Effectiveness of orthodontic treatment with functional appliances on mandibular growth in the short term

Evaluation of modified clear Twin Block aligner in treating adolescents with skeletal class II malocclusion: A two-centre cephalometric study

INTRODUCTION

The purpose of this study was to evaluate the therapeutic effect of modified clear Twin Block (CTB) aligner and traditional twin block (TB) appliance from skeletal, dentoalveolar and soft tissue changes in adolescents with skeletal class II malocclusion.

METHODS

A total of 80 adolescents, included in this study from two medical centres, were distributed into CTB group, TB group and control group based on the treatment they received. Lateral cephalograms at pre-treatment (T1) and post-treatment (T2) were measured by modified Pancherz's cephalometric analysis, and dentoskeletal and soft tissue changes were analysed by independent-sample t-test, paired-sample t-test, ANOVA test and Scheffe's Post Hoc test.

RESULTS

Seventy-five adolescents completed the study, including 32 in the CTB group, 32 in the TB group and 11 in the control group. Both CTB and TB treatment showed significant differences in most dentoskeletal and soft tissue measurements. Compared with the control group, improvements were observed in class II molar relationship through significant different in S Vert/Ms-S Vert/Mi in the CTB group (P < .01) and the TB group (P < .001), as well as deep overjet through significant different in S Vert/Is-S Vert/Ii in the CTB group (P < .001) and the TB group (P < .001). Besides, the CTB group also showed less protrusion of lower incisors and resulted in a more significant improvement in profile with fewer adverse effects on speaking, eating and social activities.

CONCLUSIONS

For adolescents with skeletal class II malocclusion, CTB appliance was as effective as TB on improving dentoskeletal and soft tissue measurements, featuring more reliable teeth control and patient acceptance.

A Three-Dimensional Evaluation of Skeletal and Dentoalveolar Changes in Growing Class II Patients after Functional Appliance Therapy: A Retrospective Case-Control Study

Background: The aim was to assess three-dimensionally mandibular and maxillary changes in growing Class II patients treated with removable functional appliances followed by fixed appliances. Methods: Twenty-four Class II patients (age range: 9 to 14, mean: 12.1 ± 1.1 years) treated with removable functional appliances followed by fixed appliances (functional appliance group-FAG) were retrospectively selected and compared to an age-matched control group (CG) treated with fixed appliances only. To be included in the study, pre- and post-treatment CBCT scans had to be available. The CBCTs were used to analyze, in 3D, the changes following treatment and growth. Results: Before treatment, overjet (FAG: 9 mm ± 2.8 (mean ± standard deviation); CG: 4 mm ± 1.7), ANB (FAG: 5.7° ± 2.0; CG: 3.2° ± 1.4), and effective mandibular length (FAG: 113.0 mm ± 4.1; CG: 116.6 mm ± 5.9) were statistically significantly different between the two groups. After treatment, overjet (FAG: -6.8 mm ± 2.8; CG: -1.8 mm ± 1.8) and effective mandibular length (FAG: 6.3 mm ± 2.6; CG: 3.9 mm ± 2.6) statistically significantly changed. There was a significant difference in the treatment effect between the FAG and the CG in overjet, ANB, and effective mandibular length. Conclusions: The results indicate that functional appliances are effective in correcting Class II malocclusions. The growth modification in the FAG resulted in an increase in mandibular length. Yet, the final length of the mandible in the FAG was smaller when compared to the CG.

Three-dimensional spatial analysis of temporomandibular joint in adolescent Class II division 1 malocclusion patients: comparison of Twin-Block and clear functional aligner

BACKGROUND

Our study aimed to use three-dimensional (3D) spatial morphological measurement methods to compare the influence of Twin-Block and clear functional aligners on the temporomandibular joint (TMJ) of adolescent Class II division 1 malocclusion mandibular retraction patients. We also aimed to explore the similarities and differences in the effects on the TMJ upon using Twin-Block and clear functional aligner.

METHODS

Cone-beam computed tomography (CBCT) data of 49 patients with Class II division 1 malocclusion (Twin-Block group: 24; clear functional aligner group: 25) were collected before and after functional orthodontic treatment, and a 3D model of the TMJ was reconstructed using MIMICS 21.0 software. Eighteen measurement parameters, including the anterior, superior, and posterior joint spaces, were measured and compared using the 3D model.

RESULTS

After the two groups underwent functional appliance treatment, the height, volume, and surface area of the condyle, length of the mandibular ramus and mandibular length increased; The retro-displaced condyle moved to the middle position of the articular fossa, while the rest of the condylar position did not change significantly. Remodeling of the articular fossa after treatment was not evident. The superior joint space of the clear functional aligner group increased, but there was no significant change after Twin-Block appliances treatment.

CONCLUSIONS

Both appliances promote condylar growth and sagittal and vertical development of the mandible in adolescent Class II division 1 malocclusion mandibular retraction patients. The length of the mandibular ramus showed a more significant increase following treatment with the Twin-Block appliances than with clear function aligners.

Skeletal Class II Malocclusion: From Clinical Treatment Strategies to the Roadmap in Identifying the Genetic Bases of Development in Humans with the Support of the Collaborative Cross Mouse Population

Depending on how severe it is, malocclusion, which may involve misaligned teeth, jaws, or a combination of the two, can hurt a person's overall facial aesthetics. The maxillary molar develops before the mandibular molar in class II malocclusion, which affects 15% of the population in the United States. With a retrusive mandible, patients typically have a convex profile. The goal of this study is to classify the skeletal and dental variability present in class II malocclusion, to reduce heterogeneity, present the current clinical treatment strategies, to summarize the previously published findings of genetic analysis, discuss these findings and their constraints, and finally, propose a comprehensive roadmap to facilitate investigations aimed at determining the genetic bases of malocclusion development using a variety of genomic approaches. To further comprehend the hereditary components involved in the onset and progression of class II malocclusion, a novel animal model for class II malocclusion should be developed while considering the variety of the human population. To overcome the constraints of the previous studies, here, we propose to conduct novel research on humans with the support of mouse models to produce contentious findings. We believe that carrying out a genome-wide association study (GWAS) on a large human cohort to search for significant genes and their modifiers; an epigenetics-wide association study (EWAS); RNA-seq analysis; integrating GWAS and the expression of quantitative trait loci (eQTL); and the testing of microRNAs, small RNAs, and long noncoding RNAs in tissues related to the skeletal class II malocclusion (SCIIMO) phenotype, such as mandibular bone, gum, and jaw in humans and the collaborative cross (CC) mouse model, will identify novel genes and genetic factors affecting this phenotype. We anticipate discovering novel genetic elements to advance our knowledge of how this malocclusion phenotype develops and open the venue for the early identification of patients carrying the susceptible genetic factors so that we can offer early prevention treatment strategies.

Twin-block and mandibular anterior repositioning appliances effects in Class II malocclusion correction

INTRODUCTION

The objective of this study was to compare the cephalometric changes in Class II Division 1 malocclusion patients treated with the Twin-block (TB) and the mandibular anterior repositioning appliance (MARA).

METHODS

This retrospective study was performed with 132 lateral cephalograms of patients with Class II malocclusion divided into 3 groups: a TB group comprised 21 patients with mean initial and final ages of 10.59 and 11.97 years, respectively, treated for a mean period of 1.38 years; a MARA group comprised 21 patients with mean initial and final ages of 11.98 and 13.20 years, respectively, treated for a mean period of 1.22 years; and a control group included 24 subjects with untreated Class II malocclusion with mean initial and final ages of 10.55 and 12.01 years, respectively, observed for a mean period of 1.46 years. Cephalometric intergroup comparisons regarding the treatment changes (T2 - T1) were performed with the analysis of covariance, followed by Tukey tests.

