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.

Non-surgical Treatment of a Late Adolescent Patient with Skeletal Class II Malocclusion Using Clear Aligners: A Case Report

Background/Introduction:

There are a variety of treatment modalities for orthodontic treatment of patients with skeletal Class II malocclusions in late adolescence. These treatment modalities may include surgical intervention, camouflage treatment, functional appliances, extraction of teeth, and/or Class II elastics mechanics. Most Class II mechanics produce retroclination of the upper incisors and proclination of lower incisors. These dentoalveolar effects limit the possibility for forward mandibular projection/growth, hence minimizing skeletal improvement.

Case Presentation:

To present a unique case report that was treated with a new perspective in maximizing skeletal improvement in a late adolescent male with skeletal Class II malocclusion and deep overbite.

A 15-year-old male presented with a skeletal Class II pattern due to mandibular retrognathism was treated with non-extraction, non-surgical technique using clear aligners in two phases. Phase 1 was designed to decompensate the compensated inclination of his anterior teeth, and phase II was planned to correct his skeletal and dental Class II malocclusion/mal relation. Results: Maxillary incisors decompensation of the inclination of the upper and lower incisors and posterior teeth intrusion allowed forward mandibular projection that led to skeletal and dental correction of his malocclusion and improvement of his chin forward projection.

Conclusion:

This case report shows successful treatment of a Class II malocclusion in alate adolescent male. This method could perhaps be used for similar cases, avoiding the need to extract teeth or include surgical intervention.

Skeletal and dentoalveolar effects of class II malocclusion treatment using bi-maxillary skeletal anchorage: a systematic review

BACKGROUND

The goal of this systematic review was to assess the available evidence regarding the skeletal and dentoalveolar effects of bi-maxillary skeletal anchorage devices (BMSADs) used in treating growing class II malocclusion patients.

METHODS

A comprehensive search was conducted on PubMed, Scopus, Science Direct, Web of Science, Cochrane, and LILACS up to November 2021, which was augmented by a manual search. The studies included were clinical trials (RCTs) and/or follow-up observational studies (retrospective and prospective). The outcomes of interest were the skeletal, dentoalveolar, and occlusal treatment-induced changes obtained from pre- and post-cephalometric measurements. The risks of bias of the included studies were assessed using an assessment tool from previous publications.

RESULTS

Out of 742 screened articles, only 4 were eligible and thus included in the qualitative synthesis. They showed a moderate overall risk of bias. The results are presented as mean changes in both the study and control groups. All studies reported retrusion of the maxillary base and advancement of the mandible (meaning reduced ANB angle). Three of the included studies reported an increase in the vertical jaw relation, which was contrary to what the fourth study reported. Three studies reported an increase in the maxillary incisors' inclination or position, while one study reported their retroclination. Proclination of the mandibular incisors happened in two studies, whereas the other two studies reported retroclination. The overjet was reduced in all included studies.

CONCLUSION

Apart from the protrusive effects on the mandible, retrusive effects on the maxilla, and the consequent reduction of the overjet, BMSADs results in inconsistent skeletal and dentoalveolar effects. However, the current evidence is limited due to the variability in the biomechanics of the intermaxillary components, type of anchorage, and comparable groups in the included studies. Further RCTs with more standardized methodologies are highly encouraged.

CLINICAL RELEVANCE

BMSADs (using miniscrews or miniplates on both jaws) induces more skeletal than dentoalveolar effects. However, this must be practiced with caution, based on the benefit to risk (surgical insertion) ratio, and the limited evidence available in hand so far. Registration The protocol for this systematic review was registered at the International Prospective Register of Systematic Reviews (PROSPERO, No.: CRD42020199601).

A Scoping Review about the Characteristics and Success-Failure Rates of Temporary Anchorage Devices in Orthodontics

This study synthesized the scientific evidence concerning the main characteristics of the Temporary Anchorage Devices (TADs) used in orthodontics and reported the success-failure rates during treatment. For that means, this scoping review collected articles from previous research. A complementary search was carried out in the databases PubMed-MEDLINE, Scopus, LILACS, and EMBASE, focusing on original studies published from 2010 to 2020. We analyzed the main characteristics of the publications. As a result, 103 articles were included. Most of the research was conducted among different groups, who needed TADs principally in the maxilla and an interradicular location between the second premolar and first molar. AbsoAnchor, Dentos Inc., Daegu, Korea, was the most used brand of TADs. The most common characteristics of the devices and biomechanics were a diameter and length of 1.6 mm and 8 mm, a self-drilled system, a closed technique for placement, immediate loading, and forces that ranged between 40 and 800 g. Of the studies, 47.6% showed success rates ≥90%. In conclusion, high success rates were found for TADs, and differences were found according to sociodemographic and clinical variables. The studies showed variability in methodological design, and scientific publications were concentrated in certain countries. We recommend further scientific research on TADs using more standardized designs.

