force applied to the tooth stimulates inflammation and alveolar bone remodeling. Less friction is produced by passive self-ligating (PSL) brackets compared to pre-adjusted edgewise (PE) brackets; therefore, PSL bracket use is thought to result in less pain than the use of PE brackets. The neuropeptide calcitonin gene-related peptide (CGRP), isolated from gingival crevicular fluid (GCF), can be used as a pain biomarker for OTM. Pain perception can be subjectively evaluated using the visual analog scale (VAS). This study aimed to analyze pain perception, using the VAS and CGRP levels, and to examine the correlation between VAS scores and CGRP levels. A total of 15 patients were included in this study (a PSL group, a PE group, and a control group). GCF was collected from the lower anterior teeth, at interproximal sites, before bracket insertion and 2 hours, 24 hours, and 168 hours after lower archwire engagement. Pain perception was recorded using the VAS. CGRP concentrations were analyzed using an enzyme-linked immunosorbent assay (ELISA). The VAS scores of the PE and PSL groups increased 2 hours after archwire engagement, peaked after 24 hours, and returned to baseline after 168 hours, and the PE group had high scores than the PSL group, with the highest score being recorded at the 24 hour time point. CGRP concentrations were also the highest at the 24 hour time point compared to the other time points. These results showed that both the VAS score and the CGRP concentration increased during initial orthodontic tooth alignment when using either the PSL or the PE bracket systems. Pain perception scores and CGRP concentrations were weakly positively correlated. The type of bracket system used influenced the patients' pain perception scores and the release of CGRP.

Evaluation of friction on self-ligating and conventional brackets associated with different types of archwires submitted to sliding mechanics

Aim: The aim of this study was to verify the frictional force during sliding mechanics in orthodontic tooth movement, using conventional metal brackets of the active and passive self-ligating types with stainless steel and copper nickel titanium archwires. Methods: This experimental in vitro study was conducted with conventional metal (Morelli, Sorocaba, SP, Brazil) brackets, active self-ligated (SLI Morelli, Sorocaba, SP, Brazil) and passive self-ligated (SLP Morelli, Sorocaba, SP, Brazil), with slot 0.022 x 0.028 inches and Roth prescription. The brackets were tested with rectangular section 0.019 x 0.025 inch copper nickel titanium and stainless steel archwires. For each type of bracket, 10 sets of plate/bracket/archwire segment (n=10) were fabricated. Non-parametric Kruskal Wallis and Dunn tests were used for comparison between types of brackets and Wilcoxon tests for comparison between types of archwires. Results: The results showed that the frictional force values were higher with copper nickel titanium than with stainless steel archwires (p<0.05). When copper nickel titanium archwires were used, the active self-ligating brackets showed higher frictional force values than the other types, followed by the conventional brackets. Lower frictional force values were observed with passive self-ligating brackets. For stainless steel archwires, no difference was observed between conventional and active self-ligating brackets, the passive self-ligating type presented lower frictional force values than the others. Conclusion: It was concluded that the higher frictional force was observed when active self-ligating brackets were associated with copper nickel titanium archwires. Lower frictional force was verified between passive self-ligating brackets combined with stainless steel archwires.

Clinical and Salivary Findings in Patients with Metal and Crystalline Conventional and Self-Ligating Orthodontic Brackets.

AimData regarding different types of orthodontic brackets and ligation and various clinical and salivary findings are scarce. Therefore, the aim of this study was to compare clinical and salivary findings in patients with different types of fixed orthodontic appliances.Subjects and methodsDecayed, missing and filled teeth index (DMFT) and plaque index, salivary flow rate, salivary pH and prevalence of white spot lesions were determined in 83 patients with different types of orthodontic brackets and ligation (metal passive self-ligating brackets, conventional metal brackets, mono-crystal brackets and polycrystalline active self-ligating brackets), before and six months after the beginning of fixed orthodontic treatment. The patients were recruited in a private dental office, in the period of two years. The group comprised 83 patients (mean age: 15.14 ± 1.66 years), including 52 women (mean age: 15.08 ± 1.68) and 31 men (15.24 ± 1.64). Statistical analysis was performed by use of dependent and independent samples t-test as well as one way ANOVA, Wilcoxon signed rank test and the Kruskal Wallis test. P-values below 0.05 (p<0.05) were considered significant.ResultsDMFT and salivary flow have shown a significant increase, while salivary pH has shown a significant decrease in the observed time interval, in all patients irrespective of type of brackets and ligation. Among patients with different bracket material, no significant differences were found in any of the observed parameters.ConclusionAlthough salivary flow rate is increased in patients with fixed orthodontic appliances which can have caries-protective effect, DMFT also increases and salivary pH decreases six months after the beginning of the treatment independently of bracket material or ligation type. All patients should receive instructions for precise oral hygiene and dietary habits before the beginning of fixed orthodontic therapy and at every dental check-up.

