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Background: This study aimed to compare the soft tissue effects of Herbst appliance in Class II malocclusion patients treated in three different craniofacial growth phases: prepubertal (PRE), circumpubertal (CIR), and postpubertal (POS)., Methods: In total, 95 patients with Class II Division 1 malocclusion previously treated with a Herbst appliance were analyzed. Through the cervical vertebral maturation stages method, patients were allocated into three groups depending on the growth craniofacial phase at the beginning of treatment: PRE, CIR, and POS. Seventeen cephalometric measures were evaluated from each lateral radiograph before and after Herbst therapy using the Radiocef 2 software (Radio Memory, Belo Horizonte). Intragroup and intergroup treatment changes were compared statistically using a paired t test and MANOVA test, respectively., Results: Soft tissue thickness changes were related only to mandible; all three mandibular measurements (L1_LL, B_B', and Pog_Pog') showed thickening for the PRE group ranging from 0.92 mm (Pog_Pog') to 2.02 mm (B_B'), and only lower lip thickened overtime for the POS group (L1_LL = 0.99 mm). Soft and hard tissue pogonion displaced anteriorly, but only the soft tissue showed differences among groups; PRE group presented more anterior displacement than POS group (3.61 mm and 1.39 mm, respectively). Hard and soft tissue facial convexity decreased more in the PRE and CIR groups than in the POS group. Mentolabial sulcus depth reduced more in the PRE (1.07 mm) and CIR (1.29 mm) groups than in the POS (0.55 mm) group. Horizontal movement of the skeletal and soft pogonion presented a moderate-high positive correlation (r = 0.783), and hard and soft facial convexity showed a moderate-low positive correlation (r = 0.403)., Conclusions: Herbst appliance therapy produces soft tissue improvements in the three phases of craniofacial growth, being greater in patients in the PRE and CIR phases., (Copyright © 2023 World Federation of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The objective of this study was to compare the skeletal and dental changes of patients with a Class II relationship treated with clear aligner mandibular advancement (MA) and Herbst appliances followed by comprehensive orthodontic treatment., Methods: The participants included 20 patients treated with MA and 20 with the Herbst appliance. Orthodontic records were taken before treatment, after the functional appliance, and completion of phase II treatment. The skeletal and dental changes across the 3-time periods were evaluated using a matched paired t test for each treatment. A 2-sample t test was used to examine the changes across periods between 2 treatment groups (P <0.05)., Results: Significant reduction in overjet, overbite, and change in molar relationship were obtained by both appliances with similar skeletal and dental contributions. This was contributed by a forward movement of the mandible and mandibular molars, backward movement of the maxillary molars, and retraction of the maxillary incisors. After phase II treatment, both appliances could maintain the skeletal and dental changes achieved during the advancement phase. Greater change in overbite (2.4 mm vs 1.4 mm), an eruption of maxillary incisors (0.9 mm vs 0.1 mm), and proclination of mandibular incisors were found with the Herbst group (3.9° vs -2.1°). The average total treatment time was similar with the 2 appliances., Conclusions: Both functional appliances were equally effective in reducing the overjet and overbite and achieving a Class I molar relationship with a similar length of treatment time. The Herbst design lacked control of the mandibular incisor proclination, and clear aligners offered better vertical control and management of the mandibular incisor inclination., (Copyright © 2023 American Association of Orthodontists. All rights reserved.)

Introduction: This study aimed to quantify the outcomes of adolescent patients with Class II malocclusion treated with the Carriere Motion 3D Appliance (CMA) combined with full fixed appliances., Methods: Cone-beam computed tomography scans of 22 patients were available before orthodontic treatment (T1), at removal of the CMA (T2), and posttreatment (T3). The average age of the patients was 13.5 ± 1.6 years at T1, 14.1 ± 0.2 years at T2, and 15.6 ± 0.5 years at T3. The 3-dimensional image analysis procedures were performed using ITK-SNAP (version 3.6.0; www.itksnap.org, Hatfield, Pa) and SlicerCMF (version 4.11.0; http://www.slicer.org, Cambridge, Mass); skeletal and dentoalveolar changes relative to cranial base, maxillary, and mandibular regional superimpositions were evaluated., Results: Changes were analyzed with 1 sample t tests using the mean differences during the CMA phase (T1 to T2) and total treatment time (T1 to T3). Significant skeletal changes included a slight reduction of ANB from T1 to T3, mandibular growth (Co-Gn increment of 1.2 mm and 3.3 mm from T1 to T2 and T1 to T3, respectively), inferior displacement of point A, and anterior and inferior displacement of point B. The mandibular plane did not change significantly during treatment. During the CMA treatment, posterior tipping and distal rotation of the maxillary molars, tip back and inferior displacement of the maxillary canines, significant mesial rotation, and superior displacement of the mandibular molars were observed. These movements rebounded during the full fixed appliance phase except for the molar and canine vertical displacements. Clinically significant dental changes during treatment included a reduction in overjet and overbite, Class II correction of the molar and canine relationship, and proclination of the mandibular incisors., Conclusions: The CMA is an effective treatment modality for Class II correction in growing patients because of a combination of mesial movement of the mandibular molar, distal rotation of the maxillary molar, and anterior displacement of the mandible., (Copyright © 2023 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The mechanical distribution of the mandible is an important factor that affects functional orthosis during Twin-block (TB) appliance correction. Changes in the mandible before and after TB appliance correction are also key factors in maintaining the therapeutic effect. Finite element analysis, a powerful numerical, analytical tool, is widely used to predict the stress and strain distribution of the craniofacial bone that orthodontics generates., Methods: The sample was a 14-year-old male patient with Class II malocclusion during growth. A cone-beam computed tomography scan was undertaken at pretreatment and posttreatment. In the Finite element analysis of the pretreatment model, the remote displacement model of the mandible was established with the sella point as the center. A mandibular model under TB appliance loading was established. Its mandibular displacement and von Mises stress were compared before and after loading. Three-dimensional registration was conducted on the pretreatment and posttreatment models to measure the sagittal displacement of the centrosome., Results: The force on the mandible occurred mainly in the condyle neck and medial mandible after the TB appliance moved the mandible. After displacement, the posterior upper margin of the condyle was farther away from the articular fossa. Three-dimensional registration results showed that