Myofunctional therapy and prefabricated functional appliances: an overview of the history and evidence

Myobrace versus twin block in the treatment of class II malocclusion in Children: A systematic review

Background

One of today's largest global problems is malocclusion. We must prevent this through the screening and early treatment of young children, because malocclusion treatment conducted during a child's growth and development stage either the primary or mixed dentition era yields the best outcomes. Functional appliances are usually used during initial orthodontic treatment, such as myobrace and twin block appliances. Myobraces come in various sizes. The size chosen depends on the treatment objectives, which may include correcting class II malocclusions. The twin block appliance is a functional device commonly employed to treat class II malocclusions.

Purpose

This investigation's main goal was to compare the efficacy of the myobrace and twin block appliances in class II malocclusion treatment to select a more appropriate pediatric dentistry device.

Results

A total of 5 articles were selected from 306 articles based on relevant keywords. All selected studies were conducted within the last 10 years.

Discussion

Myobrace and twin block appliances can address overjet issues and achieve significant overjet measurement reductions. This appliance promotes mandibular growth and enhances the facial profiles of individuals with class II malocclusions.

Conclusion

In order to treat individuals with class II malocclusions, the myobrace and the twin block both address skeletal and dentoalveolar discrepancies. But compared to the myobrace, the twin block appliance had more noteworthy outcomes.

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.

3D Printer-Assisted Layered Fabrication of a Novel Appliance for Oral Myofunctional Therapy and Functional Evaluation of Its Effects on Orofacial Muscles During Wear

Aim Balanced function of the orofacial muscles is important for normal occlusion and dentition; however, patients with malocclusion often present with myofunctional disorder (MFD). Myofunctional therapy (MFT) has received much attention as a method for reducing MFD. Moreover, prefabricated functional appliances (PFAs) have been developed as a method to eliminate abnormal muscle pressure and guide the tongue into the correct position. However, PFAs have disadvantages, such as poor intraoral retention, limited usage time due to discomfort and poor patient compliance, and changes in the axis of the mandibular anterior teeth. Therefore, this study aimed to develop a new custom-made splint-type orthodontic appliance with CAD/CAM technology. Moreover, we evaluated the characteristics of the appliance and conducted functional tests to determine the effects of the appliance on the orofacial muscles and the discomfort associated with its use. Materials and methods Twenty-five volunteers (nine females and 16 males; mean age 28.4 ± 3.4 years) with normal swallowing function were included in the study. Lip-closing strength (LCS), electromyogram during swallowing, oxygen saturation, and pulse rate were measured and compared when the appliance was not worn and when it was worn. In addition, tongue habits were evaluated, and the maximum tongue pressure was measured when the appliance was not worn. The subjects were asked to answer a questionnaire using a numerical rating scale (NRS) regarding discomfort when wearing the appliance. The evaluation items were swallowing difficulty, speaking difficulty, and breathlessness, which were rated on an 11-point scale ranging from 0 to 10. Statistical tests were conducted using IBM SPSS version 28.0.1 (IBM, Armonk, NY, USA) with the Shapiro-Wilk and Levene's test, followed by the Wilcoxon signed rank sum test. The significance level was set at α = 0.05. The measurement error for each measurement item was evaluated using an intraclass correlation coefficient. Results A new custom-made splint-type orthodontic appliance was fabricated for each subject. The fit and retention of the appliance in the mouth were good when fitted, and a comparison of the functional test measurements of 25 subjects with and without the appliance showed that the LCS decreased significantly (p<0.05) before and after wearing the appliance. However, no statistically significant differences were found for the other items. The Mann-Whitney U test regarding the effects of sex, previous orthodontic treatment, or MFT, and oral habits did not statistically significantly influence the effects of wearing the device. In the NRS results, "difficulty swallowing" was observed in half of the subjects, "difficulty breathing" was rarely observed, and "difficulty speaking" was observed in all subjects. Conclusions A novel custom-made splint-type orthodontic appliance was designed and fabricated using digital workflow and 3D printing technology. This appliance was designed to correct oral habits and was made from a new material classified as a class II medical appliance according to the international harmonized classification.

