Steel Ligature Wire Research Articles

Evaluation of Bond Strength and Adhesive Remnant Index of Different Lingual Retainers in Human Incisor Teeth

ABSTRACT Objective: This study aimed to evaluate and compare the bond strengths of four different lingual retainers and assess the adhesive remnant index (ARI) to determine their effectiveness in orthodontic retention. Methodology: Eighty human incisor teeth were divided into four groups, with each group bonded using a different retainer: Group 1 (E-Glass retainer), Group 2 (0.017” Co-axial stainless steel wire), Group 3 (Splint C.T. fiber mesh), and Group 4 (0.010” stainless steel ligature wire). Bond strength was measured using a universal testing machine, and ARI scores were recorded to assess bond failure types. Results: Group 1 (E-Glass retainer) demonstrated the highest bond strength, followed by Group 3 (Splint C.T. fiber mesh), Group 2 (Co-axial stainless steel wire), and Group 4 (stainless steel ligature wire). Cohesive bond failures were observed in most groups, except for the co-axial stainless steel wire group, which exhibited adhesive failures. Conclusion: E-Glass fiber-reinforced retainers showed the highest bond strength, making them a promising alternative to conventional stainless steel wires for orthodontic retention, especially in patients with esthetic concerns or nickel hypersensitivity. Stainless steel retainer groups exhibited lower bond strengths, and cohesive bond failures were prevalent. Further research is needed to validate these findings in clinical settings and evaluate the long-term effectiveness of different lingual retainers.

Testing the tensile fracture strength tie-wings of different orthodontic ceramic bracket using an Instron machine

IntroductionNewly released products should address the shortcomings of the older ones. Frequent breakages have always been a major drawback when using ceramic brackets. This study assessed the difference in tensile fracture strength at maximum load of tie-wings of different orthodontic ceramic brackets recently available for clinical use. Materials and MethodsIn this in-vitro study, four ceramic brackets were examined. Two monocrystalline brackets (CLEAR™, Adanta®, Germany; Inspire ICE™, Ormco®, USA), one polycrystalline bracket (Symtri Clear™, Ormco®, USA), and one clear hybrid bracket (DISCREET™, Adanta®, Germany). A steel ligature wire was placed around the tie-wing and on the Instron machine to apply tension. The mean maximum load (MxL) and fracture strength (FS) was evaluated and recorded. The significance level was set at p ≤ 0.05. ResultsStatistical difference in fracture strength of the tie-wing fracture was noted among all four groups. Inspire ICE™ showed the highest maximum load and fracture strength with (202.78 N and 107.3 MPa), followed by Symtri Clear™ (111.99 N and 59.25 MPa). In contrast, CLEAR™ and DISCREET™ showed lower MxL values (79.63 N and 47.01 N). The monocrystalline Inspire ICE™ brackets showed the greatest tie-wing fracture resistance and the hybrid clear ceramic bracket DISCREET™ exposed the least resistance to fracture. ConclusionBrand (manufacturing specifications) as well the bracket crystalline structure seems to have a direct effect on its tie-wing strength.

Comparison of Tie Wing Fracture Resistance of Differing Ceramic Brackets.

The aim of this study was to compare the tie wing fracture resistance of 4 different manufacturers' ceramic brackets currently on the market. The tie wings of ceramic brackets from 4 manufacturers were tested with 10 samples in each group. The brackets were Ormco Symetri, 3M Clarity, American Radiance Plus, and Dentsply Ovation S. The brackets were mounted and fixed in a universal testing machine. A stainless steel ligature wire was looped around a tie wing and the mean tensile strength was both tested and recorded. There was a significant overall difference in tensile strength among the 4 groups (P < .0001) with the 3M Clarity brackets having the highest MPa. When the groups were compared to each other, they also showed a significant difference in mean tensile strength with the exception being the American Radiance Plus and Ormco Symetri brackets. Test results concluded that the 3M Clarity brackets had the highest resistance to tie wing fracture, while the Dentsply Ovation S brackets had the lowest resistance.