RESULTS

Both appliances demonstrated significant restriction of the maxilla and improvement of the maxillomandibular relationship. The MARA produced a significantly greater amount of labial tipping and protrusion of the mandibular incisors than the other groups. The TB showed significant extrusion of the mandibular incisors and molars compared with MARA and control, respectively. Both treated groups reduced the overjet and overbite. The MARA presented a significantly greater reduction in the molar relationship than the other groups.

CONCLUSIONS

The appliances showed a headgear effect on the maxilla and effectively changed Class II cephalometric parameters through a combination of skeletal and dentoalveolar effects. TB showed a greater increase in LAFH. MARA promoted greater labial tipping and protrusion of the mandibular incisors.

Cephalometric effects of Twin-block and van Beek Headgear-Activator in the correction of Class II malocclusion

INTRODUCTION

The Twin-block (TB) and the van Beek Headgear-Activator (vBHGA) are indicated for patients with Class II malocclusion with a retrognathic mandible. Although the former is commonly prescribed for horizontally growing patients, the latter is often recommended for those growing vertically. This study aimed to compare the skeletal, dentoalveolar, and soft-tissue short-term effects of TB and vBHGA, taking growth patterns into account.

METHODS

Immediate prefunctional (T1) and postfunctional appliance (T2) lateral cephalometric radiographs were retrospectively obtained for vBHGA (n = 46), TB (n = 45), and untreated control (n = 45) groups. The interaction of several variables at T1, T2, and T2 - T1, as well as the resultant treatment effect, were analyzed using the analysis of covariance regression models at the 5% significance level.

RESULTS

Except for a greater reduction in Wits measurement (3.0 mm; P <0.0001) in the TB group, no anteroposterior (AP) skeletal difference was observed between the 2 appliances (ANB, 0.530; P = 0.07) (Harvold, 0.13 mm; P = 0.81). Both improved the AP skeletal relationship (ANB and Harvold) compared with the control (P <0.05). Although this mostly occurred because of the forward positioning of the mandible with the TB (SNB, 0.960; P = 0.01), the maxillary restriction was the main mechanism with the vBHGA (SNA, 1.590; P <0.01). Dentoalveolar compensations were more pronounced with the TB (IMPA, 1.92; P = 0.02), leading to greater overbite and overjet correction. Only the inclination of the maxillary incisors showed interaction with the growth pattern, with the TB horizontal growers experiencing more retroclination (U1-NA°. 3.620; P = 0.0067).

CONCLUSIONS

Both appliances produced similar modest AP skeletal changes that, together with dentoalveolar compensations, were able to correct the Class II malocclusion regardless of growth pattern.

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).

Investigation and comparison of patient experiences with removable functional appliances

OBJECTIVES

To compare patients' experiences with the Invisalign Teen with Mandibular Advancement® (ITMA) and Twin Block (TB) appliances, both initially and after several months of wear.

MATERIALS AND METHODS

Sixty-eight patients completed an anonymous survey after at least 2 months of wearing ITMA or TB. Forty-five patients treated with ITMA (18 boys, 27 girls, mean age 13.6 years, SD ± 1.54) and 23 patients treated with TB (13 boys, 10 girls, mean age 10.60 years, SD ± 1.92) were included.

RESULTS

More patients using the TB found their appliance to be visually intimidating as compared with patients using the ITMA (21.7% vs 8.9%). TB was more noticeable than the ITMA (69.6% vs 25%). Appliance insertion was more difficult for TB patients (21.8% vs 4.44% for ITMA). After several months, there were more reports of tooth soreness and lip/cheek soreness in the ITMA group. TB patients were more embarrassed even after several months (14.3% vs 0% for ITMA). More TB patients required extra appointments for breakage (50% vs 22.2% for ITMA). Speech, drooling, and jaw and lip/cheek soreness worsened initially for both groups but improved over time. There were no differences between the groups regarding visible facial changes, satisfaction with treatment experience, or time to acclimatize to the appliance.

CONCLUSIONS

TB and ITMA patients shared similar experiences for most of the parameters measured, but there were significant differences between the groups regarding appliance wear and management, discomfort, and function.

Assessment of maturation indicators in individuals with different skeletal malocclusion

PURPOSE

The aim of this study was to comparatively evaluate hand-wrist bones, cervical vertebrae and tooth development stages according to skeletal classification.

METHODS

The orthodontic initial records of 297 patients were used and separated into three groups according to the skeletal malocclusion. Three groups including 99 people each were sampled representing malocclusions with Angle classes I, II and III, respectively. The panoramic, cephalometric and hand-wrist radiographs of all patients included in this study were used to compare dental and skeletal maturation indicators. Calcification of teeth was rated according to the system of Demirjian. To evaluate the stage of skeletal maturation hand-wrist radiographs were analyzed according to the Grave and Brown method. Also, Hassel and the Farman method was used to classifying vertebral developmental stages. Spearman rank correlation tests, as well as Fisher exact χ² tests with r×c tables, were used for the comparison of categorical variables.

RESULTS

Hand-wrist, vertebral and dental development stages showed a statistically significant relationship (p < 0.01) for both genders and in all malocclusions. The association between the different maturation indicators used in this study and the type of malocclusion was also statistically significant for both genders. It was observed that the peak period of skeletal maturation according to the hand-wrist radiograph findings correlated with the cervical vertebrae stage C3 in girls (63.2%) and C2-C3 in boys (43.5-43.5%). The weakest correlation was seen between the dental development stages and the skeletal developmental stages in the class II group (r = 0.443-0.220 [girls]; r = 0.604-0.410 [boys]).

CONCLUSION

The use of the dental development stage as a reliable indicator of maturation was limited. According to the Demirjian method, the calcification stage of the second molar might indicate that the individual is in the pubertal peak period.

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

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

Verification of mechanical load generated by functional orthodontic appliances

Functional appliances are widely used for promoting mandibular growth by utilizing a construction bite position. We aimed to measure the mechanical load generated by movement of functional appliances and determine the factors influencing this load. Thirteen patients aged 8-12 years were selected for the study, and the load was measured using a previously developed measurement device. To investigate the factors affecting the load, the temporomandibular joint morphology and muscles related to the mandible were examined using cone-beam computed tomography. The standard regression coefficients of the factors affecting the load per millimeter of movement distance were 0.64 and 0.66 for (a) the inclination of the articular eminence and (b) the angle between occlusal plane and posterior temporalis, respectively. Measurement of the occlusal plane to the posterior temporalis and the inclination of the articular eminence were significantly different (p < 0.05). The angle of inclination of the articular eminence emerged as a strong influencing factor. Similarly, the influence of measurements from the occlusal plane to the posterior temporalis was considerable since the posterior temporalis muscle is the most active when the mandible is extended forward. We also found a possible relationship between the occlusal force and load at the construction bite position. To our knowledge, this is the first study to determine the actual load associated with the angle of the temporalis muscle to the occlusal plane, inclination angle of the articular eminence, angle between the occlusal plane and the Frankfort plane, and the angle between the geniohyoid muscle and the occlusal plane. Therefore, mechanical considerations need to be more accurate to facilitate safe orthodontic treatment.

Evaluation of the upper airway dimensions following Herbst appliance treatment in adolescents: A retrospective study

Objectives:

This retrospective study investigated dimensional changes in the upper airway following Herbst appliance therapy in adolescents with Class II malocclusion and compared those changes with growth data.

