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


The aim of this study was to analyze the current literature for the best evidence (randomized clinical trials) about the efficacy of functional appliances on mandibular growth in the short term.
A survey of articles published up to September 2009 was performed by using the following electronic databases: PubMed, Embase, Ovid Medline, Cochrane Central Register of Controlled Trials, Web of Science, LILACS, and Google Scholar. The reference lists of the retrieved articles were hand-searched for possible missing articles. No language restriction was applied during the identification of the published studies. A methodologic scoring process was developed to identify which randomized clinical trials were stronger methodologically. The selection process and the quality assessment were undertaken independently and in duplicate by 2 authors. A meta-analysis was attempted by using random-effects models. Clinical and statistical heterogeneity was examined, and a sensitivity analysis was performed.
Electronic searches identified the following items: 146 articles were retrieved from PubMed, 45 from Cochrane Central Register of Controlled Trials, 29 from Ovid, 42 from LILACS, 628 from Web of Science, and 1000 from Google Scholar. Thirty-two articles fulfilled the specific inclusion criteria and were identified as potentially appropriate randomized clinical trials to be included in this meta-analysis. Only 4 articles, based on data from 338 patients (168 treated vs 170 controls) with Class II malocclusion in the mixed dentition, were selected for the final analysis. The quality analysis of these studies showed that the statistical methods were at the medium-high level. The outcome measurements chosen to evaluate the efficacy of the various functional appliances were Co-Pg, Pg/Olp + Co/Olp, and Co-Gn and the values were annualized and standardized to a uniform scale with the standardized mean differences (SMD). The results of the meta-analysis from the random-effects model showed a statistically significant difference of 1.79 mm in annual mandibular growth of the treatment group compared with the control group (SMD = 0.61, 95% CI, 0.30 to -0.93; chi-square test, 5.34; 3 df; P = 0.15; I(2) = 43.9%; test for overall effect, Z = 3.83 and P = 0.0001). The sensitivity analysis showed a substantially similar outcome of 1.91 mm (SMD = 0.65, 95% CI, 0.25 to 1.25; chi-square test, 4.96; 2 df; P = 0.08; I(2) = 59.7%; test for overall effect, Z = 3.19 and P = 0.001).
The analysis of the effect of treatment with functional appliances vs an untreated control group showed that skeletal changes were statistically significant, but unlikely to be clinically significant.

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    • "Even though with diverse designs, such functional appliances are essentially based on the same principle on which the forward protruding position of the mandible would enhance condylar and mandibular bone growth, and, as a consequence, enable Class II malocclusion correction. However, according to several systematic reviews, there is still limited evidence to support a clinically significant change in mandibular length induced by functional appliances [20] [21] [22]; or to prove its predictability [23] and stability over time [24]. Therefore, many experimental studies on animal models have been carried out in order to investigate alternative methods of stimulating mandibular growth, such as pulsed electromagnetic field [25] [26], low-intensity pulsed ultrasound (LIPUS) [27] [28] [29] [30] [31] [32] [33], light emitting diode (LED) [34], low-level laser (LLL) [34], growth hormone [32], and gene therapy [33] [35] [36]. "
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    ABSTRACT: 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. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Full-text · Article · Jan 2015 · Medical Hypotheses
    • ", and Herbst [8]. All of these functional appliances have shown mandibular incisor proclination. "
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    ABSTRACT: Background This study evaluated the treatment effects of the Carrière Distalizer used with either full fixed appliances (FA group) or lower lingual arches (LLA group). Methods Cephalometric radiographs from 41 orthodontic patients with Class II Division 1 malocclusion before and after use of the Carrière Distalizer were investigated. Eligible individuals possessed a normal maxilla, retrognathic mandible, normal growth pattern, permanent dentition, minimal crowding with well-aligned dental arches, and at least an end-on Class II molar relationship bilaterally. Two matched groups were formed according to sagittal and vertical skeletal characteristics. Full fixed appliances and a lower lingual arch supported Class II elastic use in the FA (n = 19) and LLA (n = 22) groups, respectively. The Wilcoxon signed rank test was used to compare the treatment changes between the two groups. The differences between the study groups were compared using the Mann-Whitney U test. Results The maxillary molar was distalized between 1.6 and 2.5 mm, with the mean amount of molar tipping not exceeding 3.7° in the study sample. No significant differences were observed between the study groups with regard to molar distalization and tipping. Significant reductions in both the Wits and over-jet measurements were observed in both groups (all, P < 0.05 vs. baseline). Significant differences in over bite and mesial movement of both the mandibular molar and the incisors were observed between the two study groups (all, P < 0.05). Conclusions Successful correction of Class II malocclusion was achieved with the Carrière Distalizer appliance in both groups, with minimal molar tipping. However, adverse effects common with Class II elastics accompanied the correction at variable rates in the groups.
    No preview · Article · Jun 2014 · Journal of the World Federation of Orthodontists
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    • "ase angulation is more prevalent in Class II malocclusion [ Kerr and Hirst , 1987 ; Baccetti et al . , 1997 ] . The clinical relevance of this finding is emphasised when we consider that therapeutic modalities such as functional jaw orthopaedic procedures have the greatest effectiveness if the type of mandibular retrusion is identified correctly [ Marsico et al . , 2011 ; Tecco et al . , 2005 ] ."
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    ABSTRACT: The purpose of this study was to analyse the craniofacial and dentofacial skeletal characteristics in untreated subjects with Class II, division 1 malocclusion by mandibular retrusion and to identify different types and their prevalence. In 152 subjects with Class II, division 1 malocclusion by mandibular retrusion, the differences were determined by lateral cephalograms analysis of variance and chi-square test, respectively. P<0.05 was considered significant. Seven types of mandibular retrusion were identified: three pure, dimensional, rotational and positional, and four mixed. All patients showed significant inter-group differences with P between 0.005 and 0.001. The dimensional type was the most common (28.9%) and the rotational-positional type was the rarest (5.9%). The pure dimensional type had the shortest mandibular body; the pure rotational type had larger SN/GoMe and the lowest AOBO; the pure positional type presented the flattest cranial base, high AOBO. In the mixed types, dento-skeletal features changed depending on how the main types assorted. Identifying the type of mandibular retrusion is important for differential diagnosis in clinical practice and research.
    Full-text · Article · Sep 2012 · European Journal of Paediatric Dentistry
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