Evaluation of the Co-Go-Me angle as a predictor in Class II patients treated with Herbst appliance and skeletal anchorage: a retrospective cohort study.

Introduction: A condylion-gonion-menton (Co-Go-Me) angle threshold of 125.5° has been introduced as a predictive parameter of cephalometric mandibular response in the orthopedic treatment of growing Class II patients with functional appliances, despite some contradictions in the literature. Considering the lack of studies evaluating the role of skeletal anchorage, this study aims to reassess the threshold of 125.5° in the Co-Go-Me angle as a useful predictor in growing skeletal Class II patients treated with acrylic splint Herbst appliance and two mini-screws in the lower arch (STM2). Methods: Thirty-five consecutively treated patients (20 males, 15 females; mean age, 11.37 years) with mandibular retrusion were classified into two groups according to their Co-Go-Me baseline values (Group 1, <125.5°; Group 2, >125.5°). The STM2 protocol involved the use of the MTH Herbst appliance with an acrylic splint in the lower arch and two interradicular mini-screws as anchorage reinforcement. Cephalometric analysis was performed by the same operator for each patient at baseline (T0) and at the end of the Herbst phase (T1). The effects of time and group on the variables were assessed by a repeated-measures analysis of variance. The primary research outcome was the difference between the groups in terms of mandibular responsiveness to treatment referred to as the relative difference (T1-T0) in Co_Gn. Results: The mean duration of the treatment was 9.5 months. No statistically significant differences between groups were detected at baseline, except from the expected SN/GoMe° (p < 0.001) and Co-Go mm (p = 0.028). No statistically significant changes between groups, which were caused by the treatment, were found considering the mandibular sagittal and vertical skeletal parameters. Similarly, no statistically significant differences were found in the dental changes between the high-angle and low-angle patients, apart from the upper molar sagittal position (p = 0.013). Discussion and conclusions: The 125.5° threshold in the Co-Go-Me value was not a reliable predictive parameter for the mandibular response in growing patients treated with the MTH Herbst appliance and lower skeletal anchorage. Due to its effective control in the sagittal and vertical planes, the STM2 technique might be an appropriate protocol to use in treating skeletal Class II patients, regardless of the growth pattern.

Alveolar Bone and Gingival Changes in Mandibular Anterior Region Following Herbst Appliance Therapy: A Systematic Review and Meta-analysis.

Objective: To assess the alveolar bone changes and gingival recession following Herbst appliance therapy. Materials and methods: Electronic databases such as PubMed, Ovid, Cochrane Library, Lilacs, Scopus, Web of Science, and Embase were searched until August 2022. Hand-searching of major orthodontic journals was performed to identify all peer-reviewed articles potentially relevant to the review. The quality of the selected studies was ranked using the revised Cochrane risk of bias tool for nonrandomized trials-Risk of Bias In Nonrandomized Studies (ROBINS) 1. Results: Five relevant articles (all nonrandomized studies) were considered for qualitative analysis. The risk of bias was low for four studies and moderate for one. The reduction in the vertical alveolar bone height was 0.13 ± 0.07 mm, with the Herbst appliance. The mean difference in the loss of buccal cortical thickness between the Herbst appliance and untreated control group was 0.22 mm [95% confidence interval (CI) of -0.62-0.18]. Subsequent to Herbst appliance therapy, in the mandibular anterior region 0.1 ± 0.5 mm of gingival recession was observed. Conclusion: Herbst appliance treatment produces a negligible reduction in the buccal cortical thickness, vertical alveolar bone height, and gingival recession. Clinical significance: Though the changes produced by the Herbst appliance were minimal, they are clinically important considering the young age of the patients warranting periodic periodontal assessment. How to cite this article: Kumar MV, Kannan A, Kailasam V. Alveolar Bone and Gingival Changes in Mandibular Anterior Region Following Herbst Appliance Therapy: A Systematic Review and Meta-analysis. Int J Clin Pediatr Dent 2024;17(1):114-120.

Is significant mandibular advancement possible after the peak of puberty? Dento-osseous palatal expansion and the STM4 technique (Skeletal Therapy Manni Telescopic Herbst 4 miniscrews): A case report.