Preformed Elastodontic Appliances: Awareness and Attitude of Orthodontists and General Dental Practitioners

BACKGROUND

Preformed elastodontic appliances (EAs) have been described as safe, cost-effective, and easy-to-use devices for interceptive orthodontic treatment in growing patients. This study aimed to assess the knowledge and the attitude of dentists toward the use of EAs and to compare the behaviors of orthodontists (Os) with those of general dental practitioners (GDPs).

METHODS

An anonymous survey was distributed among dentists through social media. Twenty-two items were divided as follows: characteristics of respondents; general knowledge about EAs; section for EA-users; and section for EA non-users. Chi-squared tests were used to analyze differences in responses between groups.

RESULTS

Participants included 226 Os and 168 GDPs. The majority in both groups reported having adequate knowledge about EAs and utilizing them in their practice. GDPs usually use EAs to treat children during the early phase of growth, while Os also use EAs to address orthodontic problems in different stages of dentition, experiencing a chair time reduction compared with traditional appliances. Regarding EA non-users, GDPs seem not to find an application among their patients, whereas Os reported not having enough patient compliance during treatment.

CONCLUSIONS

Although treatment with EAs is common among all dentists, differences exist between Os and GDPs in the awareness and application, as well as in the reasons provided for not using EAs.

Effect of the Correction of Bilateral Differences in Masseter Muscle Functional Pressure on the Mandible of Growing Rats

The objective of this study is to clarify the effect of restoring the lowered masticatory muscle functional pressure and correcting bilateral differences in masticatory muscle functional pressure on jawbone growth during growth and development with a quantitative evaluation of the changes in the micro/nanostructural characteristics of entheses. Male Wistar rats aged 4 weeks were divided into an experimental group injected with a botulinum toxin serotype A (BoNT/A) formulation to reduce muscle function (BTX group) and a control group (CTRL group). They were euthanised after 6, 8, 10, 12, and 16 weeks after measuring the difference between the midline of the upper and lower incisors. The mandibles were harvested for histological examination, second harmonic generation imaging, and the quantitative evaluation of biological apatite (BAp) crystal alignment. The midline difference decreased with age in weeks. In rats from 6 weeks after BoNT/A administration to 12 weeks after administration, the collagen fibre bundle diameter was significantly smaller in the BTX group; the difference between the two groups decreased with increasing age. BAp crystal alignment was significantly different on the x-axis and the y-axis on the BTX group from 6 weeks after BoNT/A administration to 10 weeks after administration. Asymmetry of mandibular bone formation caused by load imbalance during growth could be corrected by the adjustment of the function of the masseter muscle on either side.

The Effects of Orofacial Myofunctional Therapy on Children with OSAHS’s Craniomaxillofacial Growth: A Systematic Review

Orofacial myofunctional therapy (OMT) is one of the therapeutic methods for neuromuscular re-education and has been considered as one of the auxiliary methods for obstructive sleep apnea hypopnea syndrome (OSAHS) and orthodontic treatment. There is a dearth of comprehensive analysis of OMT’s effects on muscle morphology and function. This systematic review examines the literature on the craniomaxillofacial effects of OMT in children with OSAHS. This systematic analysis was carried out using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) standards, and the research was scanned using PICO principles. A total of 1776 articles were retrieved within a limited time, with 146 papers accepted for full-text perusing following preliminary inspection and 9 of those ultimately included in the qualitative analysis. Three studies were rated as having a severe bias risk, and five studies were rated as having a moderate bias risk. Improvement in craniofacial function or morphology was observed in most of the 693 children. OMT can improve the function or morphology of the craniofacial surface of children with OSAHS, and its effect becomes more significant as the duration of the intervention increases and compliance improves. In the majority of the 693 infants, improvements in craniofacial function or morphology were seen. The function or morphology of a kid’s craniofacial surface can be improved with OMT, and as the duration of the intervention lengthens and compliance rises, the impact becomes more pronounced.

