Comparison of AdvanSync and intermaxillary elastics in the correction of Class II malocclusions: A retrospective clinical study

Cephalometric evaluation of pharyngeal airway and tongue space following treatment with Herbst and AdvanSync appliances : A prospective randomized clinical trial

OBJECTIVES

To evaluate and compare pharyngeal airway and tongue space changes after treatment with fixed functional appliances-Herbst and AdvanSync™ (Ormco, Orange, CA, USA) appliances-in skeletal class II patients in pre- and posttreatment lateral cephalograms.

METHODS

For this randomized, controlled trial, 40 patients (21 male, 19 female) were divided into two groups-a Herbst group (mean age 12.6 ± 0.67 years) and an AdvanSync group (mean age 12.8 ± 0.66 years). Pre- and posttreatment (appliance therapy duration-8 months) lateral cephalograms were traced using a software program to evaluate pharyngeal airway and tongue space changes.

RESULTS

Nasopharyngeal airway, velopharyngeal airway, glossopharyngeal airway, and hypopharyngeal airway increased in the Herbst group by 2.12 mm (p ≤ 0.001), 2.33 mm (p ≤ 0.001), 2.40 mm (p ≤ 0.01), and 1.57 mm (p ≤ 0.05), while in the AdvanSync group the increases were 1.89 mm (p ≤ 0.001), 1.21 mm (p ≤ 0.001), 1.18 mm (p ≤ 0.001), and 1.53 mm (p ≤ 0.001), respectively. In the Herbst group, tongue length and height increases were 2.04 mm (p ≤ 0.01) and 3.74 mm (p ≤ 0.001), while the values in the AdvanSync group were 2.41 mm (p ≤ 0.05) and 2.69 mm (p ≤ 0.001). The change of the tongue tip from the lower occlusal plane was 0.69 mm (p ≤ 0.001) in the Herbst group and 0.77 mm (p ≤ 0.001) in the AdvanSync group. The velopharyngeal airway dimension was correlated positively with that of the retroglossal oropharyngeal airway, which in-turn positively correlated with the laryngopharyngeal airway which correlated well with the distance of the tongue tip from the lower occlusal plane.

CONCLUSIONS

The airway dimensions and tongue parameters increased significantly in both treatment groups in the present study. These changes were higher in the Herbst appliance than in the AdvanSync group, except for the distance of the tongue tip from the lower occlusal plane. A significant difference between the pharyngeal airways was found only for the retropalatal oropharyngeal airway.

A Comparative Analysis of Treatment Effects of PowerScope and AdvanSync2 in Class II Division 1 Malocclusion: A Retrospective Study

INTRODUCTION

Fixed functional appliances are widely used for the treatment of retrognathic mandibles in skeletal class II malocclusion. The primary objective of the present investigation was to evaluate and compare the treatment effects induced by PowerScope (American Orthodontics, Sheboygan, WI) and AdvanSync2 (Ormco, Orange, CA). The hypothesis posited that there were no notable disparities in the therapeutic impacts of the two appliances.

MATERIALS AND METHODS

A retrospective study was undertaken involving 90 subjects with retrognathic mandibles. Group 1 was treated with AdvanSync2, group 2 received PowerScope treatment, and group 3 consisted of an untreated class II control sample. Lateral cephalograms were traced at pre-treatment (T0) and post-treatment (T1), to measure various skeletal, dental, and soft tissue parameters. The comparison between the groups was done using analysis of variance (ANOVA) and post-hoc analysis by Tukey's test.

RESULTS

Significant changes were observed in all the parameters, comparing the effects of both appliances to the control group (p < 0.05). AdvanSync2 displayed statistically significant skeletal effects on the maxilla and mandible (p < 0.05). The statistically significant differences were also seen for dental effects such as reduction in overbite and overjet. On the other hand, PowerScope exhibited effects that were not considered statistically significant on the maxilla, instead primarily manifesting dento-alveolar changes that led to a considerable reduction in overbite. In comparison to the control group, both appliances notably produced soft tissue changes.

CONCLUSIONS

Our study rejected the null hypothesis. AdvanSync2 yielded superior skeletal outcomes with greater mandibular advancement, compared to PowerScope, which exhibited enhanced dento-alveolar alterations. AdvanSync2 took less treatment time, compared to PowerScope.

Orthodontic biomechanics with intermaxillary elastics

INTRODUCTION

Intermaxillary elastics are orthodontic resources widely used in various malocclusions. Their main advantages are low cost, easy insertion and removal by patients, and application versatility. As main disadvantages, we can highlight the need for cooperation from patients and the side effects normally present in treatments with this resource. Knowledge of the biomechanics involved in the use of intermaxillary elastics is essential to take full advantage of the desired effects and avoid unwanted effects in their use.