INTRODUCTION: Treatment of skeletal class II growing patients often requires the use of functional appliances, aimed at promoting mandibular advancement. Among these, Herbst appliance is recommended for its effectiveness, efficiency, and reduced need for compliance. Despite its skeletal favourable effects, well-known dental compensations can occur, especially when the appliance is not used close to the pubertal peak: upper incisors retroclination, lower incisors proclination, upper molars distalization and lower molars mesialization could reduce the overjet needed for a proper mandibular advancement. To counteract these unfavourable effects skeletal anchorage could be crucial. AIM: The aim of this case report is to describe and evaluate the effects of using a skeletally anchored Herbst appliance in an 18-year-old (CVM5) male patient with skeletal Class II malocclusion and a convex profile. TREATMENT PROTOCOL: The treatment started with a tooth-bone-borne palatal expansion, then the upper arch was bonded with pre-adjusted ceramic brackets. After 2months, a Manni Telescopic Herbst (MTH) supported by 4 miniscrews (two in the maxilla and two in the mandible) was applied. To avoid anchorage loss, TADs were connected with elastic chains to the arches. Nine months later, the Herbst was removed, the lower teeth were bonded and the patient wore class 2 elastics to stabilise the occlusion. RESULTS AND CONCLUSIONS: After 24months the treatment goal was achieved with a considerable improvement of the profile and a clinically significant mandibular advancement (Pogonion moved forward 7mm). A one-year follow-up lateral X-rays showed a good stability of the result.

Third molar angulation and retromolar space after functional orthodontic treatment : Evaluation of panoramic radiographs after monoblock or Herbst appliance.

PURPOSE: The aim of this respectively cohort study was to evaluate the lower second and third molars and canine angulations, retromolar space and occlusal relationships after functional orthodontic treatments with the monoblock or Herbst appliance using panoramic radiographs. METHODS: Pre- and posttreatment cephalometric and panoramic radiographs of 133 patients (mean age 13.89 ± 1.14 years) treated non-extraction with monoblock (n: 44), Herbst (n: 45) and fixed orthodontic appliances (control group; n: 44) were included to the study. Dental and skeletal measurements were performed on cephalometric radiographs. The angle between the third and second molars, and canines with the lower border of the mandible and the occlusal plane, gonial angle, the angle between the third and second molars and the retromolar space width were assessed on pre- and posttreatment panoramic radiographs. Paired and independent t tests were used for the statistical analysis of the data for intragroup and intergroup comparisons. RESULTS: Functional treatment with both the monoblock and the Herbst appliances resulted in improvement of skeletal class II relationships. Retromolar space significantly increased in the functional appliance groups compared to the control group (p ≤ 0.001), but improvement of the angulations of posterior teeth was significant only in the monoblock group (p ≤ 0.001). CONCLUSION: While both the Herbst and monoblock appliances led to an increase in retromolar space, monoblock treatment resulted in more favorable angulation of the third molars compared to the Herbst treatment.

Class II subdivision treatment and stability with asymmetric Herbst appliance: A case report.

Non-surgical treatment of Class II subdivision may involve complex mechanics or asymmetric tooth extraction in its resolution. This report demonstrates the result and the short-term stability of Class II subdivision treated with asymmetrically installed Herbst appliance followed by conventional fixed orthodontic appliance. The approach allowed the correction of the unilateral Class II molar relationship and increased overjet, as well as the deviation of dental midlines, with improvement in lip posture and facial profile. The results remained stable two years after treatment, confirming the treatment success.

Comparisons of soft tissue changes after Herbst appliance treatment in three different growth phases.

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.

Dental and Skeletal Effects of Herbst Appliance, Forsus Fatigue Resistance Device, and Class II Elastics-A Systematic Review and Meta-Analysis.