Materials and Methods:

Lateral cephalograms from 44 Herbst-treated adolescents (23 boys, mean age = 13.3 ± 1.1 years, and 21 girls, mean age = 12.6 ± 1.1 years) were analyzed for the changes in the upper airway and craniofacial variables. Longitudinal cephalometric data of 34 untreated adolescents (15 boys, mean age = 12.6 ± 0.3 years, and 19 girls, mean age = 12.9 ± 0.4 years) were used as growth data for comparison.

Results:

Following treatment, significant changes were noted in most of the variables. Boys displayed greater downward movement of the hyoid bone than girls did (P = 0.021). Compared with the growth data, a greater increase in retroglossal oropharyngeal depth and hypopharyngeal depth was observed in boys and girls, respectively. Both displayed a decrease in the inclination of the soft palate and a smaller change in nasopharyngeal depth.

Conclusion:

Herbst appliance therapy enlarges the upper airway dimensions at two dissimilar sites in girls (oropharynx) and boys (hypopharynx). Boys display a greater increase in anterior and posterior facial heights than girls do, potentially accounting for the site dissimilarities. Moreover, a Herbst appliance improves the inclination of the soft palate and restricts the growth of the nasopharynx in both boys and girls.

Treatment efficiency of activator and skeletal anchored Forsus Fatigue Resistant Device appliances

OBJECTIVES

The aim of the study was to investigate the treatment efficiency of miniplate anchored Forsus Fatigue Resistant Device (MAF) as compared with the activator appliance.

MATERIALS AND METHODS

Mandibular retrognathia was treated with two methods, the MAF group (8 girls, 11 boys, mean age 13.03 ± 0.69 years) and the activator group (7 girls, 12 boys, mean age 12.68 ± 0.73 years). An untreated control group (9 girls, 10 boys, mean age 12.95 ± 0.73 years) was constructed to eliminate growth-related changes through the American Association of Orthodontists Foundation Legacy Collection. Data of 114 lateral cephalograms were analyzed.

RESULTS

The inhibition of the maxillary growth was greater in the MAF group, whereas forward displacement of the mandible was higher in the activator group (P < 0.05). Sagittal maxillomandibular relation was improved similarly in both treatment groups (P < 0.05). Mandibular length was increased in both treatment groups with the highest increase in the activator group (P < 0.05). Retroclination of the incisors was observed in the MAF group (P < 0.05). The upper lip was retruded in the MAF group and lower lip was protruded in the activator group (P < 0.05).

CONCLUSION

The activator created greater mandibular changes, whereas the MAF provides somewhat smaller mandibular changes due to the restriction caused by retroclined maxillary incisors.

CLINICAL RELEVANCE

Although both MAF and activator treatments caused favorable maxillomandibular changes, new treatment alternatives that reduce dentoalveolar side effects and eliminate patient cooperation are still required to achieve skeletal correction in class II malocclusion treatment in growing patients.

Long-term dentoskeletal changes of class II growing patients' treatment with the propulseur universal light appliance. A prospective controlled study

BACKGROUND

Class II is one of the most common malocclusions. The prevailing aspect in Class II patients is a mandibular deficiency. Various removable and fixed functional therapies are used in order to enhance the mandibular growth or position. The aim of this prospectively controlled study was to evaluate long-term dentoskeletal changes obtained by a functional appliance for Class II.

METHODS

Prospective controlled study, based on a sample size calculation. 26 Class II Division 1 patients (11.8±1.5 years) were consecutively treated with the propulseur universal light (PUL) appliance and a multi bracket appliance (PG), they were compared to a sample of 26 Class II untreated patients (11.5±0.8 years) (CG). Lateral cephalograms were taken before and after the PUL therapy, and after multibracket treatment. Interaction analysis was carried out to test whether the PUL parameters in treatment groups were different according to the acquisition times, using the Linear Mixed-Effects Model.

RESULTS

Significant ANB, Overjet and WITS differences existed in treatment groups according to the time. In particular, comparing to T1 vs. T0, the relative difference (RD) means in the control group were -0.34, -0.31 and 0.17 for ANB, Overjet and WITS, respectively. The corresponding RD means in the treated group PG were -1.58, -4.27 and -2.38. Comparing to T2 vs. T0, the RD means in the control group were -0.36, -0.51 and 0.63 for ANB, Overjet and WITS, respectively. While the corresponding RD means in the treated group were -2.08, -5.12 and -2.50.

CONCLUSIONS

The PUL appliance successfully corrected class II malocclusion. The long term correction was mainly due to dentoalveolar effects: therapy success was 91% for overjet correction and 76% for ANB correction. During the post functional appliance period, overjet was stable in 77% of the treated subjects, and ANB in 74% of the treated subjects.

[Obstructive sleep disordered breathing and orthodontics: primum non nocere]

Obstructive sleep apnoea syndrome is a widespread and under-diagnosed condition, making it a major public health and safety issue. The objective of this article was to clarify some of the evidence-based elements of therapeutic decision-making and the information provided to the patient and family on the benefit-cost-security ratio of several of his therapeutic options. Published data on the effectiveness of oral appliances and functional orthopaedic appliances for obstructive sleep apnea (OSA) in children, the durability of their effects, the therapeutic possibilities of maxillary or bimaxillary expansion, and the interrelationships between permanent teeth extractions and obstructive sleep disordered breathing, were researched and analyzed. Based on available evidence, in growing patients with Class II malocclusion, treatment with functional orthopedic devices can increase the volume of the pharyngeal airway and thus hopefully reduce the risk of developing OSA. An improvement in the apnea-hypopnea index and lower oxygen saturation was observed in children treated with rapid maxillary expansion. Permanent teeth extractions prescribed for the treatment of teeth crowding in an orthodontic age patient do not result in any significant change in the upper airway. The role of the orthodontist in the multidisciplinary team in the screening and management of Obstructive Sleep Disordered Breathing (OSDB) is essential. By combining clinical experience with published data on various therapeutic approaches, the orthodontist helps the patient to benefit from better adapted care and a more sustainable outcome, while taking into account his or her preferences.

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.

Class II correction in orthodontic patients utilizing the Mandibular Anterior Repositioning Appliance (MARA)

OBJECTIVES

To evaluate skeletal and dentoalveolar changes produced by the Mandibular Anterior Repostioning Appliance (MARA) in the treatment of Class II malocclusion in adolescent patients.

MATERIALS AND METHODS

Lateral cephalograms of 24 patients, mean age 12.40 years, with a Class II malocclusion consecutively treated with MARA were compared with a historical control group. Changes were evaluated using the Pancherz superimposition and grid analysis pre- and posttreatment. Independent sample t-test, Mann-Whitney U-test, and Pearson correlation coefficient analysis were performed.

RESULTS

Significant differences were seen between the treatment and control groups during the 12 month period. Improvement in Class II relationship in the MARA group resulted from skeletal and dentoalveolar changes. There was a 7-mm molar correction and a 4.7-mm overjet reduction. There was also an increase in the mandibular base of 3.3 mm with the lower molar and incisor coming forward 2.6 mm and 2.2 mm, respectively. No significant headgear effect was shown on the maxilla. The maxillary incisor position remained unchanged, whereas the molar distalized 1.8 mm. The anterior lower facial height had an overall increase of 2.2 mm.

CONCLUSIONS

The MARA was successful in achieving a Class I molar relationship and reducing the overjet in Class II malocclusions. This was the result of both skeletal and dentoalveolar changes.

