Herbst Treatment Research Articles

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

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. Pre- and posttreatment cephalometric and panoramic radiographs of 133 patients (mean age 13.89 ± 1.14years) 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 ttests were used for the statistical analysis of the data for intragroup and intergroup comparisons. Functional treatment with both the monoblock and the Herbst appliances resulted in improvement of skeletal classII 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). 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.

Tomographic evaluation of changes induced by herbst treatment - buccolingual inclination of mandibular canines and the intercanine distance

The aim of this study was to perform a three-dimensional evaluation of Herbst appliance effects on the mandibular canines.The subjects consisted of 23 Class II:1 patients (12 men, 11 women), mean age of 15.76± 1.75 years, consecutively treated with a Flip-Lock Herbst®appliance (TP Orthodontics, Inc., La Porte, IN, USA). The lower anchorage unit for the Herbst appliance consisted of two anchor bands connected by a lingual arch with 3mm distance from the incisor’s lingual surface. Treatment changes in mandibular canine inclination and mandibular intercanine width at the cusp and apex levels were evaluated by means of cone-beam computed tomography images (i-CAT® Classic unit, Imaging Sciences International, Hatfield, PA, USA) obtained before and after treatment with the Herbst appliance. There were no statistical differences between genders. Herbst appliance treatment did not result in any statistically significant changes for mandibular canine inclination and mandibular intercanine width. There were associations between mandibular canine inclination and mandibular intercanine width at the cusp (/r/ = 0.43 to 0.66) and apex levels (/r/ = 0.34 to 0.60). The three-dimensionalcone-beam computed tomography analysis of the mandibular canine segment revealed that the Herbst appliance with a mandibular anchorage unit distant from the incisor’s lingual surface does not change mandibular canine inclination and mandibular intercanine width significantly during treatment. However, large interindividual differences may result in undesired amount of mandibular canine anchorage loss in individual patients.

Effect of Herbst Treatment on Mandibular Length (Co-Gn) in Patients with Class II Malocclusion: A Systematic Review and Meta-analysis

Effect of Herbst Treatment on Mandibular Length (Co-Gn) in Patients with Class II Malocclusion: A Systematic Review and Meta-analysis

Long-term evaluation of soft tissue profile changes induced by Herbst appliance followed by fixed appliances

The present investigation aimed to evaluate, by cephalometric analysis, the soft tissue profile changes in adolescents with Class II Division 1 malocclusion, treated with Herbst appliance (Stage I) and fixed appliances (Stage II), followed-up for an average of 4 years (Stage III). The adolescents were divided into two groups: treated group (TG) - 33 adolescents with Class II malocclusions (17 boys and 16 girls) consecutively treated with Herbst appliance and fixed appliances; control group (CG) - 28 adolescents (13 boys and 15 girls) with untreated Class II malocclusions. Lateral cephalograms were obtained immediately before (T1) and after (T2) Herbst treatment, after fixed appliances (T3), and on average, 4 years after orthodontic treatment. Intergroup comparison was evaluated by t or Mann-Whitney tests. The TG was evaluated by analysis of variance followed by Tukey test or Friedman test followed by Dunn’s test. Compared to the CG, the TG showed significant favorable changes at Stage I: decrease in facial convexity, upper lip retrusion, lower lip protrusion, improvement of soft tissue pogonion and increase in mentolabial angle. The total posttreatment period (T2-T4) of the TG showed: increase in H line-Prn, and upper and lower lips retrusion, while the others variables remained stable. This study suggests that Herbst therapy improved features of soft tissue facial profile, which were maintained after fixed appliances and for an average of 4 years posttreatment, although the convex facial characteristic has prevailed.

Treatment and posttreatment effects of Herbst appliance therapy on trabecular structure of the mandible using fractal dimension analysis.