Background: Our study aimed to systematically summarize the dentoskeletal effects of Herbst appliance; Forsus fatigue resistance device; and Class II elastics in adolescent Class II malocclusion. Methods: Five databases; unpublished literature; and reference lists were last searched in August 2022. Randomized clinical trials and observational studies of at least 10 Class II growing patients that assessed dentoskeletal effects through cephalometric/CBCT superimpositions were eligible. The included studies quality was assessed with the RoB 2 and ROBINS-I tools. A random-effects model meta-analysis was performed. Heterogeneity was explored with subgroup and sensitivity analyses. Results: Among nine studies (298 patients); two-to-three studies were included in each meta-analysis. Less post-treatment upper incisor retroclination (<2) and no overbite; overjet; SNA; SNB; and lower incisor inclination differences were found between Herbst/Forsus and Class II elastics. No differences in maxilla; condyle; glenoid fossa; and most mandibular changes were found between Herbst and Class II elastics; except for a greater 1.5 mm increase in mandibular length and right mandibular ramus height (1.6 mm) with Herbst. Conclusions: Herbst and Class II elastics corrected the molar relationship; but Herbst moved the lower molars more mesially. Apart from an additional mandibular length increase; no other dental and anteroposterior skeletal difference was found. Forsus was more effective in molar correction; overjet reduction; and upper incisor control than Class II elastics. Trial registration number OSF: 10.17605/OSF.IO/8TK3R.

Skeletal and dental effects of Herbst appliance anchored with temporary anchorage devices: A systematic review with meta-analysis.

BACKGROUND: The aim was to evaluate the efficiency of using temporary anchorage devices (TADs) in minimizing the anchorage loss and increasing the skeletal effects during correction of Class II malocclusion with Herbst appliance. MATERIALS AND METHODS: Search without restrictions was performed up to January 2021 in three electronic databases (CENTRAL, MEDLINE and EMBASE) for randomized controlled trials (RCTs), prospective and retrospective cohort studies. The included studies assessed the dental and skeletal changes in Class II malocclusion patients who were treated using Herbst appliance with or without TADs. The strength of evidence was ranked using GRADE. RESULTS: Fifty-five records were initially retrieved. A total of 6 studies with 198 patients were finally considered. 4 studies were included in the meta-analysis. The meta-analysis showed that using TADs with acrylic splint Herbst appliance was effective in controlling the inclination of mandibular incisors by a mean difference of -5.49 degrees (95% C.I [-7.36, -3.63], P < .001) when compared to Herbst appliance alone. The results showed also that incorporating TADs with Herbst treatment resulted in greater mandibular skeletal effects including increasing mandibular bone base length by mean difference of 2.22 mm (95% C.I [0.82. 3.61], P = .002) and mandibular length by mean difference of 3.7 mm (95% C.I [1.55, 5.85], P < .001) when compared to Herbst appliance alone. CONCLUSIONS: Based on a very low level of confidence, it seems that incorporating TADs during orthodontic treatment with Herbst appliance results in minimizing the anchorage loss and increasing the skeletal effects of Herbst appliance during correction of Class II malocclusion.

The Herbst appliance and its modifications - prevalence and individuality.

OBJECTIVE: The aim of this study was to analyze the use of modified, cast splint Herbst appliances for the treatment of skeletal class II as an alternative to surgical bite correction over a period of five years. MATERIALS AND METHODS: The patient cases all originate from the patients of the Department of Orthodontics at the University Medical Center of the Johannes Gutenberg University Mainz, Germany and the orthodontic practice Dres. Zöller, Kaiserslautern, Germany. Inclusion criteria were orthodontic treatment with the Herbst appliance and its modifications. The type of modification, number and frequency of the different modifications were determined on the basis of patient files, X-ray documents, photos and models. RESULTS: Of a total of 2881 new admissions over a period of five years, 1751 patients came from the Department of Orthodontics at the University Medical Center of the Johannes Gutenberg University Mainz and 1130 from the orthodontic practice in Kaiserslautern. A total of 336 patients were treated with a Herbst appliance during the period mentioned. 14 (13%) of the cases from the Herbst patient collective of the University Medical Center and 45 (19%) of the cases from the orthodontic practice were classified as modifications. The following modifications could be determined in descending order: University Medical Center Mainz: Herbst for anchorage during space closure (65%) > distalization (14%) ≥ bar construction as a space maintainer (14%) > Herbst applicance for anchoring for the adjustment of impacted teeth (7%); orthodontic practice Kaiserslautern: Herbst appliance with quadhelix in the maxilla (42%) > distalization (27%) > space closure (15%) > bar construction as a space maintainer (9%) > adjustment of impacted teeth (7%), multiple modifications occurred at 11%. The combination of quadhelix and Herbst appliance as well as multiple modifications have not yet been used in the University Medical Center Mainz. As an alternative to dysgnathia surgery, 23 adult patients (> 18 years) from the University Medical Center and 22 from the orthodontic practice were treated with a Herbst appliance. CONCLUSION: Nearly 12% of Herbst appliances are used in everyday orthodontic practice and almost 18% of these are used with modification(s). The high anchoring quality and force-effect geometry of the Herbst appliance is suitable for combining and treating various other treatment tasks in addition to the classical treatment task of class II therapy.

