Early orthodontic treatment for Class II malocclusion reduces the chance of incisal trauma: Results of a Cochrane systematic review

Expert consensus on pediatric orthodontic therapies of malocclusions in children

Malocclusion, identified by the World Health Organization (WHO) as one of three major oral diseases, profoundly impacts the dental-maxillofacial functions, facial esthetics, and long-term development of ~260 million children in China. Beyond its physical manifestations, malocclusion also significantly influences the psycho-social well-being of these children. Timely intervention in malocclusion can foster an environment conducive to dental-maxillofacial development and substantially decrease the incidence of malocclusion or reduce the severity and complexity of malocclusion in the permanent dentition, by mitigating the negative impact of abnormal environmental influences on the growth. Early orthodontic treatment encompasses accurate identification and treatment of dental and maxillofacial morphological and functional abnormalities during various stages of dental-maxillofacial development, ranging from fetal stages to the early permanent dentition phase. From an economic and societal standpoint, the urgency for effective early orthodontic treatments for malocclusions in childhood cannot be overstated, underlining its profound practical and social importance. This consensus paper discusses the characteristics and the detrimental effects of malocclusion in children, emphasizing critical need for early treatment. It elaborates on corresponding core principles and fundamental approaches in early orthodontics, proposing comprehensive guidance for preventive and interceptive orthodontic treatment, serving as a reference for clinicians engaged in early orthodontic treatment.

Quality assessment of available Internet information on early orthodontic treatment

BACKGROUND

This study aimed to evaluate the content, reliability, quality and readability of information on Internet websites about early orthodontic treatment.

METHODS

The "early orthodontic treatment" search term was individually entered into four web search engines. The content quality and reliability were reviewed with DISCERN, Journal of American Medical Association (JAMA), and Health on the Net code (HONcode) tools using the contents of websites meeting predetermined criteria. The readability of websites was evaluated with Flesch Reading Facilitate Score (FRES) and Flesch-Kincaid Grade Level (FKGL).

RESULTS

Eighty-six websites were suitable for inclusion and scoring of the 200 websites. 80.2% of websites belonged to orthodontists, 15.1% to multidisciplinary dental clinics and 4.7% to professional organizations. The mean DISCERN score of all websites (parts 1 and 2) was 27.98/75, ranging between 19 and 67. Professional organization websites had the highest scores for DISCERN criteria. Moreover, 45.3% of websites were compatible with JAMA's disclosure criterion, 7% with the currency criterion, 5.8% with the authorship criterion and 5.8% with the attribution criterion. Only three websites met all JAMA criteria, and these websites belonged to professional organizations. None of the websites had the HONcode logo. Mean FRES and FKGL were 47.6 and 11.6, respectively.

CONCLUSIONS

The quality of web-based information about early orthodontic treatment is poor, and readability is insufficient. More accurate and higher quality Internet sources are required on the web.

Early orthodontic treatment in a Finnish public health centre: a retrospective cross-sectional study

OBJECTIVES

The aim of this observational cross-sectional one-centre study was to assess whether the previously described national orthodontic treatment practises and international recommendations are implemented in a public health care centre in Finland. We also assessed early treatment practices and appliances used.

METHODS

The study group comprised 801 children born in 2011 and 2012 residing in the Riihimäki health centre catchment area in Finland, representing 80% of the age cohort. The patient records were examined for data on orthodontic treatment, timing of treatment, appliances used, and occlusal traits.

RESULTS

The children had been examined by four orthodontist specialists and two orthodontic postgraduate students. Mean age at occlusal examination had been 9 years. Of the children, 212 (26%) were undergoing or had undergone orthodontic treatment. An additional 4.4% were scheduled for treatment. The proportion of children deemed to need treatment was significantly different between the different orthodontists. The most frequently used appliances were quad-helix (30%), eruption guidance appliance (20%), head gear (14%), fixed appliances (10%), protraction facemask (10%), and passive mandibular lingual arch (6%).

