Quantity and distribution of plaque in orthodontic patients treated with molar bands

Objective

The placement of orthodontic bands usually increases plaque accumulation due to numerous mechanical retention sites. The purpose of this investigation was to evaluate the amount and distribution pattern of biofilm in the oral (palatal and lingual) and interproximal regions surrounding orthodontic bands.

Materials and Methods

We evaluated the formation of biofilm on 32 orthodontic bands which had been placed intraorally for 6?C37?months. Two parameters were measured: the percentage of surface covered by biofilm (quantity) and the biofilm distribution pattern of accumulation. We measured these two parameters in four regions of interest: the mesial and distal interproximal regions, as well as the mesial and distal regions of the oral attachment.

Results

The quantity of biofilm formation was similar in all four regions of interest, ranging from 13.3% to 16.8%. In contrast to biofilm quantity, distribution patterns differed in the four regions. In the mesial and distal interproximal regions it appeared as extensive insular areas in 87.5% and 71.9%, respectively, whereas it appeared more often supragingival and linear in nature in regions adjacent to the oral attachment, i.e. in 65.6% and 68.8%, respectively.

Conclusion

Our results indicate that firstly, oral hygiene in the palatal and lingual regions of orthodontic bands seems as difficult as it is in the interproximal areas, thus requiring thorough hygiene in both areas. Secondly, orthodontic patients with a history of periodontal disease require special attention regarding the use of orthodontic bands.     

The biomechanics of posterior maxillary arch expansion using fixed labial and lingual appliances

ObjectiveTo compare the biomechanics of straight labial, straight lingual, and mushroom lingual archwire systems when used in posterior arch expansion.Materials and MethodsAn electro-mechanical orthodontic simulator allowing for buccal–lingual and vertical displacements of individual teeth and three-dimensional force/moment measurements was instrumented with anatomically shaped teeth for the maxillary arch. In-Ovation L brackets were bonded to lingual surfaces, and Carriere SLX brackets were bonded to labial surfaces to ensure consistency of slot dimensions. Titanium molybdenum archwires were bent to an ideal arch form, and the teeth on the orthodontic simulator were set to a passive position. Posterior teeth from the canine to second molar were moved lingually to replicate a constricted arch. From the constricted position, the posterior teeth were simultaneously moved until the expansive force decreased below 0.2 N. Initial force/moment systems and the amount of predicted expansion were compared for posterior teeth at a significance level of α = 0.05.ResultsArchwire type affected both the expected expansion and initial force/moment systems produced in the constricted position. In general, the lingual systems produced the most expansion. The archwire systems were not able to return the teeth to their ideal position, with the closest system reaching 41% of the intended expansion.ConclusionsIn general, lingual systems were able to produce greater expansion in the posterior regions when compared with labial systems. However, less than half of the intended arch expansion was achieved with all systems tested.     

A comparison of treatment results of adult deep-bite cases treated with lingual and labial fixed appliances

ObjectivesTo compare the cephalometric treatment results of adult deep-bite cases after labial and lingual fixed orthodontic treatment.Materials and MethodsA total of 102 patients underwent lingual orthodontic treatment and complete records were evaluated. The following inclusion criteria were used: patients who had Angle Class I or mild Class II malocclusion; comprehensive orthodontic treatment that did not include intrusion mechanics or any extractions; patients with an initial overbite of more than 3.7 mm. Thirteen patients met the inclusion criteria. These cases were matched with the same number of patients according to age with a labial orthodontic treatment group. Pre- and post-treatment cephalometric radiographs were evaluated. Independent t test or Fisher exact tests were performed to assess the differences between the groups.ResultsProclination of the upper incisors was higher in the labial group. Incisor mandibular plane angle (IMPA) showed an increase of 1.2° in the lingual group and 9.7° in the labial group. Lower incisor edge was approximately in a stable sagittal position in the lingual group but significant lower incisor proclination was seen in the labial group. The lower incisors were intruded (-1 mm) in the lingual group but lower incisors were minimally extruded (0.3 mm) in the labial group. No significant difference was found in the movements of upper and lower molars for both groups.ConclusionsThe nature of lower incisor movement involved less protrusion in lingual orthodontics than the labial treatment. Lingual orthodontic treatment is a better option in adult cases where intrusion of lower incisors without labial tipping is desired.     