Effects of miniplate anchored Herbst appliance on skeletal, dental and masticatory structures of the craniomandibular apparatus: A finite element study.

OBJECTIVE: To analyze the stress distribution in the hard and soft tissue structures of craniomandibular complex during mandibular advancement with miniplate anchored rigid fixed functional appliance (FFA) using Finite Element Analysis (FEA). MATERIAL AND METHODS: The virtual model consisting of all the maxillofacial bones (up to calvaria), the mandible and temporomandibular joint (TMJ) was generated using the volumetric data from pre-treatment CBCT-scan of a growing patient. The masticatory muscles, other soft tissues, Herbst appliance and plate geometry were modelled mathematically. Force vectors simulating muscle contraction at rest and advanced mandibular positions, with protraction force of 8N were applied. The final model was imported into ANSYS for analysis after assigning material properties. RESULTS: The maximum von Mises stress of 11.69MPa and 11.96MPa magnitude was observed in the region of pterygoid plates and at the bone-miniplate interface respectively, with the mandibular advancement of 7mm. Stress patterns were also noted at the condylar neck. The stress values observed in the medial and lateral pterygoid muscles were of 10.42MPa and 4.16MPa magnitude, respectively. Stress was noted in the bucco-cervical region of the upper posterior teeth, but negligible change was seen on the lower anterior teeth and periodontal ligament. CONCLUSION: Miniplate Anchored Herbst Appliance brought about Class II skeletal correction in growing children as it was accompanied by minimal changes in the inclination of the lower incisors. Soft tissue structures like pterygoid muscles and discal ligaments exhibited increased stress whereas masseter muscle displayed reduction in stresses.

Skeletal and dental changes induced by the Flip-Lock Herbst appliance in the treatment of Angle's class II division 1 malocclusion during active growth period: A preliminary study.

Background. The Flip-Lock Herbst (TP Orthodontics Inc.) is a fixed functional appliance, a variant of the Herbst appliance, introduced by Miller. It is claimed to have better patient tolerance due to its increased freedom for the mandible's lateral movements. There have been no studies on the flip lock Herbst till date. This study was undertaken to assess the efficiency of the Flip-Lock Herbst appliance in correcting Angle's class II division 1 malocclusion. Methods. Eight subjects in their active growth period with class II division 1 malocclusion due to a retrognathic mandible were included in the study. Standardized lateral cephalometric radiographs were used to evaluate skeletal and dental changes with the SO analysis. Paired samples t-test was used to assess statistical significance. Results. Statistically significant increases in mandibular length (pg/OLp) and effective mandibular length (ar/OLp + pg/OLp) were observed. There was a significant maxillary restraining effect. Dental effects were significant and exhibited class II correction features except for the position of lower incisors within the mandible (ii/OLp - pg/OLp). Skeletal changes accounted for 61% and dental changes for 39% of the total treatment for molar correction. For overjet correction, skeletal changes contributed to 63% and dental changes to 37% of the total treatment. Conclusion. The Flip-Lock Herbst appliance was efficient in correcting Angle's class II division 1 malocclusion due to a retrognathic mandible. Both skeletal and dental changes were evident, with the former predominating (60:40).

Changes of epiglottis and hyoid bone position after orthodontic treatment with cast splint fixed functional appliances.