No Compliance Correction of Class II Malocclusion in Growing Patients Whit HERBST Appliance: A Case Report

Background:

Class II malocclusion is the most common sagittal skeletal discrepancy, with a prevalent skeletal pattern of mandibular retrusion. The correction of mandibular retrusion with functional removable appliance needs a good patient’s compliance; for this reason, some clinicians prefer to use no compliance apparatus.

Objective:

Objective of the present therapy note is to demonstrate that the use of no compliance apparatus can provide a good correction of skeletal class II malocclusion.

Methods:

In the present study, authors report a therapy note referred to a 10 years old patient, woman, affected by Class II, with mandibular retrusion and deep bite, treated in 2013 at the Dep. of Orthodontics of Messina University. An orthodontic treatment has been planned with the aim of stimulating mandibular growth; an Herbst appliance with a cantilever design, bonded on first maxillary and mandibular molars, has been used. After eleven months of functional therapy a bilateral molar class I have been obtained.

Results:

In the therapy note proposed, authors obtained a resolution of mandibular retrusion, a correction of overjet, overbite and dental crowding in both arches, and a bilateral molar and canine class I has been achieved.

Conclusion:

Herbst appliance seems to be efficient in the correction of II Class Malocclusion, independently from patient’s cooperation; moreover , early correction of Class II malocclusion with functional appliances produces several clinical advantages.

[Mandibular repositioning in adult patients. An alternative to surgery in some patients? A two-year follow-up]

INTRODUCTION

A number of adult patients with skeletal discrepancies refuse surgical intervention.

AIMS

The aim was to assess the reaction to mandibular repositioning in simulating a skeletal correction in such patients.

MATERIALS AND METHODS

32 consecutive patients without any signs of temporo-mandibular dysfunction (TMD) were offered mandibular repositioning, as a non-invasive alternative and it was explained to them that the approach was based on the results described in case reports. Before initiating any treatment initial records, headfilms, study casts and photos were taken (T₀) and the mandible was repositioned to camouflage the skeletal discrepancy by means of an occlusal built-up in Triad^® Gel.

RESULTS

Three months later (T₁) 23 patients had adapted to the new occlusion reflected in absence of functional problems and lack of fracture of the built-up. In these patients the mandibular position was maintained by orthodontics adjusting the occlusion to the built-up position (T₁). The skeletal changes occurring during repositioning were assessed on sagittal and frontal head films while intra-articular changes occurring during a 2-year follow-up period (T₂) were evaluated on images constructed from CBCT images. No significant changes, neither in the direction of a relapse nor in the direction of further normalization of the condylar positioning, were observed during the 2-year observation period.

CONCLUSIONS

Repositioning is a non-invasive intervention and may be considered a valid alternative to surgery in some patients. Morphological variables from the radiographs taken at T₀ and the results of the initial clinical evaluation of dysfunction yielded only vague and insignificant indications regarding the predictability of adaptation to the repositioning.

[A change of paradigm in the treatment of Class II malocclusions in children and adolescents: the benefits of the Class II Corrector]

INTRODUCTION

The treatment of class II malocclusions is the core of our clinical activity. What elements can clinician rely on to offer their patients, whether children or adolescents, a treatment of their class II malocclusion that is not only effective but also the most appropriate for each individual case? Which schedule and what therapeutic device should be used?

MATERIALS AND METHODS

Evidence-based orthodontics, along with a search for the best data on two-phase treatments, were used to judge the validity of the main objectives sought when correcting a Class II malocclusion in children or adolescents, including treatment of mandibular retrognathy.

RESULTS

Published data show that the long-term effects of a first phase of treatment on the amount of mandibular growth are at best weak and clinically insignificant. This observation triggers a paradigm shift by refocusing patient treatment on the achievement of other therapeutic objectives. A new orthodontic appliance, the Clas II Corrector, is presented. Its advantages and its use are described and illustrated by means of clinical cases.

CONCLUSIONS

Class II Corrector allows distalization of maxillary lateral areas, effectively limits undesirable dentoalveolar compensations and facilitates the rehabilitation of orofacial functions. In addition to its clinical efficacy, patients appreciate its small footprint, ease of wearing, and lack of impact on phonation.

Comparison of surgical and non-surgical orthodontic treatment approaches on occlusal and cephalometric outcomes in patients with Class II Division I malocclusions

BACKGROUND

This study aimed to examine end-of-treatment outcomes of severe Class II Division I malocclusion patients treated with surgical or non-surgical approaches. This study tests the hypotheses that occlusal outcomes (ABO-OGS) and cephalometric outcomes differ between these groups.

METHODS

A total of 60 patients were included: 20 of which underwent surgical correction and 40 of which did not. Cast grading of initial and final study models was performed and information was gathered from pre- to post-treatment cephalometric radiographs. The end-of-treatment ABO-OGS and cephalometric outcomes were compared to Mann-Whitney U tests and multivariable linear regression models.

RESULTS

Following adjustment for multiple confounders (age, gender, complexity of case, and skeletal patterns), the final deband score (ABO-OGS) was similar for both groups (23.8 for surgical group versus 22.5 for non-surgical group). Those treated surgically had a significantly larger reduction in ANB angle, 3.4° reduction versus 1.5° reduction in the non-surgical group (p = 0.002). The surgical group also showed increased maxillary incisor proclination (p = 0.001) compared to the non-surgical group. This might be attributed to retroclination of maxillary incisors during treatment selection in the non-surgical group-namely, extraction of premolars to mask the discrepancy.

CONCLUSIONS

Those treated surgically had a significantly larger reduction in ANB angle and increased maxillary incisor proclination compared to those treated non-surgically with no significant changes in occlusal outcomes.

Cephalometric appraisal of Class II treatment effects after functional and fixed appliances: a retrospective study

Objective

To assess the dental, skeletal, and profile changes after functional appliances and subsequent fixed appliances treatment in order to quantify their effect and evaluate the influence of initial incisal inclination and growth pattern.

Materials and methods

A retrospective cephalometric analysis was performed in 125 patients (77 females and 48 males). Three lateral cephalograms per patient were available: before treatment (T0, mean age 11.9 years), after functional treatment (T1, mean age 12.9 years), and after fixed appliances (T2, mean age 14.8 years).

Results

At T1, a decrease of SNA (0.38° ± 0.77, P < 0.05), an increase of SNB (1.46° ± 0.66, P < 0.05), and a less convex profile (increase N'-Sn'-Pog' of 2.93° ± 0.87, P < 0.05) were observed as compared to T0. The position of the upper incisors normalizes: initially retroclined upper incisors showed proclination and proclined incisors retroclination. At T1, proclination of the lower incisors was also noticed, being smaller the higher the initial I^NB. At T2, no significant changes in upper and lower incisor position were noticed compared to T1, as well as a decrease of the SNA (1.17° ± 0.75, P < 0.001) and SNB angles (0.41° ± 0.64, P < 0.05) and a stable profile convexity.

Conclusion

The improvement of the Class II relationship at T1 was mostly due to dentoalveolar changes: correction of the upper incisor position and proclination of the lower incisors. Skeletal changes were also noticed: constriction of maxillary growth combined with a growth stimulation of the mandible. At T2, no further proclination of the lower incisors was noticed.

Fixed functional appliances with multibracket appliances have no skeletal effect on the mandible: A systematic review and meta-analysis

INTRODUCTION

Our aim was to assess the skeletal mandibular changes (anteroposterior and vertical) in circumpubertal patients with fixed functional appliances installed on multibracket appliances compared with untreated patients.