Gingival and labial vestibular temperature in young individuals

The objective of this investigation was to test a small thermistor for oral use and to study temperature variation in non-inflamed oral mucosa Gingival and labial vestibular or sulcus temperatures were measured in 30 young dental undergraduate students with teeth with a gingival index score of 1 or less. Four sites of measurement, mesial, labial, distal and lingual, were made around the six selected teeth and at 2-mm intervals extending down the buccal or labial sulcus into the sulcus itself. For each subject the gingival temperature was subtracted from the sublingual temperature to obtain a temperature differential and the gingival temperature differential was greater in the maxilla than in the mandible.

The method used in this study was reproducible. Temperature increased from the gingival margin to the labial sulcus, and there was an increase in temperature from incisor to molar in both jaws, and the maxillary sites were cooler than those in the mandible. An irregular variation in temperature differential was seen between mesial, labial, distal and lingual measurement sites.     

Speech performance and oral impairments with lingual and labial orthodontic appliances in the first stage of fixed treatment: A randomized controlled trial

Objectives:To compare (1) speech performance based on an auditive analysis and sonagraphy and (2) levels of oral impairment between fixed lingual and labial orthodontic appliances.Materials and Methods:Thirty-four patients with Class I division 1 malocclusion and moderate crowding of upper teeth were distributed randomly into two groups. Seventeen patients in group A (mean age: 20.6 years; standard deviation [SD]: 2.9 years) were treated with fixed lingual appliances (Stealth®, AO, Sheboygan, Wisc), whereas 17 patients in group B (mean age: 21.8 years; SD: 3.3 years) were treated with conventional fixed labial appliances. Speech performance was tested using spectrographic analysis of fricative /s/ sound before, immediately after (T1), 1 month after, and 3 months after bracket placement. The levels of oral impairment were assessed using standardized questionnaires.Results:A significant deterioration in articulation was recorded at all assessment times in group A but only at T1 in group B. Significant intergroup differences were recorded at all assessment times (P < .001). Speech difficulties were significantly higher in the lingual brackets group after 1 month of bracket placement (P < .001). Soft tissue irritation and chewing difficulty were significantly higher in the lingual appliance group after 24 hours of bracket placement (P < .001).Conclusions:The lingual appliance is more problematic than the labial one in terms of speech articulation. Although patients with both appliances suffered from different degrees of oral impairment, patients with lingual appliances had more untoward effects, particularly during the first month of treatment.     

Differences in psychological traits between lingual and labial orthodontic patients: Perfectionism,body image,and the impact of dental esthetics

Objective:To examine some of the patients'' psychological traits in relation to their levels of perfectionism and their body image, and to discover whether these differ between lingual and labial orthodontic patients.Materials and Methods:A cross-sectional study was designed with a consecutive sample of 80 patients attending a private orthodontic office. Three questionnaires were used to assess the patients'' body image and level of perfectionism. The mean age was 33 years. The men numbered 32 and the women 48. The validated Spanish version of the Psychosocial Impact of Dental Aesthetic Questionnaire (PIDAQ) was used to assess the psychosocial impact of their dental esthetics. The Multidimensional Perfectionism Scale (MPS) was used to assess how perfectionist the patients were. A version of the Multidimensional Body-Self Relations Questionnaire (MBSRQ) was used for assessment of their body image. Student''s t-test was used to compare the means and 95% confidence intervals (P < .05), and a logistic regression model was used for multivariate analysis.Results:The PIDAQ (55.4 vs 60, P  =  .218) and MBSRQ (128.7 vs 125.9, P  =  .523) results of the patients who chose lingual orthodontics did not differ significantly from those who opted for labial orthodontics. However, the MPS scores of the lingual orthodontic patients were significantly higher (95.9 vs 86.3, P  =  .044), and high social class, over 30 years of age, and perfectionist traits were significant independent variables in this group.Conclusions:This pilot study may indicate that lingual orthodontic patients are more perfectionists than labial orthodontic patients.     