Comparison of transverse maxillary dental arch width changes with self-ligating and conventional brackets in patients requiring premolar extraction – A randomised clinical trial

The purpose of this study was to evaluate, the change in the transverse maxillary arch dimensions, in patients requiring all first premolar extractions when using Active and Passive Self-ligating brackets, and comparing them with Conventional brackets. This study was a non-blinded randomised clinical trial, which consisted of 42 patients (21 males and 21 females) within the age group of 16-25 years, having bimaxillary protrusion. They were divided into three groups with 14 patients each. In Group 1-Conventional brackets (3M Unitek), in Group 2-Passive Self-ligation brackets: Smart Clip (3M Unitek), and in Group 3-Active Self-ligation brackets: Empower AO (American Orthodontics) were bonded. All brackets had MBT prescription and 0.02" slot size. Dental study models were taken before the start of treatment and after six months of retraction. Inter-canine and intermolar widths were measured in all the three groups in the above mentioned stages. As compared to Conventional brackets, Self-ligating brackets (Passive and Active) showed greater increase in the transverse arch widths. Furthermore, between Passive and Active Self-ligating brackets, Passive Self-ligating brackets-Smart Clip (Group 2) showed a greater increment in the transverse arch dimensions, with an increase of 4.89mm in the inter-canine width and 3.4mm in intermolar width. Significant difference was found between Self-ligating brackets and the Conventional bracket system regarding maxillary arch width dimensional changes. Passive Self-ligating brackets-Smart Clip (Group 2) showed the highest and inter-molar width increase.

A Comparative in vitro Investigation of the Frictional Resistance produced by Active Self-Ligating Brackets, Passive Self-Ligating Brackets and Low Friction Ligatures

A Comparative in vitro Investigation of the Frictional Resistance produced by Active Self-Ligating Brackets, Passive Self-Ligating Brackets and Low Friction Ligatures

Comparative Evaluation of Frictional Resistance of Three Different Types of Passive Self-ligating Ceramic Brackets Using Coated and Uncoated Stainless Steel and Nickel Titanium Arch Wires: An In Vitro Study

Comparative Evaluation of Frictional Resistance of Three Different Types of Passive Self-ligating Ceramic Brackets Using Coated and Uncoated Stainless Steel and Nickel Titanium Arch Wires: An In Vitro Study

Vertical incision subperiosteal tunnel access and three-dimensional OBS lever arm to recover a labially-impacted canine: Differential biomechanics to control root resorption