Self ligating brackets: from past to present

Self-ligating brackets, as the name suggests, do not use any steel ligature wires or elastic ligature modules in holding the archwires into the bracket slots. Rather they have their own mechanics of holding the archwire, either by a clip already in the bracket or a sliding lock mechanic in the bracket. These brackets can be active or passive depending on how the wire is engaged in between the slot and the self-ligating mechanism. In this review article, various systems of self-ligating brackets have been shown as they have been introduced from the past since their introduction in the early 1930s to the present.

A Comparative Analysis of Force Deflection Property of Nickel-Titanium Wires of Four Manufacturers using Five Point Bending Test: An In-vitro Study

Introduction: Over the last century, material science has made rapid progress. In orthodontics, not only the materials improved, but also the philosophies have changed. Orthodontic wires, which generate biomechanical forces through brackets for tooth movement, are central to the practice of this profession. Aim: To measure the force deflection properties of Nickel-Titanium (NiTi) wires of four manufacturers, used during orthodontic treatment. Materials and Methods: In this in-vitro study, 480 NiTi wires from four different manufacturers [American Orthodontics (AO), 3M-Unitek (3M), Rabbit Force Orthodontics (RO) and Modern Orthodontics (MO)], of various cross-sections was obtained. Samples of each wire were obtained by cutting the straightest distal portion of an arch wire, thus an approximate length of 5.5 cms was recovered. These wires were subjected to a five point bending test. Five lower anterior stainless steel brackets of tooth number 31, 32, 41, 42 (MBT 0.022” Libral traders Centrino brackets) were fixed with the face of the bracket facing upwards on the acrylic block. Each NiTi wire was placed in the slots of orthodontic brackets and secured with stainless steel ligature wires. These wires were subjected to artificial saliva (Wet Mouth) for 30 days at 37°C. This temperature was regulated by using an incubator. The main assessment criterion was the force deflection property of the wire material. Force deflection was measured using a graph paper where initially the wire was placed and plotted on the graph paper. After the deflection of the wire, it was again placed on the same graph paper such that wire ends coincided and the force deflection at the highest point was measured in millimetres using a digital Vernier Caliper (Mitutoyu). The Design of Experiments (DOE) model was used for analysis and a three-way Analysis of Variance (ANOVA) with wire shape as covariate was used for analysing the variability. Results: A 0.014” NiTi wire showed more mean deflection when compared to 0.016” NiTi wire. When a comparison between 0.016”×0.022” and 0.017”×0.025” NiTi wires was done, mean deflection was almost the same. When round and rectangular wires were compared it showed more mean deflection in round wires. When AO was compared with other three manufacturers. A significant difference (p-value &lt;0.0001) was seen in the mean deflection values of MO and RO. When 3M was compared with the other three manufacturers a significant difference (p-value &lt;0.0001) was seen in the mean deflection values of MO and RO. Three-way ANOVA test with wire shape as co-variate showed a significant amount of difference (p&lt;0.0001) for AO, 3M wires with their counterparts. Conclusion: Round NiTi wires showed more force deflection as compared to rectangular NiTi wires. AO and 3M wires were superior as compared to RO and MO wires. Superelastic wires showed more deflection as compared to conventional and heat- activated NiTi. This can be attributed to the property of the wire. Stiffer the wire, less deflection was seen. Cost of the wire also played a role. Cheaper wires were not able to match the quality and standards of their counterparts.

Evaluation and Comparison of the Effect of Elastomeric Chain and Stainless Steel Ligature Wire on Maxillary Orthodontic Miniscrew Failure.