The efficacy of fluoride varnish vs a filled resin sealant for preventing white spot lesions during orthodontic treatment:: A randomized clinical trial

ObjectivesTo compare the efficacy of casein phosphopeptide (CPP)-amorphous calcium phosphate (ACP) MI Varnish (GC America, Inc, Alsip, IL) and ProSeal (Reliance Orthodontic Products, Itasca, IL) sealant in preventing the development of white spot lesions (WSLs) in orthodontic patients.Materials and MethodsThis prospective randomized clinical trial included 40 orthodontic patients 12–17 years of age. One group had sealants placed on their anterior maxillary teeth, with reapplications every 3 months. The other group had MI Varnish applied every 4–6 weeks. WSL formation and oral hygiene were evaluated at the initial appointment before bonding (T1) and 12 months later (T2). Standardized digital photographs were analyzed using the enamel decalcification index (EDI). Statistical comparisons were made using independent and paired-sample t-tests as well as chi-square tests.ResultsIn this trial, 43% of patients and 15% of teeth developed new WSLs. Lateral incisors showed the highest incidence of decalcification and WSL formation. WSL formation and EDI score increases during treatment were significantly greater in the gingival region than in the mesial, distal, or incisal regions. Of the EDI scores at T2, 93.8% were 0 and 5.5% were 1. Poor oral hygiene at T2 showed a high positive predictive value (76%) for the development of WSLs. There were no statistically significant between-group differences for the development of WSLs.ConclusionsMI Varnish and ProSeal sealant provided similar levels of protection during the first 12 months of fixed orthodontic treatment. The severity of the WSLs that developed was minimal. WSLs were most likely to develop on lateral incisors and in the gingival regions of teeth, especially among patients with poorer oral hygiene.     

Treatment time,outcome, and anchorage loss comparisons of self-ligating and conventional brackets

Objective:To compare the treatment time, outcome, and anchorage loss among orthodontic patients treated by self-ligating brackets (SLBs) and conventional brackets (CBs).Materials and Methods:A retrospective cohort study compared 34 patients (SLB group) treated by SmartClip brackets (3M Unitek, Monrovia, Calif) to 35 patients (CB group) treated by conventional preadjusted Victory series brackets (3M Unitek) and ligated by stainless steel wire ligatures. Pretreatment (T1) and posttreatment (T2) lateral cephalograms were traced and analyzed using Pancherz sagittal-occlusion analysis to obtain skeletal and dental changes in the maxilla and the mandible. The dental cast models were assessed by the Peer Assessment Rating (PAR) Index for the treatment outcomes.Results:The mean treatment time for SLBs (19.19 months) did not show a statistically significant difference from 21.25 months of CBs; the treatment time and pretreatment PAR scores were strongly correlated. There was no difference in anchorage loss between the SLB and CB groups. There were significant dental and skeletal changes among adolescent orthodontic patients regardless of the bracket used. The lingual inclination of the mandibular incisors in the CB group was 3.62° more than in the SLB group (P < .01).Conclusions:The treatment time and anchorage loss are not influenced by the type of bracket used. There are significant dental and skeletal changes among adolescent orthodontic patients regardless of the bracket used. There is significantly greater lingual inclination of mandibular incisors in the CB group than in the SLB group.     

Maxillary canine retraction with self-ligating and conventional brackets: A randomized clinical trial

Objective:To measure space closure during the retraction of upper permanent canines with self-ligating and conventional brackets.Materials and Methods:Fifteen patients who required maxillary canine retraction into first premolar extraction sites as part of their orthodontic treatment completed this study. In a random split-mouth design, the retraction of upper canines was performed using an elastomeric chain with 150 g of force. The evaluations were performed in dental casts (T0, initial; T1, 4 weeks; T2, 8 weeks; T3, 12 weeks). The amount of movement and the rotation of the canines as well as anchorage loss of the upper first molars were evaluated.Results:There was no difference between self-ligating and conventional brackets regarding the distal movement of upper canines and mesial movement of first molars (P > .05). Rotation of the upper canines was minimized with self-ligating brackets (P < .05).Conclusion:Distal movement of the upper canines and anchorage loss of the first molars were similar with both conventional and self-ligating brackets. Rotation of the upper canines during sliding mechanics was minimized with self-ligating brackets.     