CONCLUSIONS

Nearly one-third of children aged less than 12 years in the health centre were currently or had been in orthodontic treatment. Approximately half had received treatment with either quad-helix or eruption guidance appliance.

Does Early Treatment Improve Clinical Outcome of Class II Patients? A Retrospective Study

The present study was carried out to evaluate the benefits from one-phase Class II Early Treatment (ET) using extraoral forces and functional appliances but without intermaxillary forces and eventual lower leeway space preservation compared to two-phase Class II Late Treatment (LT) with the need for extractions and full fixed appliances as well as lower incisor proclination. The ET group (n = 239, 115 M, 124 F, mean age 10.6 ± 1.2 years), with first premolars not in contact and the second deciduous lower molars preserved, was compared to the LT group (n = 288, 137 M, 151 F, mean age 12.4 ± 1.5 years). The ET group was first treated with headgears, growth guide appliances, or Teuscher activators and, in borderline crowding cases, with lower space maintenance by a lingual arch, lip bumper, or fixed utility arch. The LT group and the second phase of ET were treated with full fixed appliances including intermaxillary forces such as Class II elastics or noncompliance devices; headgear and a growth guide appliance were also used. Cephalograms and plaster models were taken before (T1) and after treatment (T2) to calculate cephalometric changes and space balance discrepancies. The differences between T1 and T2 were analyzed by a t-test for normally distributed data and by the Mann-Whitney Test for nonnormally distributed data at a level of p < 0.05. The groups were defined as statistically homogeneous at T1. A statistical analysis showed that the ET group (mean treatment time 35.3 ± 13.3 months) was significantly associated with a 22.2% lower extraction rate, 15.9% less need for a full fixed appliance, and more than 5° less incisor proclination in the nonextraction cases compared to the LT group (mean treatment time 25.9 ± 8.1 months); treatment time significantly increased in the ET group compared to the LT group. Early Class II treatment resulted in a significant treatment effort reduction in more than one third of the patients and less lower incisor proclination, even if it clinically increased treatment time.

Correlation of twin-block appliance efficacy and wear durationas assessed with a compliance indicator

BACKGROUND

The aim of this study was to investigate the association between objective wear time and treatment efficacy of a twin block (TB) appliance.

METHODS

A TB appliance incorporating a compliance indicator was delivered to 44 children in the age group of 11-14 years (25 boys and 19 girls). Participants were instructed to wear the appliance full time and were recalled at 3-4- week intervals. Cephalograms and study models were taken at baseline and after 6 months of appliance therapy.

RESULTS

Data from 41 of the 44 participants were analyzed. A wide variation in daily wear time among participants was observed. Based on wear time, they were divided into full time (FT >17 h/d) and part time (PT < 12 h/d) wear groups. Mean wear durations were 20.86 hours in the FT-wear group and 9.55 hours in the PT-wear group. In skeletal changes, the ANB (A point, nasion, B point) angle was reduced by 2.69° in the FT-wear group, and 1.33° in the PT-wear group, and statistically significant increases were seen for the mandibular base measurement (Pg/OLp) in the FT-wear group (2.22mm), compared with those in the PT-wear group (0.44mm). . In dental changes, overjet were reduced by 3.91 mm and 2.0 mm in the FT-wear and PT-wear group, respectively. This difference was statistically significant.

CONCLUSIONS

Skeletal effects were pronounced in the FT-wear group, and dentoalveolar changes were comparable in the 2 wear groups. The maximum skeletal treatment effect of a TB appliance was found to occur with FT wear over a 6-month treatment period.