Context:Orthodontic miniscrews are used for the purpose of conservation of anchorage.Aims:The aim of the study was to evaluate the orthodontic miniscrew failure between the elastomeric chain-supported retraction and stainless steel (SS) ligature-aided retraction.Settings and Design:This was a cross-sectional split mouth randomized controlled trial.Materials and Methods:The sample (30) was divided equally among the control group and the experimental group (15 each). Miniscrews were placed between second premolar and the first molar of maxilla. The experimental group was based on the split mouth technique wherein right or left side of the maxillary arch was treated using either an elastomeric power chain (EPC) engaged to the miniscrews directly (Group 1) or an EPC engaged indirectly to miniscrews with the help of SS ligature wire (Group 2). In control group, implants were placed in maxilla without any retraction force. Clinical signs of inflammation was assessed at the following interval; 7th day, 14th day, 1st month, 2nd month, and at the time of removal of implant.Statistical Analysis Used:Kruskal–Wallis ANOVA test was used.Results:Mean rank of gingival inflammation was 28.33 at the 1st-month interval in Group 1 and inflammation remained high in the this group for all time intervals in comparison to Group 2. Group 2 showed highest mean rank of inflammation of 26.10 at 7th day. In control group, the inflammation remained low at all the time intervals. Moreover, the difference noted was statistically significant.Conclusions:The gingival inflammation around the peri-implant tissue with the application of EPC at various interval remained high in comparison to the EPC with SS group. The gingival inflammation in the control group was very less, and it remained less throughout the different time periods.

Changes of bite force and occlusal contacts in the retention phase of orthodontic treatment: A controlled clinical trial.

We aimed to determine whether appliance type affects changes in maximum voluntary bite force (MVBF) and the number of occlusal contacts (NOC) during retention, controlling for sex, age, and body mass index. The sample comprised 176 examinees (70 male, 106 female) aged 14 to 20years: 30 had maxillary and mandibular Essix retainers, 30 had wrap-around retainers, and 30 had a combination of fixed mandibular canine-to-canine retainers bonded on each tooth separately (double twisted, 0.254mm in diameter, stainless steel ligature wire) and Essix retainer in the maxillary arch; 86 with normal occlusion were not treated. MVBF and the NOC were measured immediately after removal of preadjusted edgewise appliances (Roth prescription), 6weeks after that, and after the next 4weeks. Increases in MVBF and the NOC were demonstrated, but subjects with 2 Essix retainers showed lower values than did the others. Changes were related to type of appliance, sex, and age (P<0.05) but not to body mass index. The increase in NOC occurred faster than the increase of MVBF, more and sooner with the wrap-around retainer and in male subjects than with the Essix and in female subjects. MVBF and NOC nearly reached the values of the control subjects. Settling of the occlusion depends on appliance type: it takes longer in female patients and with Essix in both dental arches than with the other tested appliances.

An easy method of attachment to an impacted canine

BackgroundSince many years, various bonding attachments have been used as a mode of traction for surgically exposed impacted teeth. It has always been a challenge to select an attachment considering predictability of the bonded attachment, mucogingival and periodontal conditions of the overlying tissues, and additional inventory requirement.MethodsA 0.010-in. stainless steel ligature wire with eyelets at one end and spiral twisted at the other end was made and used as an attachment to guide surgically exposed impacted canine.ResultsOrthodontic guided eruption of an impacted canine of a 16-year-old patient using this simple attachment with 1-year follow-up illustrates adequate amount of attached gingiva.ConclusionsLigature wire attachment is a simple inexpensive attachment that can be custom made without any need for additional inventory, besides being more comfortable to patients.

A comparative study of frictional resistance during simulated canine retraction on typodont model.