This controlled study aimed to evaluate the effects of Herbst therapy on the trabecular structure of the condyle and angulus mandible using fractal dimension analysis (FD-A) accompanied by skeletal cephalometric changes. The panoramic and cephalometric radiographs of 30 patients with skeletal Class II malocclusion treated with the Herbst appliance (C II-H group, mean age: 15.23 ± 1.08), 30 patients with skeletal Class II malocclusion that received fixed orthodontic treatment (C II-C group, mean age: 15.73 ± 1.38), and 30 patients with skeletal Class I malocclusion (C I-C group, mean age: 15.90 ± 1.30) were selected. FD-A was performed on the superoposterior region (C-SP) and centre of the condyles (C-C) and the mandibular angulus (Ang) on the panoramic radiographs taken at the pretreatment (T0), intermediate stage of treatment (T1), and posttreatment (T2) timepoints just like cephalometric analysis. Herbst therapy provided a statistically significant increase in SNB, ANS-Me, Na-Me, S-Go, Co-Gn and a decrease in ANB and overjet (P < 0.05). All skeletal changes remained stable during the fixed appliance treatment after Herbst. The FD values in C-C increased (P < 0.05), and C-SP values decreased (P < 0.05) during Herbst therapy, while after removal of the Herbst appliance, no significant change was observed despite an increase in C-SP. The Ang value did not change during Herbst treatment, but then increased significantly (P < 0.05). There was no significant change in the FD values of the C I-C and C II-C groups at any stage of treatment. The C-C and C-SP changes at T1-T0 period, C-SP and Ang changes at T2-T1 period, and C-C, C-SP, and Ang values at T2-T0 period were found higher in C II-H group compared with the C II-C group significantly (P < 0.05). Herbst therapy changed the trabecular structure of the condyles in different directions at the superoposterior and central regions of the condyles, while the structural complexity of the angulus mandible, which did not change during the Herbst treatment, increased during the fixed orthodontic treatment after Herbst.

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

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. 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. 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 2.22mm (95% C.I [0.82. 3.61], P=.002) and mandibular length by mean difference of 3.7mm (95% C.I [1.55, 5.85], P<.001) when compared to Herbst appliance alone. 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.

Influence of incisor position control on the mandibular response in growing patients with skeletal Class II malocclusion

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. The lateral cephalograms of 61 patients (mean age, 12.3years; 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). 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 4.0mm (interquartile range, 2.5) in the NDR group vs 1.1mm (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). 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.

Herbst appliance anchored to miniscrews in the upper and lower arches vs standard Herbst: A pilot study

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. The treatment group (TG) consisted of 13 patients (10 males [M], 3 females [F]; mean age of 12.8years) 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 (10F, 3M, mean age of 12.2years) 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. 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: 5.70mm in the TG group and 0.8mm in the CG group (P=0.022). Mandibular incisors proclined 1.6° in the TG group and 3.7° in theCG group. Herbst treatment reinforced with 4 miniscrews (2 in each arch) increased the orthopedic effect of treatment in growing patients with Class II malocclusion.

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

To compare three-dimensional (3D) skeletal and dentoalveolar effects of the Herbst and Pendulum appliances followed by fixed orthodontic treatment in growing patients. 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). Patients with Class II malocclusion was assessed retrospectively and divided into two treatment groups: Herbst group (n=17, age: 12.0±1.6years) and Pendulum group (n=18, age: 12.1±1.5years), with a mean treatment duration of 2.8±0.8years and 2.5±0.7years, 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). Significant increase in mandibular length was observed in the Herbst group (7.3±3.5mm) relative to the Pendulum group (4.6±4.5mm). Inferior and anterior displacements of Pogonion were 2.2mm and 1.6mm greater in the Herbst group, respectively. The mesial displacement of the lower first molars was significantly greater in the Herbst group (1.9mm). The upper first molars had contrasting results in sagittal displacement, with 0.6±1.7mm of distal displacement with the Pendulum and 1.4±2.1mm of mesial displacement with the Herbst. Lower incisor projection and proclination were similar between groups. 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.

Residents' journal review

Residents' journal review

Three-dimensional treatment outcomes in Class II patients with different vertical facial patterns treated with the Herbst appliance.