new bone had formed behind and above the condyle after TB appliance treatment., Conclusion: The TB appliance provides additional advantages in treating skeletal Class II malocclusions by helping to reduce the burden on the temporomandibular joint and promoting the adaptive reconstruction of the mandible., (Copyright © 2023 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: This 2-arm parallel study aimed to compare and evaluate the efficiency of Hanks Herbst (HH) and Twin-block (TB) functional appliances in treating adolescents with Class II malocclusion., Methods: A parallel-group randomized controlled trial was undertaken in a single United Kingdom hospital. Eighty participants were recruited and randomized in a 1:1 ratio to receive either the HH or TB appliance. Eligibility criteria included children aged 10-14 years with an overjet of ≥7 mm without dental anomalies. The primary outcome was the time (in months) required to reduce overjet to normal limits (<4 mm). Secondary outcomes included treatment failure rates, complications and their impact on oral health-related quality of life (OHRQOL). Randomization was accomplished using electronic software with allocation concealed using sequentially numbered, opaque, and sealed envelopes. Blinding was only applicable for outcome assessment. Data were analyzed using descriptive statistics and regression analyses to detect between-group differences, including Cox regression for time to treatment success., Results: HH was significantly faster than TB in reducing the overjet to within normal limits (95% confidence interval [CI], -3.00 to -0.03; P = 0.046). Mean overjet reduction was more efficient with the HH than the TB appliance (ß = 1.3; 95% CI, 0.04-2.40; P = 0.04). Fifteen (37.5%) of the participants in the TB group and 7 (17.5%) in the HH group failed to complete the treatment (hazard ratio = 0.54; 95% CI, 0.32-0.91, P = 0.02). However, TB was associated with fewer routine (incidence rate ratio = 0.81; 95% CI, 0.7-0.9; P = 0.004) and emergency (incidence rate ratio = 0.1; 95% CI, 0.1-0.3; P = 0.001) visits. Chairside time was greater with the HH (ß = 2.7; 95% CI, 1.8-3.6, P = 0.001). Participants in both groups experienced complications with similar frequency. A greater deterioration in OHRQOL was found during treatment with the TB., Conclusions: Treatment with HH resulted in more efficient and predictable overjet reduction than TB. More treatment discontinuation and greater deterioration in OHRQOL were observed with the TB. However, HH was associated with more routine and emergency visits., Registration: ISRCTN11717011., Protocol: The protocol was not published before trial commencement., Funding: No specific external or internal funding was provided. Treatment for participants was provided as part of routine orthodontic treatment in the hospital., (Crown Copyright © 2023. Published by Elsevier Inc. All rights reserved.)

Background: Herbst therapy is an effective treatment for Class II malocclusions. However, the maintenance of the effects after fixed appliances treatment remains questionable. This retrospective study aimed to assess, using digital dental models, the sagittal and transverse dental arch changes in young patients during two Class II Division 1 treatment phases, first with modified Herbst appliance (HA) and then with fixed appliances., Methods: The treated group (TG) comprised 32 patients (17 boys, 15 girls; mean age, 12.85 ± 1.16 years) treated with HA and fixed appliances. The control group comprised 28 patients (13 boys, 15 girls; mean age, 12.21 ± 1.35 years) with untreated Class II malocclusions. Digital models were obtained immediately before and after HA therapy and after fixed appliances. Data were statistically analyzed., Results: Compared with the control group, the TG showed an increase in maxillary and mandibular arch perimeters and in intercanine and intermolar arch widths, a decrease in overjet and overbite, and an improvement in canine and molar relationships. In the time after HA therapy until the end of fixed appliances treatment, the TG showed a decrease in maxillary and mandibular arch perimeters, overjet, upper and lower intermolar widths; an increase in molar Class II relationship; and no changes in canine relationship, overbite, and upper and lower intercanine widths., Conclusions: In this sample of patients treated with HA, on average, there was an improvement in the Class II relationship, which seemed to remain after fixed appliances. The transverse dental changes achieved in HA phase relapsed after treatment with fixed appliances., (Copyright © 2023 World Federation of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: In this study, we compared the effects of functional treatment with Twin-block appliance on the bony architectures of the maxilla and mandible by fractal dimension (FD) analysis, and the skeletal and dentoalveolar effects by cephalometric analysis, in pubertal and postpubertal patients with Class II malocclusion., Methods: This study comprised 60 patients who underwent Twin-block treatment. Group 1 consisted of 30 patients in the pubertal period (6 boys and 24 girls; mean age 12.27 ± 1.35 years), whereas group 2 consisted of 30 patients in the postpubertal period (6 boys and 24 girls; mean age 13.73 ± 1.51 years). FD analysis was performed on the patients before and after Twin-block panoramic and lateral cephalometric radiographs. Cephalometric analysis was also conducted. Paired and Student t tests were used to compare the parametric data, and Wilcoxon signed rank and Mann-Whitney U tests were conducted to compare the nonparametric data., Results: SNB, Pg-N, N-Me, ANS-Me, IMPA, L1/NB, Co-Gn, Go-Gn, S-Go, Co-Go, and Go-Me significantly increased in both groups after treatment. FD values of tuber, condyle, and molar regions significantly decreased in group 1, whereas no significant differences were observed in group 2 after treatment., Conclusions: In the pubertal period, the Twin-block appliance resulted in skeletal correction by causing bone remodeling and reshaping in both jaws along with the dentoalveolar correction. In the postpubertal period, Twin-block had no significant effect on the bone trabecular arrangement in the investigated areas but produced cephalometric improvement to a certain extent with lower skeletal and higher dental impact., (Copyright © 2022 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: Orthodontic treatment procedures affect oral health-related quality of life. This study analyzed and compared the patients using the Frankel 2 Regulator (FR2) and Twin-block (TB) orthodontic appliances., Methods: This follow-up observational study comprised adolescents aged 10-16 years with Class II malocclusion seeking orthodontic treatment, between April and December 2019, in a private orthodontic clinic. Following the finalization of orthodontic clinical decisions, 88 patients, in a 1:1 ratio, using FR2 (n = 44) and TB (n = 44) appliances, were invited to participate in this study. An Oral Health Impact Profile-14 (OHIP-14) questionnaire was answered by the participants at 5-time points: before treatment, 1 week, 1 month, 3 months, and 6 months after wearing functional appliances. A mixed model for repeated measurements tested the OHIP-14 score mean differences over time among appliance groups and group by time interaction., Results: The TB group consisted of 15 males and 29 females, and the FR2 group included 21 males