METHODS

An open-ended electronic search of 4 databases (PubMed, Embase, Cochrane Library, and Web of Science) up to April 2014 was performed. Additional searches of relevant journals, reference lists of the retrieved articles, systematic reviews, and gray literature were performed. Specific inclusion and exclusion criteria were applied to identify relevant articles. Quality was evaluated using the Cochrane Collaboration risk of bias tool and the Newcastle-Ottawa scale for prospective controlled clinical trials. Meta-analyses were conducted with fixed and random effects models as appropriate. Statistical heterogeneity was also examined.

RESULTS

Seven articles were included in the qualitative synthesis and 5 in the meta-analysis. The included randomized controlled trials were at high risk of bias, and the methodologic quality of the prospective controlled clinical trials was high. Based on assessment of the fixed functional appliance phase in isolation, no difference in mandibular anteroposterior positional changes (SNB angle) (standard mean difference, 0.11°; 95% CI, -0.28, 0.50) was found between the treated and control groups. The vertical dimension was not influenced by the fixed functional appliance treatment.

CONCLUSIONS

There is little high-quality evidence concerning the relative influence of fixed functional appliances on skeletal and dentoalveolar changes. However, based on the limited evidence, it appears that they have little effect on the skeletal mandibular parameters.

Effectiveness of orthodontic treatment with functional appliances on maxillary growth in the short term: A systematic review and meta-analysis

INTRODUCTION

The aim of this systematic review was to evaluate the treatment effects on maxillary growth of removable functional appliances that advance the mandible to a more forward position in patients with Class II malocclusion.

METHODS

Sixteen electronic databases and reference lists of studies were searched up to April 2015. Only randomized clinical trials and prospective controlled clinical trials investigating Class II growing patients treated with removable functional appliances were included. Two authors independently accomplished study selection, data extraction, and risk of bias assessment. All pooled analyses of data were based on random-effects models. Statistical heterogeneity was evaluated.

RESULTS

In total, 14 studies were included (5 randomized clinical trials, 9 prospective controlled clinical trials) that collected data from 765 patients (405 treated, 360 untreated controls). The mean differences in treatment effect of functional appliances, relative to the untreated controls, were -0.61° per year (95% CI, -0.69° to -0.25°) for SNA angle, -0.61 mm per year (95% CI, -0.90 to -0.32 mm) for anterior maxillary displacement, and +0.07° per year (95% CI, -0.17° to +0.32°) for maxillary plane rotation.

CONCLUSIONS

Removable functional appliances in Class II growing patients have a slight inhibitory effect on the sagittal growth of the maxilla in the short term, but they do not seem to affect rotation of the maxillary plane.

Effect of removable functional appliances on mandibular length in patients with class II with retrognathism: systematic review and meta-analysis

BACKGROUND

Orthopedic functional devices, are used to improve mandibular length in skeletal class II patients. However, the orthopedic functional device with the best effect to increasing the mandibular length, has not been identified before. Thus, the aim of the present investigation was to evaluate Randomized Controlled Trials (RCT), to determine the best functional appliance improving mandibular length in subjects with retrognathism.

METHODS

A systematic review and meta-analysis was performed, including studies published and indexed in databases between 1966 and 2016. RCTs evaluating functional appliances' effects on mandibular length (Condilion-Gnation (Co-Gn) and Condilion-Pogonion (Co-Po)), were included. Reports' structure was evaluated according to 2010 CONSORT guide. The outcome measure was distance between Co-Gn and/or Co-Po after treatment. Data were analyzed with Cochran Q Test and random effects model.

RESULTS

Five studies were included in the meta-analysis. The overall difference in mandibular length was 1.53 mm (Confidence Interval (CI) 95% 1.15-1.92) in comparison to non-treated group. The Sander Bite Jumping reported the greatest increase in mandibular length (3.40 mm; CI 95% 1.69-5.11), followed by Twin Block, Bionator, Harvold Activator and Frankel devices.

CONCLUSIONS

All removable functional appliances, aiming to increase mandibular length, are useful. Sander Bite Jumping was observed to be the most effective device to improve the mandibular length.

Reliability of Growth Indicators and Efficiency of Functional Treatment for Skeletal Class II Malocclusion: Current Evidence and Controversies

Current evidence on the reliability of growth indicators in the identification of the pubertal growth spurt and efficiency of functional treatment for skeletal Class II malocclusion, the timing of which relies on such indicators, is highly controversial. Regarding growth indicators, the hand and wrist (including the sole middle phalanx of the third finger) maturation method and the standing height recording appear to be most reliable. Other methods are subjected to controversies or were showed to be unreliable. Main sources of controversies include use of single stages instead of ossification events and diagnostic reliability conjecturally based on correlation analyses. Regarding evidence on the efficiency of functional treatment, when treated during the pubertal growth spurt, more favorable response is seen in skeletal Class II patients even though large individual responsiveness remains. Main sources of controversies include design of clinical trials, definition of Class II malocclusion, and lack of inclusion of skeletal maturity among the prognostic factors. While no growth indicator may be considered to have a full diagnostic reliability in the identification of the pubertal growth spurt, their use may still be recommended for increasing efficiency of functional treatment for skeletal Class II malocclusion.

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

INTRODUCTION

The Herbst appliance has been used in the treatment of Class II malocclusions with deficient mandibles. Various protocols, including different durations of the orthopedic treatment phase and stepwise advancement of the mandible, have been advocated for increasing the orthopedic effects. The objective of this study was to investigate the skeletal and dental changes in patients treated with a reinforced banded Herbst appliance for an extended duration and fixed appliance therapy.

METHODS

The study group consisted of 30 patients (16 boys, 14 girls; mean age, 12.3 ± 2.5 years) with Class II Division 1 malocclusions who were successfully treated with the new Herbst protocol followed by fixed appliances. Lateral cephalometric radiographs were taken before treatment, at the completion of Herbst treatment, and after removal of fixed appliances. The average treatment times were 1.5 ± 0.7 years for the Herbst treatment and 1.8 ± 0.5 years for the fixed appliances. A control Class II sample from the Bolton-Brush study was used to subtract growth from treatment changes to determine the appliance effect. Data were analyzed using analysis of variance and the Tukey-Kramer test.

RESULTS

After the Herbst treatment, the incisal relationships of all subjects had been overcorrected to end-to-end relationships. Overjet was reduced by 7.2 mm after subtracting changes from growth. The skeletal contribution was 2.5 mm (35%), and the dental contribution was 4.7 mm (65%). The molar relationship was overcorrected to a more Class I relationship by 7.5 mm. The Wits appraisal was improved by 4.2 mm. Vertically, overbite was decreased by 3.3 mm. The maxillary and mandibular molars were extruded by 1 mm. The occlusal plane rotated clockwise by 5° with little change in the mandibular plane angle. After the treatment with fixed appliances, the overjet correction was maintained at 7.6 mm. The skeletal contribution was 2.9 mm (38%), and the dental contribution was 4.7 mm (62%). The molar relationship was corrected to a Class I relationship by 5.9 mm. The Wits appraisal was improved by 3.2 mm. Vertically, overbite was decreased by 4.2 mm. The maxillary and mandibular molars were extruded by 0.3 and 0.8 mm, respectively. The occlusal plane rotated clockwise by 1.2° with little change in the mandibular plane angle.

CONCLUSIONS

Doubling the usual orthopedic treatment time with the reinforced Herbst appliance followed by fixed appliance therapy was effective in correcting Class II Division 1 malocclusions with excess overjet and overbite. In this sample of successfully treated patients, most changes after Herbst and fixed appliance therapy were dentoalveolar (62%). However, the skeletal changes attained in the orthopedic phase of treatment were maintained after fixed appliance therapy.