OBJECTIVE

Therefore, the objective of this article is to describe the anchorage preparation, connection methods, time and force of use, and side effects involved in the use of intermaxillary elastics for the treatment of anteroposterior, vertical and transverse problems. For that, clinical cases and biomechanics schemes will be presented, in which all these details will be described.

Evaluation of stress distribution patterns produced with the Advansync2 class II corrector - A finite element analysis

Background

This study used finite element modeling to investigate stress distribution patterns during treatment with Advan Sync 2 Class II correctors.

Methods

- A 3-D finite element model of the skull was constructed from images obtained from cone-beam computerized tomography images. Surface data of the AdvanSync2, brackets and archwires were derived and used to construct 3-D models. Stress distribution patterns and variations were assessed and quantified during appliance simulation and after advancement by 4 mm using spacers, on the finite element model.

Results

Stress levels were recorded in Megapascals (MPa) and were visualized with a color scale. Maximum stress was evident in the mandible near the neck of condyle, anterior part of ramus and medial part of the coronoid process. Maxillary and mandibular teeth experienced negligible stress. Stress levels increased on advancing the appliance with spacers, though the regions and patterns of stress concentration in the maxilla and mandible remained constant to a great extent.

Conclusion

The AdvanSync2 is an appropriate fixed functional appliance to correct Class II malocclusions with a retrognathic mandible, as it does not apply unnecessary and deleterious stresses on the maxillary and mandibular teeth.

Evaluation of Clinical Efficacy Between Forsus and Advansync Fixed Functional Appliance for the Treatment of Skeletal Class II Malocclusion Using 3D Cone Beam Computed Tomography (CBCT): A Prospective Randomized Clinical Trial

OBJECTIVES

The objective is to assess and compare whether AdvanSync gives better skeletal, dental, and soft tissue outcomes than Forsus fixed functional appliance in post-pubertal skeletal Class II malocclusion patients.

METHODOLOGY

A prospective study was conducted using 3D-CBCT of patients taken before and after fixed functional appliance therapy. The sample consisted of 16 patients divided into two groups: Group 1 was treated with Forsus and group 2 with AdvanSync appliance. All subjects were in their post-pubertal growth phase. Treatment changes were evaluated between the study groups using 12 angular and 14 linear parameters. The data were subjected to statistical analysis.

RESULTS

Statistically significant changes in SNB (P:0.04) and ANB (P:0.01) in Forsus appliance and AdvanSync (SNB, P:008), (ANB, P: <0.001) were found between the pre and post-fixed functional appliance protocol. The effective mandibular length increased in both groups Forsus(P-value: 0.01) and AdvanSync (P-value: 0.01). Group 1 resulted in lower incisor proclination and intrusion, a reduction in an overbite, whereas group 2 resulted in lower incisor proclination, upper incisor extrusion, and retroclination. Both groups showed significant improvement in the molar relation and overjet. An increase in the total facial convexity was shown in group 1; group 2 showed an increase in the facial convexity and total facial convexity. There was no statistically significant difference between the effects of the Forsus and Advansync appliance groups in the post-fixed functional period. Both groups presented similar results.

CONCLUSION

Forsus and Advansync appliances are effective with similar results in normalizing skeletal Class II malocclusion in post-pubertal patients. There was no statistically significant difference between the groups using Forsus or AdvanSync. The changes were minimal - mandibular skeletal effects, majorly dentoalveolar effects, and mild soft tissue effects.

Comparison of AdvanSync2® and Twin Block Appliances in Treatment of Class II Malocclusion With Retrognathic Mandible—An Observational Retrospective Study

Objectives:

To evaluate the treatment outcomes between Twin Block and AdvanSync2® appliances by comparing the skeletal, dentoalveolar, and soft tissue changes.

Materials and Methods:

Radiographic data of 20 patients were retrospectively analyzed. Data were selected from patients in their skeletal growth spurt as evaluated by the cervical vertebral maturation method (CVMI 2, 3, and 4), with class II malocclusion characterized with retrognathic mandible (ANB > 4°, SNB < 77°, FMA = 25 ± 5°, overjet > 5 mm). There were 10 patients in each group that underwent orthodontic correction for class II malocclusion: either using Twin Block or AdvanSync2®. Independent t test and Paired t test and chi-square tests were used for the data analysis. The level of statistical significance was set at P value ≤.05.