OBJECTIVES: Angle Class II malocclusions including a retrognathic mandible are the most frequent orthodontic problems. Both removable and fixed functional appliances can be used for mandibular advancement. Mandibular advancement after treatment with any fixed functional appliance has numerous therapeutic effects, such as stretching of masticatory muscles, ligaments, membranes and surrounding soft tissues, thus causing positional changes of the hyoid bone and epiglottis. This retrospective study investigates and compares treatment effects upon epiglottis- and hyoid bone position and posterior airway space in class II patients who received mandibular advancement through two different cast splint fixed functional appliances. MATERIAL AND METHODS: Two groups of 21 patients each ('Functional Mandibular Advancer' (FMA) and Herbst appliance) were investigated. The same experienced orthodontist performed the treatment in all patients, employing a single-step advancement protocol. The mandible always received initial protrusion into an edge-to-edge position. Conventional lateral cephalograms were available pre-treatment (T1) and immediately after appliance removal (T2) for all patients. The measurements comprised (I) hyoid bone, (II) epiglottis or (III) posterior airway space. Treatment-related changes were analysed with one-sample Student's t tests for intragroup comparisons and independent Student's t tests for intergroup comparisons. Statistical significance was set at p < 0.05. RESULTS: Measurements of the hyoid bone showed mostly increases for both appliances after treatment. Intergroup comparisons were not significant for FMA patients but significant for selected measurements in Herbst appliance patients. Intergroup comparisons showed insignificant changes. The posterior airway space was always insignificantly increased after treatment. The greatest increase was found caudally. Intergroup comparisons showed insignificant changes. CONCLUSIONS: Both fixed functional appliances cause an anterior and caudal displacement of epiglottis and hyoid bone and enlarge the posterior airway space. The therapeutic effects of the Herbst appliance are slightly larger, although not significantly. CLINICAL RELEVANCE: Treatment with either Herbst appliance of FMA alters the hyoid bone position and enlarges the posterior airway space. Still, long-term data are as yet unavailable; it remains unknown if the effects upon posterior airway space remain stable, and if a resulting posterior airway space enlargement may have clinical influence upon obstructive sleep apnoea syndrome.

Mandibular orthopedic advancement in different facial patterns and distinct stages of skeletal maturation

ABSTRACT The Herbst appliance can be very effective in treatment of Class II patients with mandibular retrognathism. Because of the continuous action in a full-time basis, treatment time using it normally takes from six to ten months, and is usually followed by a second phase of full fixed appliances, in order to obtain both occlusal refinement and long term stability. Despite Herbst appliance's effectiveness in the occlusal and dentoalveolar perspectives, its facial results may differ among patients with different growth patterns, as well as in distinct stages of skeletal maturation. In the current paper, two patients with different facial patterns are presented, who were treated under the same protocol, using Herbst and full fixed appliances in different skeletal maturation stages, and both dentoalveolar and facial results are compared and discussed.

RESUMO Um número significativo de pacientes que procuram o tratamento ortodôntico apresenta má oclusão de Classe II acompanhada pelo retrognatismo mandibular. Abordagens ortopédicas para avanço mandibular são comumente utilizadas enquanto houver crescimento facial remanescente e, nesses casos, o estágio de maturação esquelética deve ser avaliado para definir a melhor época de intervenção terapêutica. Após concluída a fase ortopédica, normalmente é realizada uma segunda fase ortodôntica para refinamento oclusal, com o intuito de oferecer maior estabilidade das correções em longo prazo. No presente artigo, serão discutidos os resultados do avanço mandibular ortopédico considerando-se diferentes estágios de crescimento.

Tratamento da Classe II com propulsor mandibular Herbst modificado ­ relato de caso / Class II treatment with modified Herbst ­ case report

A Classe II representa uma parte considerável dos problemas ortodônticos a serem tratados nas clínicas odontológicas. Para a correção desta má oclusão existem atualmente diversas formas de tratamento. Dentre os aparelhos ortopédico funcionais, o aparelho de Herbst tem se destacado devido a sua eficiência e praticidade por ser fixo e não necessitar da colaboração do paciente. O objetivo deste artigo é apresentar, através de um relato de caso clínico, o tratamento da má oclusão Classe II com aparelho de Herbst modificado com "splint" de acrílico inferior. A paciente do sexo feminino, apresentava inicialmente 11 anos e 11 meses, dentição permanente, retrusão mandibular e atresia das arcadas. Inicialmente, foi utilizado disjuntor maxilar e expansor inferior, seguido do aparelho de Herbst e finalizado com Ortodontia fixa. Ao final do tratamento o aparelho de Herbst modificado mostrou-se efetivo proporcionando uma relação molar Classe I, melhora do perfil da paciente e diminuição do espaço entre os lábios em repouso. (AU)

