Evaluation of the influence of mandibular third molars on mandibular anterior crowding relapse.

Objective: To evaluate the influence of mandibular third molars on relapse of mandibular anterior crowding in orthodontically treated patients.Material and Methods: Sample included orthodontic records of 108 patients: Group 1: 72 patients (39 female; 33 male) with third molars present in the postretention evaluation stage. Group 2: 36 patients (18 female; 18 male) who did not present the third molars in the postretention evaluation stage. Panoramic radiographs and dental models were evaluated at three different stages: pre-treatment; posttreatment and postretention. Panoramic radiographs showed the presence or absence of third molars in the 3 evaluated stages and on the dental models, overbite and mandibular anterior crowding was measured by the Little Irregularity Index. For intergroup comparisons, t-tests and a multifactorial regression analysis were used.Results: There was no statistically significant difference in the relapse of mandibular anterior crowding among the groups with and without mandibular third molars at the postretention stage.Conclusion: The presence or absence of mandibular third molars did not influence the relapse of mandibular anterior crowding in orthodontically treated patients.

Anterior open-bite treatment with bonded vs conventional lingual spurs: A comparative study.

INTRODUCTION: The purpose of this study was to compare the isolated effects of bonded and conventional spurs on the craniofacial and dentoalveolar complexes of patients in the mixed dentition with anterior open bite. METHODS: The sample included 68 subjects with anterior open bite and Class I malocclusion. Group 1 comprised 20 patients treated with bonded lingual spurs with a mean initial age of 9.31 years (SD, 1.17). Group 2 consisted of 21 patients treated with conventional lingual spurs with a mean initial age of 9.22 years (SD, 1.62). The control group (group 3) consisted of 27 untreated subjects. One-way analysis of variance tests followed by Tukey tests were used for intergroup cephalometric comparisons. After 1 month of treatment, patient acceptance of the spurs was evaluated with a questionnaire. RESULTS: There were significantly greater overbite increases in the experimental groups than in the control group. The group with bonded lingual spurs showed significantly better acceptance than did the group with conventional lingual spurs during chewing and eating. CONCLUSIONS: The 2 appliances resulted in similar overbite increases during early open-bite treatment. After a week or less of treatment, 92.5% of the children had adjusted to the spurs.

Dentoskeletal changes induced by the Jasper jumper and the activator-headgear combination appliances followed by fixed orthodontic treatment.

INTRODUCTION: The aim of this study was to compare the dentoskeletal changes of patients with Class II Division 1 malocclusion treated with either the Jasper jumper appliance or the activator-headgear combination, both associated with fixed appliances. METHODS: The sample comprised 72 subjects with Class II Division 1 malocclusion divided into 3 groups: group 1 included 25 subjects treated with fixed appliances and the force modules of the Jasper jumper at an initial mean age of 12.72 years, group 2 included 25 subjects treated with the activator-headgear combination followed by fixed appliances at an initial mean age of 11.07 years, and group 3 included 22 untreated subjects at an initial mean age of 12.67 years. Initial cephalometric characteristics and dentoskeletal changes were compared with analysis of variance. RESULTS: Both experimental groups had similar dentoskeletal changes: restrictive effect on the maxilla, clockwise mandibular rotation and a slight increase in anterior face height, retrusion of the maxillary incisors, distalization of the maxillary molars, protrusion of the mandibular incisors, extrusion of the mandibular molars, and significant improvements of the maxillomandibular relationship, overjet, overbite, and the molar relationship. CONCLUSIONS: The effects of the Jasper jumper and the activator-headgear combination followed by fixed orthodontic appliances were similar in Class II malocclusion treatment.

Comparison of deactivation forces between thermally activated nickel-titanium archwires.