A 15-year-old female presented with a chief complaint of unesthetic smile and protrusive lips. Lower facial height and convexity were within normal limits, but the lower lip was protrusive (3mm to the E-Line). Bimaxillary retrusion (SNA 79.5˚, SNB 76˚, and ANB 3.5˚) and a high mandibular angle (SN-MP 38˚) were noted. Lower incisors were prominent (L1 to MP 96˚ and L1 to NB 8 mm). Molars were Class I, but the upper right canine (UR3) was Class II. The upper left deciduous canine (ULc) was retained, and the UL3 was labially impacted. An oblique direction of canine eruption wedged the impaction between the keratinized mucosa and the adjacent incisor, eliciting root resorption on the labial surface of the UL2. The discrepancy index (DI) was 16. Following extraction of all four first premolars and the ULc, all teeth except the UL2 were bonded with a Damon Q® passive self-ligating bracket system. Vertical incision subperiosteal tunnel access (VISTA) technique was performed to produce a submucosal space for retraction and extrusion of the impacted UR3. A button was bonded on the UL3, and a power chain was attached. The elastomer chain exited the mucosa through a more distal incision, and traction was applied with a custom lever arm, anchored by an OBS® inserted into the left infrazygomatic crest. The impaction was retracted into a normal position between the UL2 and UL4. Once the UL3 was extruded to the occlusal plane, the UL2 was bonded and its axial inclination was corrected with a labial root torquing auxiliary. Both arches were detailed and finished. After 24 months of active treatment, the UL3 was well aligned, but the labial gingiva supporting it was immature and only partially keratinized. Follow-up visit 1.5 years later showed its maturation into a stable but relatively thin band of gingiva. In retrospect, this UL3 gingival problem may have been avoided by adjusting the three-dimensional (3D) lever arm for a more palatal emersion of the impaction. There was no change in the preexisting labial root resorption of the UL2, but no additional root resorption on any teeth occurred during active treatment. Final alignment and dental esthetics were excellent as evidenced by an American Board of Orthodontics Cast-Radiograph Evaluation score of 12, and the IBOI Pink and White Esthetic Score of 2. VISTA with an OBS 3D lever arm is an important advance for orthodontic impaction recovery. Submucosal retraction of a labially- impacted, partially transposed maxillary canine permits optimal emergence into the arch. Differential biomechanics of soft and hard tissue explains impaction-related root loss before treatment, as well as the mechanism for protecting an unrestrained lateral incisor while the impacted canine is recovered.

The influence of bracket type on the external apical root resorption in class I extraction patients - a retrospective study

BackgroundThe relationship between orthodontic treatment-related factors and EARR has never been fully answered. The aim of this study was to investigate whether conventional and passive self-ligating brackets affect the amount and severity of external apical root resorption (EARR) in withdrawal patients.MethodsNinety-eight patients were selected from department of orthodontic, hospital of stamotology, Wenzhou medical university. Patients received treatment with either a conventional edgewise appliance (n = 49, Mini, 3 M Unitek, USA) or a passive self-ligating bracket system (n = 49, Damon, Ormco, USA). EARR of the maxillary incisors was evaluated on panoramic radiographs at the before and end of orthodontic treatment, respectively. Intergroup comparisons of root resorption were performed with Mann-Whitney tests. The univariate and multivariate regression model was used to assess the appliance type, age, sex and duration of treatment on EARR.ResultsThere was no significant difference in the amount of EARR between the two groups was found. Age and gender were not association with EARR, however, EARR was positively correlated with treatment duration.ConclusionsThe type of bracket did not influence the occurrence and severity of the external apical root resorption in class I extraction patients.

Comparison of frictional resistance between passive self-ligating brackets and slide-type low-friction ligature brackets during the alignment and leveling stage.

BackgroundTo compare the frictional resistance between passive self-ligating brackets and conventional brackets with low-friction ligature under bracket/archwire and root/bone interface during dental alignment and leveling.Material and MethodsA tridimensional model of the maxilla and teeth of a patient treated with conventional brackets, and slide ligatures was generated employing the SolidWorks modeling software. SmartClip self-ligating brackets and Logic Line conventional brackets were assembled with slide low-friction ligatures, utilizing archwires with different diameters and alloys used for the alignment and leveling stage. Friction caused during the bracket/archwire interface and stress during the bone/root interface were compared through a finite element model.ResultsSmartClip and Logic Line brackets with slide elastomeric low-friction elastomeric ligature showed similar frictional stress values of 0.50 MPa and 0.64 MPa, respectively. Passive self-ligating brackets transmitted a lower load along the periodontal ligament, compared to conventional brackets with a low-friction ligature.ConclusionsSlide low-friction elastomeric ligatures showed frictional forces during the bracket/archwire interface similar to those of the SmartClip brackets, while the distribution of stresses and deformations during the root/bone interface were lower in the passive self-ligating brackets. Key words:Orthodontic friction, finite element analysis, orthodontic brackets, orthodontic wires.

Comparison of frictional forces during the closure of extraction spaces in passive self-ligating brackets and conventionally ligated brackets using the finite element method.