Class II represents a considerable part of orthodontic problems to be treated in dental clinics. To correct this malocclusion, there are currently several forms of treatment. Among the functional orthopedic devices, the Herbst device has stood out due to its efficiency and practicality for being fixed and not requiring the collaboration of the patient. The purpose of this article is to present, through a clinical case report, the treatment of class II malocclusion with a modified Herbst appliance with a lower acrylic splint. The female patient initially had 11 years and 11 months, permanent dentition, mandibular retrusion and atresia of the arches. Initially, a maxillary circuit breaker and lower expander were used, followed by the Herbst appliance and finished with fixed orthodontics. At the end of the treatment, the modified Herbst appliance proved to be effective, providing a class I molar relationship, improving the patient's profile and decreasing the space between the resting lips. (AU)

The Herbst appliance combined with a completely customized lingual appliance: A retrospective cohort study of clinical outcomes using the American Board of Orthodontics Objective Grading System.

OBJECTIVES: In this retrospective study we aimed to evaluate the quality of treatment outcomes using the American Board of Orthodontics (ABO) scoring system with a completely customized lingual appliance used in combination with a Herbst appliance for Class II correction. MATERIALS AND METHODS: Patient selection criteria for this study were Class II division 1, II/2 or subdivision treated with a WIN® lingual appliance combined with an L-pin Herbst device. Thirty-two consecutively debonded cases were included in this retrospective case series. Pre- and post- treatment dental casts, dental set-ups, panoramic X-rays, cephalometric analysis, photographs and clinical files were available for data collection. The primary outcome was the ABO score based on the Discrepancy Index (ABO DI) including: overjet, overbite, anterior open bite, lateral open bite, crowding, occlusion (Angle class), lingual posterior crossbite, buccal posterior crossbite, ANB, IMPA and SN-GoGN angles and the Cast-Radiograph Evaluation (ABO CR-Eval) comprising of alignment/rotations, marginal ridges, buccolingual inclination, overjet, occlusal contacts, occlusal relationship (Angle class), interproximal contacts and root angulation. In addition, overjet, overbite and Class II correction were also evaluated on pre- and post-treatment models. The secondary outcome was bracket failure and complications related to the Herbst device. RESULTS: The study cohort included 18 female and 12 male patients with a mean age of 15.8 (range 12, 6- 18, 5). Twenty patients were Class II division 1 and ten were Class II division 2. The mean pre-treatment value of ABO DI was 20.8 (range 10-39); more than two-thirds of the sample were rated as being either of moderate difficulty (ABO DI: 16-24) or severe (ABO DI: over 25). The average post-treatment ABO Cast-Radiograph Evaluation score was 15.0 (SD=4.4), which is considered a passing score. Twenty-six patients had a score equal or lower than 20 (undisputed passing score). The Class II discrepancy was effectively corrected from a score of 16.83 penalty points (SD: 3.65) pre-treatment to a score of 1.57 (SD: 1.70) post-treatment. No association was found between initial and final Class II occlusal relationships (P=0.42), indicating that regardless of the initial discrepancy, no difference in the success of Class II correction was observed. The mean bracket failure rate was 3.8 per patient. Herbst related complications were few: 1.6 per patient, with the majority of complications being of little consequence and with 43% of the patients having no breakages. CONCLUSION: The completely customized lingual appliance assessed in this study combined with an L-pin Herbst led to effective Class II correction regardless of the initial severity of the sagittal discrepancy. The average ABO CR-Eval score for this sample was well below the undisputed passing score indicating a high quality of treatment outcomes.

Angle class II correction: stepwise mandibular advancement or bite jumping? : A systematic review and meta-analysis of skeletal, dental and condylar effects.