Prevalence and severity of vestibular recession in mandibular incisors after orthodontic treatment: A case-control retrospective study

Objective:To assess the prevalence and severity of vestibular gingival recession of mandibular incisors after orthodontic treatment and to evaluate possible contributing factors.Materials and Methods:From the record pool of patients who completed orthodontic treatment from 1999–2006 at the Department of Orthodontics, University of Oslo, Norway, 588 patients fulfilled the inclusion criteria. Intraoral color slides were used for the evaluation of gingival recessions (based on Miller classification), presence of visible plaque, and gingival inflammation. Cephalometric radiographs were used to assess the sagittal intermaxillary relation, mandibular and intermaxillary angles, and the position of the lower incisors. A control group was drawn from the same pool of 588 patients. All statistical analyses were performed using SPSS.Results:The prevalence of gingival recessions after orthodontic treatment was 10.3%. Most (8.6%) were classified as Miller Class I, and 1.7% were classified as Miller Class II. Gingival recession was predominantly found on central incisors. Reduction of the sagittal intermaxillary angle and retroclination of the lower incisors was correlated with the development of a more severe gingival recession.Conclusions:The present study indicates that vestibular gingival recession of mandibular incisors after orthodontic treatment is of minor prevalence and severity. The presence of gingival recession or retroclination of the incisors with mesial basal relations increases the risk of more severe gingival recession.     

Comparison of the transfer accuracy of two digital indirect bonding trays for labial bracket bonding

ObjectivesTo compare the transfer accuracy of two digital transfer trays, the three-dimensional printed (3D printed) tray and the vacuum-formed tray, in the indirect bonding of labial brackets.Materials and MethodsTen digital dental models were constructed by oral scans using an optical scanning system. 3D printed trays and vacuum-formed trays were obtained through the 3Shape indirect bonding system and rapid prototyping technology (10 in each group). Then labial brackets were transferred to 3D printed models, and the models with final bracket positioning were scanned. Linear (mesiodistal, vertical, buccolingual) and angular (angulation, torque, rotation) transfer errors were measured using GOM Inspect software. The mean transfer errors and prevalence of clinically acceptable errors (linear errors of ≤0.5 mm and angular errors of ≤2°) of two digital trays were compared using the Mann-Whitney U-test and the Chi-square test, respectively.ResultsThe 3D printed tray had a lower mean mesiodistal transfer error (P < .01) and a higher prevalence of rotation error within the limit of 2° (P = .03) than did the vacuum-formed tray. Linear errors within 0.5 mm were higher than 90% for both groups, while torque errors within 2° were lowest at 50.9% and 52.9% for the 3D printed tray and vacuum-formed tray, respectively. Both groups had a directional bias toward the occlusal, mesial, and buccal.ConclusionsThe 3D printed tray generally scored better in terms of transfer accuracy than did the vacuum-formed tray. Both types of trays had better linear control than angular control of brackets.     

Marginal bone loss adjacent to conventional and immediate loaded two implants supporting a ball-retained mandibular overdenture: a 3-year randomized clinical trial