OBJECTIVE: The aim of the present study was to investigate and compare load-deflection characteristics of commercially available thermally activated nickel-titanium archwires using a three-point bending test. MATERIALS AND METHODS: Sixty thermally activated 0.019×0.025-inch nickel-titanium archwires from six different manufacturers were investigated. The superelastic properties of these archwires were evaluated by conducting a three-point bending test under identical testing conditions. Forces generated at deactivation for a deflection of 0.5, 1, 2 and 3 mm at a temperature of 37° C were selected for statistical comparison of the data. The results of forces of deactivation at all deflections applied were compared by two-way analysis of variance and the Tukey test. RESULTS: Statistical differences (P<0.05) were found at all force levels during deactivations. The results showed that the range of forces displayed great variation in quantitative behaviour. None of the archwires showed permanent deformation after the three-point bending test. CONCLUSIONS: This study revealed significant differences in deactivation forces among the six types of thermally activated nickel-titanium archwires tested. NiTinol Termoativado (Aditek) and NeoSentalloy F200 (GAC) produced the least amount of force in all four deactivation categories.

Efficacy of Low-Level Laser Therapy in Reducing Pain in the Initial Stages of Orthodontic Treatment.

Purpose: There is no consensus about the mechanism and efficacy in alleviating pain of the lower-level laser therapy (LLLT) during orthodontic treatment. This study aimed to evaluate the LLLT effectiveness clinically in reducing pain caused by orthodontic movement that occurs in the early stages of treatment. Methods: The sample consisted of 54 patients in need of orthodontic treatment divided into two groups. A 28 experimental patients group (initial mean age: 26.84 years old) was undergone gallium-aluminum-arsenide infrared laser application on 12 points for each tooth immediately after the installation of the first alignment archwire, and a 26 patients control group (initial mean age: 29.13 years old) was undergone to no pain control intervention at all. Pain intensity was measured by using a visual analog scale, which was marked pain level (mm) reported in 06, 24, 48, and 72 hours. The perception of pain (beginning, peak, decline, and absence) was evaluated by filling up a questionnaire. To compare the intensity and perception of pain between groups, a nonparametric Mann-Whitney has been performed. Results: The experimental group showed levels (mm) at 6 (p < 0.001), 24 (p=0.004), and 48 hours (p=0.007) and perception of pain (hours) in the peak (p=0.026), decline (p=0.025), and absence (p=0.008) significantly lower compared to the group control. Conclusion: Low-level laser therapy is effective in reducing pain severity caused by orthodontic forces activation, and it promotes the analgesic action lasting effect during the most painful feeling time.

Treatment Effects of the Herbst Appliance in Class II Malocclusion Patients after the Growth Peak.

OBJECTIVE: The aim of this study was to evaluate dentoskeletal changes in the treatment of Class II malocclusion with the Herbst Cantilever Bite Jumper (CBJ) appliance, associated with multibracket appliances after the growth peak, at pretreatment. MATERIALS AND METHODS: A sample of 37 individuals was divided into two groups: the experimental group comprised 16 patients treated consecutively for a mean period of 2.52 years with the Herbst CBJ appliance associated with multibracket appliances. A total of 21 subjects (10 males and 11 females) with Class II malocclusion and mean age at T1 of 16.08 years were followed for a mean period of 2.12 years composed the control group. Comparisons between the two groups were performed using initial and final lateral cephalograms. Comparisons between experimental and control groups at pretreatment and of the treatment changes were performed by Mann-Whitney or independent t-tests. RESULTS: Experimental group exhibited a significantly greater labial inclination of the mandibular incisors in comparison to the control group. Additionally, significantly greater corrections in overbite, overjet, and molar relationship were observed in the experimental than in the control groups. CONCLUSION: The effects of the Herbst CBJ appliance, associated with fixed appliances after the growth peak in Class II malocclusion treatment are correction in molar relationship toward a Class I relationship, decrease of the overjet, decrease of the overbite, and mandibular incisors labial inclination.

Attractiveness of the facial profile: comparison of Class II patients treated with Twin Force® or intermaxillary elastics.