Objectives:Frictional resistance is an important counterforce to orthodontic tooth movement during sliding mechanics. This study was carried out to evaluate the effect of different bracket-archwire-ligation combinations on “resistance to sliding” during simulated canine retraction on typodont model.Materials and Methods:the frictional resistance was tested between three modern orthodontic brackets-stainless steel, ceramic, and ceramic with metal slot (0.022-inch), and seven different archwires (0.019 × 0.025-inch)-stainless steel, nickel-titanium, Teflon coated stainless steel, stainless steel with the reverse curve of spee (RCS), Teflon coated stainless steel with RCS, Teflon coated nickel-titanium and nickel-titanium with RCS ligated with stainless steel ligature wire and regular clear elastomeric modules. All tests were carried out in a dry state on an Instron universal testing machine (crosshead speed: 0.5 mm/min). 10 measurements were made from each bracket-archwire-ligature combinations.Results:The highest mean frictional resistance was found in ceramic brackets with nickel-titanium RCS archwire ligated with elastomeric modules while minimum frictional resistance was found in stainless steel brackets with Teflon coated stainless steel archwire ligated with stainless steel ligature. Metal slot ceramic brackets generated significantly lower frictional forces than ceramic brackets, but higher values than stainless steel brackets. Teflon coated archwires shows highly significant reduction of the frictional resistance than their corresponding uncoated archwires. Archwires with RCS had the higher frictional resistance than normal counterpart archwires.Conclusion:Ceramic brackets with metal slot and Teflon coated SS archwires seem to be a good alternative to conventional stainless steel brackets and archwires in space closure with sliding mechanics in patients with esthetic demands.

Utility Ties: Modified Kobayashi Ties

This article shows a simple and effective means to modify Kobayashi Ties. Ties made of 0.014 AJ Wilcock wire are stable and can be fabricated in multiple shapes. The final step of finishing, called settling, aims to bring all the teeth into proper occlusal inter digitation before the patient is placed in retention. Vertical elastics in triangular fashion, or light Class II or III elastics are enough to achieve the desired settling. Light or heavy elastics are needed even in the immediate postsurgical period to provide the required guidance of occlusion. The Kobayashi tie is commonly used for attaching elastics during the treatment. The technique, utilizing 0.010 stainless steel ligature wire to make Kobayashi ties, has already been suggested. 1,2

Mini-screw implant or transpalatal arch-mediated anchorage reinforcement during canine retraction: A randomized clinical trial

To compare mesial movement of upper first molars during maxillary canine retraction using a pre-adjusted edgewise appliance provided by anchorage reinforcement and a transpalatal arch or mini-screw implant. Randomized clinical trial. Department of Orthodontics and Dentofacial Orthopedics, Armed Forces Medical College, Pune, India. From a cohort of subjects requiring the extraction of both upper first premolars and pre-adjusted edgewise appliances to correct their malocclusion, a total of 30 were randomly allocated to receive two different forms of anchorage reinforcement: group A--receiving mini-screw implant and group B--receiving a transpalatal arch Group A subjects received titanium mini-screw implants placed at the start of treatment between the maxillary second premolar and maxillary first molar. Maxillary second premolars were secured to the mini-screw implants using of 0.010-inch stainless steel ligature wire. Group B subjects received a custom-made transpalatal arch which was soldered to maxillary first molar bands. Active canine retraction was initiated in both groups on placement of a 0.019×0.025-inch stainless steel archwire using nickel titanium closed coil springs. Mesial movement of the upper first molars as measured on pre- (T1) and post-treatment (T2) lateral skull radiographs. The results showed that in group A the mean mesial movement of the first molars between T1 and T2 was 0.0 mm (SD 0.02; P = 0.90), whereas in Group B there was a mean forward movement of the first maolars of 2.48 mm (SD 0.71; P<0.001). In this trial, mini-screw implants placed prior to levelling and aligning were able to provide absolute anchorage during maxillary canine retraction, in contrast to a transpalatal arch.

Simple Method for Securing a Decompression Tube for Odontogenic Cysts and Tumors: A Technical Note