INTRODUCTION: There is no consensus regarding which mode of activation or mandibular advancement (stepwise [SW] or maximum bite-jumping [BJ]) of fixed or removable functional appliances (FFA; RFA) for correction of Angle class II malocclusion is advantageous to produce dental, skeletal or condylar effects and has the lowest rate of undesired dental or technical side-effects. METHODS: A systematic search was conducted up to Oct. 20, 2019 in the MEDLINE, EMBASE, Scopus, Central Cochrane Library, and BBO databases. Included were preadolescent, adolescent, and adult humans with initial (pretreatment) Angle class II malocclusion, without further restriction. The intervention group was composed of subjects treated with FFA or RFA in SW mandibular advancement; the control group received BJ advancement. Search terms included prospective randomized and nonrandomized trials in English, German, Spanish, and Portuguese with the primary outcomes of skeletal and dental class II correction, effects on condylar growth, lower incisor proclination, overjet and overbite reduction. The risk of bias (ROB) was assessed using the Cochrane Collaboration's ROB2 tool. Mean differences were calculated and pooled by a meta-analysis using a random effects model. RESULTS: Data from five randomized controlled trials (RCT) with 401 participants (mean age 13.84 years; SD 1.53) were included; 331 derived from four studies were included in the meta-analysis. The ROB in the selected articles was high. We detected a slightly increased reduction of the ANB (mean difference [MD] -0.95°, 95% confidence interval [CI] -1.80 to -0.10°; I2 = 72%) that may be attributed to a slightly more pronounced increase of the SNB angle in SW-advanced mandibles (MD 0.27°; 95% CI -0.47 to 1.00°; I2 = 38%). SW advancement tended to reduce the undesired side effect of lower incisor proclination (MD = -1.59°; 95% CI -3.98 to 0.8°; I2 = 0%), indicating more pronounced mandibular incisor changes with bite-jumping advancement. CONCLUSION: There is weak evidence indicating a slightly increased reduction of the ANB and less lower incisor proclination with SW advancement compared to BJ, but the clinical relevance is debatable due to the small overall magnitude and small number of high-quality papers. REGISTRATION: Prospero #CRD42017075469 (www.crd.york.ac.uk/prospero).

3D assessment of mandibular skeletal effects produced by the Herbst appliance.

BACKGROUND: A functional appliance is commonly used to optimize the development of the facial skeleton in the treatment of Class II malocclusion. Recent three-dimensional(3D) image-based analysis offers numerous advantages in quantitative measurement and visualization in orthodontics. The aim of this study was to localize in 3D the skeletal effect produced by the Herbst appliance on the mandible using the geometric morphometric technique. METHODS: Twenty patients treated with a Herbst appliance and subsequent fixed appliances were included. Cone-beam computed tomography (CBCT) images were taken before treatment (T1), 8 weeks after Herbst appliance removal (T2), and after subsequent fixed appliance treatment (T3). Spatially dense morphometric techniques were used to establish the corresponding points of the mandible. The mandibular morphological changes from T1-T2, T2-T3, and T1-T3 were calculated for each patient by superimposing two mandibular models at two time points with robust Procrustes superimposition. These changes were then compared to the morphological changes estimated from normative mandibular growth curves over the same period. The proportion of cases exceeding the growth expression for controls was compared to a normal population using a one tailed binomial test. RESULTS: Approximately 1.5-2 mm greater condylar changes and 0.5 mm greater changes in the chin occurred from Tl to T2. This effect lasted until the completion of treatment (T1-T3), but there was no obvious skeletal effect during the orthodontic phase (T2-T3). Approximately 40-50% of the patient sample exceeded condylar growth by > 1.5 mm compared to untreated controls (p < .05). However, changes at the chin were not statistically significant. CONCLUSIONS: The principal skeletal effect of Herbst appliance treatment was additional increase in condylar length for about half of the sample. This inconsistency may relate to the degree of mandibular growth suppression associated with a specific malocclusion.

Three-dimensional comparison of the skeletal and dentoalveolar effects of the Herbst and Pendulum appliances followed by fixed appliances: A CBCT study.

OBJECTIVES: To compare three-dimensional (3D) skeletal and dentoalveolar effects of the Herbst and Pendulum appliances followed by fixed orthodontic treatment in growing patients. SETTING AND SAMPLE POPULATION: A sample of 35 adolescents with cone-beam computed tomography scans obtained prior to Herbst and Pendulum treatment (T1) and immediately after fixed appliance treatment (T2). MATERIALS AND METHODS: Patients with Class II malocclusion was assessed retrospectively and divided into two treatment groups: Herbst group (n = 17, age: 12.0 ± 1.6 years) and Pendulum group (n = 18, age: 12.1 ± 1.5 years), with a mean treatment duration of 2.8 ± 0.8 years and 2.5 ± 0.7 years, respectively. Reconstructions of the maxillomandibular and dentoalveolar regions and data in 3D were obtained relative to cranial base, maxillary and mandibular regional superimpositions. Treatment outcomes (T2-T1) were compared between both groups using t tests for independent samples (P<.05). RESULTS: Significant increase in mandibular length was observed in the Herbst group (7.3 ± 3.5 mm) relative to the Pendulum group (4.6 ± 4.5 mm). Inferior and anterior displacements of Pogonion were 2.2 mm and 1.6 mm greater in the Herbst group, respectively. The mesial displacement of the lower first molars was significantly greater in the Herbst group (1.9 mm). The upper first molars had contrasting results in sagittal displacement, with 0.6 ± 1.7 mm of distal displacement with the Pendulum and 1.4 ± 2.1 mm of mesial displacement with the Herbst. Lower incisor projection and proclination were similar between groups. CONCLUSIONS: The Herbst and Pendulum appliances followed by comprehensive orthodontic treatment effectively corrected Class II malocclusion in growing patients, but with differing skeletal and dentoalveolar effects.