Can Orthodontic Treatment Be Stable 20 Years after the End of the Treatment Scheme? Treatment of a Class 2, Division 1 Malocclusion with Severe Skeletal Discrepancy and Its 20-Year Follow-Up

Class II malocclusions, after class I malocclusions, are the most frequent in the juvenile Italian population. They are most often skeletal in origin and due to mandibular retrusion. Functional devices seem to have a beneficial effect on the growth of the jaw. Long-term maintenance of the achieved results is essential for therapeutic success in any orthodontic treatment; moreover, the retention phase should last as long as possible, especially in the lower anterior sector. A female patient aged 10 years and 3 months presented a visibly convex profile and a severe mandibular retrusion. The anamnesis brought to light the habit of oral breathing and lower-lip sucking. The cephalometric analysis showed a normodivergent skeletal class II. The first treatment phase involved the use of a Bass type for 12 months at the end of the functional treatment; the second phase of fixed therapy was carried out following the principles of bioprogressive techniques. The photos at the end of treatment show an important improvement in the profile; a full class I ratio of molar and canine teeth was achieved with an excellent interarch relationship and a correction of the V-shaped upper arch. The result is occlusally and profilometrically stable after 2, 4, 5, 10, 14, and 20 years. The maintenance of a stable orthodontic result over time is the result not only of a correct and physiological occlusion but also and above all of a correct diagnosis and correct identification of problems that can cause the malocclusion itself. Flawed habits such as interposition of the lower lip and oral breathing must be intercepted and corrected early in order to correct them and not affect the long-term result of orthodontic treatment. In this case, a functional device associated with an orthodontic fixed finishing and a correct retention phase were necessary to correctly treat a second-class mandibular retrusion whose result remained stable 20 years after the end of therapy.

Does observational study on the effectiveness of the Twin Blocks overestimate or underestimate the results? A comparative analysis of retrospective samples versus randomized controlled trial

BACKGROUND AND OBJECTIVES

Class II malocclusion is one of the most common orthodontic problems. The Twin Block appliance has proven to be the most popular appliance for the correction of these malocclusions. Although randomized controlled trials (RCTs) on the Twin Block appliance have reported the changes to be mainly dentoalveolar, several nonrandomized studies have reported a significant skeletal improvement in these patients. Hence, the aim of this study was to compare the effectiveness of Twin Block appliance evaluated using an RCT or retrospectively selected cases (RSC) for the treatment of Class II Division 1 malocclusion in an adolescent population.

METHODS

This was a retrospective study. The results for an RCT were selected from a UK Class II multicenter study. Sixty-three patients from the trial were included. This group was matched with retrospectively selected Class II cases treated with a Twin Block functional appliance and their results submitted for Membership in Orthodontics examination in the United Kingdom, from four centers. The primary outcome was skeletal measurement ANB (A point, nasion, B point). Secondary outcomes included final peer assessment rating (PAR) scores and final overjet. Intrarater reliability of measurements was assessed. Independent samples t-test was carried out to look at the difference between the groups.

RESULTS

The reliability assessment showed excellent agreement for all measurements. The data were normally distributed. There was a statistically significant difference favoring the RSC group for final overjet (mean difference [MD] = 1.068, 95% confidence interval [CI] -0.67 to 1.47, P = 0.000) and final PAR (MD = 4.0, 95% CI -0.79 to 5.5, P = 0.000). There was no significant difference in the scores for final ANB (MD = 0.34, 95% CI -0.39 to 1.07, P = 0.33).

CONCLUSION

The RSCs show significantly improved overjet and PAR scores at the end of treatment and no statistically significant difference for skeletal change. The study raises the question of a potential role of observational studies in evaluating the effect of an intervention in orthodontics.

A cross-sectional evaluation of the impact of Class II Division 1 malocclusion in treated and untreated adolescents on oral health-related quality of life

INTRODUCTION

The relationship between malocclusion, orthodontic treatment, and oral health-related quality of life (OHRQOL) is complicated, with some traits, such as increased overjet, having a potentially greater adverse effect on an adolescent's OHRQOL. The aim of this study was to evaluate the impact of malocclusion and orthodontic treatment on OHRQOL in adolescents presenting with Class II Division 1 malocclusion and explore the relationship between OHRQOL using a condition-specific and generic instrument and occlusal outcome.