Clinical effectiveness of the Eruption Guidance Appliances in treating malocclusion in the mixed dentition: A systematic review and meta-analysis

AIM

To evaluate the clinical effectiveness of the eruption guidance appliances (EGAs) in treating malocclusion in the early mixed dentition.

DESIGN

Electronic databases were comprehensively searched for the eligibility literature of the EGA treatment for a period spanning from the earliest available date in each database up to July 2021. Randomized controlled trials, controlled clinical trials, and prospective and retrospective cohort studies were included in the present review. The quality of clinical trials was assessed according to the Cochrane Collaboration's tools (RoB2.0 and ROBINS-I), whereas cohort studies were based on the Newcastle-Ottawa Scale (NOS). The data were gathered and synthesized with the Stata software (version 12).

RESULTS

The screen yielded 436 articles, of which 17 papers were potentially eligible, and 7 articles from 3 studies (1 RCT, 1 CCT, and 1 PCS) were qualified for the final review and analysis. The meta-analysis showed both favorable dentoalveolar and skeletal changes in short term. Both overjet and overbite had a significant decrease after treatment (MD = -2.38 mm, 95% CI: -2.82 to -1.94, p < .001, and MD = -2.43 mm, 95% CI: -3.52 to -1.35, p < .001, respectively), and SNB increased significantly by 0.73 degrees (95% CI: 0.17-1.28, p = .01). After the retention period, however, overbite had a significant increase of 0.88mm, which indicated the occurrence of a relapse (95% CI: 0.60-1.16, p < .001).

CONCLUSIONS

According to the existing evidence, the EGA treatment is effectively correcting overjet and overbite in the early mixed dentition in short term; furthermore, high-quality and long-term studies are warranted to determine its long-term effectiveness.

A non-randomized concurrent controlled trial of myofunctional treatment in the mixed dentition children with functional mouth breathing assessed by cephalometric radiographs and study models

Objectives

This study aimed to examine the clinical effects of myofunctional treatment on children with functional mouth breathing by cephalometric radiographs and study models.

Methods

A total of 224 children (6–10 years old; 114 males and 110 females; SNA°: 82.24 ± 1.67°; ANB°: 2.79 ± 0.80°, 28° < SN-GoGn° < 37°) formed three groups: MB-M group (mouth breathers with myofunctional treatment,n = 75); MB-N group (mouth breathers with no treatment,n = 70); NB group (nasal breathers with no treatment, n = 79). A blind evaluation of cephalometric radiographs and study models was conducted at T1(pre-study) and T2 (post-study), respectively.

Results

Two hundred four children (MB-M:66, MB-N:68, NB:70) completed the present study. At T1, MB-M and MB-N groups, compared to their NB counterpart, had greater anterior lower facial height(P < 0.01) and overjet(P < 0.001) but shorter overbite and maxillary canines width (P < 0.001). At T2, the MB-N group exhibited a higher ANB angle, anterior lower facial height, and overjet, but shorter overbite and maxillary canines width (P < 0.001). From T1 to T2, the anterior lower facial height increased, overbite and the maxillary canines width further decreased in the MB-N group (P < 0.001). However, in the MB-M group, the incisors were retracted, overbite increased (P < 0.001), anterior lower facial height increased insignificantly (P > 0.05), and maxillary canines width increased slightly (P < 0.05). In the NB and MB-M groups, the mandible showed a normal tendency to grow forward, whereas, in the MB-N group, the mandible showed a tendency to grow downward (P < 0.001).

Conclusions

Mouth breathers demonstrated increased anterior facial height and overjet but reduced overbite and maxillary arch width, which improved significantly following myofunctional treatment.

