The effect of different functional appliances on the sagittal pharyngeal airway dimension in skeletal class II: a retrospective study.

The aim of this study was to compare the changes in the sagittal pharyngeal airway dimension (SPAD) in adolescents with Class II mandibular retrusion treated with Invisalign Mandibular Advancement (IMA), prefabricated Myobrace (MB), and Twin block (TB). For this retrospective study, the pre-treatment and post-treatment lateral cephalograms of 60 patients who underwent myofunctional treatment, using either one of the tested appliances were gathered from the files of treated patients. Changes in the SPAD were measured in each group, and comparisons were carried out between the three study groups. Additionally, sagittal skeletal measurements were carried out. Comparisons of the study variables at T0 and T1 between the three groups were performed using one-way ANOVA, while comparisons of the difference (T1-T0) were performed using Kruskal Wallis test. A significant SPAD increase has been reported using the three tested appliances (p < 0.05), with the least change documented with MB use (p < 0.05). Significant antero-posterior improvements have been found with IMA, MB, and TB with an increase in the SNB°, and a decrease in ANB° and Wits appraisal (p < 0.05). Non-significant FMA° changes have been observed post-treatment in the three test groups (p > 0.05). The IMA, MB, and TB generated significant SPAD and sagittal changes, with both IMA and TB surpassing MB in the airway area improvement post-treatment. Moreover, the three tested Class II functional appliances did not affect the vertical dimension.

In-office distalizer as Motion Carriere versus Herbst appliance: a comparative study by superimpositions on 156 cases / Distaliseur in-office façon Motion Carriere versus les bielles de Herbst : une étude comparative par superposition sur 156 cas.

Introduction: Among the class II dental supported therapeutic devices, the Carriere Motion Appliance (Henri Schein) was introduced in 2004 followed by in-office adjustments. The objective of this study was to evaluate, by superimpositions, the dento-skeletal effects of the in-office distalizer (D) close to the Carriere Motion Appliance compared to the reference treatment: the Herbst appliance (B). Material and Method: A retrospective intention-to-treat study was conducted. Patients had to be in class II, 1 bilateral, have growth potential, two successive lateral cephalograms. The criteria evaluated were cephalometric, mainly from the Pancherz analysis. Statistical tests were performed with a threshold of 5%. Results: Overall, 116 patients treated with D and multi-attachment appliance (MA) and 40 patients treated with B and MA were included. D and B slow maxillary advance, stimulate mandibular advance and correct the skeletal Class II. They normalize the molar class by distalizing the maxillary arch (palato-position of the maxillary incisors, retreat of the maxillary first molar) and by mesializing the mandibular arch (vestibulo-position and vestibulo-version of the mandibular incisors by 5 to 6°, advance of the mandibular first molar). They provide good control of facial divergence, but with a clockwise tilt of the occlusal plane. Discussion: Randomized trials are needed to confirm our results. Conclusion: With similar adverse effects, the in-office distalizer may be an interesting alternative because of its smaller volume, comfort and easy manufacture.

Introduction: Parmi les dispositifs thérapeutiques de classe II à appui dentaire, le Carriere Motion Appliance (Henri Schein) a été proposé en 2004 puis des adaptations in-office. L'objectif de cette étude était d'évaluer, par superpositions, les effets dento-squelettiques du distaliseur in-office (D) proche du Carriere Motion Appliance par rapport au traitement de référence, les bielles de Herbst (B). Matériel et méthode: Une étude rétrospective en intention de traiter a été menée. Les patients devaient être en classe II, division 1 bilatérale, avoir du potentiel de croissance, deux téléradiographies de profil successives. Les critères évalués étaient céphalométriques, essentiellement issus de l'analyse de Pancherz. Des tests statistiques ont été réalisés avec un seuil de 5 %. Résultats: Au total, 116 patients traités par D et appareil multi-attache (MA) et 40 patients traités par B et MA ont été inclus. D et B permettent de freiner l'avancée maxillaire, favoriser l'avancée mandibulaire et corriger le décalage squelettique de classe II. Ils normalisent la classe molaire en distalant l'arcade maxillaire (palato-position des incisives maxillaires, recul de la première molaire maxillaire) et en mésialant l'arcade mandibulaire (vestibulo-position et vestibulo-version des incisives mandibulaires de 5 à 6°, avancée de la première molaire mandibulaire). Ils permettent un bon contrôle de la divergence faciale avec néanmoins une bascule horaire du plan d'occlusion. Discussion: Des essais randomisés sont nécessaires pour confirmer nos résultats. Conclusion: À effets indésirables proches, le distaliseur in-office peut constituer une alternative intéressante par son volume moindre, son confort et sa facilité de conception.