BackgroundThis study compared the frictional force resulting from the bracket/archwire interface and the stress at the root/periodontal ligament/bone interface, between passive self-ligating brackets and conventionally ligated brackets, during the space closure stage.Material and MethodsA cone beam tomography was taken to a female patient that required extraction of upper first premolars and passive self-ligating system; three months after its activation, a cone beam tomography was taken again. The designs of the maxillary bone and the entire system were possible through tomography images and stereomicroscopic photographs. Validation of the Finite Element Method (FEM) was achieved comparing the amount of movement seen through tomography images and the FEM. Space closure was simulated for each system through the FEM and a comparison was made between the frictional force at the bracket/archwire interface, and the root/periodontal ligament/bone interface.ResultsThe most significant representation of frictional force at bracket/archwire interface and bone stress was found at the conventionally ligated system, while the passive self-ligating system accounted for the highest distribution of stress over the root.ConclusionsThe FEM is an accurate tool used to quantify frictional force and stress concentration during the orthodontic closure. The passive self-ligating system was seen less frictional during the closure state compared to conventional brackets. Key words:Friction, orthodontic bracket, finite element analysis.

Comparative evaluation of the maxillary canine retraction rate and anchorage loss between two types of self-ligating brackets using sliding mechanics.

OBJECTIVE:To evaluate the maxillary canine retraction rate and anchorage loss with active and passive self-ligating brackets (SLBs).MATERIALS AND METHODS:The study was conducted on 10 patients whose age ranged from 14–20 years. The patients had minimal to no crowding with a dental protrusion of maxillary incisor that required the extraction of maxillary first premolars and retraction of canines. The maxillary canines had to be in a good alignment and level before treatment to ensure that canine retraction had started from the same point bilaterally. A cone beam computed tomography (CBCT) had been taken for each patient's maxilla before treatment initiation and after complete canine retraction. Using nickel titanium, close-coil spring canine retraction on both sides and the rate of canine movement was measured.RESULTS:The patients were checked every 2 weeks to measure the retraction rate and ensure that a constant force (150 g) was being delivered to both canines. The pre- and post-canine retractions CBCT were superimposed to evaluate the pattern and rate of canine movement and anchorage loss. The result of this study showed no statistically significant difference between the two groups.CONCLUSION:The type of SLB, either active or passive, does not affect the rate or type of canine movement during its retraction in the orthodontic extraction cases, and the anchorage loss of the upper molars was nearly the same in both type.

The use of four different lasers in a “surgery first” case, for orthodontic movement acceleration, paresthesia, aphthous ulcer, edema, and pain control

Photobiomodulation is an important resource during an orthodontic treatment. It is useful to control post archwire activation pain, reduce orthodontic treatment time, and achieve faster-wound healing. The aim of this report is to present an ortho-surgical case treated with four different laser wavelengths applied during all stages of the treatment to achieve different results in the benefit of the patient. A severe class II 52-year-old female patient with muscular pain and temporomandibular disorders. The patient was treated with a surgery-first protocol and passive self-ligating brackets to achieve dental movement acceleration and pain control; the patient was irradiated using 808 nm wavelength, 100 mW, ED 80 J/cm2, E 2.2 J, 22 s along the vestibular and palatal surface performing a scanning movement. After surgery, the patient has irradiated 6 sessions for edema and inflammation control, with a 940 nm, in continuous mode, 2.5 W, 120 s, 85.71 J/cm2, over the right and left side. After 2 weeks, the patient reports paresthesia in her left lower lip. A paresthesia protocol was started with a 650 nm wavelength laser, using the following parameters: 100 mW, PD 0.2 W/cm2, E 6 J, 60 s, one session every 2 days for 3 weeks. When the patient reported one aphthous ulcer in her left lower lip, the affected surface was irradiated with a wavelength of the 660 nm laser, 25 J/cm2, 100 mW, for 14 s, applying laser by scanning the lesion 1 mm away. Only one laser application per aphthous lesion was made. The patient finished all the ortho-surgical treatment in 4 and a half months. Four successful wavelengths, but also two laser protocols were applied during the treatment, not only to accelerate orthodontic movement but also to reduce edema after orthognathic surgery, paresthesia, and aphthous ulcer as well.