OBJECTIVE: To compare the facial profile attractiveness of Class II patients treated with Twin Force® or intermaxillary elastics. METHODS: Sample comprised 47 Class II patients divided into two groups: G1) TWIN FORCE - 25 patients treated with fixed appliances and Twin Force® fixed functional appliance (mean initial age was 17.91 ± 7.13 years, mean final age was 20.45 ± 7.18 years, and mean treatment time was 2.53 ± 0.83 years); G2) ELASTICS - 22 patients treated with fixed appliances and Class II intermaxillary elastics (mean initial age was 15.87 ± 5.64 years, mean final age was 18.63 ± 5.79 years and mean treatment time was 2.75 ± 0.60 years). Lateral cephalograms from pretreatment and posttreatment were used. Cephalometric variables were measured and silhouettes of facial profile were constructed and evaluated by 48 laypeople and 63 orthodontists, rating the attractiveness from 0 (most unattractive profile) to 10 (most attractive profile). Intergroup comparisons were performed with Mann-Whitney and independent t-tests. RESULTS: At pretreatment, facial profile of the Twin Force® group was less attractive than the Elastics group. Treatment with Twin Force® or Class II elastics resulted in similar facial profile attractiveness, but the facial convexity was more reduced in the Twin Force® group. Orthodontists were more critical than laypeople. CONCLUSIONS: Treatment with Twin Force® or Class II elastics produced similar facial profile attractiveness at posttreatment. Profile attractiveness was reduced with treatment in the elastic group, and improved in the Twin Force® group. Facial convexity was more reduced with treatment in the Twin Force® group.

Soft tissue profile changes in Angle class II patients treated with Twin Force or intermaxillary elastics-a comparison.

PROPOSITION: This study aimed to compare soft tissue profile changes in Angle class II malocclusion patients treated with a Twin Force appliance (Ortho Organizers, Inc., Carlsbad, CA, USA) or class II elastics. METHODS: The sample comprised 47 class II malocclusion patients treated orthodontically without extractions, divided into two groups. Group 1 (Twin Force): 25 patients were treated with the Twin Force, with initial and final mean ages of 17.91 and 20.45 years, respectively, and mean treatment time of 2.53 years. Group 2 (elastics): 22 patients were treated with class II elastics, with initial and final mean age of 15.87 and 18.63 years, respectively, and mean treatment time of 2.75 years. The lateral cephalograms were evaluated at the initial and final stages. Intragroup comparisons were performed with dependent t-tests and intergroup comparisons were performed with independent t-tests. RESULTS: Treatment-related changes in the Twin Force group included reduction of facial convexity, retrusion of the upper lip, increase of the H­Nose distance, and decrease in Sn­H distance, indicating improvement in facial profile. In the elastics group, treatment resulted in an increase in nasolabial angle, retrusion of the upper lip, increase of the H­Nose distance, and decrease in Sn­H distance, indicating improvement in facial profile. The Twin Force group showed a greater reduction of the facial convexity with treatment than the elastics group. CONCLUSIONS: Class II patients treated with the Twin Force appliance showed greater reduction in facial convexity than patients treated with class II elastics. The other soft tissue changes were similar for both groups.

Comparison of the facial profile attractiveness in Class III borderline patients after surgical or compensatory orthodontic treatment.

BACKGROUND: This study aimed to compare the facial profile attractiveness of Class III borderline patients after surgical or compensatory orthodontic treatment. MATERIAL AND METHODS: The sample consisted of 60 borderline Class III malocclusion patients, divided into two groups: Group 1 (Surgical): 30 patients (16 male; 14 female) treated with orthodontic fixed appliances and bimaxillary orthognathic surgery. Mean initial age was 20.05 years (s.d.=2.40) and mean treatment time was 2.23 years (s.d.=0.82). Group 2 (Compensatory): 30 patients (13 male; 17 female) treated compensatorily with fixed appliances and Class III elastics. Mean initial age was 18.53 years (s.d.=4.35) and mean treatment time was 2.08 years (s.d.=0.67). Silhouettes of the facial profile were constructed obtained from the pretreatment and posttreatment lateral cephalograms and evaluated by orthodontists (N=41, 22 females and 19 males, mean age of 35.65 years), assigning scores from 1 (least attractive) to 10 (most attractive). Intergroup comparison of profile attractiveness was performed by Mann-Whitney test. For intragroup comparison of initial and final stages, the Wilcoxon test was used. RESULTS: At initial stage, the compensatory group presented a statistically significant greater attractiveness of the profile than the surgical group. With treatment, the surgical group presented significantly more improvement in facial profile than the compensatory group. At the final stage, profile attractiveness of surgical and compensatory groups was similar. CONCLUSIONS: The facial profile attractiveness is similar in Class III patients after orthognathic surgery or compensatory orthodontic treatment. However, surgery provided more improvement in profile attractiveness than the compensatory treatment in Class III patients. Key words:Malocclusion, angle Class III, orthognathic surgery, corrective orthodontics.