Development of a questionnaire for patient perception to functional appliances.

OBJECTIVE: To developed and evaluate the validity, reliability, and Arabic translation of a questionnaire for preadolescent perception to removable functional appliances. SUBJECTS AND METHODS: A new questionnaire was drafted based on previously used questionnaires. Twelve orthodontic experts were selected within content and face validity panel and twenty preadolescents wearing functional appliances were participated in the face validation of the questionnaire. Two rounds of content validity were performed with the same experts. The final form of the validated questionnaire was translated from English to Arabic language. The content validity index (CVI) was used for content validity and the Cronbach's alpha test was used to assess the internal consistency reliability of the questionnaire. RESULTS: During the first round of content validity, 50 items were relevant to the underlying construct (Item-CVI ≥ 0.78), while four items were considered not valid (Item-CVI < 0.78) and the average scale-CVI was 0.93. In terms of face validation by experts, the percentage of agreement was adequate (96.4%). The questionnaire was modified by removing the non-valid items, adding/modifying items, and merging some categories. For second round of content validity, all items were found to be valid (I-CVI ≥ 0.78) and the overall questionnaire had adequate content validity (Scale-CVI/Ave = 0.94). The translated valid questionnaire also achieved a perfect agreement (100%) for face validity by patients. The internal consistency was appropriate (≥ 0.7). CONCLUSIONS: A new valid, reliable, and translated questionnaire (English and Arabic versions) that cover the majority of aspects of patients' perception during treatment with removable functional appliances has been developed.

Orthodontic and orthopedic management of dentofacial deformity from juvenile idiopathic arthritis: a systematic literature review.

BACKGROUND: An update on the knowledge regarding the orthopedic/orthodontic role in treating JIA-related dentofacial deformities is relevant. OBJECTIVES: This systematic review aimed to assess the level of evidence regarding the management of dentofacial deformity from juvenile idiopathic arthritis (JIA) with orthodontics and/or dentofacial orthopedics. SEARCH METHODS: The following databases were searched without time or language restrictions up to 31 January 2024 (Medline, Embase, Cochrane Central Register of Controlled Trials, Scopus, Web of Science, and Latin American and Caribbean Health Sciences Literature). SELECTION CRITERIA: Inclusion criteria were studies dealing with JIA subjects receiving treatment with orthodontic and/or dentofacial orthopedic functional appliances. DATA COLLECTION AND ANALYSIS: After the removal of duplicate studies, data extraction, and risk of bias assessment according to ROBINS-I guidelines were conducted. Data extraction was conducted by two independent authors. RESULTS: The electronic database search identified 397 eligible articles after the removal of duplicates. Following the application of the pre-defined inclusion and exclusion criteria, 11 articles were left for inclusion. Two trials were associated with a severe risk of bias, four trials were at moderate risk of bias, and the other five presented a low risk of bias. Various research groups employed and documented the effects of different types of appliances and methodologies. The study heterogeneity did not allow for meta-analyses. In addition, a lack of uniformity in treatment objectives was observed across the included studies. After treatment with dentofacial orthopedics skeletal improvement was demonstrated in 10 studies, and a decrease in orofacial signs and symptoms was reported in 7 studies. CONCLUSIONS: Across the available literature, there is minor evidence to suggest that dentofacial orthopedics may be beneficial in the management of dentofacial deformities from JIA. There is little evidence to suggest that it can reduce orofacial signs and symptoms in patients with JIA. Based on current evidence, it is not possible to outline clinical recommendations for specific aspects of orthopedic management in growing subjects with JIA-related dentofacial deformity. REGISTRATION: PROSPERO (CRD42023390746).