The aims of this study were to evaluate, using 3-dimensional superimposition techniques, the skeletal changes in Class II subjects with different vertical facial patterns treated with the Herbst appliance and to compare these skeletal changes to those of Class II controls treated with elastics. Sixteen Herbst patients who met the inclusion criteria were divided into 2 equal groups based on vertical facial pattern as determined by the Frankfort mandibular plane angle (brachyfacial,≤22°; mesofacial, 23°-29°) and had cone-beam computed tomographs taken before treatment, 8weeks after Herbst appliance removal, and after subsequent fixed appliance treatment. Eleven Class II control patients treated with fixed appliances and elastics had cone-beam computed tomographs taken before and after treatment. Three-dimensional models were generated from the cone-beam computed tomography images, registered on the anterior cranial bases, and analyzed using color maps and point-to-point measurements. There were minimal differences in treatment response between the 2 Herbst groups across all skeletal parameters measured. The Herbst subjects showed a greater inferior displacement of anterior nasal spine compared with the Class II controls (Herbst brachyfacial, -1.44mm; Herbst mesofacial, -1.95mm) with other maxillary changes being clinically insignificant. The Herbst subjects showed greater inferior displacement of B-point compared with the Class II controls (Herbst brachyfacial, -2.59mm; Herbst mesofacial, -2.75mm). There were no statistically significant differences in mean linear mandibular measurements. All groups showed a trend toward posterior displacement of the condyles and glenoid fossae from the start to the end of treatment, with no significant differences across the 3 groups. There were minimal differences in the changes in gonial angle and Frankfort mandibular plane angle across all groups. Approximately 2years after Herbst treatment, the Herbst subjects with different vertical facial patterns showed similar patterns of skeletal change compared with the Class II controls treated with elastics.

Treatment changes of hypo- and hyperdivergent Class II Herbst patients.

To determine the relative effects of Herbst appliance therapy in hypo- and hyperdivergent patients. The treated group included 45 growing Class II, division 1, patients treated with stainless steel crown Herbst appliances, followed by fixed edgewise appliances. The untreated control group consisted of 45 Class II, division 1, subjects, matched to the treated sample based on Angle classification, age, sex, and pretreatment mandibular plane angle (MPA). Subjects were categorized as hypo- or hyperdivergent based on their MPAs. Pre- and posttreatment cephalograms were traced and superimposed on cranial base and mandibular structures. The primary effect of the Herbst in terms of maxillomandibular correction was in the maxilla. It significantly restricted maxillary growth, producing a "headgear effect." Mandibular treatment changes depended on divergence. Hyperdivergent patients experienced a deleterious backward true mandibular rotation with Herbst treatment. Hypodivergent patients, as well as untreated hypo- and hyperdivergent controls, underwent forward true mandibular rotation. However, hypodivergent chins did not advance any more than expected for untreated hypodivergent Class II patients. Hypo- and hyperdivergent patients benefit from the Herbst's headgear effect. While the mandibular growth of hypodivergent patients overcomes the negative rotational effects, hyperdivergent patients undergo a deleterious backward mandibular rotation and increases in facial height.

Long-term effects of Class II Herbst treatment on the pharyngeal airway width.

The aim was to assess the long-term effects of Class II malocclusion treatment with the Herbst appliance on the pharyngeal airway (PA) width in comparison to untreated individuals with Classes I and II malocclusion. Lateral cephalometric radiographs of 13 male Class II patients from before (T1) and after (T2) treatment with the Herbst appliance as well as after the end of growth (T3) were retrospectively analyzed and compared to two untreated age- and gender-matched samples with Class I (n = 13) or Class II (n = 13) malocclusion. The PA dimensions were measured using the parameters p (narrowest distance between the soft palate and the posterior pharyngeal wall) and t (narrowest distance between the base of the tongue and the posterior pharyngeal wall). In addition, standard cephalometric measurements were performed. Relevant changes in PA dimensions were only seen for the post-treatment period, during which the distances p and t showed a significant increase in the Herbst group only (∆p: 2.3 mm, ∆t: 3.3 mm) while remaining similar in both untreated groups (∆p: 0.5 mm, ∆t: 0.5 mm, respectively, ∆p: 0.7 mm, ∆t: 1.6 mm). During the same period, posterior face height showed a significantly larger increase in the Herbst group than in both control groups (8.2 versus 5.8 mm, respectively, 5.4 mm), whereas anterior face height (NL-Me) showed a similar development in all groups (4.6 versus 4.4 mm, respectively 3.2 mm). In the long term, Herbst treatment resulted in a significant post-treatment increase of PA width, possibly due to an increased lower posterior facial height development compared to untreated individuals.