Objectives: The aim of this study was to evaluate and compare marginal bone loss and clinical outcomes of conventionally and immediately loaded two implants supporting a ball‐retained mandibular overdenture. Materials and methods: Thirty six completely edentulous patients (22 males and 14 females) were randomly assigned into two groups. Each patient received two implants in the canine area of the mandible after a minimal flap reflection. Implants were loaded by mandibular overdentures either 3 months (conventional loading group) or the same day (immediate loading group) after implant placement. Ball attachments were used to retain all overdentures to the implants. Vertical and horizontal alveolar bone losses were evaluated in both groups 1 and 3 years after implant placement using multislice computed tomography, which allow evaluation of peri‐implant buccal and lingual alveolar bone. Plaque scores, gingival scores, probing depths and periotest values (PTVs) were evaluated at 4 months (baseline), 1 and 3 years after implant placement. Clinical and radiographic evaluations were performed at distal, labial, mesial and lingual peri‐implant sites. Results: After 3 years of follow‐up period, the immediate loading group recorded significant vertical bone loss at distal and labial sites than the conventional loading group and no significant differences in horizontal bone loss between groups were observed. Probing depth at distal and labial sites in the immediate loading group were higher than the conventional loading group, while plaque scores, gingival scores and PTVs showed no significant differences between the two groups. A low level of positive correlation between plaque scores, gingival scores, probing depths and vertical bone loss was noted. Conclusion: Immediately loaded two implants supporting a ball‐retained mandibular overdenture are associated with more marginal bone resorption and increased probing depths when compared with conventionally loaded implants after 3 years. The bone resorption and probing depths at distal and labial sites are significantly higher than those at mesial and lingual sites. Clinical outcomes do not differ significantly between loading protocols. To cite this article :
Elsyad MA, Al‐Mahdy YF, Fouad MM. Marginal bone loss adjacent to conventional and immediate loaded two implants supporting a ball‐retained mandibular overdenture: a 3‐year randomized clinical trial.
Clin. Oral Impl. Res. 23 , 23, 2012 496‐503.
doi: 10.1111/j.1600‐0501.2011.02173.x     

唇舌侧托槽转矩控制性能的有限元对比分析

目的：分析唇舌侧托槽转矩控制性能的差异,同时探讨不同材质不同尺寸的弓丝对舌侧托槽转矩控制的影响规律。方法：建立左上尖牙到右上尖牙的唇舌侧托槽三维有限元模型,在弓丝尺寸及材质不同的情况下,模拟临床左上中切牙转矩加载±20°。结果：随着转矩角度的增大,唇舌侧托槽转矩值逐渐增大,舌侧托槽转矩值为唇侧托槽的3～5倍;0．48 mm ×0．64 mm 弓丝的转矩值大于0．43 mm ×0．64 mm;弓丝尺寸相同时,不锈钢丝（SS）,β－钛丝（TMA）,镍钛丝（NiTi）,转矩值依次减小。结论：唇舌侧托槽转矩均随着转矩角度和弓丝的弹性模量的增大而增大;在相同的转矩角度下,舌侧托槽产生的转矩值大于唇侧托槽;舌侧托槽的转矩值与弓丝尺寸及材质有关。     

Comparative study of root resorption of maxillary incisors in patients treated with lingual and buccal orthodontics

Objective:To compare the magnitude of external apical root resorption (EARR) of maxillary incisors in patients with mild to moderate anterior crowding, treated with lingual and conventional (labial) orthodontics.Materials and Methods:The sample comprised 40 patients divided into two groups: lingual (20 patients) and conventional buccal brackets (20 patients). Patient ages ranged from 11 to 45 years, and the study included 12 men and 28 women. Apical root resorption was measured from periapical radiographs obtained at the beginning of treatment (T1) and at the end of the leveling phase (T2). Periapical radiographs were scanned and transferred to the CorelDraw X7 image-processing program, in which measurements of root lengths were performed. For intragroup and intergroup comparisons between the T1 and T2 phases, paired and independent t-tests, respectively, were used at 5% significance.Results:There was significant apical root resorption for all teeth evaluated; the magnitude of the EARR (T2−T1) ranged from −0.35 mm to −0.63 mm in the lingual group, and from −0.66 mm to −0.85 mm in the conventional group. Although there was an intergroup variation in the magnitude of EARR observed, no statistically significant differences were found. Neither group presented any teeth with resorption ≥1 mm.Conclusions:The magnitude of apical root resorption in maxillary incisors in patients with anterior crowding was similar regardless of orthodontic technique, lingual or conventional. Both techniques resulting in an apical rounding considered clinically insignificant.     