Trial registration

TCTR: TCTR20220401001. Registered 1^stApril 2022-Retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03559-w.

Elastodontic Devices in Orthodontics: An In-Vitro Study on Mechanical Deformation under Loading

The purpose of the present study was to evaluate the mechanical resistance of elastodontic devices (ED): their maximum compression loads and plastic deformation under loading (percentage). An Instron universal machine (Model 3365, Instron, Industrial Product Group, Grove City, PA, USA) was employed with a 100 N load cell and with Bluehill software for loading analyses. Each device was submitted to a five-cycles test. The following ED were evaluated: A.M.C.O.P. (Micerium, Genova, Italy) in red color, in orange color, and in blue color; HealthyStart (Ortho-Tain, Winnetka, IL, USA), and T4K™ phase 1 (Myofunctional Research Co., Helensvale, Australia). During the five-cycles test, the Ortho-Tain device delivered the greatest compression load (7.56 N), with the lowest percentage of deformation (0.95%). For all devices, a slight plastic deformation of the material was registered, ranging from 0.95% to 1.75%. For the T4K device it was not possible to complete the five-cycles test. For all the analyzed ED, a slight plastic deformation under loading was registered, that in all cases can be considered clinically acceptable. Further studies are needed to test the appliances after clinical usage.

Clinical Use of Aligners Associated with Nuvola® OP System for Transverse Maxillary Deficiency: A Retrospective Study on 100 Patients

Introduction: Aligners represent a common treatment for orthodontic patients thanks to their countless advantages including aesthetics, comfort, and oral hygiene maintenance; at the same time, they are associated with a reduced number of visits and a low incidence of complications. Although aligners have undergone considerable improvements over time, to date they have limitations in resolving the most serious malocclusions related to transverse maxillary deficiency. The aim of the present study was to retrospectively evaluate an orthodontic protocol (the Nuvola® OP System) which associates a morpho-functional corrector (to be used for 30 min/day) with the aligner, allowing for the treatment of cases that would be difficult or unpredictable with aligners alone. Methods: Linear measurements were taken on STL files of 100 patients. In 77 patients between 18 and 55 years (mean 28.6 ± 16.2 (standard deviation) years), 3D superimpositions of the maxilla obtained from intraoral scans before and after treatment were performed in order to evaluate the degree of maxillary expansion. The normality of the data distribution was tested. The pre- and post-treatment data were compared using a paired t-test with a 5% significance level. After treatment, a questionnaire was proposed to assess patients’ degree of satisfaction and compliance. Results: A statistically significant difference (p < 0.05) for each distance evaluated was found. The maximum expansion was obtained at the first molar level (2.35 ± 1.64 mm). Of the subjects who completed the questionnaire, 96% were satisfied and 90% were able to perform the protocol without difficulty for the required duration. Conclusions: A significant expansion of the maxillary arch as well as a high degree of patient satisfaction and compliance were observed with the Nuvola® OP System. Further studies are needed in order to clinically evaluate the relative contribution of the aligners and morpho-functional device to the obtained expansion.

Improving Adherence to Myofunctional Therapy in the Treatment of Sleep-Disordered Breathing

Myofunctional therapy (MT) is used to treat sleep-disordered breathing. However, MT has low adherence-only ~10% in most studies. We describe our experiences with MT delivered through a mobile health app named Airway Gym®, which is used by patients who have rejected continuous positive airway pressure and other therapies. We compared ear, nose, and throat examination findings, Friedman stage, tongue-tie presence, tongue strength measured using the Iowa oral performance instrument (IOPI), and full polysomnography before and after the 3 months of therapy. Participants were taught how to perform the exercises using the app at the start. Telemedicine allowed physicians to record adherence to and accuracy of the exercise performance. Fifty-four patients were enrolled; 35 (64.8%) were adherent and performed exercises for 15 min/day on five days/week. We found significant changes (p < 0.05) in the apnoea-hypopnoea index (AHI; 32.97 ± 1.8 to 21.9 ± 14.5 events/h); IOPI score (44.4 ± 11.08 to 49.66 ± 10.2); and minimum O2 saturation (80.91% ± 6.1% to 85.09% ± 5.3%). IOPI scores correlated significantly with AHI after the therapy (Pearson r = 0.4; p = 0.01). The 19 patients who did not adhere to the protocol showed no changes. MT based on telemedicine had good adherence, and its effect on AHI correlated with IOPI and improvement in tongue-tie.