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.

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.

Effects of fixed functional appliances with temporary anchorage devices on Class II malocclusion: A systematic review and meta‑analysis

BACKGROUND

The use of fixed functional appliances (FFAs) in conjunction with temporary anchorage devices (TADs) has been proposed to enhance skeletal changes and reduce proclination of the lower incisors.

OBJECTIVES

To systematically investigate the skeletal and dentoalveolar effects of FFAs with TADs on Class II malocclusion in adolescents.

METHODS

Electronic searches of databases and manual searches of references were performed up to August 30, 2020. Randomized controlled trials (RCTs) and clinical controlled trials (CCTs) focusing on adolescent patients treated with FFAs combining TADs were included. The modified Cochrane risk-of-bias tool (R.O.B 2.0) and ROBINS-I (Risk of Bias in Non-randomized Studies-of Interventions) Tool were used to assess the risk of bias in RCTs and CCTs, respectively. Meta-analyses of SNA, SNB, ANB, Co-Gn, SN-MP, the lower and upper incisor inclination changes were performed. Subgroup analyses and sensitivity analyses were conducted based on TAD types, FFA types, record types and types of study designs.

RESULTS

Ten studies were included with a sample size of 281. Meta-analyses revealed significant differences in the changes in SNB (mean difference [MD] 0.67; 95% confidence interval [CI] 0.04-1.29), ANB (MD -1.22, 95% CI -2.04 to -0.39), Co-Gn (MD 1.57; 95% CI 0.22-2.92), inclination of the lower incisors (MD -5.64, 95% CI -7.78 to -3.50)] and inclination of the upper incisors (MD -1.91; 95% CI -3.69 to -0.13). TAD types and FFA types seem to affect the treatment outcome.

CONCLUSIONS

Compared with FFAs alone, FFAs with TADs exhibit superior skeletal effects and reduce the inclination of the lower incisors in the short term; however, the evidence showed moderate to high risk of bias. Registration number CRD42020177611.

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

INTRODUCTION

This study aimed to test whether control in maxillary and mandibular incisor position, during treatment with an acrylic splint Herbst appliance, could influence the mandibular response in growing patients with skeletal Class II malocclusion.

METHODS

The lateral cephalograms of 61 patients (mean age, 12.3 years; standard deviation, 1.6) with skeletal and dental Class II malocclusion were retrospectively analyzed both at baseline and after Herbst appliance removal, using a modified Pancherz cephalomeric analysis. Forty-five patients had received miniscrew in the mandibular arch to control mandibular incisor anchorage. In 21 patients, the maxillary incisors had been proclinated before starting the treatment for deepbite and maxillary incisor lingual inclination. All the patients were categorized a posteriori into 2 homogeneous groups, according to dental overjet reduction: 30 patients with dental overjet reduction (DR) and 31 patients without dental overjet reduction (NDR).

RESULTS

Both groups presented a significant skeletal correction. However, the change was significantly greater in the NDR group than in the DR group (P <0.01). The mandibular bone base reached a median value of 4.0 mm (interquartile range, 2.5) in the NDR group vs 1.1 mm (interquartile range, 2.8) in the DR group (P <0.001). The 2 groups were also significantly different in terms of the positional change of maxillary incisor, which was proclinated in group NDR and lingualized in group DR (P <0.001).

CONCLUSIONS

The results showed that dental control of overjet was beneficial to improve the effectiveness of Herbst treatment in increasing mandibular length in growing patients with skeletal Class II malocclusion.