Evaluation of different types of self-ligating brackets guided by electromagnetic field simulator on rotational control

Aim: The objective of this study was to measure and compare the in vitro performance of active and passive self-ligating brackets in orthodontic rotation by means of an electromagnetic field simulation. Methods: The study sample consisted of 32 mandibular right central incisor brackets (n=8), slot 0.022", that were divided into the following groups: 1) BioQuick® (Forestadent, Pforzheim, Germany) active brackets; 2) In-Ovation®R (Dentsply-GAC, Central Islip, New York, USA) active brackets; 3) Damon-Q® (Ormco, Orange, California, USA) passive brackets, and 4) Smartclip® (3M, Monrovia, California, USA) passive brackets. The orthodontic wire used was CuNiTi round section 0.016", thermoactivated at 35o C (ORMCO-Orthodontics Glendora, California, USA). The experiment was performed in a simulator machine, composed of two fixed lateral axes and a movable central axis, which simulated the dental rotation. Qualitative analysis (n = 4) was performed using SEM. After the descriptive and exploratory analysis, the yield and grade data were submitted to one-way analysis of variance (ANOVA) followed by the Tukey test, considering the level of significance of 5%. Results: In-Ovation®R brackets showed significantly higher yield than BioQuick® and Damon-Q®. Damon-Q® brackets presented a significantly lower mean value than In-Ovation R and Smartclip®. BioQuick® did not differ significantly from Damon-Q® and Smartclip®. In-Ovation®R did not differ significantly from Smartclip®. Conclusion: In the present study, it was observed that there is a difference in rotational control in the different self-ligating brackets tested being the best rotational control was the In-Ovation R® group (active), followed in descending order by the groups Smartclip® (passive), Bioquick® (active) and Damon Q® (passive).

Are self-ligating brackets’ slots dimensions accurate?

The purpose of this study is to measure the dimensions of the slot's top and base of passive self-ligating brackets of three commercial and available systems and to compare the measured dimensions with the manufacturers' published dimensions. Digital microscope was used to measure the slot's top and base of 40 Central incisor brackets by three different manufacturers, Carriere SLX (Ortho Organizer, USA), Damon Q (Oramco USA) and Smart Clip (3M Unitek USA). The measurements were taken after the doors of all brackets were removed and compared with the manufacturers' claimed dimensions. All brackets showed a significant increase in dimensions from both the slot's top and base compared to the manufacturers' published dimensions. For the base of the bracket's slot, Carriere SLX brackets showed the least difference while Damon Q brackets had the greatest. Moreover, for the top of the bracket's slot, the Smart clip brackets showed the greatest difference. The percentage of difference between the actual measurements and the manufacturers' prescriptions shows that for the slot's base, Carriere SLX brackets had the smallest percentage increase by .36%, followed by Smart clip by 6.7% and the Damon Q brackets by 8.1%. While for the slot's top Carriere SLX had the smallest percentage increase by .72%, followed by Damon Q by 12.3% increase and finally Smart Clip brackets by 12.8%. The actual measurements of passive self-ligating brackets from 3 manufacturers were larger than the manufacturers' published dimension. This amount of increase may affect the amount torque expression.

Severe unilateral scissors-bite with a constricted mandibular arch: Bite turbos and extra-alveolar bone screws in the infrazygomatic crests and mandibular buccal shelf