Toxicological Profile of Biological Environment of Two Elastodontic Devices

Malocclusion and teething problems are common health problems globally, affecting people of all ages, especially children and adolescents. In addition to the pathophysiological complications associated with orthodontic problems, they also affect the well-being of the individual. Orthodontic appliances are frequently used, even from an early age, and their activity in different biological environments is very varied and incompletely described. Due to these considerations, the purpose of the study was to evaluate the toxicological profile of the biological environment (saliva at three pH values: 3, 7, and 10) of two elastodontic orthodontic appliances: Myobrace (MB) and LM TrainerTM 2 (LMD). In vitro techniques applied were conducted on human keratinocytes to evaluate cell viability (Alamar blue assay) and gene expression real-time reverse transcription–polymerase chain reaction (RT-PCR technique). In addition, it was assessed the irritating effect on the vascular plexus using as a biological model the chorioallantoic membrane of the hen’s egg by applying the hen’s egg-chorioallantoic membrane (HET-CAM) method. The obtained results showed a decrease in cell viability up to 82% in the case of LMD at pH = 3, a slight increase in mRNA expression for the anti-apoptotic marker (Bcl-2 and Bcl-xL), and a decrease in mRNA expression for the pro-apoptotic marker (Bad), and any type of toxic change at the capillary level (irritation score being below 0.9). Based on the data obtained, it can be stated that MB and LMD biological environments, at different pH values, present a safe toxicological profile.

Unilateral Scissor Bite Managed with Prefabricated Functional Appliances in Primary Dentition—A New Interceptive Orthodontic Protocol

A unilateral scissor bite is a type of severe malocclusion in primary dentition that can influence the development of the mandible and face. The present case report describes an interceptive treatment on a 4-year-old girl with a unilateral scissor bite combined with an anterior crossbite, increased reverse overjet, and overbite on a skeletal Class III base. The patient was treated with a new Prefabricated Functional Appliance (PFA) which was modified from a Frankel-III appliance to induce a mandible to move backwards and relieve an occlusion discrepancy of the dental arch, and a functional dental rehabilitation with resin and myofunctional exercises with a PFA which was modified from an oral screen appliance were performed during the treatment. The total treatment time was 11 months and a satisfactory improvement of occlusion and facial esthetics was achieved. This case report presents a new PFA system and treatment protocol in primary dentition which results in a favorable outcome, and the clinical effectiveness of this appliance system warrants further investigation.

Effects of miniplate anchored Herbst appliance on skeletal, dental and masticatory structures of the craniomandibular apparatus: A finite element study

OBJECTIVE

To analyze the stress distribution in the hard and soft tissue structures of craniomandibular complex during mandibular advancement with miniplate anchored rigid fixed functional appliance (FFA) using Finite Element Analysis (FEA).

MATERIAL AND METHODS

The virtual model consisting of all the maxillofacial bones (up to calvaria), the mandible and temporomandibular joint (TMJ) was generated using the volumetric data from pre-treatment CBCT-scan of a growing patient. The masticatory muscles, other soft tissues, Herbst appliance and plate geometry were modelled mathematically. Force vectors simulating muscle contraction at rest and advanced mandibular positions, with protraction force of 8N were applied. The final model was imported into ANSYS for analysis after assigning material properties.

