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

Abstract

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risks (RRs) with their 95% confidence intervals (CIs) were conducted on seven publications (three published and one unpublished trials; 232 patients; 53% male; mean age 10.2 years).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.

A narrative review on the use of lip trainer (Patakara) in oral rehabilitation

“…In the early 1900s, in the field of orthodontic therapy, with the help of orofacial muscular training, Rogers introduced oro-myofunctional appliances (OMFA) to Introduction the patients with growing maldentition to correct the unusual pattern of deglutition, treating the myofunctional and/or myoskeletal problems [10], focusing on the normal swallowing and nasal breathing, improving the balance of oro-facial musculature, and to promote mandibular development [11].…”

Orthopedic Treatment for Class II Malocclusion with Functional Appliances and Its Effect on Upper Airways: A Systematic Review with Meta-Analysis

“…Removable functional appliances (Activator, Fränkel-2, Twin Block, or Sander appliance) were used in 16 studies, while fixed functional appliances (Herbst, Forsus Fatigue Resistant Device, Mandibular Protraction Appliance-IV, Mandibular Anterior Repositioning Appliance, or X-Bow appliance) were used in 8 studies (with 4 studies using both removable and fixed appliances). One study [32] also included a prefabricated myofunctional appliance (Trainer 4 Kids), but this was omitted from the review, due to the different modus operandi [49]. One study [44] incorporated headgear to the Activator for anchorage reinforcement, while another study [31] also included a second phase treatment with braces after a first phase with Twin Block.…”

Micro/nanostructural Characteristic Changes in the Mandibles of Rats after Injection of Botulinum Neurotoxin

“…Frongia et al investigated masticatory muscle function in 17 patients with jaw deformities, and reported that masticatory muscle function was bilaterally unbalanced 7) . Myofunctional therapy has been shown to eliminate the functional pressure of the masticatory muscles from the mechanical environment in the maxillofacial region, promoting the healthy development not only of the dentition but also of the maxilla and mandible, and is now widely used [8][9][10] . Inoue et al found that osteocytes were activated in mice given a high masticatory load, generating new bone at entheses of the masticatory muscles, and therefore these muscles undoubtedly have a major effect on the bone dynamics of the mandible 11) .…”