Effects of Removable Functional Appliances on the Dentoalveolar Unit in Growing Patients.

Background and Objectives: The objective of this retrospective controlled study is to compare class II growing patients who underwent treatment with two different functional appliances: the Fraenkel regulator (FR-2), utilized as the control group, and the elastodontic device "Cranium Occluded Postural Multifunctional Harmonizers" (AMCOP), utilized as the test group. Materials and Methods: The study sample consisted of 52 patients with class II division I malocclusion (30 males, 22 females, mean age 8.6 ± 1.4 years) who were treated with the two different types of appliances: Group 1 (n = 27, mean age 8 [7.00, 9.00] years, 12 females, 15 males) received treatment with AMCOP, while Group 2 (n = 25, mean age 9.2 years [8.20, 10.00], 10 females, 15 males) received treatment with FR-2. The mean treatment duration for Group 1 was 28.00 [21.50, 38.00] months, while for Group 2 it was 23.70 [17.80, 27.40] months. Cephalometric analyses were performed on lateral cephalograms taken before treatment (T1) and after treatment (T2). Results: Significant intragroup differences were observed over time in Group 1 for 1^/PP. Similarly, significant intragroup differences were observed over time in Group 2 for SNB, ANB, and IMPA. Conclusions: Both treatment modalities resulted in the correction of class II malocclusion with dentoalveolar compensation, although the treatment duration with AMCOP tended to be longer on average.

A retrospective study evaluating the influence of Class III correction appliances on the sagittal pharyngeal airway dimension.

The aim of this study was to compare the effects of Class III correction appliances including the Facemask (FM), and the new non-compliance fixed functional appliances such as the Reversed Forsus Fatigue Resistant Device (FRD), as well as the CS-2000 (CS), on the sagittal pharyngeal airway dimension (SPAD). Pre-treatment and post-treatment lateral cephalograms of 45 patients who underwent Class III appliance treatment, using either FM, Reversed FRD, or CS were collected from the files of treated patients. SPAD changes were evaluated in each group, and comparisons were conducted between the three study groups. Additionally, sagittal and vertical skeletal measurements were conducted. The FM, the Reversed FRD, and the CS, were found to generate a significant increase in the SPAD, with the Reversed FRD contributing to the most significant change at the OPAA (116.80 ± 26.36 mm2). All three appliances elicited significant antero-posterior changes in the SNA°, SNB°, and ANB°, also with the greatest intermaxillary change documented with the employment of the Reversed FRD (ANB° = 3.33 ± 0.82°). As for the vertical dimension, the FM, the Reversed FRD, and the CS elicited significant FMA° increases, with the greatest change attributed to the FM (FMA° = 2.32 ± 0.97°). Therefore, the three tested Class III corrective appliances generated significant SPAD, antero-posterior, and vertical changes. However, the Revered FRD showed a superior impact in increasing the SPAD at the OPAA level and in eliciting significant intermaxillary changes.

Comparative assessment of two-phase class II treatment with Activator or Bionator followed by fixed appliances: A retrospective controlled before-and-after study.