METHODS

Two groups of adolescents were recruited from a United Kingdom university hospital: a pretreatment group of adolescents with Class II Division 1 malocclusion and a treated (posttreatment) group whose Class II Division 1 malocclusion had been corrected. Self-reported OHRQOL was assessed using the malocclusion impact questionnaire (MIQ) and the short form of Child Oral Health Impact Profile questionnaires. Occlusion severity and outcome were assessed using Peer Assessment Rating scores.

RESULTS

A total of 241 participants (106 male; 135 female) were recruited. MIQ scores differed significantly between the pretreatment and posttreatment groups, with scores being 11.35 times lower posttreatment than pretreatment, after adjusting for age and sex (95% confidence interval, -17.28 to -5.42; P <0.001). Females had higher total MIQ scores by 2.6 (95% confidence interval, 0.38 to 4.82), which was statistically significant (P = 0.022). There was a moderate correlation between MIQ and Peer Assessment Rating scores, but this relationship strengthened when omitting the global MIQ questions (Spearman's correlation coefficient, 0.59).

CONCLUSIONS

Increased overjet was associated with impaired OHRQOL using a condition-specific measure. A deeper understanding of associations between malocclusion, orthodontic treatment, and OHRQOL would benefit from longitudinal evaluation.

A national survey of orthodontists in Malaysia and their use of functional appliances for Class II malocclusions

Objectives

The aim of this study was to evaluate the use of functional appliances by the currently practising orthodontists in Malaysia. The objectives were to identify the different types of functional appliances used by Malaysian orthodontists and to investigate the variation in treatment protocols when attempting growth modification.

Methods

An online questionnaire consisting of 24 open-ended and multiple-choice questions was emailed to members of the Malaysian Association of Orthodontists (MAO) (n = 183). The survey was based on a previous study conducted by members of the British Orthodontic Society and was modified to suit the Malaysian population. The data were analysed using SPSS to generate frequency tables and descriptive statistics.

Results

Seventy-two responses were received from current Malaysian orthodontists. Of the respondents, 71% practised in a government setting and 29% were in private practice. The Clark Twin Block was the most frequently used functional appliance by 90% of Malaysian orthodontists. Many of the respondents (57%) prescribed full-time wear of removable functional appliances for 6–9 months (except during mealtimes) (51%). Following active removable functional appliance therapy, 91% prescribed a period of retention which involved a reduction in the duration of wear. The retention phase extended for 2 to 3 months (41%) or for 4 to 6 months (39%) for the majority of the respondents.

Conclusions

The Clark Twin Block is the most frequently-used functional appliance for the management of a Class II malocclusion by orthodontists currently practising in Malaysia.

Large overjet as a risk factor of traumatic dental injuries: a prospective longitudinal study

Purpose

The aim of this longitudinal prospective study was to evaluate if schoolchildren with large overjet experience a greater risk of traumatic dental injuries (TDI) compared to children with normal or small overjet.

Methods

A sample of children aged 6‑13 years was prospectively evaluated after 1 year: from the initial sample, data concerning trauma cases of 1413 children were collected to determine the number and types of injuries, the influence of overjet on the risk of TDI, and the relationships between trauma, age, and gender.

Results

The observed prevalence of trauma was higher for boys, with the largest frequency between the ages of 8 to 12 years: 67.9% of all injuries were hard tissue injuries and 32.1% subluxation and luxation injuries. Children with an overjet of 6 mm or more showed a statistically increased risk of getting trauma [RR = 3.37 with CI (1.81; 6.27)].