and 23 females. The mean age of participants was 12.18 ± 1.29 years. The mean of OHIP-14 scores in FR2 users was significantly lower than the TB appliance group at all intervals (P <0.05). Although the total score of OHIP-14 increased 1 week after appliance wearing, it declined during the 1, 3, and 6 months after wearing appliances in both groups., Conclusions: The results can help orthodontists better select treatment approaches by considering their effect on oral health-related quality of life., (Copyright © 2022 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The objective of this study was to compare the cephalometric changes in Class II Division 1 malocclusion patients treated with the Twin-block (TB) and the mandibular anterior repositioning appliance (MARA)., Methods: This retrospective study was performed with 132 lateral cephalograms of patients with Class II malocclusion divided into 3 groups: a TB group comprised 21 patients with mean initial and final ages of 10.59 and 11.97 years, respectively, treated for a mean period of 1.38 years; a MARA group comprised 21 patients with mean initial and final ages of 11.98 and 13.20 years, respectively, treated for a mean period of 1.22 years; and a control group included 24 subjects with untreated Class II malocclusion with mean initial and final ages of 10.55 and 12.01 years, respectively, observed for a mean period of 1.46 years. Cephalometric intergroup comparisons regarding the treatment changes (T2 - T1) were performed with the analysis of covariance, followed by Tukey tests., Results: Both appliances demonstrated significant restriction of the maxilla and improvement of the maxillomandibular relationship. The MARA produced a significantly greater amount of labial tipping and protrusion of the mandibular incisors than the other groups. The TB showed significant extrusion of the mandibular incisors and molars compared with MARA and control, respectively. Both treated groups reduced the overjet and overbite. The MARA presented a significantly greater reduction in the molar relationship than the other groups., Conclusions: The appliances showed a headgear effect on the maxilla and effectively changed Class II cephalometric parameters through a combination of skeletal and dentoalveolar effects. TB showed a greater increase in LAFH. MARA promoted greater labial tipping and protrusion of the mandibular incisors., (Copyright © 2022 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: Fixed functional appliances have been used to treat Class II malocclusion by a huge number of professionals. This retrospective study aimed to analyze the effects of the Forsus fatigue-resistant device and compare the findings with a well-matched group treated with the mandibular anterior repositioning appliance (MARA)., Methods: The Forsus group was composed of 14 patients at an initial mean age of 12.4 ± 1.3 years, treated with the Forsus fatigue-resistant device followed by a fixed orthodontic appliance. The MARA group comprised 18 patients at an initial mean age of 12.1 ± 1.3 years, treated with MARA followed by fixed orthodontic appliances. The untreated control group consisted of 14 patients matched with the other groups. Posttreatment changes were calculated as T1 - T2. Intergroup comparisons regarding treatment changes were performed using repeated-measures analysis of variance followed by Tukey's test., Results: During treatment, the Forsus group showed a statistically significant decrease in maxillary protrusion and maxillomandibular sagittal discrepancy in the control group. The MARA group showed significantly greater retrusion of maxillary incisors than the Forsus and the control group. Overjet decreased significantly more in the treated groups in relation to the control group. Molar relationship improved significantly more in both treated groups, and both showed more correction than the untreated control group., Conclusions: The Forsus and MARA associated with fixed appliances effectively corrected the Class II malocclusion, mostly using dentoalveolar changes and maxillary growth restriction., (Copyright © 2022. Published by Elsevier Inc.)

Introduction: This study aimed to determine the influence of Clark's twin block (CTB) appliance therapy on achieving golden proportion in post-treatment facial profiles in skeletal Class II patients., Methods: A retrospective longitudinal study was conducted on a sample of 44 skeletal Class II subjects treated with CTB, followed by nonextraction mechanotherapy. Ricketts' 13 dentoskeletal ratios were measured on pre- and post-treatment lateral cephalograms. Paired Student's t test was used to analyze the existence of golden proportion in the values of the pre- and post-treatment ratios. The influence of pretreatment variables was tested on post-treatment ratio 4 using simple and multiple linear regression analyses., Results: A statistically significant difference in pre- and post-treatment values was found for ratios 4 (P = 0.02), 9 (P = 0.04), 10 (P < 0.001), and 13 (P = 0.01). Ratios 4, 9, and 13 moved closer to the golden proportion, whereas ratio 10 moved away from the golden proportion after CTB therapy. Simple linear regression analysis showed a statistically significant association of post-treatment ratio 4 with pretreatment ratios 1, 4, 8, 9, and 12. Multiple linear regression analysis showed a statistically significant association of post-treatment ratio 4 with pretreatment ratios 4 and 12., Conclusions: Treatment with CTB appliance may well move various facial ratios in individual patients toward the published Ricketts ideals. Ricketts' published golden proportion may be used as one guide when planning for attempted dentofacial change in individual patients., (Copyright © 2022 World Federation of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Removable appliances are an important part of orthodontic treatment. The Twin-block is widely used for Class II correction. Traditionally, an impression, bite registration, and mounted plaster casts are required to fabricate the acrylic appliance, which usually requires a specialized laboratory. This makes the process expensive and also time-consuming. This paper aims to present an innovative approach for the virtual design and direct printing of removable orthodontic appliances, particularly the Twin-block, that can be done in-office without the need for casts or a specialized laboratory., (Copyright © 2022 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: This study aimed to assess sagittal and vertical skeletal and dentoalveolar changes through the use of 3-dimensional imaging in prepubertal Class II malocclusion patients treated with a cantilever Herbst appliance (HA). Condyle-glenoid fossa positional changes were also quantified., Methods: This retrospective cohort study assessed 22 children (11.2 years ± 1.2) consecutively treated with a cantilever HA for 12 months and 11 untreated children (aged 9.3 ± 0.30 years) that served as controls. Cone-beam computed tomography was performed at baseline (T1) and at the end of the observation period (T2). Movements in the regions of interest were measured as linear displacements from cone-beam computed tomography images through algebraic calculations. A Student t test for independent samples was used for group equivalence testing at T1, and the treatment differences between T2 and T1 were evaluated by 2 analyses of covariance, one considering the expected