AIM: Two-phase treatment for children with Class II malocclusion with several functional appliances is still performed by many orthodontists, while the Activator and the Bionator appliances are two of the most popular ones. Aim of this study was to compare the skeletal and dentoalveolar effects of treatment with these two appliances. METHODS: Class II children treated with Activator or Bionator in the first phase, followed by a phase of fixed appliances were included. Skeletal and dentoalveolar parameters were assessed from lateral cephalograms and analysed with linear regressions at 5%. RESULTS: A total of 89 patients (mean age 10.0 years; 47% female) were included. During the first phase, Bionator increased less the SNB (difference in mean treatment-induced changes [MD] -0.7°; 95% confidence interval [CI] -1.3 to -0.2°; P=0.01) and decreased less the ANB angle (MD 0.6°; 95% CI 0 to 1.1°; P=0.03) compared to Activator. Activator slightly increased the facial axis and Bionator reduced it (MD -1.6°; 95% CI -2.3 to -0.8°; P<0.001). Compared to Activator, the Bionator retroclined more the upper incisors (MD -2.4°; 95% CI -4.6 to -0.2°; P=0.03) and increased more the interincisal angle (MD 2.9°; 95% CI 0.5 to 5.4°; P=0.02). After the second phase (6.2 years after baseline), the only differences were a reduced facial axis (MD -1.3°; 95% CI -2.2 to -0.3°; P=0.008) and an increased maxillary rotation (MD 0.9°; 95% CI 0 to 1.8°; P=0.04) with Bionator compared to Activator. CONCLUSION: Similar dentoalveolar effects were seen overall with two-phase treatment with either appliance, with Bionator being associated with more vertical increase compared to Activator.

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.

Functional treatment of bilateral posterior crossbite improves mandibular kinematics during chewing.

OBJECTIVES: To evaluate the effects of treatment of bilateral posterior crossbite (BPXB) on mandibular kinematics by the percentage of reverse chewing cycles (RCCs) during soft and hard bolus chewing before and after the correction of the malocclusion with function-generating bite (FGB). MATERIALS AND METHODS: This prospective study included 71 subjects: 19 patients with occlusally symmetric BPXB (M = 9; F = 10; mean age 9.3 ± 2.2[yr.mo]), 32 patients with occlusally asymmetric BPXB (19 with more teeth in crossbite on the right side (right prevalent side), M = 7; F = 12; mean age 8.2 ± 1.6 [yr.mo] and 13 on the left side, M = 7; F = 6; mean age 9.6 ± 1.9 [yr.mo]) and 20 controls without malocclusion (M = 8; F = 12; mean age 10.2 ± 1.7 [yr.mo]). Masticatory patterns were recorded before (T0) and after (T1) the correction of the malocclusion with FGB, with the K7-I® kinesiograph using standardized soft and hard boluses. RESULTS: BPXB was corrected in all included patients. At T0, the percentage of RCCs in BPXB was significantly increased compared to controls (P < .0001); symmetric BPXB showed no difference in RCCs between the sides, whereas asymmetric BPXB showed significantly more RCCs on the side with more teeth in crossbite (prevalent side). After treatment with FGB (T1), the percentage of RCCs was significantly reduced in both symmetric BPXB patients (soft bolus, P = .003; hard bolus, P < .001) and asymmetric BPXB patients (prevalent side: soft and hard bolus, P < .00001; non-prevalent side: soft bolus, P = .01 and hard bolus, P = .0002). CONCLUSION: Functional correction of BPXB with FGB significantly improved mandibular kinematics during chewing.

Comparison of Twin Block appliance and Herbst appliance in the treatment of Class II malocclusion among children: a meta-analysis.