Conclusion

In this prospective study, overjet stood out among variables as the most significant risk factor of TDI: an increased overjet of 6 mm or more had a major impact on the risk of trauma, which would speak in favor of early orthodontic correction of an increased overjet to reduce the prevalence of dental trauma

Effect of Orthodontic Bracket Type and Mouthguard Presence on the Stress and Strain during a Frontal Impact

The aim of this study was to analyze the influence of orthodontic bracket type (metallic or ceramic) and mouthguard on biomechanical response during impact. Two-dimensional plane-strain models of a patient with increased positive overjet of the maxillary central incisor was created based on a CT scan, simulating the periodontal ligament, bone support, gingival tissue, orthodontic brackets (metallic or ceramic) and mouthguard. A nonlinear dynamic impact finite element analysis was performed in which a steel object hit the model at 1 m/s. Stress distributions (Von Mises and Modified Von Mises) and strain were evaluated. Stress distributions were affected by the bracket presence and type. Models with metallic and ceramic bracket had higher stresses over a larger buccal enamel impact area. Models with ceramic brackets generated higher stresses than the metallic brackets. Mouthguards reduced the stress and strain values regardless of bracket type. Mouthguard shock absorption were 88.37% and 89.27% for the metallic and ceramic bracket, respectively. Orthodontic bracket presence and type influenced the stress and strain generated during an impact. Ceramic brackets generated higher stresses than metallic brackets. Mouthguards substantially reduced impact stress and strain peaks, regardless of bracket type.

Phosphorylated GSK‑3β protects stress‑induced apoptosis of myoblasts via the PI3K/Akt signaling pathway

Facial jaw muscle is involved in the occurrence, development, treatment and maintenance of maxillofacial deformities. The structure and function of this tissue can be altered by changes in external stimuli, and orthodontists can regulate its reconstruction using orthopedic forces. The PI3K/Akt signaling pathway is most well‑known for its biological functions in cell proliferation, survival and apoptosis. In the present study, the effects of the PI3K/Akt signaling pathway in cyclic stretch‑induced myoblast apoptosis were investigated. For this purpose, L6 rat myoblasts were cultured under mechanical stimulation and treated with the PI3K kinase inhibitor, LY294002, to elucidate the role of the PI3K/Akt signaling pathway. Cells were stained with Hoechst 33258 to visualize morphological changes and apoptosis of myoblasts, and western blotting was performed to detect expression of Akt, phosphorylated (p)‑Akt (Ser473), glycogen synthase kinase 3β (GSK‑3β) and p‑GSK‑3β (Ser9). After addition of PI3K inhibitor, the expression of total Akt and GSK‑3β did not significantly differ among groups; however, the levels of p‑Akt and p‑GSK‑3β were lower in inhibitor‑treated groups than in those treated with loading stress alone. In addition, the rate of apoptosis in myoblasts subjected to cyclic stretch increased in a time‑dependent manner, peaking at 24 h. Collectively, it was also demonstrated that the PI3K/Akt/GSK‑3β pathway plays an important role in stretch‑induced myoblast apoptosis.

Interceptive Dentofacial Orthopedics (Growth Modification)

Although all dentofacial deformities involve deviation of skeletal and dental units that require correction, the timing and method of treatment can vary considerably. Growth is a key consideration when managing dentofacial deformities, because it has a direct impact on the timing and method of management. Some deformities may be intercepted and managed during growth, whereas others can only be definitively managed after cessation of growth. This article focuses on clinical considerations of growth in managing dentofacial deformities, and discusses methods of growth evaluation and interceptive orthodontic management strategies in different types of dentofacial deformities.

Systematic reviews in orthodontics: Impact of the PRISMA for Abstracts checklist on completeness of reporting

INTRODUCTION

This study evaluated and compared the completeness of reporting of abstracts of orthodontics systematic reviews before and after the publication of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for Abstracts Checklist (PRISMA-A).

METHODS

Abstracts of systematic reviews and meta-analyses in orthodontics published in PubMed, Latin American and Caribbean Health Sciences Literature, and the Cochrane Database of Systematic Reviews databases before March 23, 2018, that met the predefined inclusion and exclusion criteria, were evaluated using the 12 items of PRISMA-A, scoring each item from 0 to 2. Abstracts were classified into 2 groups: before and after publication of the PRISMA-A checklist. Three calibrated evaluators (intraclass correlation coefficient and kappa > 0.8) assessed the scores for compliance with the checklist. The number of authors, country of affiliation of the first author, performance of meta-analysis, and topic of the article were recorded. A regression analysis was performed to assess the associations between abstract characteristics and the PRISMA-A scores.