growth unit as a covariate and the other with an annualized factor., Results: The largest dental movement was a mesial movement of mandibular molars (3.70 mm), whereas the largest skeletal changes consisted of a larger relative length of the mandible (difference of 1.2 mm) in the HA group than in the control group., Conclusions: Within the study limitations (retrospective cohort, historical control group, and sample size), 3-dimensional imaging suggests that HA corrected Class II malocclusion in a predominantly prepubertal sample through more dental than skeletal changes. The changes were more significant in the sagittal than in the vertical direction. In addition, relative stability in the condyle-fossa relationship was noted., (Copyright © 2021 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The objective was to describe the dental and skeletal changes obtained using the Carriere Motion Appliance (CMA), lateral cephalogram, and the corresponding cephalometric tracings., Methods: A sample of 29 patients with Class II malocclusion (mean age, 12.6 ± 1.7 years) was retrospectively selected. All patients were treated at a single center using a CMA as the primary sagittal correction device. Cephalometric tracings at the beginning and end of treatment were compared. Each cephalometric tracing was performed 3 times by the same operator., Results: Using the CMA, the 29 patients studied reached dental Class I in 4.4 ± 0.98 months. All measurements were subjected to statistical analysis, paired t test, and all displayed differences between T0 and T1 (P <0.05) except for the SNA. At the end of treatment, the Wits and ANB values were reduced by 1.38 mm and 0.8°, respectively. Overbite and overjet were also reduced by 1.4 mm and 2 mm, respectively. The SNB, FMA, LAFH, and IMPA increased to a lesser extent (ie, 0.7°, 0.4°, 1.5 mm, and 1.5°, respectively)., Conclusions: The CMA is a rapid and efficient means of correcting Class II malocclusion. Its effects are predominantly dentoalveolar, with minimal skeletal alteration of little clinical significance., (Copyright © 2021 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Background: The aim of this study was to investigate the association between objective wear time and treatment efficacy of a twin block (TB) appliance., Methods: A TB appliance incorporating a compliance indicator was delivered to 44 children in the age group of 11-14 years (25 boys and 19 girls). Participants were instructed to wear the appliance full time and were recalled at 3-4- week intervals. Cephalograms and study models were taken at baseline and after 6 months of appliance therapy., Results: Data from 41 of the 44 participants were analyzed. A wide variation in daily wear time among participants was observed. Based on wear time, they were divided into full time (FT >17 h/d) and part time (PT < 12 h/d) wear groups. Mean wear durations were 20.86 hours in the FT-wear group and 9.55 hours in the PT-wear group. In skeletal changes, the ANB (A point, nasion, B point) angle was reduced by 2.69° in the FT-wear group, and 1.33° in the PT-wear group, and statistically significant increases were seen for the mandibular base measurement (Pg/OLp) in the FT-wear group (2.22mm), compared with those in the PT-wear group (0.44mm). . In dental changes, overjet were reduced by 3.91 mm and 2.0 mm in the FT-wear and PT-wear group, respectively. This difference was statistically significant., Conclusions: Skeletal effects were pronounced in the FT-wear group, and dentoalveolar changes were comparable in the 2 wear groups. The maximum skeletal treatment effect of a TB appliance was found to occur with FT wear over a 6-month treatment period., (Copyright © 2021 World Federation of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The purpose of this research was to compare dentoskeletal changes produced by Herbst and Xbow appliances in late mixed/early permanent dentition patients with Class II Division 1 malocclusion to an untreated control group., Methods: The retrospective cohort consisted of 41 patients treated with the Herbst appliance on average for 14 months (mean age of 11.3 years), 41 patients treated with Xbow appliance on average for 14 months (mean age of 11.11 years), and an untreated control sample of 25 patients followed on average for 21 months (mean age of 11.9 years). All patients had Class II Division 1 malocclusion characteristics. Lateral cephalometric radiographs were taken before and after phase 1 treatment/follow-up. Data were analyzed by an analysis of variance followed by Tukey post-hoc tests., Results: Although there was a high equivalence among the groups in the pretreatment cephalometric values, 4 variables showed differences (U6-FHp, L6-FHp, LAFH, and PP-U1). When comparing the mean changes (before and after phase 1 treatment/follow-up), incisor mandibular plane angle (IMPA), Wits appraisal, L6-FHp, Co-Pog, and PP-U1 measurements showed statistically significant differences. In addition, more relative mesial movement of the mandibular molars (an additional 2.4 mm) and a larger increase in mandibular length (an additional 3.2 mm) was noted for the Herbst group., Conclusions: Class II correction using Herbst and Xbow occurred in both groups through improvement in the maxillomandibular relationship and labial inclination of the mandibular incisors, as well as a relatively increased mesialization of the mandibular molars. Although both appliances improve occlusal features, the portrayed changes were not always similar. Herbst seems to produce more mandibular size increase over a similar treatment period., (Copyright © 2021 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: As a powerful numerical approximation tool, finite element analysis (FEA) has been widely used to predict stress and strain distributions in facial bones generated by orthodontic appliances. Previous FEA models were constructed on the basis of a linear elastic phase of the bone response (eg, elastic bone strains to loading). However, what is more useful for clinical understanding would be predicting long-term strains and displacements of bone-segments responding to loading, yet tissue responses are (1) not promptly observable and (2) hard to predict in nature., Methods: Viscoelastic property of the mandibular bone was incorporated into FEA models to visualize long-term, time-dependent stress and strain patterns in the mandible after being exposed to orthopedic stress. A mandible under loading by a Herbst appliance was modeled, and outcomes of the constructed elastic and viscoelastic models were compared., Results: Patterns and magnitudes of the displacement throughout the mandible predicted by the viscoelastic model were exhibited in accordance with previous clinical outcomes of Herbst appliance therapy. The elastic models exhibited similar displacement patterns; however, the magnitude of the displacements in the models was invariably small (approximately 1 per 100) compared with those outputs of corresponding viscoelastic models. The corresponding maximum stress level in our viscoelastic mandible subjected to the Herbst appliance with the same loading was considerably low and relaxed in various regions when compared with the elastic model., Conclusions: We suggest that a viscoelastic model of the mandible mimics our general prediction of orthopedic treatment outcomes better than those by elastic models., (Copyright © 2020. Published by Elsevier Inc.)