Decompression of odontogenic cysts and certain odontogenic tumors is a straightforward procedure used very commonly in the treatment of these entities. The goals for use of the decompression technique are usually determined by the size, location, and type of the pathology encountered. The most common reason for incorporating the decompression technique in the treatment algorithm for an odontogenic entity is the keratocystic odontogenic tumor. Several “decompression tubes” have been described and successfully used for this purpose. Some of the common problems encountered during the course of this type of treatment, which is extended over several months, originate from the size of the decompression tube itself and/or the trauma to the soft tissues from resorbable or nonresorbable sutures, or malposition or dislodgment of the tube. Although these are not major complications, they contribute to the discomfort and inconvenience for the patient and the clinician. The aim of this technical note is to describe a straightforward way of securing a polyethylene tube, commonly used for decompression, to minimize the trauma to the surrounding soft tissues, and to maximize retention in the proper location and position in relation to the cyst or tumor. Twenty-two patients were treated with this approach at our institution. The technique involves using a 28-gauge stainless steel ligature wire that secures the tube around the tooth/teeth immediately adjacent to the site of the lesion. In this manner, the soft tissues around the tube are not traumatized from any suture material or tube displacement because the position is secured with a wire, and adequate oral hygiene can be performed easily. Additionally, tube length adjustments may be required often during the treatment course, and these may be performed in a noninvasive fashion, and without the need for administration of local anesthesia.

Comparison of the force systems of 3 appliances on palatally impacted canines

Although much imaging research has focused on the localization and the management of impacted canines, optimal biomechanics for successful recovery are not clear. The purpose of this research was to compare the 3 mechanics--Kilroy spring, elastic chain, and steel ligature wire--used for the management of impacted canines by quantifying the 6 components of force systems involved with each system. A dentoform model was modified to simulate a palatally impacted canine. Load cells installed in the dentoform simultaneously measured the 3 forces (Fx, Fy, Fz) and the 3 moments (Tx, Ty, Tz) on the canine. The activation range and force system attenuation as the canine moved were also measured. The results were analyzed statistically. The Kilroy spring has an activation range of 13 mm (Fz), the elastic chain has an activation range of 12 mm (Fz), and the ligature wire has an activation range of 1 mm (Fz). The full range of the elastic chain cannot be used because of its limited elastic behavior. The 3-dimensional force system for canine recovery mechanics can be quantified by using these devices. Quantification of the force system provides critical information for appropriate selection of an optimal appliance.

Frictional Resistance between Orthodontic Brackets and Archwire: An in vitro Study

The purpose of this investigation was to determine the kinetic frictional resistance offered by stainless steel and Titanium bracket used in combination with rectangular stainless steel wire during in vitro translatory displacement of brackets. In this study. Brackets: (All brackets used had a torque of - 7° and an angulation of 0°): (1) Dynalock (Unitek) 0.018'' slot, 3.3 mm bracket width, (2) Mini Uni-Twin (Unitek) 0.018'' slot, 1.6 mm bracket width, (3) Ultra-Minitrim (Dentaurum) 0.022'' slot 3.3 mm bracket width, (4) Titanium (Dentaurum) 0.022'' slot, 3.3 mm bracket width. WIRES: (1) 0.016 x 0.022'' stainless steel (Dentaurum), (2) 0.017 x 0.025''stainless steel (Unitek), (3) 0.018 x 0.025'' stainless steel (Dentaurum), elastomeric modules (Ortho Organisers), 0. 009'' stainless steel ligature wires, hooks made of 0.021 x 0.025'' stainless steel wires, super glue to bond the hooks to the base of the bracket, acetone to condition the bracket and wires before testing and artificial saliva. Brackets were moved along the wire by means of an Instron universal testing machine (1101) and forces were measured by a load cell. All values were recorded in Newtons and then converted into gms (1N-102 gm). 200 gm was then subtracted from these values to find out the frictional force for each archwire/bracket combination. For each archwire/ bracket combination three readings were taken under wet and dry condition and also with stainless steel ligature and elastomeric modules separately. The results showed that narrow brackets generated more friction than wider brackets. Frictional force was directly proportional to wire dimension. Titanium brackets generated more friction than stainless steel brackets. Archwire and bracket ligated with elastomeric module generated more friction than when ligated with stainless steel ligature wire. Frictional forces in the wet condition were greater than in the dry condition for all archwire to bracket combinations. Frictional force was seen to be inversely proportional to bracket width, frictional force was inversely proportional to bracket width, and in the wet condition were greater than in the dry condition for all archwire to bracket combinations. This study of friction is its role in lessening the force actually received by a tooth from an active component such as a spring, loop or elastic. Hence greater applied force is needed to move a tooth with a bracket archwire combination demonstrating high magnitudes of friction compared with one with a low frictional value.