BACKGROUND: Our meta-analysis aimed to evaluate the efficacy of applying Herbst and Twin Block appliances in the treatment of Class II malocclusion among children. METHODS: Databases, including PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), China VIP Database (VIP), and Wanfang were thoroughly searched from inception to August 9, 2023. The outcomes included skeletal, dental, and soft tissue changes. The weighted mean difference (WMD) was used as the effect indicator, and the effect size was expressed with a 95% confidence interval (CI). The heterogeneity of each outcome effect size was tested, and the heterogeneity statistic I2 ≥ 50% was analyzed by the random-effect model, otherwise, the fixed-effect model was conducted. Sensitivity analysis was performed. RESULTS: A total of 12 studies involving 574 patients were included in this meta-analysis. Herbst appliance had a statistically significant increase in mandibular body length (WMD: 1.44, 95% CI: 0.93 to 1.96, P < 0.001) compared with the Twin Block appliance. More increases in angle and distance of L1 to mandibular plane (MP) were found in the Herbst appliance compared with the Twin Block appliance. Significant and greater improvements in molar relationship (WMD: 0.79, 95% CI: 0.28 to 1.29, P = 0.002), posterior facial height (WMD: -1.23, 95% CI: -2.08 to -0.38, P = 0.005), convexity angle (WMD: -1.89, 95% CI: -3.12 to -0.66, P = 0.003), and Sella-Nasion plane angle (U1 to SN) (WMD: 3.34, 95% CI: 2.25 to 4.43, P < 0.001) were achieved in the Twin Block appliance. Herbst and Twin Block appliances produced similar effects in the skeletal and dentoalveolar changes including Sella-Nasion-point A (SNA), Sella-Nasion-point B, point A-Nasion-point B (ANB), overjet, and overbite. CONCLUSION: As the findings revealed both Herbst and Twin Block appliances contributed successfully to the correction of Class II malocclusion. Compared with the Twin Block appliance, the Herbst appliance may have more advantages in mandibular bone movement. Twin Block therapy resulted in more improvement in the aesthetics of the face.

Impact of initial lip competence on the outcome of class II functional appliances therapy.

OBJECTIVES: The aim of this prospective clinical study was to evaluate the impact of initial lip position on class II functional appliance therapy. MATERIALS AND METHODS: In total, 34 class II division 1 patients (23 females, 19 males; mean age 12.4 ± 0.9 years) that met the inclusion criteria (> ½ class II molar relationship, overjet > 6 mm, ANB > 4°, neutral or horizontal growth pattern, cervical vertebral maturation stage (CVMS) II - III, mean wear-time > 10 h/day) were consecutively divided into two groups (lip incompetence (LI); lip competence (LC)). All patients were treated with the Sander bite jumping appliance (BJA). Wear time was microelectronically measured. Lateral cephalograms were taken at the beginning (T0) and after 1 year of treatment (T1). An untreated class II group served as a control (CG). Inter-group comparisons were determined with Mann-Whitney U tests for independent samples. RESULTS: Significant skeletal treatment effects were found in both treated groups when compared to the CG with significantly more pronounced mandibular skeletal effects in the LI than in the LC group (mandibular base length p < 0.001, composite mandibular base length p < 0.001, condylar head growth p = 0.002, co-pg p < 0.00, go-pg p = 0.003, reduction of the ANB angle p = 0.009, and Wits appraisal p < 0.001). CONCLUSION: The more pronounced mandibular effects in the LI group were composed of the functional orthopedic effect plus harmonization of the lip competence. CLINICAL RELEVANCE: Functional harmonization of lip incompetence with BJA enhances mandibular growth stimulation. Lip incompetence seems to impede mandibular growth and its harmonization seems to be a preventive approach.

Skeletal and dental effects of function-generating bite appliance compared to rapid palatal expander and untreated controls.

INTRODUCTION: Maxillary expansion is a fundamental interceptive orthodontic treatment, which can be achieved through either a rapid expansion protocol or functional devices. However, no data exist about the efficacy of functional devices in achieving skeletal expansion. Therefore, the aim of this study was to compare the effects of the rapid palatal expander (RPE) and the function-generating bite type M (FGB-M) on the transversal dimension of the maxilla, and on the maxillary and mandibular dental arch width. METHODS: One hundred eighty-one skeletal Class I patients, aged between 6 and 12 years and with a cervical vertebral maturation stage II or III, with maxillary transversal deficiency were retrospectively enrolled; among these 55 were treated with FGB-M, 73 were treated with RPE and 51 were untreated subjects retrieved from historical databases. The pre-treatment (T0) and post-treatment (T1) frontal cephalograms were retrieved, and the maxillary and mandibular widths, and the distance between upper and lower first molars were measured. T1-T0 interval was of 17.3 months (RPE), 24.6 months (FGB-M) and 18.2 months (controls). RESULTS: The statistical analysis showed that there were no statistically significant differences between the RPE and FGB-M groups regarding skeletal and dental expansion, while the untreated control group differed significantly from the other two groups. CONCLUSION: The comparison between patients treated with RPE and FGB-M showed that there were no statistically significant differences between the RPE and FGB-M groups regarding the amount of skeletal expansion and dental arch width, suggesting that both appliances can be used to achieve similar results.