Attractiveness of different esthetic orthodontic wires.

OBJECTIVE: The aim of this study was to evaluate the attractiveness of different types of esthetic orthodontic wires by laypeople and dentists. METHODS: Five different types of orthodontic wires were evaluated: three esthetic wires (Teflon-coated, epoxy resin-coated and rhodium-coated wires), and two metallic wires (stainless steel and NiTi), as control. Monocrystalline ceramic brackets were installed in the maxillary arch of a patient presenting good dental alignment. The five evaluated wires were attached to the orthodontic appliance with an esthetic silicone elastic and photographed. The photographs were evaluated by 163 individuals, 110 dentists and 53 laypeople. The data were statistically evaluated by two-way ANOVA and one-way ANOVA, followed by Tukey tests. RESULTS: There was a statistically significant difference in the attractiveness among the wires evaluated; the most esthetic was the rhodium-coated wire, followed by the epoxy resin-coated wire and, finally, the Teflon-coated wire, with no significant difference from the stainless steel and NiTi control archwires. There was no significant difference between the groups of evaluators. CONCLUSION: The most attractive was the rhodium-coated wire, followed by the epoxy resin-coated wire and, finally, the least attractive wire was the Teflon-coated wire, without statistically significant difference to the stainless steel and NiTi wires, used as control.

Comparison of Profile Attractiveness between Class III Orthodontic Camouflage and Predictive Tracing of Orthognathic Surgery.

OBJECTIVE: The aim of this study was to compare the profile attractiveness between orthodontic camouflage of the Class III malocclusion and the predictive tracing simulating orthognathic surgery evaluated by dentists and laypeople. Settings and sample population. The sample consisted of 21 patients (9 male; 12 female) with Class III malocclusion treated with orthodontic camouflage and Class III intermaxillary elastics. Material and Methods. The mean initial age of the patients was 24.38 years (SD 3.32), and the mean ANB angle was -1.91° (SD 0.83°). Patients presented skeletal Class III and normal growth patterns. Initial and final lateral cephalograms of each patient were used. The initial cephalogram was used to perform the treatment simulation of orthognathic surgery, and its silhouette was compared to the silhouette obtained from the final cephalogram after Class III orthodontic camouflage. A subjective analysis of profile attractiveness was performed by 47 laypeople and 60 dentists, with scores from 1 (less attractive) to 10 (most attractive). Mann-Whitney tests were used to compare profile attractiveness between the orthodontic treatment and the predictive tracing groups and between dentists and laypeople. RESULTS: The predictive tracing of orthognathic surgery showed to be statistically significantly more attractive (mean score 4.57, SD 2.47) than that of the Class III camouflage orthodontic treatment (mean score 4.22, SD 2.40), with a mean numerical but significant difference of 0.35 (SD 2.01) (P < 0.001). Laypeople were more critical than dentists in evaluating profile attractiveness, but numerical difference between the groups was also small. CONCLUSION: The profile silhouette of predictive tracing simulating orthognathic surgery showed to be more attractive than that of Class III camouflage orthodontic treatment; however, differences were small but statistically significant. Laypeople showed to be more critical than dentists.

Level of satisfaction in the use of the wraparound Hawley and thermoplastic maxillary retainers.