Expressions of RANKL/RANK and M-CSF/c-fms in root resorption lacunae in rat molar by heavy orthodontic force

The differentiation and functions of osteoclasts are regulated by receptor activator of nuclear factor-κB (RANK)/receptor activator of nuclear factor-κB ligand (RANKL) system that stimulates osteoclasts formation. Macrophage colony-stimulating factor (M-CSF) is also essential for osteoclastogenesis. A recent immunocytochemical study reported that RANKL/RANK and M-CSF/c-fms were localized in the periodontal ligament of rat molars during experimental orthodontic tooth movement. The present study focused on the expressions of RANKL/RANK and M-CSF/c-fms in root resorption area during experimental tooth movement in rats. Forty 6-week-old male Wistar rats were subjected to an orthodontic force of 10 or 50 g with a closed coil spring (wire size: 0.005 inch, diameter: 1/12 inch) ligated to the maxillary first molar cleat by a 0.008 inch stainless steel ligature wire to induce a mesial tipping movement of the upper first molars. Experimental tooth movement was undertaken for 10 days. Each sample was sliced into 6 μm continuous sections in a horizontal direction and prepared for haematoxylin and eosin (H and E) and immunohistochemistry staining for tartrate-resistant acid phosphatase (TRAP), RANK, RANKL M-CSF, and c-fms in root resorption area. Statistical analysis was carried out using a Mann-Whitney U-test with a significance level of P<0.01. On days 7 and 10, immunoreactivity for RANKL/RANK and M-CSF/c-fms was detected in odontoclasts with an orthodontic force of 50 g, but not 10 g. Therefore, RANKL/RANK and M-CSF/c-fms systems may be involved in the process of root resorption by heavy orthodontic force.

In vitro evaluation of the frictional forces between brackets and archwire with three passive self-ligating brackets

The aim of this in vitro study was to evaluate the frictional forces between bracket and archwire that included three passive self-ligating brackets (Damon SL2 SDS). The brackets were individually bonded to a brass mount using a preformed 0.021 x 0.025 inch stainless steel wire jig in order to exclude adverse tipping or torsion. The central bracket was positioned 1 mm higher than the others, in order that the three brackets were vertically unaligned. Thirty-six similar set-ups including in total 108 brackets were investigated using the same wire: copper (nickel-titanium) 0.014 inches. A testing machine was designed and constructed to measure the frictional forces between the wire and the three-bracket set-up. Twelve set-ups were tested to measure kinetic frictional forces between the wire and unaligned passive self-ligating brackets used in the closed position. The frictional properties of two sets of 12 three-bracket set-ups (control) were tested and measured with an open slide and conventional ligation. A stainless steel ligature wire was used in the former, while elastomeric modules were employed in the latter. One-way analysis of variance showed a significant effect of ligation mode on the frictional properties of the three-bracket set-ups (P < 0.001). Post hoc pairwise comparison showed that the frictional forces arising from passive self-ligation were significantly lower (P < 0.01) than those resulting from elastic ligation. The same result was achieved when comparing self-ligation and metallic ligation (P < 0.01). No significant difference was found when comparing elastic and metallic ligation.

Archwire ligation techniques, microbial colonization, and periodontal status in orthodontically treated patients.

