Protraction Facemask Research Articles

Dentofacial and skeletal effects of two orthodontic maxillary protraction protocols: bone anchors versus facemask

BackgroundMaxillary retrognathia and/or mandibular prognathia are resulting in class III malocclusion. Regarding orthodontic class III malocclusion treatment, the literature reports several treatment approaches. This comparative clinical study investigated two maxillary protraction protocols including bone anchors and Delaire type facemask.MethodsCephalometric radiographs of n = 31 patients were used for data acquisition. The patients were divided into two groups according to their treatment protocol: bone anchored protraction (n = 12, 8 female, 4 male; mean age 11.00 ± 1.76 years; average application: 13.50 ± 5.87 months) and facemask protraction (n = 19, 11 female, 8 male; mean age 6.74 ± 1.15 years; average application: 9.95 ± 4.17 months). The evaluation included established procedures for measurements of the maxilla, mandibula, incisor inclination and soft tissue. Statistics included Shapiro-Wilk- and T-Tests for the radiographs. The level of significance was set at p < 0.05.ResultsThe cephalometric analysis showed differences among the two groups. SNA angle showed significant improvements during protraction with bone anchors (2.30 ± 1.18°) with increase in the Wits appraisal of 2.01 ± 2.65 mm. SNA angle improved also during protraction with facemask (1.22 ± 2.28°) with increase in the Wits appraisal of 1.85 ± 4.09 mm. Proclination of maxillary incisors was larger in patients with facemask (3.35 ± 6.18°) and ML-SN angle increased more (1.05 ± 1.51°) than in patients with bone anchors. Loosening rate of bone anchors was 14.58%.ConclusionsBoth treatment protocols led to correction of a class III malocclusion. However, this study was obtained immediately after protraction treatment and longitudinal observations after growth spurt will be needed to verify the treatment effects over a longer period. The use of skeletal anchorage for maxillary protraction reduces unwanted side effects and increases skeletal effects needed for class III correction.

Profile Changes in Class III Malocclusion using Protraction Facemask in Indonesian Young Patients (Cephalometric Study)

Background: The prevalence of Class III malocclusion is highest in Southeast Asia. In countries such as Malaysia and Indonesia, the prevalence is as high as 15.80%. Treatment timing and options are very important in treating Class III malocclusion. A protraction facemask or also known as reverse headgear is one of the most used appliances as an interceptive tool for Class III malocclusion in young patients. Objectives: This study aims to evaluate the profile changes in treating Indonesian young patients using a protraction facemask. Methods: The sample consisted of 63 subjects, 25 males and 38 females. Lateral cephalograms were traced and analyzed using CephaloMetrics AtoZ™ ver. 12 (Yasunaga Computer Systems, Co. Inc., Hanando-Minami, Fukui, Japan). A total of 16 traditional cephalometric measurements (13 skeletal measurements and 3 dental measurements) were used to describe changes between pretreatment and posttreatment cephalograms. All recorded data were analyzed using IBM SPSS version 21 (IBM Corporation, Armonk, New York, USA). Results: SNA (p˂0.030), ANB (p=0.000), and Wits appraisal values (p=0.000) showed significant differences out of all measurements. FMA and occlusal plane also showed changes and indicated that a facemask is helpful with treatment. Conclusion: Timing, duration, and patient compliance are very important in the management of Class III skeletal malocclusion using a protraction facemask. The use of facemask therapy among Indonesian pediatric patients resulted in an anterior and downward movement of the maxilla, backward rotation of the mandible, and a better orthopedic response.