The effect of Herbst treatment on amount and direction changes of temporomandibular joint growth: a short-term investigation of cone-beam computed tomography

The effect of Herbst treatment on amount and direction changes of temporomandibular joint growth: a short-term investigation of cone-beam computed tomography

Meta-analysis of the condylar position changes produced by functional appliances in class Ⅱ malocclusion

This study aimed to analyze the condylar position changes produced by functional appliances in class Ⅱ malocclusion by systematic review. Electronic search was conducted using Chinese Biomedical Literature Database, China National Knowledge Infrastructure, VIP Database for Chinese Technical Periodicals, Medline, Embase, Pubmed, and Cochrane Central Register of Controlled Trials. Studies on condylar position changes produced by functional appliances in class Ⅱ malocclusion were included. Risk of bias assessment and data extraction of included studies were conducted by two reviewers independently. The meta-analysis was carried out using Revman 5.1. Six studies were included (five high quality and one low quality). The condylar position showed no changes after Herbst treatment. The condylar posterior space after Twin-block treatment averagely increased by 0.31 mm (P<0.000 01), whereas the condylar anterior space averagely reduced by 0.32 mm (P<0.000 01). Twin-block appliance enables forward movement of the condylar position. This result contributes to the correction of class Ⅱ malocclusion.

Cephalometric study of Class II Division 1 patients treated with an extended-duration, reinforced, banded Herbst appliance followed by fixed appliances.

The Herbst appliance has been used in the treatment of Class II malocclusions with deficient mandibles. Various protocols, including different durations of the orthopedic treatment phase and stepwise advancement of the mandible, have been advocated for increasing the orthopedic effects. The objective of this study was to investigate the skeletal and dental changes in patients treated with a reinforced banded Herbst appliance for an extended duration and fixed appliance therapy. The study group consisted of 30 patients (16 boys, 14 girls; mean age, 12.3±2.5years) with Class II Division 1 malocclusions who were successfully treated with the new Herbst protocol followed by fixed appliances. Lateral cephalometric radiographs were taken before treatment, at the completion of Herbst treatment, and after removal of fixed appliances. The average treatment times were 1.5±0.7years for the Herbst treatment and 1.8±0.5years for the fixed appliances. A control Class II sample from the Bolton-Brush study was used to subtract growth from treatment changes to determine the appliance effect. Data were analyzed using analysis of variance and the Tukey-Kramer test. After the Herbst treatment, the incisal relationships of all subjects had been overcorrected to end-to-end relationships. Overjet was reduced by 7.2mm after subtracting changes from growth. The skeletal contribution was 2.5mm (35%), and the dental contribution was 4.7mm (65%). The molar relationship was overcorrected to a more Class I relationship by 7.5mm. The Wits appraisal was improved by 4.2mm. Vertically, overbite was decreased by 3.3mm. The maxillary and mandibular molars were extruded by 1mm. The occlusal plane rotated clockwise by 5° with little change in the mandibular plane angle. After the treatment with fixed appliances, the overjet correction was maintained at 7.6mm. The skeletal contribution was 2.9mm (38%), and the dental contribution was 4.7mm (62%). The molar relationship was corrected to a Class I relationship by 5.9mm. The Wits appraisal was improved by 3.2mm. Vertically, overbite was decreased by 4.2mm. The maxillary and mandibular molars were extruded by 0.3 and 0.8mm, respectively. The occlusal plane rotated clockwise by 1.2° with little change in the mandibular plane angle. Doubling the usual orthopedic treatment time with the reinforced Herbst appliance followed by fixed appliance therapy was effective in correcting Class II Division 1 malocclusions with excess overjet and overbite. In this sample of successfully treated patients, most changes after Herbst and fixed appliance therapy were dentoalveolar (62%). However, the skeletal changes attained in the orthopedic phase of treatment were maintained after fixed appliance therapy.