Skeletally anchored forsus fatigue resistant device for correction of Class II malocclusions-A systematic review and meta-analysis

The use of skeletal anchorage with fixed functional appliances (FFA) has been proposed by various authors to produce skeletal changes and reduce lower incisor proclination. To compare the skeletal and dentoalveolar effects of Forsus Fatigue Resistant Device (FFRD) with or without skeletal anchorage (miniplates and mini-implants). The electronic database PubMed, Cochrane Library, Medline, Embase and Google Scholar along with a manual search of orthodontic journals till the year 2019. Only randomized control trials (RCTs) were included in the systematic review. One controlled clinical trial (CCT) which involved FFRD was included in the review since it was a continuation of an RCT which was expanded to a CCT. Skeletal and dentoalveolar outcome data were extracted to collect study characteristics. After evaluating risk of bias, the standardized mean differences (SMDs) and 95% confidence intervals (CIs) were calculated. Three RCTs and one prospective CCT were evaluated. The analysis included data from 116 Class II subjects [(58) treated with FFA along with skeletal anchorage and (58) treated with FFA]. There were no significant difference between the two groups with respect to mandibular length changes (P value = .10) and SNB angle changes (P value = .22). With respect to lower incisor inclination however, there was a significant difference between the two groups (P value = .005) signifying better results with respect to skeletal anchorage. The studies reviewed provide insufficient evidence to form a conclusion regarding the effects of the use of skeletal anchorage with FFRD. The available weak evidence suggests that the use of skeletal anchorage with FFRD has no superior skeletal effects but is able to reduce proclination of the lower incisors. Control of lower incisor proclination remains the most significant advantage of skeletal reinforcement, and miniplate-anchored FFRD showed more promising results in preventing lower incisor proclination than miniscrew-anchored FFRD.

Management of skeletal class II malocclusion using bimaxillary skeletal anchorage supported fixed functional appliances : A novel technique

AIM

To evaluate the treatment effects in growing skeletal class II patients subjected to a novel treatment technique, i.e., bimaxillary miniplates supported fixed functional appliance. The null hypothesis was that there is no statistically significant difference in skeletal changes of patients with class II malocclusion treated with bimaxillary skeletal anchorage supported fixed functional appliance and those who were not provided any intervention.

METHODS

The sample comprised 32 skeletal class II subjects (17 males and 15 females) with a Cervical Vertebrae Maturity Index (CVMI) demonstrating peak of pubertal growth spurt. Sixteen patients (12.37 ±1.09 years of age) were treated with bimaxillary skeletal anchorage supported fixed function appliance, while 16 well-matched subjects (12.06 ± 1.34 years of age) were included as controls. For both groups, cephalograms (T1, T2) were taken with a matched observational interval of about 7.5 months; 17 linear and 10 angular measurements were recorded. The intraclass correlation coefficient (ICC) was used to determine reliability of measurements recorded. Student t test was carried out to determine the changes produced by the treatment relative to control.

RESULTS

When compared with the control group, the treatment group demonstrated significant maxillary retrusion. No significant changes were seen in mandibular growth pattern, whereas mandibular length increased significantly more than in the control group (B-VP: 3.05 mm; Co-Gn: 2.65 mm). Treatment mechanics had minimal effects on maxillary dentition. Mandibular incisors proclined by an average of 3.06°. Maxilla-mandibular relation improved significantly (ANB: -4.29°; NA-Pog: -3.76°).

CONCLUSION

The new bimaxillary skeletal anchorage supported fixed functional appliance technique was found to be highly effective in the treatment of class II malocclusion with significant skeletal changes.

Effects of Twin-block vs sagittal-guidance Twin-block appliance on alveolar bone around mandibular incisors in growing patients with Class II Division 1 malocclusion

INTRODUCTION

The purpose of this study was to comparatively evaluate the effects of Twin-block (TB) appliance and sagittal-guidance Twin-block (SGTB) appliance on alveolar bone around mandibular incisors in growing patients with Class II Division 1 malocclusion, using cone-beam computed tomography.

METHODS

The sample consisted of 25 growing patients with Class II Division 1 malocclusion (14 boys and 11 girls, mean age 11.92 ± 1.62 years) and was randomly distributed into the TB group (n = 13) and the SGTB group (n = 12). The treatment duration was 11.56 ± 1.73 months. Pretreatment (T1) and posttreatment (T2) cone-beam computed tomography scans were taken in both groups. Height, thickness at apex level, and volume of the alveolar bone around mandibular left central incisors were measured respectively on labial and lingual side, using Mimics software (version 19.0; Materialise, Leuven, Belgium). Based on the stable structures, 3-dimensional (3D) registrations of T1 and T2 models were taken to measure the sagittal displacement of incisors. Intragroup comparisons were evaluated by paired-samples t tests and Wilcoxon tests. Independent-samples t tests and Mann-Whitney U tests were used for intergroup comparisons.