Introduction: This research aimed to compare treatment effects of functional appliances between children with and without morphologic deviations in the upper spine and analyze associations between Atlas dimensions and the short- and long-term treatment effects., Methods: Sixty-eight prepubertal or pubertal children (35 boys and 33 girls; mean age, 11.47 ± 1.39 years) treated with Class II functional appliances were included. Lateral cephalograms were taken at pretreatment (T1), postfunctional appliance treatment (T2), and after retention at postpuberty (T3). Upper spine morphology and Atlas dimensions were evaluated at T1. T1-T2 and T1-T3 lateral cephalograms were superimposed using a structural method. Changes in the jaws were compared with multiple linear regression analysis between children with and without deviations in the upper spine. Associations between the changes and Atlas dimensions were analyzed by partial correlation., Results: Children with morphologic deviations in the upper spine showed significantly more backward rotation of the mandible (P <0.01) and increased inclination of the jaws (P <0.05, P <0.01) from T1-T2 and significantly smaller condylar growth (P <0.01) from T1-T3 compared with children without the deviations. Atlas height was significantly associated with vertical and rotational changes in the mandible (P <0.01) from T1-T2 and condylar growth (P <0.05) from T1-T2 and T1-T3., Conclusions: Morphologic deviations in the upper spine and low Atlas height were significantly associated with smaller condylar growth induced by functional appliances in the long term. Upper spine morphology and the Atlas dimension may be valuable in phenotypic differentiation in children with Class II malocclusion for optimal treatment outcome., (Copyright © 2021 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Background and Objectives: Class II malocclusion is one of the most common orthodontic problems. The Twin Block appliance has proven to be the most popular appliance for the correction of these malocclusions. Although randomized controlled trials (RCTs) on the Twin Block appliance have reported the changes to be mainly dentoalveolar, several nonrandomized studies have reported a significant skeletal improvement in these patients. Hence, the aim of this study was to compare the effectiveness of Twin Block appliance evaluated using an RCT or retrospectively selected cases (RSC) for the treatment of Class II Division 1 malocclusion in an adolescent population., Methods: This was a retrospective study. The results for an RCT were selected from a UK Class II multicenter study. Sixty-three patients from the trial were included. This group was matched with retrospectively selected Class II cases treated with a Twin Block functional appliance and their results submitted for Membership in Orthodontics examination in the United Kingdom, from four centers. The primary outcome was skeletal measurement ANB (A point, nasion, B point). Secondary outcomes included final peer assessment rating (PAR) scores and final overjet. Intrarater reliability of measurements was assessed. Independent samples t-test was carried out to look at the difference between the groups., Results: The reliability assessment showed excellent agreement for all measurements. The data were normally distributed. There was a statistically significant difference favoring the RSC group for final overjet (mean difference [MD] = 1.068, 95% confidence interval [CI] -0.67 to 1.47, P = 0.000) and final PAR (MD = 4.0, 95% CI -0.79 to 5.5, P = 0.000). There was no significant difference in the scores for final ANB (MD = 0.34, 95% CI -0.39 to 1.07, P = 0.33)., Conclusion: The RSCs show significantly improved overjet and PAR scores at the end of treatment and no statistically significant difference for skeletal change. The study raises the question of a potential role of observational studies in evaluating the effect of an intervention in orthodontics., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: The use of fixed functional appliances (FFAs) in conjunction with temporary anchorage devices (TADs) has been proposed to enhance skeletal changes and reduce proclination of the lower incisors., Objectives: To systematically investigate the skeletal and dentoalveolar effects of FFAs with TADs on Class II malocclusion in adolescents., Methods: Electronic searches of databases and manual searches of references were performed up to August 30, 2020. Randomized controlled trials (RCTs) and clinical controlled trials (CCTs) focusing on adolescent patients treated with FFAs combining TADs were included. The modified Cochrane risk-of-bias tool (R.O.B 2.0) and ROBINS-I (Risk of Bias in Non-randomized Studies-of Interventions) Tool were used to assess the risk of bias in RCTs and CCTs, respectively. Meta-analyses of SNA, SNB, ANB, Co-Gn, SN-MP, the lower and upper incisor inclination changes were performed. Subgroup analyses and sensitivity analyses were conducted based on TAD types, FFA types, record types and types of study designs., Results: Ten studies were included with a sample size of 281. Meta-analyses revealed significant differences in the changes in SNB (mean difference [MD] 0.67; 95% confidence interval [CI] 0.04-1.29), ANB (MD -1.22, 95% CI -2.04 to -0.39), Co-Gn (MD 1.57; 95% CI 0.22-2.92), inclination of the lower incisors (MD -5.64, 95% CI -7.78 to -3.50)] and inclination of the upper incisors (MD -1.91; 95% CI -3.69 to -0.13). TAD types and FFA types seem to affect the treatment outcome., Conclusions: Compared with FFAs alone, FFAs with TADs exhibit superior skeletal effects and reduce the inclination of the lower incisors in the short term; however, the evidence showed moderate to high risk of bias. Registration number CRD42020177611., (Copyright © 2021. Published by Elsevier Inc.)