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.

Evaluation of the antibacterial effect of titanium dioxide nanoparticles combined with acrylic laminates for functional orthodontic appliances: a randomized controlled clinical trial.

BACKGROUND: The objective of this study was to evaluate the antibacterial effect of titanium dioxide nanoparticles incorporated into the acrylic baseplates of the maxillary part of twin block appliances in orthodontic patients during the treatment period. MATERIALS AND METHODS: Twenty-six patients were selected randomly and divided into two groups(n = 13). Test group patients used orthodontic functional appliances containing 1% titanium dioxide nanoparticles in acrylic baseplates. Control group patients used orthodontic functional appliances without titanium dioxide nanoparticles in acrylic baseplates. Swap samples were taken from the palatal gingiva facing the fitting surface of the acrylic component of the maxillary part of a twin block appliance for each patient at five-time intervals (baseline sample, after one, two, four, and six months) and then cultured in blood agar plates to calculate bacterial colony count. The Mann‒Whitney U test and the Friedman test were used to compare data. Bonferroni correction (p value ≤ 0.05) was applied to detect significant differences. THE RESULTS: showed a decrease in the bacterial colony count in the test group compared to the control group. Pairwise comparisons revealed a statistically significant difference in samples after four- and six-month groups (p values = 0.002 and 0.011, respectively) vs. the one-month test group. A higher statistically significant difference was observed in the six-month group (p-value = 0.037) vs. the baseline group in the control group. CONCLUSION: The addition of 1% titanium dioxide nanoparticles to acrylic baseplates of orthodontic functional appliances significantly reduced the bacterial colony count under the base plate after at least four months of application.

Prevalence of temporomandibular disorders diagnosis in patients treated with Herbst appliance: a systematic review and meta-analysis.

BACKGROUND: The Herbst appliance is an excellent therapy for treating class II malocclusions with increased overjet. Its mechanics involve propelling the mandibular bone using two pistons the patient cannot remove. The so-called bite-jumping keeps the mandible in a more anterior position for a variable period, usually at least 6 months. This appliance does not inhibit joint functions and movements, although there are scientific papers in the literature investigating whether this appliance can lead to temporomandibular disorders. This systematic review aims to evaluate whether Herbst's device can cause temporomandibular diseases by assessing the presence of TMD in patients before and after treatment. METHODS: A literature search up to 3 May 2023 was carried out on three online databases: PubMed, Scopus and Web of Science. Only studies that evaluated patients with Helkimo scores and Manual functional analysis were considered, as studies that assessed the difference in TMD before and after Herbst therapy. Review Manager version 5.2.8 (Cochrane Collaboration) was used for the pooled analysis. We measured the odds ratio (OR) between the two groups (pre and post-Herbst). RESULTS: The included papers in this review were 60. Fifty-seven were excluded. In addition, a manual search was performed. After the search phase, four articles were considered in the study, one of which was found through a manual search. The overall effect showed that there was no difference in TMD prevalence between pre-Herbst and post-Herbst therapy (OR 0.74; 95% CI: 0.33-1.68). CONCLUSION: Herbst appliance seems not to lead to an increase in the incidence of TMD in treated patients; on the contrary, it appears to decrease it. Further studies are needed to assess the possible influence of Herbst on TMDs.