RESULTS

In both groups, alveolar bone height and volume on the labial side of the incisors significantly decreased after treatment (P <0.05). Lingual alveolar bone height, lingual and total alveolar bone volume, labial, lingual and total alveolar bone thickness showed no significant difference between T1 and T2 (P >0.05). In both groups the incisors tipped labially and drifted to the labial side. Compared with the TB group, less labial alveolar bone loss, less incisor proclination and crown edge drift were found in the SGTB group (P <0.05).

CONCLUSIONS

Labial alveolar bone loss around mandibular incisors was observed after both types of appliances treatment in growing patients with Class II Division 1 malocclusion. Less labial alveolar bone loss, less incisor proclination, and crown edge drift were found in the SGTB group than in the TB group during treatment.

Class II:2 malocclusion-prevalence and progression of labial gingival recessions during Herbst-Multibracket appliance treatment

OBJECTIVES

To determine the prevalence, incidence, and changes in magnitude of labial gingival recessions (LGR) in class II:2 patients during Herbst-Multibracket appliance (Herbst-MBA) treatment (Tx) plus retention.

SUBJECTS AND METHODS

All class II:2 patients of the Department of Orthodontics, University of Giessen, Germany who completed Herbst-MBA Tx (mean pre-Tx age 15.6 years). The cohort had undergone a Herbst phase (mean 8.1 months) as well as a subsequent MBA phase (mean 14.4 months). Study casts were evaluated from pre-Tx and after Herbst-MBA Tx plus ≥ 24 months of retention.

RESULTS

Ratable pre-Tx and post-retention study casts (total observation period 53.5 ± 10.3 months) were available from 94 out of 173 patients. No significant difference existed regarding pre-Tx LGR data between patients with and without complete records. The prevalence for teeth with LGR ≥ 0.5 mm was 1.4% pre-Tx respectively 6.7% post-retention. The highest values of up to 5.3% (pre-Tx) and 20.2% (post-retention) were determined for the upper first premolars and lower central incisors. Incidence values of 4.7% (all teeth) and up to 14.9% (upper first right premolars) respectively 11.1% (lower central incisors) were calculated (LGR ≥ 0.5 mm). The overall LGR mean magnitudes were 0.01 mm pre-Tx respectively 0.06 mm post-retention.

CONCLUSIONS

For the prevalence of LGR ≥ 0.5 mm an average increase of 5.3% was determined during ≈ 4.5 years of Herbst-MBA Tx plus retention. The highest incidence was seen for lower central incisors and upper right premolars (11.1/14.9%). The overall LGR mean magnitude increased by 0.05 mm.

CLINICAL RELEVANCE

Herbst-MBA Tx is a common approach for class II:2 malocclusions. Very little, however, is known regarding LGR development in respective patients.

Four TADs supported Herbst mechanics: A case report

The Herbst appliance (HA) is considered an efficient method to treat class II malocclusion characterized by mandibular retrusion. Nevertheless, HA is although hampered by side effects reducing its therapeutic potentialities. The association between HA and TADs in the lower arch has proved to be very effective in controlling lower incisor flaring. This case report shows that the insertion of TADs in both arches offers a satisfactory control of the vertical dimension, by avoiding a maxillary clockwise inclination.

Prevalence, magnitude, and incidence of labial gingival recession with Herbst-multibracket appliance treatment: A retrospective cohort study

OBJECTIVE

To assess the prevalence and magnitude of labial gingival recession (LGR) before and after as well as the incidence during Class II:1 Herbst-Multibracket appliance (Herbst-MBA) treatment (Tx) plus retention in a retrospective cohort study.

MATERIALS AND METHODS

Records of Class II:1 patients who completed Herbst-MBA Tx (mean pre-Tx age 14.4 years) at Department of Orthodontics, University of Giessen, Giessen, Germany were analyzed. Tx consisted of a Herbst phase (mean 8.1 months) and a subsequent MBA phase (mean 16.1 months). Study casts from before and after Herbst-MBA Tx plus ≥24 months of retention were evaluated.