Miniscope-Herbst digital / Digital miniscope-Herbst

O aparelho de Herbst tem sido amplamente utilizado no mundo todo para tratar a má oclusão de Classe II com retrognatismo mandibular. Entretanto, no Brasil tem sido pouco utilizado. O custo do aparelho, a curva de aprendizado acentuada para manipular o aparelho e a falta de laboratórios com conhecimento para confeccioná-lo adequadamente têm contribuído para este fato. Sendo assim, o objetivo deste artigo é mostrar o fluxo digital para a confecção do aparelho MiniScope Herbst e demonstrar as facilidades de trabalhar desta forma. Após a confecção e instalação do aparelho aqui mostrado, pode-se concluir que a utilização de modelos digitais, juntamente com o sistema MiniScope e a soldagem a laser, tornou a confecção do aparelho de Herbst muito mais previsível e confiável. Espera-se assim contribuir para a facilidade de utilização clínica do aparelho e para diminuir o número de intercorrências. (AU)

The Herbst appliance has been widely used worldwide to treat Class II malocclusion with mandibular retrognathism. However, in Brazil it has been little used. The cost of the device, the steep learning curve for handling the device, and the lack of laboratories with the knowledge to properly manufacture it have contributed to this fact. Therefore, the objective of this article is to show the digital flow for the manufacture of the MiniScope Herbst device and demonstrate the facilities of working in this way. After making and installing the device shown here, it can be concluded that the use of digital models, together with the MiniScope system and laser welding made the fabrication of the Herbst appliance much more predictable and reliable. Thus, it is expected to contribute to the ease of clinical use of the device and to reduce the number of complications (AU)

Acompanhamento longitudinal do tratamento da Classe II com o aparelho de Herbst ­ relato de caso / Longitudinal follow-up of Class II treatment with Herbst appliance ­ case report

Resumo O tratamento ortodôntico possui diversos objetivos, sendo que um dos mais importantes é a estabilidade das correções alcançadas. A estabilidade longitudinal dos resultados do tratamento é uma das chaves para o tratamento ortodôntico bem-sucedido. Desta forma, este artigo se destina a descrever um caso clínico de uma paciente com má oclusão de Classe II Divisão 1, tratada com o aparelho de Herbst. Na primeira fase do tratamento a paciente utilizou um aparelho de Herbst com splint de acrílico inferior removível. Na segunda fase, utilizou aparelho fixo nas arcadas superior e inferior. Como contenção, utilizou uma placa de Hawley modificada superior e uma contenção fixa 3×3 inferior. A avaliação 11 anos após o final do tratamento permite concluir que o tratamento da Classe II com o aparelho de Herbst em duas fases foi eficaz, promovendo alterações esqueléticas, dentárias e faciais que se mostraram estáveis.(AU)

Abstract Orthodontic treatment has several objectives, one of the most important of which is the stability of the corrections achieved. Longitudinal stability of treatment results is one of the keys to successful orthodontic treatment. Thus, this article is intended to describe a clinical case of a patient with Class II Division 1 malocclusion, treated with the Herbst appliance. In the first phase of treatment, the patient used a Herbst appliance with removable lower acrylic splint. In the second phase, she used a fixed appliance in the upper and lower arches. As a retainer, she used a modified upper Hawley plate and a fixed 3×3 lower retainer. The evaluation 11 years after the end of the treatment allows us to conclude that the Class II treatment with the Herbst appliance in two phases was effective, promoting skeletal, dental and facial changes that were stable. (AU)