Results:

The chronological and skeletal age were similar in both the groups. Records were taken for the functional treatment with mean treatment span of 8 ± 1 month. Changes in SNB (group I = 1.59°, group II = 3.11°) ( P < .01), Co-Gn (group I = 2.89 mm, group II = 5.34 mm), and U1-L1° (group I = −1.51°, group II = 2.97°) showed statistically different outcome between the groups, when the pre-post data were studied. Rest of the variables—cranial base, maxillary skeletal, mandibular skeletal, intermaxillary, vertical skeletal, maxillary dentoalveolar, mandibular dentoalveolar, and soft tissue—showed similar outcome ( P > .05).

Conclusion:

Both appliances lead to desirable outcomes in the correction of class II malocclusion. AdvanSync2® resulted in inducing more of changes in SNB and effective mandibular length as compared to Twin Block. Overjet and molar relation improved significantly with both the appliances. Both the appliances resulted in similar skeletal, dentoalveolar, and soft tissue changes.

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.

Implications of pretreatment incisor inclinations for the achievement of cephalometric normal values-a study on two patient collectives

PURPOSE

The objective was to clarify whether standardized multibracket therapies-differing only in finishing-wire dimensions (0.016 × 0.022 inch vs. 0.017 × 0.025 inch CNA [Connecticut New Archwire]) and excluding any extraction treatment or additional appliances other than intermaxillary elastics-can produce normal incisor inclinations starting from different baseline inclinations.

METHODS

We analyzed pre- and posttreatment cephalograms of 156 patients (age: 15.6 ± 1.3 years) treated with Roth system (0.018 inch slot). Each archwire group (n = 89 or 67) was divided into subjects with initially retroclined, orthograde, or proclined upper and/or lower incisors (U1, L1). For the resultant 12 subgroups, descriptive statistics were compiled relative to five reference planes (NL, ML, NA, NB, BOP), followed by multiple intragroup (Kolmogoroff-Smirnoff and Wilcoxon signed-rank test) and intergroup (Kruskal-Wallis and Mann-Whitney U test) comparisons relative to NL or ML.

RESULTS

The following intra- (1, 2) and intergroup (3, 4) differences were statistically significant (p ≤ 0.05) in both archwire groups: (1) post- vs. pretreatment inclinations in the subgroups initially retroclined U1, retroclined L1 and orthograde U1, but without normal values being achieved (subgroups retroclined U1, L1) or preserved (subgroup orthograde U1); (2) observed vs. expected alterations for the subgroups initially orthograde and proclined U1 and L1; (3) posttreatment inclinations for the subgroups initially retroclined vs. orthograde L1 and proclined L1; (4) observed alterations for the subgroups initially retroclined vs. proclined U1 and L1, but neither retroclined nor proclined vs. orthograde. Archwire thickness influenced the outcome to only a limited extent under the special circumstances of this study.

CONCLUSION

The bracket/archwire combinations evaluated did not lead to normal incisor inclinations in most cases. Posttreatment values did significantly depend on the pretreatment situation. Most frequently, alterations were protrusive in direction, which notably even included incisors that showed norm values at the outset of treatment. It can be concluded that bracket torque will influence but not dominate incisor inclinations.

Effective and Efficient Correction of Severe Skeletal Class II Division 1 Malocclusion with Intermaxillary Elastics

Treatment of Class II malocclusion accompanied with a skeletal discrepancy is challenging. The approach of correction depends on several factors such as the status and pattern of growth, severity of the malocclusion, and patient cooperation. This case report describes a successful management of a 12-year-old young adolescent boy that was presented with a Class II division 1 malocclusion with an underlying skeletal discrepancy in horizontal and vertical dimensions. Growth modification was achieved by means of bite opening and unlocking the mandible together with Class II elastics and mechanics. Treatment was highly effective and efficient by achieving all treatment goals within a period of 18 months.

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 H‑Nose distance, and decrease in Sn‑H 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 H‑Nose distance, and decrease in Sn‑H 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.

Orthodontists' preference on type of rigid fixed functional appliance for skeletal Class II correction: A survey study

Background

Rigid fixed functional appliances are most commonly used to correct skeletal Class II malocclusions. The objective of this study was to assess orthodontists' preference of different rigid fixed functional appliances used in the U.S.A for correction of skeletal Class II malocclusions.

Material and Methods

A survey on use and preference of rigid fixed functional appliances for skeletal Class II correction was emailed to 2,227 members of the American Association of Orthodontists (AAO) in the U.S.A. Frequency distribution of different responses and their association with demographic factors was assessed.