Introduction: This study aimed to test whether control in maxillary and mandibular incisor position, during treatment with an acrylic splint Herbst appliance, could influence the mandibular response in growing patients with skeletal Class II malocclusion., Methods: The lateral cephalograms of 61 patients (mean age, 12.3 years; standard deviation, 1.6) with skeletal and dental Class II malocclusion were retrospectively analyzed both at baseline and after Herbst appliance removal, using a modified Pancherz cephalomeric analysis. Forty-five patients had received miniscrew in the mandibular arch to control mandibular incisor anchorage. In 21 patients, the maxillary incisors had been proclinated before starting the treatment for deepbite and maxillary incisor lingual inclination. All the patients were categorized a posteriori into 2 homogeneous groups, according to dental overjet reduction: 30 patients with dental overjet reduction (DR) and 31 patients without dental overjet reduction (NDR)., Results: Both groups presented a significant skeletal correction. However, the change was significantly greater in the NDR group than in the DR group (P <0.01). The mandibular bone base reached a median value of 4.0 mm (interquartile range, 2.5) in the NDR group vs 1.1 mm (interquartile range, 2.8) in the DR group (P <0.001). The 2 groups were also significantly different in terms of the positional change of maxillary incisor, which was proclinated in group NDR and lingualized in group DR (P <0.001)., Conclusions: The results showed that dental control of overjet was beneficial to improve the effectiveness of Herbst treatment in increasing mandibular length in growing patients with skeletal Class II malocclusion., (Copyright © 2020 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Objective: The objective of this study was to evaluate the effect of combined temporomandibular joint (TMJ) disk repositioning by suturing through open incision and orthodontic functional appliance (OFA) treatment for adolescents with mandibular asymmetry., Study Design: Adolescent patients (12-20 years old) with mandibular asymmetry combined with unilateral TMJ disk displacement without reduction were treated with disk repositioning by suturing through open incision with and without postoperative OFA. Magnetic resonance imaging and posteroanterior cephalometric radiographs (PA) were used to measure and compare the changes in condylar height, joint space, and menton deviation pre- and postoperatively., Results: Twenty-six patients were included in the study. Joint space was significantly increased postoperatively and new bone mostly formed at the superior or posterior superior part of the condyle after 6 to 18 months in all surgically treated joints. Fourteen patients with OFA had a significant increase in condylar height and menton deviation compared to 12 patients without OFA (2.29 ± 0.91 mm vs 1.22 ± 0.69 mm, P = .003; 4.56 ± 1.48 mm vs 2.01 ± 0.74 mm, P = .000)., Conclusions: Combined treatment with TMJ disk repositioning by suturing through open incision and OFA can promote condylar growth and correct mandibular deviation in adolescent patients. Postoperative OFA can maintain the increased joint space created by disk repositioning and promote new bone formation at the superior and posterior parts of the condyle., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Introduction: The purpose of this prospective clinical trial is to evaluate the changes of soft tissues and designate the esthetic perceptions of children with Class II malocclusion after Herbst appliance therapy and maxillary molar distalization using stereophotogrammetry., Methods: Thirty patients were allocated either to Herbst (6 boys and 9 girls; mean age = 11.60 ± 0.82 years) or distalization (4 boys and 11 girls; mean age = 11.46 ± 1.30 years) groups. Dentoskeletal and soft-tissue treatment changes were examined objectively by cephalometric analysis and stereophotogrammetry, respectively. Pre- and posttreatment profile views were evaluated subjectively by orthodontists and laypeople using the 7-point Likert scale. Intra- and intergroup comparisons for the repeated measurements were performed with 2-way variance analysis. Bonferroni test was used for multiple comparisons (P ≤0.05)., Results: Greater skeletal changes were observed in the Herbst group than in the distalization group. Maxillary incisor retrusion and mandibular incisor protrusion were observed in the distalization and Herbst groups, respectively. Stereophotogrammetric measurements showed that mandibular body length and lower and anterior facial height increased in both treatment groups. Convexity angle (P = 0.020) and labiomental angle (P = 0.033) were greater in the Herbst group than the distalization group., Conclusions: The skeletal contribution to correction of maxillomandibular discrepancy was greater in the Herbst group than the distalization group. Significant profile improvements were recorded for both groups with treatment. After both treatments, orthodontists were found to have higher rates of detection in the profiles than laypeople. The esthetic contribution of treatments to the facial profile was found similar in both groups., (Copyright © 2020. Published by Elsevier Inc.)

Introduction: This study aimed to compare cephalometrically the pharyngeal airway, hyoid bone, and soft palate (SP) changes after Class II malocclusion treatments using Twin-block (TWB) and Forsus Fatigue Resistant Device (FFRD) (3M Unitek Corp, 3M Dental Products, Monrovia, Calif) during the postpeak growth period., Methods: Forty-two patients with Class II malocclusion treated during the postpeak growth period were randomly and retrospectively included in this study. These patients were divided into 2 treatment groups: TWB and FFRD. The skeletal, dental, pharyngeal airway, hyoid bone position, and SP measurements were obtained from the lateral cephalometric radiographs taken at the beginning and at the end of the treatment. Paired-samples and independent-samples t tests were used for the intragroup and intergroup comparisons, respectively., Results: In the TWB group, the SNB (°), Md1-NB (mm), Md1-NB (°), and McNamara upper and lower pharyngeal airway dimensions significantly increased, whereas the ANB (°), AD1-Ba (mm), AD2-H (mm), adenoidal nasopharyngeal area, and SP angle decreased (P < 0.05). In the FFRD group, the SNB (°), Md1-NB (mm), Md1-NB (°), Ptm-Ba (mm), and McNamara upper airway dimensions significantly increased, whereas the ANB (°), AD2-H (mm), and interincisor angle decreased (P < 0.05). Moreover, there were statistically significant differences in the Md1-NB angles and SP thicknesses between the 2 groups (P < 0.05)., Conclusions: The effects of TWB and FFRD treatment on the airway during the postpeak growth period were similar. However, the FFRD caused a greater mandibular incisor protrusion., (Copyright © 2020 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The purpose of this study was to quantify and qualify the 3-dimensional (3D) condylar changes using mandibular 3D regional superimposition techniques in adolescent patients with Class II Division 1 malocclusions treated with either a 2-phase or single-phase approach., Methods: Twenty patients with Herbst appliances who met the inclusion criteria and had cone-beam computed tomography (CBCT) images taken before, 8 weeks after Herbst removal, and after the completion of multibracket appliance treatment constituted the Herbst group. They were compared with 11 subjects with Class II malocclusion who were treated with elastics and multibracket appliances and who had CBCT images taken before and after treatment. Three-dimensional models generated from the CBCT images were registered on the mandible using 3D voxel-based superimposition techniques and analyzed using semitransparent overlays and point-to-point measurements., Results: The magnitude of lateral condylar growth during the orthodontic phase (T2-T3) was greater than that during the orthopedic phase (T1-T2) for all condylar fiducials with the exception of the superior condyle (P <0.05). Conversely, posterior