Perception of Esthetic Orthodontic Appliances: An Eye Tracking and Cross-sectional study

ObjectiveTo evaluate the perception of esthetic orthodontic appliances by means of eye-tracking measurements and survey investigation.Materials and MethodsEn face and close-up images with different orthodontic appliances (aligner appliance [a], aligner appliance and attachments [b], lingual appliance [c], ceramic brackets [d], no appliance [e; control]) were shown to 140 participants. Eye movement and gaze direction was recorded by eye-tracking system. For different anatomical areas and areas of the appliances, time to first fixation and total fixation time were recorded. The questions included in a visual analog scale regarding individual sentiency were answered by the participants.ResultsFor all groups, the anatomical landmarks were inspected in the following order: (1) eyes, (2) mouth, (3) nose, (4) hair, and (5) ears. Only in group d, first fixation was on the mouth region (1.10 ± 1.05 seconds). All appliances except the lingual appliance (1.87 ± 1.31 seconds) resulted in a longer fixation on the mouth area (a, 2.97 ± 1.32 seconds; b, 3.35 ± 1.38 seconds; d, 3.29 ± 1.36 seconds). For close-up pictures, the fastest (0.58 seconds) and longest (3.14 seconds) fixation was found for group d, followed by group b (1.02 seconds/2.3 seconds), group a (2.57 seconds/0.83 seconds), and group c (3.28 seconds/0.05 seconds). Visual analog scale scoring of questions on visibility were consistent with eye-tracking measurements. With increasing visibility, the feeling of esthetic impairment was considered higher.ConclusionsLingual orthodontic appliances do not change how the face is perceived. Other esthetic orthodontic appliances may change the pattern of facial inspection and are different in subjective perception.     

A novel biomimetic orthodontic bonding agent helps prevent white spot lesions adjacent to brackets

Objective:To compare changes in enamel microhardness adjacent to orthodontic brackets after using bonding agents containing various compositions of bioactive glass compared to a traditional resin adhesive following a simulated caries challenge.Materials and Methods:Extracted human third molars (n  =  10 per group) had orthodontic brackets bonded using one of four novel bioactive glass (BAG)-containing orthodontic bonding agents (BAG-Bonds) or commercially available Transbond-XT. The four new adhesives contained BAG in varying percentages incorporated into a traditional resin monomer mixture. Teeth were cycled through low-pH demineralizing and physiologic-pH remineralizing solutions once each day over 14 days. Microhardness was measured on longitudinal sections of the teeth 100, 200, and 300 µm from the bracket edge and beneath the brackets, at depths of 25 to 200 µm from the enamel surface. Normalized hardness values were compared using three-way analysis of variance.Results:Significantly less reduction in enamel microhardness was found with the experimental adhesives at depths of 25 and 50 µm at all distances from the bracket edge. In all groups, there were no significant changes in enamel microhardness past 125-µm depth. Results varied with the different BAG-Bonds, with 81BAG-Bond showing the smallest decrease in enamel microhardness.Conclusions:The BAG-Bonds tested in this study showed a reduction in the amount of superficial enamel softening surrounding orthodontic brackets compared to a traditional bonding agent. The results indicate that clinically, BAG-Bonds may aid in maintaining enamel surface hardness, therefore helping prevent white spot lesions adjacent to orthodontic brackets.     

Effect of time and pH on physical-chemical properties of orthodontic brackets and wires

Objective:To test the hypothesis that treatment time, debris/biofilm, and oral pH have an influence on the physical-chemical properties of orthodontic brackets and arch wires.Materials and Methods:One hundred twenty metal brackets were evaluated. They were divided into four groups (n  =  30) according to treatment time: group C (control) and groups T12, T24, and T36 (brackets recovered after 12, 24, and 36 months of treatment, respectively). Rectangular stainless-steel arch wires that remained in the oral cavity for 12 to 24 months were also analyzed. Dimensional stability, surface morphology, composition of brackets, resistance to sliding of the bracket-wire set, surface roughness of wires, and oral pH were analyzed. One-way analysis of variance, followed by a Tukey multiple comparisons test, was used for statistical analysis (P < .05).Results:Carbon and oxygen were shown to be elements that increased expressively and in direct proportion to time, and there was a progressive increase in the coefficient of friction and roughness of wires as a function of time of clinical use after 36 months. Oral pH showed a significant difference between group T36 and its control (P  =  .014).Conclusions:The hypothesis was partially accepted: treatment time and biofilm and debris accumulation in bracket slots were shown to have more influence on the degradation process and frictional force of these devices than did oral pH.     