Fixed or removable orthodontic appliances impede the maintenance of oral hygiene and result in plaque accumulation. Plaque retention surrounding orthodontic appliances leads to enamel demineralization caused by organic acids produced by bacteria in the dental plaque. Many studies have evaluated the effects of fixed orthodontic appliances on microbial flora and periodontal status, but only a few have evaluated the method of ligation as an additional factor. The aim of this study was to determine the changes in microbial flora and periodontal status after orthodontic bonding and to determine whether two different archwire ligation techniques affect these changes. A total of 21 orthodontic patients scheduled for fixed orthodontic treatment were selected for this split-mouth study. Two commonly used auxiliaries (elastomeric rings and ligature wires) for tying archwires were tested. Microbial and periodontal records were obtained before bonding (T0), one week later (T1), and five weeks after bonding (T2). Paired t-test and Wilcoxon signed rank test were used to compare the groups statistically. Although, teeth ligated with elastomeric rings exhibited slightly greater numbers of microorganisms than teeth ligated with steel ligature wires, the differences were not statistically significant and could be ignored. The two archwire ligation techniques showed no significant differences in the gingival index, bonded bracket plaque index, or pocket depths of the bonded teeth. However, teeth ligated with elastomeric rings were more prone to bleeding. Therefore, elastomeric ring use is not recommended in patients with poor oral hygiene.

Comparison of the frictional coefficients for selected archwire-bracket slot combinations in the dry and wet states.

Coefficients of friction were evaluated in the dry and wet (saliva) states for stainless steel, cobalt-chromium, nickel titanium, and beta-titanium wires against either stainless steel or polycrystalline alumina brackets. For both operators' experiments, an 0.010" stainless steel ligature wire pressed each archwire into the 0.018" or 0.022" bracket slot at 34 degrees C. In the dry state and regardless of slot size, the mean kinetic coefficients of friction were smallest for the all-stainless steel combinations (0.14) and largest for the beta-titanium wire combinations (0.46). The coefficients of the polycrystalline alumina combinations were generally greater than the corresponding combinations that included stainless steel brackets. In the wet state, the kinetic coefficients of the all-stainless steel combinations increased up to 0.05 over the dry state. In contrast, all beta-titanium wire combinations in the wet state decreased to 50% of the values in the dry state. The mixed reports that saliva may promote adhesive and lubricious behaviors may have some substance.

Easy come, easy go: A simple and effective orthodontic enamel anchor for endotracheal tube stabilization in a child with extensive facial burns

Endotracheal tube stabilization in patients with facial burns is crucial and often challenging. We present a simple method of securing an endotracheal tube using two orthodontic brackets bonded to the maxillary central incisor teeth and a 0.08″ stainless steel ligature wire. Our technique is less traumatic, and is easier to maintain oral hygiene than with previously described methods. This anchorage system takes 5 min to apply and can be removed on the ward without the need for a general anaesthetic.

Evaluation of frictional forces during dental alignment: An experimental model with 3 nonleveled brackets

The aim of this in-vitro study was to evaluate the frictional forces generated by various combinations of brackets and orthodontic wires by using an experimental model with 3 nonleveled brackets to gain a better understanding of the resistance to sliding during dental alignment and leveling. Two kinds of orthodontic brackets were tested: passive self-ligating brackets and conventional twin stainless steel brackets. The following wires were tested: 3 nickel-titanium (.014, .016, and .016 x .022 in), 2 stainless steel (multistranded .0155 and .016 in), and 1 beta-titanium alloy (.016 in). The ligatures used with conventional brackets were elastomeric modules (power 'O' 110) and preformed stainless steel ligature wire (.010). Each of the 10 bracket-archwire combinations was tested 10 times. Kinetic frictional forces were measured on a specially designed testing machine. The wires tested were pulled through a set of multiple nonleveled brackets at a speed of 4 mm per minute over a distance of 5 mm. All data were statistically analyzed. The sliding of the wire in the 3-bracket nonaligned system was significantly influenced by wire cross-section dimension (P < 0.001), wire material (P < 0.001), number of wire strands (P < 0.001), and type of ligation (P < 0.001). Frictional forces can be reduced during alignment by using self-ligating brackets, small dimensions, and less stiff wires, thereby inducing the wire to slide in the slots. Under such conditions, the force required by the orthodontic wire to overcome resistance to sliding is reduced. This allows the wire to exploit its mechanical characteristics more efficiently.