OBJECTIVE: To compare the level of satisfaction in the use of wraparound Hawley and thermoplastic maxillary retainers. MATERIALS AND METHODS: The study sample included 70 orthodontic patients (24 males and 46 females), who were in the retention stage (mean age = 20.80 years). All patients wore the two types of maxillary retainer for 1 month each, along with a 3×3 fixed mandibular retainer. After the use of each retainer, the patients responded to a questionnaire evaluating the level of satisfaction with their use of the maxillary retainer. Intergroup comparison was performed by independent t tests. Chi-square test was used to evaluate preference for the type of retainer by gender. RESULTS: The thermoplastic retainer was better for swallowing and the wraparound Hawley appliance was better for hygiene and durability. The other factors evaluated (adaptation, speech, comfort, esthetics, satisfaction, and fitting) did not show significant differences between the retainers. There was also no significant difference in preference for the appliances. CONCLUSIONS: Regarding the overall satisfaction and the preference, there was no difference between the wraparound Hawley and thermoplastic retainers. The wraparound Hawley appliance was better in hygiene and resistance than the thermoplastic retainer; and the thermoplastic appliance was better than the wraparound Hawley for swallowing fluids and saliva.

Relationship between malocclusion severity and treatment success rate in Class II nonextraction therapy.

INTRODUCTION: The purpose of this study was to evaluate the treatment success rate of Class II malocclusion without extractions, according to initial severity. METHODS: Class II subjects (n = 276) were divided into 2 groups according to the severity of the malocclusion. Group 1 comprised 144 patients with bilateral half Class II malocclusion at the initial mean age of 12.27 years. Group 2 comprised 132 patients who initially had bilateral complete Class II malocclusion at the initial mean age of 12.32 years. The patients' initial and final study models were evaluated with Grainger's treatment priority index. Chi-square tests were used to test for differences between the 2 groups for categorical variables. Variables regarding occlusal results were compared with independent t tests. RESULTS: Group 1 had a significantly better final occlusal result, a shorter treatment time, and a higher treatment efficiency index. CONCLUSIONS: Based on these results, it was concluded that bilateral half Class II malocclusion has a better treatment success rate than bilateral complete Class II malocclusion when treatment is conducted without extractions.

Comparison of WALA ridge and dental arch dimensions changes after orthodontic treatment using a passive self-ligating system or conventional fixed appliance.

OBJECTIVE: To compare changes in WALA ridge and mandibular dental arch dimensions in orthodontic patients treated with a passive self-ligating system and conventional appliances. DESIGN: Original paper. SETTING: Orthodontic department at Inga University Center, Maringá, PR, Brazil. MATERIALS AND METHODS: Pretreatment (T1) and posttreatment (T2) dental casts of 60 patients with Class I malocclusion treated with slight to moderate crowding that were divided into two groups. Group 1: 30 patients treated with a passive self-ligating system, at a mean initial age of 17.68 years and mean treatment time of 2.31 years. Group 2: 30 patients treated with conventional appliances, at a mean initial age of 19.23 years and mean treatment time of 2.56 years. Measurements were taken using a digital caliper directly on pre and posttreatment dental casts to evaluate the transversal dimension behavior of the mandibular dental arch and the WALA ridge width. RESULTS: Self-ligating group presented an increase in WALA ridge width and mandibular transversal dimensions significantly greater than the conventional group, with the exception of intermolar cusp tip distance and intercanine WALA ridge. There was no statistically significant difference between the groups. There was also observed a significantly greater increase of the transversal buccal axis dimensions in the premolar area when compared to the WALA ridge increase in both groups. CONCLUSIONS: Treatment with a passive self-ligating system resulted in a significantly greater increase of the WALA ridge width and mandibular arch dimensions when compared to conventional appliance.

Comparison of torque expression in esthetic brackets.