condylar growth was greater during the orthopedic phase than the subsequent orthodontic phase for all condylar fiducials (P <0.05). The magnitude of vertical condylar development was similar during both the orthopedic (T1-T2) and orthodontic phases (T2-T3) across all condylar fiducials (P <0.05). Posterior condylar growth during the orthodontic phase (T2-T3) of the 2-phase approach decreased for all condylar fiducials with the exception of the posterior condylar fiducial (P <0.05) when compared with the single-phase approach., Conclusions: Two-phase treatment using a Herbst appliance accelerates condylar growth when compared with a single-phase regime with Class II elastics. Whereas the posterior condylar growth manifested primarily during the orthopedic phase, the vertical condylar gains occurred in equal magnitude throughout both phases of the 2-phase treatment regime., (Copyright © 2020 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: This study aimed to evaluate the effects of the Forsus fatigue-resistant device (FRD) EZ2 appliance (3M Unitek, Monrovia, Calif) on facial soft tissues by using images obtained from cephalometric radiographs and 3-dimensional (3D) facial scanning system., Methods: A total of 20 patients treated with the Forsus FRD EZ2 appliance were included in this study. The cervical vertebral maturation index was used to determine growth and development stages, and the subjects were investigated at cervical vertebral maturation stages 5 and 6 (ie, postpeak period). Three-dimensional facial scanning images were obtained with 3dMD Face (3dMD Ltd, Atlanta, Ga). Cephalometric radiographic images were taken before placement of the appliance (T0), immediately after removal (T1), and at the 6-month (T2) follow-up after the removal of the appliance. For comparison of the data, one-way repeated-measures analysis of variance and paired t test were used at P < 0.05., Results: Statistically significant changes were found in the Wits value, IMPA, L1P-NB (°), L1-NB (mm), L1P-APog, U1P-L1P, overjet, overbite, Ls-E, and labiomental angle in T0-T1. In T0-T2, statistically significant changes in the Wits, IMPA, L1P-NB (°), overjet, overbite and Ls-E values were observed., Conclusions: The results revealed that the correction of malocclusion with Forsus FRD EZ2 appliance in patients at the postpeak period was mainly dentoalveolar. The soft tissues were affected to a limited extent. Three-dimensional facial scanning demonstrated similar accuracy and precision to traditional cephalometry, being a repeatable and accurate tool for linear and surface measurements., (Copyright © 2020 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The objective of this research was to compare the 2 treatment protocols including a functional mandibular advancer (FMA; Forestadent, Pforzheim, Germany) followed by multibracket appliances (MBAs) vs a Forsus device (3M Unitek, Monrovia, Calif) in combination with MBA concerning treatment outcomes and posttreatment stability., Methods: This study was conducted using lateral cephalograms of patients who were treated with MBA, which was used either after an FMA or concurrently with a Forsus device, and of patients who had untreated Class II malocclusion (control group). Each group consisted of 19 subjects in cervical stage 2 or cervical stage 3 stages according to the cervical vertebral maturation index. Cephalograms were taken for the treated groups at T1 (pretreatment), T2 (completion of the MBA treatment), and T3 (at least 2 years after T2)., Results: Significant intergroup differences at the T1-T2 period were observed in favor of the FMA concerning mandibular advancement, intermaxillary relationship, and mandibular elongation. With Forsus treatment, restrained maxillary growth and a slightly improved intermaxillary relationship rebounded after treatment (P <0.05). At the end of treatment, mandibular incisor protrusion and occlusal plane rotation were greater in the Forsus group than in the FMA group (P <0.05), and maxillary incisor retroclination was significant in the Forsus group. During the posttreatment period, although no significant changes were present in the incisors' inclination, relapses of the T1-T2 improvements in overjet and overbite and the recidive of the occlusal plane rotation were significantly higher in the Forsus group., Conclusions: Treatment protocol including an FMA was found to be more effective with mandibular skeletal effects and was more stable with a lesser degree of relapse in overjet and overbite than the Forsus protocol., (Copyright © 2020 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Background: Functional appliances has been used for treatment of skeletal Class II malocclusion for a long time; however, the real skeletal effects, mandibular growth particularly, remain insufficient. Several auxiliary approaches have been attempted with the hope of enhancing treatment effects. In this review, we summarize and discuss the use of additional nutrition and hormones to assist the functional appliance treatment on patients with skeletal Class II malocclusion., Methods: Relevant articles were identified by electronic research in MEDLINE Ovid using keywords such as "nutrition," "hormone," "functional appliance," "orthodontics," "maxillofacial development," and "maxillofacial abnormalities." References of related articles were assessed for relevant studies to identify additional published references., Results: The literature search yielded 239 studies. According to the current literature, use of additional nutrition and hormones, including growth hormones, sex hormones, insulin, and insulin-like growth factor I, seem to improve the effects of functional appliance treatment on patients with skeletal Class II malocclusion., Conclusions: The current evidence indicates that additional nutrition or hormones might improve the treatment effects on mandibular hypoplasia compared with the functional appliance alone, which is a promising approach and calls for further studies., (Copyright © 2020 World Federation of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: This study aimed to determine the volumetric effects on the upper airways of growing patients with Class II malocclusion treated with the Herbst appliance (HA)., Methods: Volumetric measurements of the upper airways of 42 skeletal Class II malocclusion patients (mean age: 13.8 ± 1.2 years; ranging from 12.0 to 16.9 years) were assessed using cone-beam computed tomography scans acquired before treatment (T0) and approximately 1 year later (T1). The sample comprised a Herbst appliance group (HA group [HAG]; n = 24), and a comparison group (comparison group [CG]; n = 18) of orthodontic patients who had received dental treatments other than mandibular advancement with dentofacial orthopedics., Results: In CG, nasopharynx and oropharynx volumes decreased slightly during the observation period (9% and 3%, respectively), whereas the nasal cavity volume increased significantly (12%; P = 0.046). In HAG, there was an increase in the volume of all regions (nasal cavity, 5.5%; nasopharynx, 11.7%; and oropharynx, 29.7%). However, only the oropharynx showed a statistically significant increase (P = 0.003), presenting significant volumetric changes along the time (T1-T0) in HAG., Conclusion: Mandibular advancement with the HA significantly increased the volume of the oropharynx, but no significant volumetric modifications were observed in the nasal cavity and nasopharynx., (Copyright © 2019 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: Modified Twin-block therapy followed by fixed appliances (TBFA) is a standard treatment modality in Class II malocclusion; however, there is little information regarding the stability of this approach. We aimed to assess the stability of Class II correction with TBFA and to evaluate factors that may affect stability., Methods: A prospective evaluation involving convenience sampling of 64 participants treated with TBFA was undertaken over 12 months. Study models and lateral cephalometric radiographs were obtained to record overjet and molar relationship, Peer