Effect of lingual enamel sandblasting with aluminum oxide of different particle sizes in combination with phosphoric acid etching on indirect bonding of lingual brackets

Objective:To compare bond strength and bond failure location of lingual brackets indirectly bonded after lingual enamel sandblasting with 27-, 50-, and 90-µm aluminum oxide particles followed by 37% phosphoric acid etching.Material and Methods:Eighty maxillary premolars were randomly divided into four equal groups according to the method of lingual enamel surface conditioning: Group 1 (control) was etched with 37% phosphoric acid, and group 2, group 3, and group 4 were sandblasted with 27-, 50-, and 90-µm aluminum oxide particles, respectively, prior to acid etching. Lingual brackets were indirectly bonded using the same protocol and adhesive (Sondhi) in all groups. The maximum shear bond strength required to debond the brackets was measured using a testing machine, and the bond failure location was classified according to the adhesive remnant index (ARI). Analysis of variance was used to compare the mean bond strength between groups. The differences between ARI scores were evaluated using the Kruskal-Wallis test.Results:There were no statistically significant differences in mean shear bond strength or ARI scores between the four enamel-conditioning procedures.Conclusion:Lingual enamel sandblasting using different particle sizes of aluminum oxide prior to phosphoric acid etching did not increase the shear bond strength of indirectly bonded brackets and did not affect the amount of adhesive remnant on the enamel.     

Outcome assessment of lingual and labial appliances compared with cephalometric analysis,peer assessment rating,and objective grading system in Angle Class II extraction cases

Objective:To validate our hypothesis that there would be significant differences in treatment outcomes, including cephalometric values, degree of root resorption, occlusal indices, and functional aspect, between cases treated with labial and lingual appliances.Materials and Methods:Twenty-four consecutively treated Class II cases with extractions and lingual appliance were compared with 25 matched cases treated with extraction and labial appliance. Orthodontic treatment outcomes were evaluated by cephalometric analysis, peer assessment rating, and an objective grading system (OGS). Additionally, functional analysis was also performed in both groups after orthodontic treatment. Statistical comparison was performed using the Wilcoxon signed rank test within the groups, and the Mann-Whitney U-test was used to compare between the labial and lingual groups.Results:The only significant difference between the groups was that the interincisal angle was larger in the lingual group than in the labial group. OGS evaluation showed that control over root angulation was significantly worse in the lingual group than in the labial group. There was no significant difference between groups in the amount of root resorption or in functional evaluation.Conclusions:Generally, lingual appliances offer comparable treatment results to those obtained with labial appliances. However, care should be taken with lingual appliances because they are more prone to produce uprighted incisors and root angulation.     

Evaluation of soft tissue changes around the lips after bracket debonding using three-dimensional stereophotogrammetry

Objective:To evaluate the changes in soft tissue around the lips after orthodontic bracket debonding using three-dimensional (3-D) stereophotogrammetry.Materials and Methods:3-D facial images of 20 subjects (10 men and 10 women; mean age, 26.81 ± 7.23 years) were taken with a white light scanner before and after debonding the labial brackets. Two images acquired from each subject were superimposed, and 15 soft tissue landmarks around the lips were plotted and analyzed. Statistical analysis was performed using both paired and independent t-tests (P < .05).Results:There were no significant changes in position of any landmark on the x (left-right)- or y (vertical)-axes after removal of the brackets. However, the landmarks in the oral commissures and lower lip (LLP, −0.55 mm; Li, −0.44 mm; Ch-L, −0.56 mm, all P < .05) on the z (anteroposterior)-axis showed statistically significant differences. There were no significant positional changes of most landmarks on the x-, y-, or z- axes after bracket removal among the various genders and lip thicknesses.Conclusions:There was a slight retrusion in the oral commissure and lower lip areas after debonding, but no changes were found in the upper lip area. This study showed that 3-D stereophotogrammetry can be useful in evaluating facial soft tissue changes in orthodontic patients.