Sagittal and Vertical Craniofacial Growth Pattern and Timing of Circumpubertal Skeletal Maturation: A Multiple Regression Study

The knowledge of the associations between the timing of skeletal maturation and craniofacial growth is of primary importance when planning a functional treatment for most of the skeletal malocclusions. This cross-sectional study was thus aimed at evaluating whether sagittal and vertical craniofacial growth has an association with the timing of circumpubertal skeletal maturation. A total of 320 subjects (160 females and 160 males) were included in the study (mean age, 12.3 ± 1.7 years; range, 7.6-16.7 years). These subjects were equally distributed in the circumpubertal cervical vertebral maturation (CVM) stages 2 to 5. Each CVM stage group also had equal number of females and males. Multiple regression models were run for each CVM stage group to assess the significance of the association of cephalometric parameters (ANB, SN/MP, and NSBa angles) with age of attainment of the corresponding CVM stage (in months). Significant associations were seen only for stage 3, where the SN/MP angle was negatively associated with age (β coefficient, -0.7). These results show that hyperdivergent and hypodivergent subjects may have an anticipated and delayed attainment of the pubertal CVM stage 3, respectively. However, such association remains of little entity and it would become clinically relevant only in extreme cases.

Craniofacial morphology in pediatric patients with Prader-Willi syndrome: a retrospective study

OBJECTIVE

To investigate craniofacial characteristics in pediatric patients with Prader-Willi syndrome (PWS).

SETTING AND SAMPLE POPULATION

A retrospective sample of 20 consecutive patients with PWS who had lateral and antero-posterior (AP) cephalograms (14 males and six females; average age 10.2 ± 3 years) was compared to 20 controls matched for age and sex (14 males and six females; average age 10.5 ± 3.7 years).

MATERIALS AND METHODS

Cephalometric skeletal measurements were performed twice at a 1-week interval by one calibrated operator, and random error was calculated using Dahlberg's formula. Mean values and standard deviations were computed for all variables. Student's t-test for independent samples was used to determine significant differences between PWS and controls. The level of significance was set at p < 0.05.

RESULTS

Cephalometric values for the length of the maxilla (p < 0.01), mandibular length (p < 0.05) at both the ramus (p < 0.05) and the mandibular body (p < 0.01), and posterior and anterior facial height (p < 0.01) were significantly lower in patients with PWS compared to controls. The AP cephalometric analysis revealed a significant reduction (p < 0.01) in maxillary skeletal width, mandibular skeletal width, and interzygomatic distance.

CONCLUSIONS

Pediatric patients with PWS seem to have a general reduction in certain craniofacial skeletal parameters (i.e., maxillary and mandibular length) compared to controls, but this study did not assess the overall craniofacial characteristics.

Treatment Effects of Removable Functional Appliances in Pre-Pubertal and Pubertal Class II Patients: A Systematic Review and Meta-Analysis of Controlled Studies

BACKGROUND

Treatment effects of removable functional appliances in Class II malocclusion patients according to the pre-pubertal or pubertal growth phase has yet to be clarified.

OBJECTIVES

To assess and compare skeletal and dentoalveolar effects of removable functional appliances in Class II malocclusion treatment between pre-pubertal and pubertal patients.

SEARCH METHODS

Literature survey using the Medline, SCOPUS, LILACS and SciELO databases, the Cochrane Library from inception to May 31, 2015. A manual search was also performed.

SELECTION CRITERIA

Randomised (RCTs) or controlled clinical trials with a matched untreated control group. No restrictions were set regarding the type of removable appliance whenever used alone.

DATA COLLECTION AND ANALYSIS

For the meta-analysis, cephalometric parameters on the supplementary mandibular growth were the main outcomes, with other cephalometric parameters considered as secondary outcomes. Risk of bias in individual and across studies were evaluated along with sensitivity analysis for low quality studies. Mean differences and 95% confidence intervals for annualised changes were computed according to a random model. Differences between pre-pubertal and pubertal patients were assessed by subgroup analyses. GRADE assessment was performed for the main outcomes.

RESULTS

Twelve articles (but only 3 RCTs) were included accounting for 8 pre-pubertal and 7 pubertal groups. Overall supplementary total mandibular length and mandibular ramus height were 0.95 mm (0.38, 1.51) and 0.00 mm (-0.52, 0.53) for pre-pubertal patients and 2.91 mm (2.04, 3.79) and 2.18 mm (1.51, 2.86) for pubertal patients, respectively. The subgroup difference was significant for both parameters (p<0.001). No maxillary growth restrain or increase in facial divergence was seen in either subgroup. The GRADE assessment was low for the pre-pubertal patients, and generally moderate for the pubertal patients.

CONCLUSIONS

Taking into account the limited quality and heterogeneity of the included studies, functional treatment by removable appliances may be effective in treating Class II malocclusion with clinically relevant skeletal effects if performed during the pubertal growth phase.

Therapeutic approach to Class II, Division 1 malocclusion with maxillary functional orthopedics

INTRODUCTION:

Interceptive treatment of Class II, Division 1 malocclusion is a challenge orthodontists commonly face due to the different growth patterns they come across and the different treatment strategies they have available.

OBJECTIVE:

To report five cases of interceptive orthodontics performed with the aid of Klammt's elastic open activator (KEOA) to treat Class II, Division 1 malocclusion.

METHODS:

Treatment comprehends one or two phases; and the use of functional orthopedic appliances, whenever properly recommended, is able to minimize dentoskeletal discrepancies with consequent improvement in facial esthetics during the first stage of mixed dentition. The triad of diagnosis, correct appliance manufacture and patient's compliance is imperative to allow KEOA to contribute to Class II malocclusion treatment.

RESULTS:

Cases reported herein showed significant improvement in skeletal, dental and profile aspects, as evinced by cephalometric analysis and clinical photographs taken before, during and after interceptive orthodontics.

Treatment effects of fixed functional appliances alone or in combination with multibracket appliances: A systematic review and meta-analysis

OBJECTIVE

To assess skeletal and dentoalveolar effects of fixed functional appliances, alone or in combination with multibracket appliances (comprehensive treatment), on Class II malocclusion in pubertal and postpubertal patients.

MATERIALS AND METHODS

Literature survey was conducted using the Medline, SCOPUS, LILACS, and SciELO databases and The Cochrane Library, and through a manual search. The studies retrieved had to have a matched untreated control group. No restrictions were set regarding the type of fixed appliance, treatment length, or to the cephalometric analysis used. Data extraction was mostly predefined at the protocol stage by two authors. Supplementary mandibular elongation was used for the meta-analysis.

RESULTS

Twelve articles qualified for the final analysis of which eight articles were on pubertal patients and four were on postpubertal patients. Overall supplementary total mandibular elongations as mean (95% confidence interval) were 1.95 mm (1.47 to 2.44) and 2.22 mm (1.63 to 2.82) among pubertal patients and -1.73 mm (-2.60 to -0.86) and 0.44 mm (-0.78 to 1.66) among postpubertal patients, for the functional and comprehensive treatments, respectively. For pubertal subjects, maxillary growth restraint was also reported. Nevertheless, skeletal effects alone would not account for the whole Class II correction even in pubertal subjects with dentoalveolar effects always present.

CONCLUSIONS

Fixed functional treatment is effective in treating Class II malocclusion with skeletal effects when performed during the pubertal growth phase, very few data are available on postpubertal patients.