RESULTS

The maximum von Mises stress of 11.69MPa and 11.96MPa magnitude was observed in the region of pterygoid plates and at the bone-miniplate interface respectively, with the mandibular advancement of 7mm. Stress patterns were also noted at the condylar neck. The stress values observed in the medial and lateral pterygoid muscles were of 10.42MPa and 4.16MPa magnitude, respectively. Stress was noted in the bucco-cervical region of the upper posterior teeth, but negligible change was seen on the lower anterior teeth and periodontal ligament.

CONCLUSION

Miniplate Anchored Herbst Appliance brought about Class II skeletal correction in growing children as it was accompanied by minimal changes in the inclination of the lower incisors. Soft tissue structures like pterygoid muscles and discal ligaments exhibited increased stress whereas masseter muscle displayed reduction in stresses.

Orofacial Myofunctional Therapy and Myofunctional Devices Used in Speech Pathology Treatment: A Systematic Quantitative Review of the Literature

Purpose A growing number of speech-language pathologists (SLPs) are using orofacial myofunctional therapy (OMT) and/or myofunctional devices (MDs) in the treatment of their clients. However, governing bodies suggest SLPs carefully consider the availability and quality of evidence in the utilization of these therapies in speech-language pathology treatment. The purpose of this study was to review the existing evidence for OMT and MDs used by SLPs. Method A systematic quantitative review was conducted using key search terms in three electronic platforms housing multiple databases, along with a hand search, to identify additional literature. All studies published in English in full text were included if they reported pre- and posttreatment data of OMT and/or MDs provided by an SLP. Data were extracted and analyzed by the first author and confirmed by the co-authors. Results Twenty-eight studies met the criteria for inclusion in the review. Two thirds were published in the last decade and involved the use of OMT/MDs targeting multiple areas of speech pathology intervention within the same study, that is, swallowing, breathing, oral hygiene, and speech production. Majority of studies were rated as low level of evidence. All studies used OMT, with very few using MDs. While the assessment, treatment protocols, and outcome measures were highly variable, all of the studies reported an improvement in the function of the orofacial systems posttreatment. Few studies reported long-term follow-up data. Almost half of the studies recommended the use of OMT/MDs in a multidisciplinary/interdisciplinary team or in conjunction with other therapy. Conclusions There has been an increase in literature over the last decade in SLPs' use of OMT; however, there are only a small number of studies to date that explore the use of MDs. There is a growing body of evidence to support the use of OMT and MDs within a multidisciplinary team for people with communication and swallow difficulties. However, development of future research should consider investigating assessment and outcome measures, optimal dosage, and service delivery.

Breathing Re-Education and Phenotypes of Sleep Apnea: A Review

Four phenotypes of obstructive sleep apnea hypopnea syndrome (OSAHS) have been identified. Only one of these is anatomical. As such, anatomically based treatments for OSAHS may not fully resolve the condition. Equally, compliance and uptake of gold-standard treatments is inadequate. This has led to interest in novel therapies that provide the basis for personalized treatment protocols. This review examines each of the four phenotypes of OSAHS and explores how these could be targeted using breathing re-education from three dimensions of functional breathing: biochemical, biomechanical and resonant frequency. Breathing re-education and myofunctional therapy may be helpful for patients across all four phenotypes of OSAHS. More research is urgently needed to investigate the therapeutic benefits of restoring nasal breathing and functional breathing patterns across all three dimensions in order to provide a treatment approach that is tailored to the individual patient.