A 33-year-old woman had a chief complaint of difficulty chewing, caused by a constricted mandibular arch and a unilateral full buccal crossbite (scissors-bite or Brodie bite). She requested minimally invasive treatment but agreed to anchorage with extra-alveolar temporary anchorage devices as needed. Her facial form was convex with protrusive but competent lips. Skeletally, the maxilla was protrusive (SNA, 86°) with an ANB angle of 5°. Amounts of crowding were 5mm in the mandibular arch and 3mm in the maxillary arch. The mandibular midline was deviated to the left about 2mm, which was consistent with a medially and inferiorly displaced mandibular right condyle. Ectopic eruption of the maxillary right permanent first molar to the buccal side of the mandibular first molar cusps resulted in a 2-mm functional shift of the mandible to the left, which subsequently developed into a full buccal crossbite on the right side. Treatment was a conservative nonextraction approach with passive self-ligating brackets. Glass ionomer bite turbos were bonded on the occlusal surfaces of the maxillary left molars at 1month into treatment. An extra-alveolar temporary anchorage device, a 2×12-mm OrthoBoneScrew (Newton A, HsinChu City, Taiwan), was inserted in the right mandibular buccal shelf. Elastomeric chains, anchored by the OrthoBoneScrew, extended to lingual buttons bonded on the lingually inclined mandibular right molars. Cross elastics were added as secondary uprighting mechanics. The maxillary right bite turbos were reduced at 4months and removed 1month later. At 11months, bite turbos were bonded on the lingual surfaces of the maxillary central incisors, and an OrthoBoneScrew was inserted in each infrazygomatic crest. The Class II relationship was resolved with bimaxillary retraction of the maxillary arch with infrazygomatic crest anchorage and intermaxillary elastics. Interproximal reduction was performed to correct the black interdental spaces and the anterior flaring of the incisors. The scissors-bite and linguallyinclined mandibular right posterior segment were sufficiently corrected after 3months of treatment to establish adequate intermaxillary occlusion in the right posterior segments to intrude the maxillary right molars. The anterior bite turbos opened space for extrusion of the posterior teeth to level the mandibular arch, and the infrazygomatic crest bone screws anchored the retraction of the maxillary arch. In 27months, this difficult malocclusion, with a Discrepancy Index score of 25, was treated to a Cast-Radiograph Evaluation score of 22 and a pink and white esthetic score of3.

RANKL concentrations in early orthodontic treatment using passive self-ligating and preadjusted edgewise appliance bracket systems

The receptor activator of nuclear factor κ-B ligand (RANKL) is a cytokine that helps remodel bone by forming osteoclasts. During tooth movement phases, osteoclasts resorb the hyalinization areas of alveolar bone, triggering tooth movement. We determined the differences in RANKL concentrations in early orthodontic treatment between preadjusted edgewise appliances (PEA) and self-ligating (SL) bracket systems. Gingival crevicular fluid was retrieved before treatment and at 1, 24, and 168 hours after treatment from five maxillary anterior proximal sites on the mesiolabial side of the upper right-to-left canines. An enzyme-linked immunosorbent assay was used to determine RANKL concentrations. The results showed differences in RANKL concentrations between the SL and PEA groups at 1, 24, and 168 hours after bracket insertion. The RANKL concentration at 168 hours in the SL group was higher compared to that in the PEA group, whereas that in the PEA group decreased to the baseline value after 24 hours. RANKL concentration in the passive SL bracket system was higher compared to that in the PEA system due to differences in the force and mechanotherapy of the SL brackets.

Frictional resistance of different types of self-ligating brackets with different wire combinations

The purpose of this study was to compare the effect of the mode of ligation on the frictional resistance of ceramic brackets and the effect of the bracket material on the frictional resistance whether it is static or kinetic. To achieve this one passive self-ligating ceramic bracket (Damon Clear 2), one active self-ligating ceramic bracket (Empower Clear) in addition to one passive self-ligating metal bracket (Damon Q) were used. These brackets were coupled with two sizes of stainless steel (SS) archwires (0.017 x 0.025-in and 0.019 x 0.025-in). A universal testing machine was used to pull the brackets along the straight distal end of the wire segments at a crosshead speed of 5 mm/min over a distance of 8 mm/min. The test was undergone under dry conditions. The results showed that the passive self-ligating brackets (PSLB) had significantly lower static friction (SF) and kinetic friction (KF) than the active self-ligating bracket (ASLB) with no significant differences between the ceramic and metal PSLB’s. Also inceasing wire size increased the SF and KF for the PSLB’s but did not affect the ASLB significantly.