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.

Effects of Twin-Block with an expanding device on the upper airway in growing children with skeletal class II malocclusion-a retrospective study based on the consistency of three-dimensional and two-dimensional data.

OBJECTIVES: Skeletal class II malocclusion is one of the most common malocclusions. Among the functional appliances for skeletal class II malocclusion, the Twin-Block appliance with a maxillary expander is effective in repositioning the mandible forward. In this study, we focused our efforts on investigating the effects of Twin-Block appliances with maxillary expanders on the upper airway in growing children with skeletal class II malocclusion by tracing and measuring lateral cephalograms after evaluating the consistency of three-dimensional CBCT data and two-dimensional lateral cephalogram data. MATERIALS AND METHODS: A total of 102 patients ranging from 9 to 15 years old (11.37 ± 2.80, male/female ratio = 1:1) with skeletal class II malocclusion were selected to evaluate the consistency of CBCT data and lateral cephalogram data. The strongly and moderately correlated segments were then selected to study the effects of Twin-Block with a maxillary expander on the upper airway in 66 growing children with skeletal class II malocclusion (11.31 ± 1.23 years old, male/female ratio = 1:1) by lateral cephalograms. RESULTS: The results showed a strong significant correlation in the nasopharynx (r = 0.708) and moderate significant correlations in the overall upper airway (r = 0.641), palatopharynx (r = 0.553), and glossopharynx (r = 0.575) but a weak correlation in the hypopharynx (r = 0.323). The corresponding determination coefficient (R2) was also determined by scatter plot analysis. Moreover, compared with the pretreatment data (T1), the total area of the upper airway and the areas of the nasopharynx, palatopharynx, and glossopharynx after functional treatment (T2) increased statistically and significantly. CONCLUSIONS: Lateral cephalograms can reflect the volume of the nasopharynx and oropharynx in skeletal class II children to a certain extent, while Twin-Block appliances with maxillary expanders can widen the volume of the nasopharynx and oropharynx significantly. CLINICAL RELEVANCE: The lateral cephalogram is reliable for analyzing the nasopharynx, palatopharynx, and glossopharynx in orthodontic clinical practice. Twin-Block appliances with maxillary expanders have a positive effect on skeletal class II patients with airway stenosis.

Mandibular advancement with clear aligners and functional appliances in the treatment of skeletal ClassⅡmalocclusion: a systematic review and meta-analysis / 华西口腔医学杂志

OBJECTIVES@#This study aimed to conduct a meta-analysis of the efficacy of mandibular advance clear alig-ners with traditional functional appliances as the control group.@*METHODS@#PubMed, Web of Science, Embase, Cochrane Library, China Biomedical Abstracts Database, China Knowledge Network Database, Wanfang Database, and Weipu Database were used in this study. The two groups of researchers screened the literature and extracted data based on the inclusion and exclusion criteria established by PICOS entries, and used the ROBINS-I scale for quality evaluation. Revman 5.4 and Stata 17.0 software were used for meta-analysis.@*RESULTS@#Nine clinical controlled trials were included in this study with a total sample size of 283 cases. No significant difference was found in SNA, SNB, ANB, Go-Pog, U1-SN, Overjet, and other aspects between the invisible group and the traditional group in the treatment of skeletal class Ⅱ ma-locclusion patients; there was a 0.90° difference in mandibular plane angle between the two groups; the growth of the mandibular ramus (Co-Go) in the traditional group was 1.10 mm more than that in the invisible group; the lip inclination of the lower teeth in the invisible group was better controlled, 1.94° less than that in the control group.@*CONCLUSIONS@#The invisible group can better control the lip inclination of the mandibular anterior teeth when guiding the mandible. Furthermore, the mandibular plane angle (MP-SN) can remain unchanged, but the growth of the mandibular ramus is not as good as the traditional group, and auxiliary measures should be taken to improve it in clinical practice.