[The contribution of orofacial myofunctional reeducation to the treatment of obstructive sleep apnoea syndrome (OSA): a systematic review of the literature]

Obstructive sleep apnoea syndrome (OSA) is a widespread and under-diagnosed condition, making it a major public health and safety problem. Orofacial myofunctional reeducation (OMR) has been shown to be effective in the multidisciplinary treatment of OSA in children, adolescents and adults and is prescribed at several stages of OSA management. The main objective of this systematic literature review was to evaluate the effectiveness of active or passive orofacial myofunctional reeducation (OMR) in the treatment of obstructive sleep apnoea syndrome in children, adolescents and adults. The systematic literature review was undertaken from the three electronic databases: Medline (via PubMed), Cochrane Library, Web of Science Core Collection, and supplemented by a limited grey literature search (Google Scholar) in order to identify the studies evaluating the effectiveness of the OMR on OSA. The primary outcome of interest was a decrease in the Apnea-Hypopnea Index (AHI) of at least five episodes per hour compared to the baseline state. Secondary outcomes were an improvement in subjective sleep quality, sleep quality measured by night polysomnography and subjectively measured quality of life. Only ten studies met all the inclusion criteria. Eight were randomized controlled clinical trials, one was a prospective cohort study and another was a retrospective cohort study. Six studies were devoted to adult OSA and four to pediatric OSA. All included studies were assessed as "low risk of bias" based on the 12 bias risk criteria of the Cochrane Back Review Group. Based on the available evidence, RMO allows a significant reduction in AHI, up to 90.6% in children and up to 92.06% in adults. It significantly reduces the intensity and frequency of snoring, helps reduce daytime sleepiness, limits the recurrence of OSA symptoms after adenoamygdalectomy in children and improves adherence to PPC therapy. Passive RMO, with the assistance provided to the patient by wearing a custom orthosis, increases adherence to reeducation, significantly improves snoring intensity, AHI and significantly increases the upper airway. Published data show that orofacial myofunctional rééducation is effective in the multidisciplinary treatment of OSA in children, adolescents and adults and should be widely prescribed at several stages of OSA management. Passive RMO, with the pearl mandibular advancement orthosis designed by Michèle Hervy-Auboiron, helps to compensate for the frequent non-compliance observed during active RMO treatments.

What evidence exists for myofunctional therapy with prefabricated appliances? A systematic review with meta-analyses of randomised trials

OBJECTIVE

To assess the treatment efficacy/efficiency with prefabricated myofunctional appliances (PMA) for children with malocclusion.

DATA SOURCES

Nine databases searched without limitations till July 2019.

DATA SELECTION

Randomised trials comparing PMAs to functional appliance treatment or no treatment.

DATA EXTRACTION

Study selection, data extraction and risk of bias assessment were done in duplicate.

DATA SYNTHESIS

Random-effects meta-analyses of mean differences (MDs) or relative risks (RRs) with their 95% confidence intervals (CIs) were conducted on seven publications (three published and one unpublished trials; 232 patients; 53% male; mean age 10.2 years). Compared to no treatment, one trial indicated that PMAs were somewhat effective in reducing overjet (MD -2.4; 95% CI -3.3 to -1.5), reducing overbite (MD -2.5; 95% CI -3.2 to -1.8), reducing mandibular crowding (RR 0.4; 95% CI 0.2-0.8) and establishing Class I canine relationship (RR = 2.3; 95% CI 1.1-4.9). However, compared to custom-made functional appliances, three trials indicated that PMAs were less effective in reducing the ANB angle (MD 0.9; 95% CI 0.5-1.4), increasing mandibular ramus length (MD -2.2; 95% CI -2.9 to -1.51), reducing overjet (MD 1.5; 95% CI 0.9-2.1), establishing a solid Class I molar relationship (RR 0.3; 95% CI 0.2-0.7), reducing the nasolabial angle (MD 5.8; 95% CI 0.8-10.8) and reducing facial convexity (MD -2.6; 95% CI -4.3 to -0.9). Finally, the quality of evidence was moderate to low due to risk of bias.

CONCLUSIONS

PMAs are more effective in reducing overjet, overbite, mandibular crowding and establishing Class I canine relationship than no treatment. However, compared to custom-made functional appliances, PMAs are less effective in producing dental, skeletal or soft-tissue changes, even though they are less costly.