Treatment effects produced by the Twin-block appliance vs the Forsus Fatigue Resistant Device in growing Class II patients

OBJECTIVE

To compare the dentoskeletal changes produced by the Twin-block appliance (TB) followed by fixed appliances vs the Forsus Fatigue Resistant Device (FRD) in combination with fixed appliances in growing patients having Class II division 1 malocclusion.

MATERIALS AND METHODS

Twenty-eight Class II patients (19 females and 9 males; mean age, 12.4 years) treated consecutively with the TB followed by fixed appliances were compared with a group of 36 patients (16 females and 20 males; mean age, 12.3 years) treated consecutively with the FRD in combination with fixed appliances and with a sample of 27 subjects having untreated Class II malocclusion (13 females and 14 males; mean age, 12.2 years). Mean observation interval was 2.3 years in all groups. Cephalometric changes were compared among the three groups by means of ANOVA and Tukey's post hoc tests.

RESULTS

The FRD produced a significant restraint of the maxilla compared with the TB and control samples (SNA, -1.1° and -1.8°, respectively). The TB sample exhibited significantly greater mandibular advancement and greater increments in total mandibular length than either the FRD or control groups (SNB, 1.9° and 1.5°, respectively; and Co-Gn, 2.0 mm and 3.4 mm, respectively). The FRD produced a significantly greater amount of proclination of the mandibular incisors than what occurred with the TB or the control samples (2.9° and 5.6°, respectively).

CONCLUSION

The TB appliance produced greater skeletal effects in terms of mandibular advancement and growth stimulation while the Forsus caused significant proclination of the mandibular incisors.

Change of mandibular position during two-phase orthodontic treatment of skeletal class II in the Chinese population

The aim of this study was to evaluate the change in mandibular position during a two-phase orthodontic treatment of skeletal Class II malocclusion. Thirty consecutively treated Chinese male adolescents who had undergone two-phase treatment with Herbst appliance and fixed appliance and fulfilled the specific selection criteria were sampled. Cephalograms taken at T0 (before treatment), T1 (at the end of functional appliance treatment), and T2 (at the end of fixed appliance treatment) were analyzed. The change in sagittal positioning of the mandible was 6.8±3.44 mm in phase I (T0-T1), 0.4±2.79 mm in phase II (T1-T2), and 7.2±4.61 mm in total. The mandible came forward in 100% of the patients at T1. In phase II, it came forward in one-third (positive group) remained unchanged in one-third (stable group) and went backward in one-third (negative group) of the patients. At T2, it came forward twice as much in the positive group compared to the negative group. Mandibular length was significantly increased in 100% of the patients in both phases. In conclusion, during the treatment with functional appliance, the mandibular prognathism increases in all patients, whereas during the treatment with fixed appliance there is no significant change in mandibular prognathism.

Adjunctive techniques for enhancing mandibular growth in Class II malocclusion

Class II malocclusions are generally characterized by mandible retrusion. For this reason, forward bite jumping appliances, also known as functional appliances were originally designed to enhance mandibular forward projection. However, there is still insufficient evidence to support the effectiveness, predictability and stability of functional appliances in modifying mandibular growth. This article was aimed at presenting evidences and hypotheses that mandibular growth may be enhanced through the use of adjunctive methods in conjunction with functional appliances. In formulating our hypothesis, we considered relevant data, mostly derived from animal studies, concerning alternative methods, such as low-intensity ultrasound and light-emitting diode, as well as their related cellular and molecular mechanisms. According to the evidences covered in this article, we suggest that both methods are potentially effective, and theoretically able to act in synergistic way to enhance functional appliances treatment on mandibular and condylar additional growth. The rationale for the use of these methods as adjunctive therapies for mandibular underdevelopment is attributed to their abilities on stimulating angiogenesis, cell differentiation, proliferation, and hypertrophy, as well as enhancing matrix production and endochondoral bone formation, especially on the condyle of growing animals. This article also proposed a study design which would be able to either prove or refute our hypothesis. If ratified, it would represent a significant scientific accomplishment which provides support for further investigations to be carried out on well-designed clinical trials.

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

OBJECTIVE

To assess the treatment effects of removable functional appliances (RFAs) in treated versus untreated patients with Class II malocclusion by means of lateral cephalometric radiographs.

SEARCH METHODS

Unrestricted electronic search of 18 databases and manual searches up to October 2013.

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

Skeletal, dental, and soft tissue changes were annualized and stratified to short- and long-term effects. Methodological limitations were evaluated with the Cochrane Risk of Bias tool and the Downs and Black checklist. Mean differences (MDs) with their 95% confidence intervals (CIs) were calculated from random-effects meta-analyses. Patient- or appliance-related subgroup analyses and sensitivity analyses were performed with mixed-effects models.

RESULTS

Seventeen studies were included (1031 patients; mean age: 10.6 years), with most of them originating from university clinics and reporting short-term effects (directly after the removal of RFAs). Treatment was associated with minimal reduction of SNA angle (11 studies, MD = -0.28 degree/year, 95% CI: -0.44 to -0.12 degree/year), minimal increase of SNB angle (11 studies, MD = 0.62 degree/year, 95% CI: 0.36-0.88 degree/year), and small decrease of ANB angle (10 studies, MD = -1.14 degree/year, 95% CI: -1.52 to -0.77 degree/year) compared to untreated Class II patients. RFAs caused significant dentoalveolar changes (predominantly retroclination of the upper incisors) and significant soft tissue changes. Skeletal changes were more pronounced with the Twin Block appliance. Various patient- or appliance-related factors influenced the results of the subgroup analyses, while the sensitivity analyses indicated robustness. Existing evidence was inadequate to assess the long-term effectiveness of RFAs.

CONCLUSIONS

The short-term evidence indicates that RFAs are effective in improving Class II malocclusion, although their effects are mainly dentoalveolar, rather than skeletal.

Meta-analysis on the mandibular dimensions effects of the MARA appliance in patients with Class II malocclusions

OBJECTIVES

To evaluate the short- and long-term effects of the mandibular anterior repositioning appliance (MARA) on mandibular dimensions in patients with Class II malocclusion and to assess the stability of the MARA results.

MATERIALS AND METHODS

Multiple electronic databases were searched for articles published in any language until March 2014. A manual search was also performed of reference lists of retrieved articles. The primary outcomes were the short-and long-term effects of the MARA appliance on mandible dimensions. The secondary outcome was postretention stability. Outcome measures were total mandibular unit length, corpus length, and ramus height. Two reviewers examined all articles independently and assessed their methodologic quality. Meta-analyses were conducted using random-effects models. The Cochrane test and the I(2) statistic were used to assess heterogeneity. Sensitivity analyses were performed and publication bias was evaluated.

RESULTS

Seven retrospective clinical controlled studies that compared MARA with controls were included. Three of the studies were medium quality; the rest were low quality. Meta-analysis of the short-term effects revealed a significant increase in total mandibular unit length (1.16 mm/y) and ramus height (1.58 mm/y) with MARA and a nonsignificant increase in corpus length (0.21 mm/y). Analyses of the long-term effects showed a statistically significant advantage of MARA over controls for all three variables, but the effect sizes were small. More high-quality studies are warranted.

CONCLUSIONS

The MARA appliance produced statistically significant mandibular growth enhancement in the short- and long-term. These findings, however, may not be clinically significant.