Evaluation of lower anterior dental changes in patients treated with self-ligating brackets

The aim of this study was to evaluate and compare changes in linear distance and inclination of lower incisors and canines and intercanine distance after a 30 months orthodontic treatment with self-ligating appliances. Seven patients were treated orthodontically with a Roth prescription passive self-ligating bracket. To perform the measurements and comparisons, CBCT scans were taken before the start of the orthodontic treatment (T1) and after a period of 30 months treatment (T2). The following measurements were performed: (1) the lower incisors and canines inclination in relation to the mandibular plane, (2) intercanine linear distance in millimeters and (3) linear distance in millimeters of the incisal and apical part of lower anterior teeth to a plane (POGM) passing through pogonion point and perpendicular to the mandibular plane. No significant difference were observed between T1 and T2 for canine inclination (p=0.835), incisors inclination (p=0.149), canine incisal distance to POGM (p=0.423) and incisors incisal distance to POGM (p=0.966), however canine apical distance (p=0.049) and incisors apical distance (p=0.002) to POGM was lower at T1 than at T2. The intercanine distance was significantly lower (p=0.022) at T1 when compared to T2. The use of passive self-ligating brackets in orthodontic treatment to solve 4mm tooth crowding were able to produce dental arch expansion by bodily tooth movement.

Comparison of the efficacy of tooth alignment among lingual and labial brackets: an in vitro study.

The aim of this study was to evaluate the efficacy of tooth alignment with conventional and self-ligating labial and lingual orthodontic bracket systems. We tested labial brackets (0.022″ slot size) and lingual brackets (0.018″ slot size). The labial brackets were: (i) regular twin brackets (GAC-Twin [Dentsply]), (ii) passive self-ligating brackets including (Damon-Q® [ORMCO]; Ortho classic H4™ [Orthoclassic]; FLI®SL [RMO]), and (iii) active self-ligating brackets (GAC In-Ovation®C [DENTSPLY] and SPEED™[Strite]). The lingual brackets included (i) twin bracket systems (Incognito [3M] and Joy™ [Adenta]), (ii) passive self-ligating bracket system (GAC In-Ovation®LM™ [Dentsply]), and (iii) active self-ligating bracket system (Evolution SLT [Adenta]). The tested wires were Thermalloy-NiTi 0.013″ and 0.014″ (RMO). The archwires were tied to the regular twin brackets with stainless steel ligatures 0.010″ (RMO). The malocclusion simulated a displaced maxillary central incisor in the x-axis (2 mm gingivally) and in the z-axis (2 mm labially). The results showed that lingual brackets are less efficient in aligning teeth when compared with labial brackets in general. The vertical correction achieved by labial bracket systems ranged from 72 to 95 per cent with 13″ Thermalloy wires and from 70 to 87 per cent with 14″ Thermalloy wires. In contrast, the achieved corrections by lingual brackets with 13″ Thermalloy wires ranged between 25-44 per cent and 29-52 per cent for the 14" Thermalloy wires. The anteroposterior correction achieved by labial brackets ranged between 83 and 138 per cent for the 13″ Thermalloy and between 82 and 129 per cent for the 14″ Thermalloy wires. On the other hand, lingual brackets corrections ranged between 12 and 40 per cent for the 13″ Thermalloy wires and between 30 and 45 per cent for the 14″ Thermalloy wires. This is a lab-based study with different labial and lingual bracket slot sizes (however they are the commonly used ones in clinical orthodontics) and study did not consider saliva, periodontal ligament, mastication and other oral functions. The effectiveness of lingual brackets in correcting vertical and anteroposterior displacement achieved during the initial alignment phase of orthodontic treatment is lower than that of the effectiveness of labial brackets.

Effect of Self-ligating on Bone Density and Root Surface in Maxilla and Mandiblec

Objective: This study was designed to evaluate radiographically the effect of passive self-ligating bracket on root surface and bone density in both arches.Patients, materials and methods: The present study was conducted on 20 patients which were divided into two groups; the first group includes 10 adolescent patients aged 13-16 years old and the second group includes 10 adult patients aged 18-21 years old. For each arch of the individuals participating; a quadrant was bonded with passive self-ligating brackets and the other quadrant within the same arch was bonded by conventionalbrackets. Standardized reproducible digital panoramic radiographs for each patient were evaluated preoperatively (T0), 6 months (T1) and 1 year (T2) after beginningthe orthodontic treatment. The four permanent canines were evaluated regarding the root length and bone density. An indirect digital image radiographic system was followed in this study to obtain and evaluate bone density and degree of root resorption. Results: There was no statistical significant difference in bone density and root resorptionchanges of the maxillary and the mandibular arches between both age groups. Conclusions: Passive self-ligating brackets tend to have the same effect on the bone density and root surface of both the maxilla and the mandible.