RESULTS

A total of 460 pre-Tx and 222 postretention study casts were available (total observation period: 59.2 ± 14.8 months). The overall prevalence for teeth with LGR ≥0.5 mm was 1.1% pre-Tx and 5.3% postretention. The highest prevalence of up to 5.3% (pre-Tx) and 16.4% (postretention) were seen for the lower incisors. Overall, the median magnitude of LGR was 0.0 mm pre-Tx/postretention (mean: 0.05 mm/0.08 mm). Incidence values of 4.0% (all teeth) and 10.0% to 11.4% (lower central incisors) were calculated for LGR ≥0.5 mm.

CONCLUSIONS

The prevalence of LGR ≥0.5 mm increased from, on average, 1.1% to 5.3% during ≈6 years of Herbst-MBA Tx plus retention. The highest incidence was seen in lower incisors (10.0%-11.4%). However, because of the overall mean magnitude of 0.08 mm postretention, the clinical relevance can be considered as insignificant.

Role of anatomical sites and correlated risk factors on the survival of orthodontic miniscrew implants: a systematic review and meta-analysis

Objectives

The aim of this review was to systematically evaluate the failure rates of miniscrews related to their specific insertion site and explore the insertion site dependent risk factors contributing to their failure.

Search methods

An electronic search was conducted in the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Knowledge, Scopus, MEDLINE and PubMed up to October 2017. A comprehensive manual search was also performed.

Eligibility criteria

Randomised clinical trials and prospective non-randomised studies, reporting a minimum of 20 inserted miniscrews in a specific insertion site and reporting the miniscrews’ failure rate in that insertion site, were included.

Data collection and analysis

Study selection, data extraction and quality assessment were performed independently by two reviewers. Studies were sub-grouped according to the insertion site, and the failure rates for every individual insertion site were analysed using a random-effects model with corresponding 95% confidence interval. Sensitivity analyses were performed in order to test the robustness of the reported results.

Results

Overall, 61 studies were included in the quantitative synthesis. Palatal sites had failure rates of 1.3% (95% CI 0.3–6), 4.8% (95% CI 1.6–13.4) and 5.5% (95% CI 2.8–10.7) for the midpalatal, paramedian and parapalatal insertion sites, respectively. The failure rates for the maxillary buccal sites were 9.2% (95% CI 7.4–11.4), 9.7% (95% CI 5.1–17.6) and 16.4% (95% CI 4.9–42.5) for the interradicular miniscrews inserted between maxillary first molars and second premolars and between maxillary canines and lateral incisors, and those inserted in the zygomatic buttress respectively. The failure rates for the mandibular buccal insertion sites were 13.5% (95% CI 7.3–23.6) and 9.9% (95% CI 4.9–19.1) for the interradicular miniscrews inserted between mandibular first molars and second premolars and between mandibular canines and first premolars, respectively. The risk of failure increased when the miniscrews contacted the roots, with a risk ratio of 8.7 (95% CI 5.1–14.7).

Conclusions

Orthodontic miniscrew implants provide acceptable success rates that vary among the explored insertion sites. Very low to low quality of evidence suggests that miniscrews inserted in midpalatal locations have a failure rate of 1.3% and those inserted in the zygomatic buttress have a failure rate of 16.4%. Moderate quality of evidence indicates that root contact significantly contributes to the failure of interradicular miniscrews placed between the first molars and second premolars. Results should be interpreted with caution due to methodological drawbacks in some of the included studies.

Electronic supplementary material

The online version of this article (10.1186/s40510-018-0225-1) contains supplementary material, which is available to authorized users.

Orthodontic treatment for prominent upper front teeth (Class II malocclusion) in children and adolescents

BACKGROUND

Prominent upper front teeth are a common problem affecting about a quarter of 12-year-old children in the UK. The condition develops when permanent teeth erupt. These teeth are more likely to be injured and their appearance can cause significant distress. Children are often referred to an orthodontist for treatment with dental braces to reduce the prominence of their teeth. If a child is referred at a young age, the orthodontist is faced with the dilemma of whether to treat the patient early or to wait and provide treatment in adolescence.