[Methodology for clinical research in Orthodontics, the assets of the beOrtho website]

The rules applying to the "evidence-based" methodology strongly influenced the clinical research in orthodontics. However, the implementation of clinical studies requires rigour, important statistical and methodological knowledge, as well as a reliable environment in order to compile and store the data obtained from research. We developed the project "beOrtho.com" (based on orthodontic evidence) in order to fill up the gap between our desire to drive clinical research and the necessity of methodological rigour in the exploitation of its results. BeOrtho website was created to answer the issue of sample recruitment, data compilation and storage, while providing help for the methodological design of clinical studies. It allows the development and monitoring of clinical studies, as well as the creation of databases. On the other hand, we designed an evaluation grid for clinical studies which helps developing systematic reviews. In order to illustrate our point, we tested a research protocol evaluating the interest of the mandibular advancement in the framework of Class II treatment.

Phenotypic diversity in white adults with moderate to severe Class II malocclusion

INTRODUCTION

Class II malocclusion affects about 15% of the population in the United States and is characterized by a convex profile and occlusal disharmonies. The specific etiologic mechanisms resulting in the range of Class II dentoskeletal combinations observed are not yet understood. Most studies describing Class II phenotypic diversity have used moderate sample sizes or focused on younger patients who later in life might outgrow their Class II discrepancies; such a focus might also preclude the visualization of adult Class II features. The majority have used simple correlation methods resulting in phenotypes that might not be generalizable to different samples and thus might not be suitable for studies of malocclusion etiology. The purpose of this study was to address these knowledge gaps by capturing the maximum phenotypic variations in a large sample of white Class II subjects selected with strict eligibility criteria and rigorously standardized multivariate reduction analyses.

METHODS

Sixty-three lateral cephalometric variables were measured from the pretreatment records of 309 white Class II adults (82 male, 227 female; ages, 16-60 years). Principal component analysis and cluster analysis were used to generate comprehensive phenotypes to identify the most homogeneous groups of subjects, reducing heterogeneity and improving the power of future malocclusion etiology studies.

RESULTS

Principal component analysis resulted in 7 principal components that accounted for 81% of the variation. The first 3 components represented variation on mandibular rotation, maxillary incisor angulation, and mandibular length. The cluster analysis identified 5 distinct Class II phenotypes.

CONCLUSIONS

A comprehensive spectrum of Class II phenotypic definitions was obtained that can be generalized to other samples to advance our efforts for identifying the etiologic factors underlying Class II malocclusion.

Morphological integration of mandible and cranium: orthodontic implications

OBJECTIVES

This study aimed at clarifying the morphological interactions among the cranial base, face, and mandible, to improve the assessment and treatment of skeletal malocclusions involving the mandible.

DESIGN

Untreated adult subjects (n=187) were grouped according to standard cephalometric criteria of vertical and sagittal relationships. Geometric morphometrics were used to test the null hypothesis that integration patterns between the mandible and its associated basicranial and upper midfacial counterparts would be similar among various vertical and sagittal facial patterns.

RESULTS

The null hypothesis was rejected for vertical groups, because the dolicho- and brachyfacial subjects showed significantly different integration patterns, but was accepted for sagittal groups, which showed identical covariation patterns. The morphological integration between the cranium-face and mandible were similarly high in the three skeletal classes, which explained the similarly large covariance between the two structures (57.80% in Class II to 60% in Class III).

CONCLUSIONS

Dolicho- and brachi-facial subjects showed specific and different cranium-face and associated mandible configurations. The cranium-face configuration may have an important influence (∼60%) on the generation of sagittal (anteroposterior) skeletal malocclusions. The remaining morphological component of the skeletal malocclusion (∼40%) would be independent of this particular integration (PLS1) between the cranium-face and mandible.

Low-dose protocol of the spiral CT in orthodontics: comparative evaluation of entrance skin dose with traditional X-ray techniques

BACKGROUND

The aim of this study was to evaluate the amount of radiation doses absorbed by soft tissues (entrance skin dose) with a low-dose spiral computed tomography (CT) protocol compared to conventional X-ray techniques commonly used in orthodontics.

METHODS

The amount of skin dose has been evaluated using a tissue-equivalent head-neck radiotherapy humanoid phantom with thermoluminescent dosimeters placed at the level of eye lens, parotid glands, and thyroid glands. CT images have been taken using a Sensation 16 Siemens CT scan and a low-dose protocol (15 mAs, 1 pitch, 2.5 mGy (CTDIvol), 80 kV, 1-mm slice thickness).

RESULTS

The difference in image quality between traditional X-ray techniques and low-dose spiral CT was statistically significant (P<0.05). The difference in mean absorbed dose instead was not statistically significant.

CONCLUSIONS

Our protocol allows a more accurate orthodontic diagnosis without an increase of radiological risk for the patients in comparison to traditional X-ray techniques.

Establishing better biological models to understand occlusion. I: TM joint anatomic relationships

Belief in and rejection of a relationship of occlusion and temporomandibular joint (TMJ) condyle-fossa position with normal and abnormal function are still contentious issues. Clinical opinions can be strong, but support in most published data (mostly univariate) is problematic. Distribution overlap, low sensitivity and specificity are a common basis to reject any useful prediction value. Notwithstanding, a relationship of form with function is a basic tenet of biology. These are multifactor problems, but the questions mostly have not been analysed as such. This review moves the question forward by focusing on TM joint anatomic organisation as the multifactor system it is expected to be in a closed system like a synovial joint. Multifactor analysis allows the data to speak for itself and reduces bias. Classification tree analysis revealed useful prediction values and usable clinical models which are illustrated, backed up by stepwise logistic regression. Explained variance, R(2), predicting normals from pooled TMJ patients was 32·6%, sensitivity 67·9%, specificity 85·7%; 37% versus disc displacement with reduction; and 28·8% versus disc displacement without reduction. Significant osseous organisational differences between TM joints with clicking and locking suggest that this is not necessarily a single disease continuum. However, a subset of joints with clicking contained characteristics of joints with locking that might contribute to symptom progression versus resistance. Moderately strong models confirm there is a relationship between TMJ osseous organisation and function, but it should not be overstated. More than one model of normals and of TM derangement organisation is revealed. The implications to clinical decision-making are discussed.

Long-term skeletal and dental effects and treatment timing for functional appliances in Class II malocclusion

OBJECTIVE

To analyze the long-term skeletal and dentoalveolar effects and to evaluate treatment timing of Class II treatment with functional appliances followed by fixed appliances.

MATERIALS AND METHODS

A group of 40 patients (22 females and 18 males) with Class II malocclusion consecutively treated either with a Bionator or an Activator followed by fixed appliances was compared with a control group of 20 subjects (9 females and 11 males) with untreated Class II malocclusion. Lateral cephalograms were available at the start of treatment (mean age 10 years), end of treatment with functional appliances (mean age 12 years), and long-term observation (mean age 18.6 years). The treated sample also was divided into two groups according to skeletal maturity. The early-treatment group was composed of 20 subjects (12 females and 8 males) treated before puberty, while the late-treatment group included 20 subjects (10 females and 10 males) treated at puberty. Statistical comparisons were performed with analysis of variance followed by Tukey's post hoc tests.

RESULTS

Significant long-term mandibular changes (Co-Gn) in the treated group (3.6 mm over the controls) were associated with improvements in the skeletal sagittal intermaxillary relationship, overjet, and molar relationship (∼3.0-3.5 mm). Treatment during the pubertal peak was able to produce significantly greater increases in total mandibular length (4.3 mm) and mandibular ramus height (3.1 mm) associated with a significant advancement of the bony chin (3.9 mm) when compared with treatment before puberty.

CONCLUSION

Treatment of Class II malocclusion with functional appliances appears to be more effective at puberty.