RESULTS

Of 1034 abstracts evaluated, 389 were included in the analysis. The mean PRISMA-A score was 53.39 (95% CI, 51.83-54.96). The overall score for studies published after the publication of the checklist was significantly higher than for studies published before (P ≤ 0.0001). The components returning significantly higher scores after publication of PRISMA-A were title (P = 0.024), information from databases (P = 0.026), risk of bias (P ≤ 0.0001), included studies (P ≤ 0.0001), synthesis of results (P ≤ 0.0001), interpretation of results (P = 0.035), financing and conflict of interest (P ≤ 0.0001), and registration (P ≤ 0.0001). These results showed the positive effect of PRISMA-A had on the quality of reporting of orthodontics systematic reviews. Nevertheless, the poor adherence revealed that there is still need for improvement in the quality of abstract reporting.

CONCLUSIONS

The quality of reporting of abstracts of orthodontic systematic reviews and meta-analyses increased after the introduction of PRISMA-A.

Efficiency in the correction of Class II division 1 malocclusions with prominent upper incisors and increased overjet: a comparison between two methods

BACKGROUND

The aim of the present study was to evaluate the efficiency and effectiveness of high-pull traction on a Stephenson plate as well as cervical headgear treatments in Class II Division 1 growing subjects with prominent upper teeth and an increased overjet.

METHODS

A prospective study was undertaken, involving participants who underwent maxillary correction of Class II malocclusions. Twenty-three patients (Stephenson plate group, SPG, mean age 10.4±0.9 years) were treated and compared with 24 subjects treated with headgear (HGG, mean age 9.6±1.2 years). Lateral cephalograms were analysed using Jarabak and Pancherz analysis. Shapiro-Wilk's and Student's t tests were applied.

RESULTS

The SPG showed significant decreases in the overjet (-4.1 versus -0.8 mm) and molar relationship (-6.1 versus -1.5 mm). A significant upper-incisor correction was found in SPG (1/SpP -10.3° versus + 2.2°). SNA (-1.4 versus 0.3°) and WITS (-1 versus 0.3 mm) were reduced in SPG, showing a partial maxillary restraint. In SPG, the overjet correction (4.1 mm) was mainly due to the dental component (65.9%) and occurred almost completely in the maxilla (92.7%); the molar relationships improvement of 6.1 mm was mainly dental (77%); in HGG, the reduction of the overjet was limited (-0.8 mm), and the skeletal maxillary contribution was negligible.

CONCLUSIONS

The high-pull traction on the Stephenson plate was more efficient and effective than HG in the treatment of Class II dentoskeletal malocclusions with prominent upper teeth and a severe overjet; the overjet reduction was obtained at approximately 6 months, contributing to the substantial Class II correction.

Soft tissue changes: a comparison between changes caused by the construction bite and by successful treatment with a modified Twin-block appliance

Background/objectives

Functional appliances are commonly used to correct Class II malocclusion. This study aimed to compare the facial soft tissue changes in Caucasians between pre-treatment and with the construction bite versus pre-treatment and completion of treatment with a modified Twin-block appliance (MTBA).

Materials and methods

Fifty-eight Caucasian subjects with Class II division 1 malocclusion had 3D stereophotogrammetric images captured pre-treatment (T1), with the construction bite (T2), and on completion of MTBA treatment (T3). Twenty-six landmarks were located on each image and 10% were re-landmarked 1 month later. Soft-tissue linear and volumetric changes (T1-T2 and T1-T3) were analyzed using linear mixed effect models (SAS® Version 9.4, www.sas.com).