OBJECTIVES

To assess the effects of orthodontic treatment for prominent upper front teeth initiated when children are seven to 11 years old ('early treatment' in two phases) compared to in adolescence at around 12 to 16 years old ('late treatment' in one phase); to assess the effects of late treatment compared to no treatment; and to assess the effects of different types of orthodontic braces.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 27 September 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2017, Issue 8), MEDLINE Ovid (1946 to 27 September 2017), and Embase Ovid (1980 to 27 September 2017). The US National Institutes of Health Ongoing Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

Randomised controlled trials of orthodontic treatments to correct prominent upper front teeth (Class II malocclusion) in children and adolescents. We included trials that compared early treatment in children (two-phase) with any type of orthodontic braces (removable, fixed, functional) or head-braces versus late treatment in adolescents (one-phase) with any type of orthodontic braces or head-braces, and trials that compared any type of orthodontic braces or head-braces versus no treatment or another type of orthodontic brace or appliance (where treatment started at a similar age in the intervention groups).We excluded trials involving participants with a cleft lip or palate, or other craniofacial deformity/syndrome, and trials that recruited patients who had previously received surgical treatment for their Class II malocclusion.

DATA COLLECTION AND ANALYSIS

Review authors screened the search results, extracted data and assessed risk of bias independently. We used odds ratios (ORs) and 95% confidence intervals (CIs) for dichotomous outcomes, and mean differences (MDs) and 95% CIs for continuous outcomes. We used the fixed-effect model for meta-analyses including two or three studies and the random-effects model for more than three studies.

MAIN RESULTS

We included 27 RCTs based on data from 1251 participants.Three trials compared early treatment with a functional appliance versus late treatment for overjet, ANB and incisal trauma. After phase one of early treatment (i.e. before the other group had received any intervention), there was a reduction in overjet and ANB reduction favouring treatment with a functional appliance; however, when both groups had completed treatment, there was no difference between groups in final overjet (MD 0.21, 95% CI -0.10 to 0.51, P = 0.18; 343 participants) (low-quality evidence) or ANB (MD -0.02, 95% CI -0.47 to 0.43; 347 participants) (moderate-quality evidence). Early treatment with functional appliances reduced the incidence of incisal trauma compared to late treatment (OR 0.56, 95% CI 0.33 to 0.95; 332 participants) (moderate-quality evidence). The difference in the incidence of incisal trauma was clinically important with 30% (51/171) of participants reporting new trauma in the late treatment group compared to only 19% (31/161) of participants who had received early treatment.Two trials compared early treatment using headgear versus late treatment. After phase one of early treatment, headgear had reduced overjet and ANB; however, when both groups had completed treatment, there was no evidence of a difference between groups in overjet (MD -0.22, 95% CI -0.56 to 0.12; 238 participants) (low-quality evidence) or ANB (MD -0.27, 95% CI -0.80 to 0.26; 231 participants) (low-quality evidence). Early (two-phase) treatment with headgear reduced the incidence of incisal trauma (OR 0.45, 95% CI 0.25 to 0.80; 237 participants) (low-quality evidence), with almost half the incidence of new incisal trauma (24/117) compared to the late treatment group (44/120).Seven trials compared late treatment with functional appliances versus no treatment. There was a reduction in final overjet with both fixed functional appliances (MD -5.46 mm, 95% CI -6.63 to -4.28; 2 trials, 61 participants) and removable functional appliances (MD -4.62, 95% CI -5.33 to -3.92; 3 trials, 122 participants) (low-quality evidence). There was no evidence of a difference in final ANB between fixed functional appliances and no treatment (MD -0.53°, 95% CI -1.27 to -0.22; 3 trials, 89 participants) (low-quality evidence), but removable functional appliances seemed to reduce ANB compared to no treatment (MD -2.37°, 95% CI -3.01 to -1.74; 2 trials, 99 participants) (low-quality evidence).Six trials compared orthodontic treatment for adolescents with Twin Block versus other appliances and found no difference in overjet (0.08 mm, 95% CI -0.60 to 0.76; 4 trials, 259 participants) (low-quality evidence). The reduction in ANB favoured treatment with a Twin Block (-0.56°, 95% CI -0.96 to -0.16; 6 trials, 320 participants) (low-quality evidence).Three trials compared orthodontic treatment for adolescents with removable functional appliances versus fixed functional appliances and found a reduction in overjet in favour of fixed appliances (0.74, 95% CI 0.15 to 1.33; two trials, 154 participants) (low-quality evidence), and a reduction in ANB in favour of removable appliances (-1.04°, 95% CI -1.60 to -0.49; 3 trials, 185 participants) (low-quality evidence).