Authors' response

Authors' response

Cone beam computed tomography analysis of the bony structure of the temporomandibular joint during two phase treatment with Herbst appliance

This study assessed the effects of two-phase treatment with Herbst appliance on the bony structure of the temporomandibular joint via cone beam computed tomography (CBCT) analysis. This study selected 15 patients exhibiting early permanent dentition and classⅡmalocclusion combined with mandibular retrusion treated by a two phase treatment (Herbst and fixed appliance). The CBCT scans of the patients were obtained at the following stages: 2 weeks before Herbst treatment (T1), at the start of treatment when the Herbst appliance was set in place (T2), immediately after removal of the Herbst appliance (T3), and immediately after removal of the edgewise appliance (T4). Three-dimensional reconstruction and related measurements were performed using InvivoDental software, and the acquired data were statistically analyzed. 1) CBCT showed a crescent-shaped hyperplasia at the posterior-superior border of the condyles that the outer edge was highly dense and the inner region was lowly dense in T3 in 14 patients (28 condyles). 2) In T3-T2 and T4-T1, the diameters of the anteroposterior condyles increased by 0.62 and 0.66 mm, respectively (P<0.01), and the condylar head height correspondingly increased by 0.54 and 0.53 mm (P<0.01). Condylar growth remodeling occurs during Herbst treatment. .

Changes in alveolar bone support induced by the Herbst appliance: a tomographic evaluation.

ABSTRACTObjective: This study evaluated alveolar bone loss around mandibular incisors, induced by the Herbst appliance. Methods: The sample consisted of 23 patients (11 men, 12 women; mean age of 15.76 ± 1.75 years), Class II, Division 1 malocclusion, treated with the Herbst appliance. CBCT scans were obtained before treatment (T0) and after Herbst treatment (T1). Vertical alveolar bone level and alveolar bone thickness of mandibular incisors were assessed. Buccal (B), lingual (L) and total (T) bone thicknesses were assessed at crestal (1), midroot (2) and apical (3) levels of mandibular incisors. Student's t-test and Wilcoxon t-test were used to compare dependent samples in parametric and nonparametric cases, respectively. Pearson's and Spearman's rank correlation analyses were performed to determine the relationship of changes in alveolar bone thickness. Results were considered at a significance level of 5%. Results: Mandibular incisors showed no statistical significance for vertical alveolar bone level. Alveolar bone thickness of mandibular incisors significantly reduced after treatment at B1, B2, B3, T1 and significantly increased at L2. The magnitude of the statistically significant changes was less than 0.2 mm. The changes in alveolar bone thickness showed no statistical significance with incisor inclination degree. Conclusions: CBCT scans showed an association between the Herbst appliance and alveolar bone loss on the buccal surface of mandibular incisors; however, without clinical significance.

Cone beam computed tomography study of apical root resorption induced by Herbst appliance.

Objective This study evaluated the frequency of root resorption during the orthodontic treatment with Herbst appliance by Cone Beam Computed Tomography (CBCT).Material and Methods The sample comprised 23 patients (11 men, 12 women; mean ages 15.76±1.75 years) with Class II division 1 malocclusion, treated with Herbst appliance. CBCT was obtained before treatment (T0) and after Herbst treatment (T1). All the dental roots, except third molars, were evaluated, and apical root resorption was determined using the axial guided navigation method. Paired t-tests and Wilcoxon T Test were used to compare the dependent samples in parametric and nonparametric cases, respectively. Chi-Square Test with Yates’ correction was used to evaluate the relationship between apical root resorption and gender. Results were considered at a significance level of 5%.Results Apical resorption was detected by CBCT in 57.96% of 980 roots that underwent Herbst appliance treatment. All patients had minimal resorption and there was no statistical significance between the genders.Conclusion CBCT three-dimensional evaluation showed association between Herbst appliance and minimal apical root resorption, mostly in the anchoring teeth, without clinical significance.