Assessment Rating score, and skeletal parameters, and a new objective buccal segment interdigitation scoring system was developed. Multivariate logistic regression analysis was used to assess the stability of anteroposterior occlusal correction and the degree of buccal interdigitation, pretreatment skeletal discrepancy, and change in overjet during treatment., Results: Mean overjet reduction of 6.22 mm arose during treatment, with the canine and molar relationships improving by 3.34 mm and 2.67 mm, respectively. In the 12 months posttreatment, a relapse of 0.67 mm and 0.06 mm in overjet and molar relationship, respectively, was observed, with 25% of subjects having overjet relapse of >1 mm. There is weak evidence that the treatment-induced change in overjet is linked with overjet relapse (P = 0.05; odds ratio, 0.67; 95% confidence interval, 0.44, 1.01). No significant relationship was observed, however, between anteroposterior stability and buccal segment interdigitation (P = 0.99), pretreatment skeletal discrepancy (P = 0.10) or prescribed retention regime (P = 0.63)., Conclusions: Overall, acceptable levels of stability were observed, although appreciable relapse was noted in 25% of participants. Neither the degree of buccal segment interdigitation nor pretreatment skeletal discrepancy was predictive of anteroposterior occlusal stability., (Copyright © 2019 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The aim of this pilot study was to present the preliminary results of Class II malocclusion treatment using a skeletally anchored Herbst appliance with miniscrews inserted in the maxillary and mandibular arches to improve anchorage control and skeletal effects., Methods: The treatment group (TG) consisted of 13 patients (10 males [M], 3 females [F]; mean age of 12.8 years) with Class II Division 1 malocclusion who were treated with the Herbst appliance and miniscrews inserted in the maxillary and mandibular arches. They were compared with a control group (CG) of 13 patients (10 F, 3 M, mean age of 12.2 years) with Class II Division 1 malocclusion treated with the standard Herbst appliance without miniscrews. Lateral cephalograms were taken before and after Herbst treatment, and cephalometric analysis was performed., Results: In the TG group SNB (°) increased by 2.9°, whereas in CG group SNB (°) increased by 1.1° (P = 0.017). ANB (°) decreased in both groups: -3.3° in the TG group vs -1.3° in the CG group (P = 0.014). Pg-OLp distance increased in both groups: 5.70 mm in the TG group and 0.8 mm in the CG group (P = 0.022). Mandibular incisors proclined 1.6° in the TG group and 3.7° in the CG group., Conclusions: Herbst treatment reinforced with 4 miniscrews (2 in each arch) increased the orthopedic effect of treatment in growing patients with Class II malocclusion., (Copyright © 2019 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The purpose of this study was to evaluate the therapeutic effect of a hybrid treatment for hemifacial microsomia that combines distraction osteogenesis and a mandible-guided functional appliance to correct mandibular asymmetry., Methods: This was a retrospective analysis of 10 patients with unilateral hemifacial microsomia who underwent mandibular ramus distraction osteogenesis in our hospital from February 2013 to July 2015. The cases were classified into 2 comparison groups: 5 patients were in the MG-DO group (distraction osteogenesis combined with an mandible-guided functional appliance) and 5 in the control group (distraction osteogenesis only). Anteroposterior cephalometric analyses were conducted before and after treatment. Soft tissue symmetry and the occlusal relationship were observed from facial and intraoral photographs. Statistical analyses were performed to determine changes between before and after treatment as well as intergroup differences., Results: The MG-DO group showed greater vertical elongation of the mandibular ramus and less overcorrection and mandibular deviation than the control group. Occlusal reconstruction was enabled by the mandible-guided functional appliance owing to a decrease in lateral shifting. The symmetry of both skeletal and soft tissues was significantly improved in the MG-DO group., Conclusions: The hybrid technique combining distraction osteogenesis and the mandible-guided functional appliance proved to be effective in correcting canting and deviation during mandibular elongation, which improved facial symmetry and occlusal balance in patients with hemifacial microsomia., (Copyright © 2019 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Effective torque control is crucial for the successful treatment of impacted incisors; however, torque control is often a challenge with the use of conventional bracket systems, especially when the adjacent teeth require opposite torque managements. A novel approach of torque control for adjacent anterior teeth is introduced in this case report. A 12-year-old boy had an impacted maxillary right central incisor with the adjacent teeth severely displaced. The treatment plan was to regain space and pull the impacted incisor into the dentition. An upper removable appliance was first used to regain space for the impacted central incisor, followed by a spontaneous eruption of the impacted incisor. Subsequently, fixed appliances were bonded to level and align the dentition. However, the crown of the maxillary right central incisor was found to be tipped lingually, while the maxillary right lateral incisor was tipped labially. Traditional torque control, including torque bend and the use of a Warren spring, were first used for the correction, but they were ineffective due to the overlap of the root apex of the maxillary central incisor and lateral incisor. After the roots were separated with a V-shaped curve, auxiliary brackets were bonded on the gingival one-third areas of the maxillary incisors and canine with nickel-titanium wires used for the torque control. This approach of using the auxiliary brackets and wires was demonstrated to be efficient and effective in the torque control of adjacent anterior teeth with opposite torque control requirements. The final result and the 2-year follow-up records demonstrated the proper torque of anterior teeth and good and stable dental and profile esthetics., (Copyright © 2019 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: It has been postulated that a change in cervical posture occurs as a consequence of forward repositioning of the mandible. Therefore, the objective of this study was to compare the cervical spine posture between subjects with and without functional appliance therapy., Methods: A retrospective cohort study was conducted with the use of pre- and post-functional therapy cephalograms of orthodontic patients. A total of 60 subjects was composed of 2 groups of 30 subjects each: those who underwent treatment with a twin-block (TB) functional appliance and a control group selected from the Bolton-Brush Growth Study. Three sagittal and 7 cervical vertebral parameters were compared between the groups. The Wilcoxon signed-rank test was used to compare pre- and postfunctional mean angular measurements. The Mann-Whitney U test was used to compare the mean changes in cervical parameters between the groups., Results: A significant difference existed between pre- and postfunctional SNB (P <0.001) and ANB (P <0.001) angles, showing a change in maxillomandibular relationship. Comparison of mean changes in angular measurements between the 2 groups showed a significant difference (P = 0.032) in the sella-nasion to odontoid process tangent (SN-OPT) angle. The SN-OPT angle predicted that the probability of developing an altered cervical posture with the TB appliance is 2.08 times greater than without the TB appliance., Conclusions: SN-OPT angle can predict a change in skeletal relationships after treatment with the TB functional appliance. The TB causes the craniocervical posture to be more upright. Subjects with reduced vertical dimensions have greater change in cervical posture., (Copyright © 2019 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)