Results

Forty-seven subjects [mean age 13.2 (SD 1.7) years] completed treatment [mean duration 9.8 (SD 3.8) months]. Differences between the changes from T1 to T2 versus T1 to T3 for upper facial and upper lip landmarks were insignificant (all P > 0.05) except for nasion, orbitale right, pronasale, and subnasale. For the same comparisons, lower lip and chin landmarks changed significantly (all P < 0.05) as did facial soft tissue volume (P< 0.0001).

Limitations

There was no control group.

Conclusion

The facial soft tissue changes from pre-treatment to with the construction bite were considerably more than those from pre-treatment to completion of treatment with a MTBA.

Implication

With MTBA treatment, the soft tissue changes from pre-treatment to with the construction bite in situ, overestimate those from pre- to post-treatment.

Orthodontic management of a dental concrescence: a case report

Dental concrescence is a rare dental abnormality resulting in the joining of two teeth at the level of the cementum. This is the first reported case of the orthodontic management of a dental concrescence and the options for patient treatment are discussed. In this case, a compromised occlusal result was accepted with restorative masking of the affected teeth.

Perception of changes in soft-tissue profile after Herbst appliance treatment of Class II Division 1 malocclusion

INTRODUCTION

In this study, we sought to assess the perception of changes in soft-tissue profile after Herbst appliance treatment by comparing facial profile silhouettes before treatment, immediately after treatment, and 2 years after treatment, as examined by orthodontists, general dentists, and laypersons.

METHODS

The sample comprised 21 patients (mean age, 9.5 ± 0.5 years), who were treated with the Herbst appliance for a mean period of 12 (±1.1) months. Three lateral cephalograms were obtained at different times: baseline, immediately after removal of the Herbst appliance, and 2 years after removal of the appliance. The 63 resulting profile silhouettes were evaluated by 120 examiners divided into 3 groups: orthodontists, general dentists, and laypersons. The examiners were instructed to choose their preferred profile and note how much change they perceived across profiles using a visual analog scale.

RESULTS

All groups of examiners preferred the posttreatment profiles. However, on quantitative assessment, the magnitudes of changes in the profile were found to be variable and rather small, with laypersons quantifying the greatest magnitude of change.

CONCLUSIONS

Early Herbst appliance treatment produced positive changes in the facial profile that were visually appreciable both immediately after removal of the appliance and 2 years after treatment.

Changes in apical base sagittal relationship in Class II malocclusion treatment with and without premolar extractions: A systematic review and meta-analysis

OBJECTIVE

To evaluate the changes in apical base sagittal relationship in Class II treatment with and without premolar extractions.

MATERIALS AND METHODS

Controlled studies evaluating ANB angle changes after Class II Division 1 malocclusion treatment with or without premolar extractions were considered. Electronic databases (PubMed, Embase, Web of Science, Scopus, The Cochrane Library, Lilacs, and Google Scholar) without limitations regarding publication year or language were searched. Risk of bias was assessed with Risk Of Bias in Non-randomized Studies-of Interventions tool of the Cochrane Collaboration. Mean difference (MD) and 95% confidence interval (CI) were calculated from the random-effects meta-analysis. Subgroup and sensitivity analyses were also performed.

RESULTS

Twenty-five studies satisfied the inclusion criteria and were included in the qualitative synthesis. Eleven nonextraction and only one extraction Class II treatment studies presented untreated Class II control group. Therefore, meta-analysis was performed only for the nonextraction protocol. In treated Class II nonextraction patients, the average of the various effects was a reduction in the ANB angle of 1.56° (95% CI: 1.03, 2.09, P < .001) compared with untreated Class II subjects. Class II malocclusions treated with two maxillary-premolar extractions and four-premolar extractions produced estimated mean reductions in ANB of -1.88° and -2.55°, respectively. However, there is a lack of low-risk-of-bias studies.

CONCLUSIONS

According to the existing low quality evidence, the apical base sagittal relationship in nonextraction, two-maxillary and four-premolar extractions Class II treatments decreases -1.56°, 1.88° and 2.55°, respectively. Further studies are necessary to obtain more robust information.