Results

Out of 140 orthodontists completing the survey, 110 responded as using rigid fixed functional appliances. Eight incomplete responses were eliminated from data analysis. 51.5% (68/132) orthodontists used rigid fixed functional appliances. The most preferred rigid fixed functional appliance was the Herbst appliance with 72% response followed by Mandibular Anterior Repositioning Appliance (24%) and AdvanSync (4%). There was no statistically significant difference in use of rigid fixed functional appliances between different age groups (p=0.284). However, the 40-54 age group used the most rigid fixed functional appliances in practice, followed by the 25-39 year age group and the 55-69 age group using these appliances the least. There was statistical significance between the type of practice setting one works in and the use of rigid fixed functional appliances in practice (p=0.022).

Conclusions

About 52% of orthodontists use rigid fixed functional appliances to correct skeletal Class II malocclusions. The Herbst appliance is the most commonly used and most preferred amongst all rigid fixed functional appliances with a 72% preferred rate. Key words:Orthodontic, Rigid fixed functional appliance, Skeletal Class II, Class II Malocclusion, Mandibular retrognathism, Herbst, Mandibular Anterior Repositioning Appliance (MARA), AdvanSync, Molar to molar, M2M.

Therapeutic effectiveness of AdvanSync2 at different stages of skeletal maturity in skeletal Class II malocclusion: A single-blind clinical trial

Objectives:

AdvanSync2 (Ormco, Glendora, California, USA) is a molar-to-molar fixed Class II corrector, based on the philosophy of Herbst which allows the bonding of the both upper and lower arches simultaneously along with fixed functional therapy. The purpose of this study was to cephalometrically compare the skeletal and dentoalveolar effects of AdvanSync2 in the correction of Class II malocclusions in circumpubertal and post-pubertal patients.

Materials and Methods:

Forty-eight samples were selected and divided into two groups based on their CVMI staging, Group A, i.e., at CVMI Stages 2 and 3 (18 girls and six boys) and Group B, i.e., CVMI Stages 4, 5, and 6 (19 girls and five boys). Cephalograms taken at pre- and post-AdvanSync2 stages were compared and analyzed.

Results:

The results showed that there was a significant increase in mandibular length in both groups. Both the groups also showed sagittal maxillary restriction, maxillary molar distalization, and retroclination of maxillary incisors. On comparison between Group A and Group B, there was no statistically significant differences in terms of maxillary position, size of maxilla, as well as upper and lower incisor inclinations in Group A except for improvement of mandibular position (SNB; P ≤ 0.01) and greater amount of chin growth (B -Pg; P ≤ 0.01) with respect to Group B.

Conclusion:

AdvanSync2 can be used as an effective fixed functional appliance in post-pubertal group for sagittal mandibular correction in skeletal Class II patients.

Comparison of the dentoskeletal and soft tissue changes with the cervical headgear and Jones Jig followed by fixed appliances in Class II malocclusion patients: A retrospective study

OBJECTIVE

To retrospectively compare the dentoskeletal and soft tissue changes of patients with Class II malocclusion treated with cervical headgear and Jones Jig appliances, followed by fixed appliances.

MATERIAL AND METHODS

The sample comprised 46 Class II malocclusion patients divided into two groups. Patients with Class II malocclusion based on the ANB angle and plaster model analyses, needing non-extraction orthodontic treatment, absence of mandibular crowding and no previous orthodontic treatment were eligible to be selected. Group 1 consisted of 25 patients treated with cervical headgear (CH) followed by fixed appliances for a mean period of 3.26 years and group 2 consisted of 21 patients treated with the Jones Jig (JJ) appliance for a mean of 4.29 years. Lateral cephalograms were evaluated at the beginning and at the end of orthodontic treatment. For intergroup comparisons, t and Mann-Whitney tests were performed.

RESULTS

The cervical headgear group produced significantly greater maxillary anterior displacement restriction (SNA; CH: -0.97°±1.33; JJ: 0.07°±1.73; P=0.025), apical base discrepancy improvement (ANB; CH: -1.52°±1.25; JJ: 0.36°±1.46; P=0.006), FMA reduction (CH: -0.78°±2.68; JJ: 1.07°±2.84; P=0.028) and distal mandibular molar angulation (Md6.PM; CH: 6.97°±3.66; JJ: 2.77°±6.87; P=0.013) than the Jones Jig group.

CONCLUSIONS

Both distalizers followed by fixed appliances were effective to correct Class II malocclusion. The cervical headgear group presented skeletal effects with less treatment time and there were no significant intergroup differences regarding soft tissue changes.