AUTHORS' CONCLUSIONS

Evidence of low to moderate quality suggests that providing early orthodontic treatment for children with prominent upper front teeth is more effective for reducing the incidence of incisal trauma than providing one course of orthodontic treatment in adolescence. There appear to be no other advantages of providing early treatment when compared to late treatment. Low-quality evidence suggests that, compared to no treatment, late treatment in adolescence with functional appliances, is effective for reducing the prominence of upper front teeth.

Bone-anchored intermaxillary elastics in an asymmetric Class II malocclusion: A case report

PURPOSE

A 13-year-old male patient, presenting a Class II, division 1 malocclusion and crowding was treated by an innovative technique.

METHODS

After rapid palatal expansion by a Hyrax appliance, the teeth were bonded with straightwire brackets. Two miniscrews were inserted, one per side, in the mandibular buccal bone between the roots of the mandibular first molar and the second premolar. On the right side, the miniscrew implant was connected to the hook clamped on a 0.021×0.028″ SS wire with a twisted SS ligature in order to maintain the inclination of the frontal incisors during the Class II mechanics. On the left side, where the Class II relationship was more marked, intermaxillary elastics were applied from the upper left hook clamped on the archwire to the lower first molar and a power chain (100g) was stretched from the lower left hook to the miniscrew implant. Class II correction was accomplished using sequential Class II elastics of progressive strength coupled with rectangular stainless steel wires.

RESULTS

After 22 months of active treatment, the results were balanced facial esthetics and a good occlusion.

CONCLUSIONS

This dual anchorage set-up of Class II elastics reinforced with TADs produced protrusive action on the mandible with minimal side effects and with no significant change in the vertical dimension during the sagittal correction of the Class II malocclusion.

Herbst appliance anchored to miniscrews with 2 types of ligation: Effectiveness in skeletal Class II treatment

INTRODUCTION

The aim of this study was to evaluate the effectiveness of the treatment of skeletal Class II malocclusions with an acrylic splint Herbst appliance anchored to miniscrews with 2 types of ligation.

METHODS

Sixty patients (mean age, 11.6 years; SD, 1.9) with a bilateral Angle Class II Division 1 malocclusion were retrospectively selected and divided into 3 homogeneous and balanced groups on the basis of the Herbst anchorage used: without anchorage, miniscrews with elastic chains, and miniscrews with metallic ligatures. A cephalometric sagittal occlusion analysis merged with mandibular incisor proclination and skeletal divergence was carried out before and after treatment. To compare the absolute variations within and among the groups, we performed the 1-sample t test for repeated measures and 1-way analysis of variance, respectively.

RESULTS

Overjet was reduced similarly in all groups (P <0.05). The mandibular bone base length increased in the group with elastic chains only (P = 0.001). The change in the distance between Point A and pogonion showed the most reduction in the group with elastic chains (P <0.05). Incisive flaring was more pronounced in the group with no anchorage than in the group with elastic chains (P <0.001) and the group with metallic ligatures (P = 0.003).

CONCLUSIONS

Anchorage to miniscrews with elastic chains increases the orthopedic effect of the acrylic splint Herbst appliance. It has been confirmed that skeletal anchorage reduces incisor flaring.

A retrospective cephalometric study on pharyngeal airway space changes after rapid palatal expansion and Herbst appliance with or without skeletal anchorage

Background

The aim of this study is to investigate the pharyngeal airway space changes in patients treated with rapid palatal expansion (RPE) and Herbst appliance with or without skeletal anchorage.

Methods

A 40-patient study group treated with the Herbst RME combination was included; moreover, a comparison between two subgroups based on whether miniscrews were used was evaluated. A subgroup 1 included 20 patients who were treated with RPE and an acrylic splint Herbst with miniscrews, and subgroup 2 included 20 patients who were treated with RPE and an acrylic splint Herbst. A cephalometric analysis was performed before (T1) and after (T2) treatment. The skeletal parameters of the sagittal occlusion analysis of Pancherz were utilized together with some extra measurements to evaluate the airways.