BACKGROUND: The objective of this work is to test the null hypothesis that there is no difference in the torque expression among different esthetic brackets. MATERIAL AND METHODS: Five ceramic self-ligating brackets (In-Ovation C - GAC, Damon Clear-Ormco, QuicKlear-Forestadent, Click-It -TP Orthodontics, Clarity SL-3M Unitek) and 4 ceramic conventional brackets (Inspire Ice-Ormco, InVu Ceramic-TP Orthodontics, Ceramic Roth-Morelli, Clarity Metal-Reinforced Ceramic Bracket-3M Unitek) were selected. Metallic Damon MX self-ligating bracket (Ormco) was used as control. Third-order moments were measured at 12º, 24º and 36º using an archwire torsion device associated with a Universal Testing Machine (EMIC DL2000), with 0.019x0.025-inch stainless steel wire. Anova followed by Tukey tests were used for intergroup comparisons. RESULTS: In all tested angulations the Damon Clear bracket presented the highest torque expression, followed by Clarity, Clarity SL and Damon Mx brackets, with the worst torque expression shown by the InVu Ceramic bracket. The InVu Ceramic demonstrated the largest while the Damon Clear brackets demonstrated the smallest slot height and clearance. CONCLUSIONS: The null hypothesis was rejected since torque expression was different among the esthetic brackets evaluated. It was also concluded that the slot height is directly related to torque expression. Key words:Torque, orthodontic brackets, orthodontic appliances, incisor, ceramics.

Comparison of the Force Released by Intermaxillary Elastics Used for Different Time Periods.

OBJECTIVE: The objective of the present study was to compare the strength degradation of the force of intermaxillary elastic used for different periods. METHODS: The sample included intermaxillary elastics used for 20 adult patients with bilateral Class II or III malocclusion in orthodontic treatment with fixed appliances, with a mean age of 27.25 years. Latex orthodontic elastics with 3/16 inch of diameter were used, with an average stretching of three times its diameter. The elastics were used in the same patient bilaterally for different periods, with each pair of elastics used for 1, 12, 24, and 48h. Thus, the sample consisted of 200 elastics, with 40 being used in each period (one pair used by each patient) and 40 new elastics without use tested as control. Elastics were tested using a universal testing machine, stretched with a velocity of 30 mm/min, and the force was evaluated in stretches of 15, 20, 25, and 30 mm. The degradation force was compared in the four different times of use and control by one-way ANOVA (analysis of variance) and Tukey tests. RESULTS: There were significant differences among the groups in all evaluated stretches (15, 20, 25, and 30 mm). The control elastics presented higher average forces numerically and statistically significant for all tested times, except for the elastic used for 1h. The elastics used for 1, 12, and 24h had similar forces among them, with a significant difference to the elastics used for 48h. CONCLUSION: It is recommended to change the intermaxillary elastics after 24 h of use.

Occlusal outcomes and efficiency of 1- and 2-phase protocols in the treatment of Class II Division 1 malocclusion.

INTRODUCTION: The purpose of this study was to compare the occlusal outcomes and the efficiency of 1-phase and 2-phase treatment protocols in Class II Division 1 malocclusions. Treatment efficiency was defined as a change in the occlusal characteristics in a shorter treatment time. METHODS: Class II Division 1 subjects (n = 139) were divided into 2 groups according to the treatment protocol for Class II correction. Group 1 comprised 78 patients treated with a 1-phase treatment protocol at initial and final mean ages of 12.51 and 14.68 years. Group 2 comprised 61 patients treated with a 2-phase treatment protocol at initial and final mean ages of 11.21 and 14.70 years. Lateral cephalometric radiographs were taken at the pretreatment stage to evaluate morphological differences in the groups. The initial and final study models of the patients were evaluated by using the peer assessment rating index. Chi-square tests were used to test for differences between the 2 groups for categorical variables. Variables regarding occlusal results were compared by using independent t tests. A linear regression analysis was completed, with total treatment time as the dependent variable, to identify clinical factors that predict treatment length for patients with Class II malocclusions. RESULTS: Similar occlusal outcomes were obtained between the 1-phase and the 2-phase treatment protocols, but the duration of treatment was significantly shorter in the 1-phase treatment protocol group. CONCLUSIONS: Treatment of Class II Division 1 malocclusions is more efficient with the 1-phase than the 2-phase treatment protocol.