Results

An increased nasopharyngeal airway space was observed in group 1 (p < 0.05) from T1 to T2. Furthermore, the increase in nasopharyngeal airway space was significantly higher in subgroup 1 (p < 0.05) in comparison to the subgroup 2. Oropharyngeal (OA) and laryngopharyngeal (LA) dimensions were significantly increased in the subgroup 1 at the end of the treatment. In the subgroup 1, a significant decrease in SNA, a significant increase in SNB, and a significant decrease in ANB were observed from T1 to T2. In the subgroup 2, the treatment resulted in a significant decrease in ANB. In both groups, Pogonion increased significantly from T1 to T2.

Conclusions

The results suggest that the RPE and the Herbst appliance allow a slight improvement of the sagittal dimensions of the airways. The oropharyngeal dimension increased significantly more in the skeletal anchorage group.

Herbst plus Lingual versus Herbst plus Labial: a comparison of occlusal outcome and gingival health

OBJECTIVES

To analyse and compare the effects during Herbst treatment combined with a lingual (completely customized) or labial (straight-wire) multibracket appliance (MBA), with special regard to lower incisor gingival recessions.

SUBJECTS AND METHODS

Eighteen Class II:1 patients [overjet ≥ 5mm, Class II molar relationship ≥ 0.5 cusp widths (CW) bilaterally or 1.0 CW unilaterally, median age 16.0 years] treated with a Herbst appliance in combination with a lingual MBA (group LINGUAL) were retrospectively matched (molar relationship and skeletal maturity) to 18 Class II:1 patients treated with a Herbst appliance combined with a labial MBA (group LABIAL). Study models and intraoral photographs from before and after treatment were evaluated regarding occlusal variables and gingival recessions. Lateral cephalograms from before, during (before and after Herbst), and after treatment were analysed to assess lower incisor changes.

RESULTS

Both groups showed similar reductions of overjet (5.4/5.6mm), overbite, (2.9/2.7mm) and sagittal molar relationship (0.9/0.8 CW). During the Herbst phase, the changes in lower incisor inclination and incisal edge position were significantly smaller in the LINGUAL than in the LABIAL group (iiL/ML: +7.0/+12.7degrees, P = 0.002; ii-MLppg: +2.5/+3.9mm, P = 0.004). For the total treatment period, no significant differences were found (iiL/ML: +5.3/+8.6degrees; ii-MLppg: +2.1/+2.4mm). No clinically relevant gingival recessions were seen.

CONCLUSION

Both treatment approaches successfully corrected the malocclusion. The group LINGUAL exhibited significantly less proclination during the Herbst phase only. Neither treatment approach induced deleterious gingival recessions.

Treatment effects of fixed functional appliances in patients with Class II malocclusion: a systematic review and meta-analysis

OBJECTIVE

To assess the treatment effects of fixed functional appliances (FFAs) in treated versus untreated Class II patients by means of lateral cephalometric radiographs.

SEARCH METHODS

Unrestricted electronic search of 18 databases and additional manual searches up to October 2014.

SELECTION CRITERIA

Prospective randomized and non-randomized controlled trials reporting on cephalometric angular measurements of Class II patients treated with FFAs and their matched untreated controls.

DATA COLLECTION AND ANALYSIS

Skeletal, dental, and soft tissue cephalometric data were annualized and stratified according to the time of evaluation in effects. Following risk of bias evaluation, the mean differences (MDs) and 95 % confidence intervals (CIs) were calculated with random-effects models. Patient- and appliance-related subgroup analyses and sensitivity analyses were performed with mixed-effects models.

RESULTS

Nine studies were included (244 patients; mean age: 13.5 years and 174 untreated controls; mean age: 12.8 years) reporting on cephalometric effects directly after the removal of FFAs. FFAs were found to induce a small reduction of SNA angle (MD = -0.83 degree/year, 95 % CI: -1.17 to -0.48), a small increase of SNB angle (MD = 0.87 degree/year, 95 % CI: 0.30-1.43), and moderate decrease of ANB angle (MD = -1.74 degree/year, 95 % CI: -2.50 to -0.98) compared to untreated Class II patients. FFA treatment resulted in significant dentoalveolar and soft tissue changes. Several patient- or appliance-related factors seem to affect the treatment outcome. Long-term effectiveness of FFAs could not be assessed due to limited evidence.

CONCLUSIONS

According to existing evidence, FFAs seem to be effective in improving Class II malocclusion in the short term, although their effects seem to be mainly dentoalveolar rather than skeletal.