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

Objectives The aim of this observational cross-sectional one-centre study was to assess whether the previously described national orthodontic treatment practises and international recommendations are implemented in a public health care centre in Finland. We also assessed early treatment practices and appliances used. Methods The study group comprised 801 children born in 2011 and 2012 residing in the Riihimäki health centre catchment area in Finland, representing 80% of the age cohort. The patient records were examined for data on orthodontic treatment, timing of treatment, appliances used, and occlusal traits. Results The children had been examined by four orthodontist specialists and two orthodontic postgraduate students. Mean age at occlusal examination had been 9 years. Of the children, 212 (26%) were undergoing or had undergone orthodontic treatment. An additional 4.4% were scheduled for treatment. The proportion of children deemed to need treatment was significantly different between the different orthodontists. The most frequently used appliances were quad-helix (30%), eruption guidance appliance (20%), head gear (14%), fixed appliances (10%), protraction facemask (10%), and passive mandibular lingual arch (6%). Conclusions Nearly one-third of children aged less than 12 years in the health centre were currently or had been in orthodontic treatment. Approximately half had received treatment with either quad-helix or eruption guidance appliance.

Long-term skeletal and dentoalveolar effects of hybrid rapid maxillary expansion and facemask treatment in growing skeletal Class III patients: a retrospective follow-up study

BackgroundRegardless of the treatment protocol, stability in Class III patients always represents a major concern. The aim of this study was to assess the short and long-term skeletal and dentoalveolar modifications in a group of class III patients treated with hybrid rapid maxillary expander (RME) and facemask (FM). Indeed, no long-term studies have been conducted yet with the objective of evaluating the effects of this kind of approach when applied to patients who have already gone thought their peak of growth.Material and methods27 patients with skeletal Class III malocclusion were treated using hybrid RME according to alternating rapid maxillary expansion and constriction (ALT-RAMEC) protocol, followed by 4 months of facemask therapy. After the orthopaedic phase, each patient underwent orthodontic treatment with fixed multibracket appliances. A mean follow-up of 7 years, 10 months was performed. Pre-treatment (TO), post-treatment (T1) and follow up (T2) cephalometric tracing were analysed, comparing dental and skeletal measurements.ResultsPoint A advanced by a mean of 3.5 mm with respect to VerT, then relapsed by 0.7 in the post-facemask period, thereby yielding of a mean advancement of 2.7 at T2. The sagittal relationship significantly changed after RME + facemask protraction (3.8° of ANB and 5.189 mm of Wits). Although both Wits and ANB values worsened over time, the improvement from T0 is still appreciable at T2.ConclusionDespite the physiological relapse due to mandibular growth, the long-term cephalometric follow-up confirms the maintenance of all positive outcomes of the previous orthopaedic treatment with hybrid RME and facemask.

Stability of protraction Facemask/Rapid Maxillary Expansion in skeletal class III malocclusion with maxillary deficiency: Rapid Review

this study aimed to evaluate the stability of PFM/RME outcomes in class III skeletal malocclusionwith maxillary deficiency performed during childhood. Electronic database search conducted from 2011-2020 withcriteria RCT, clinical trials, and cohort studies with a treatment group of class III skeletal malocclusion withmaxillary deficiency patients, using PFM/RME and a minimum of 2 years follow-up. The PFM/RME device hasbeen commonly used for maxillary protraction in cases of maxillary growth deficiency and is used duringchildhood. The stability of the PFM/RME protocol results aims to maintain the best possible treatment results.There were 439 articles from the preliminary search. Six articles were included in this study, two articles were RCTtypes, and the other four were CCT types. Clinical evaluation and cephalometric are used to evaluate skeletal anddentoalveolar changes. 68%-90% of participants maintained overjet until the follow-up period ended. PFM/RMEprotocol reduced the need for orthognathic surgery by 3,5 times compared with a control group with notreatment.PFM/RME treatment can effectively show in the short term from skeletal dan dentoalveolar changes.There were relapses during the long-term follow-up period. Further evaluation and research are needed regardingthe long-term stability of PFM/RME outcomes. KEYWORDS: Class III malocclusion, Growth modification, Maxillary deficiency Protraction facemask (PFM), Rapidmaxillary expansion (RME)

Changes in Temporomandibular Joint Disc and Condyle after Rapid Maxillary Expansion Combined with Protraction Facemask Therapy: A Prospective Magnetic Resonance Imaging Study

Changes in Temporomandibular Joint Disc and Condyle after Rapid Maxillary Expansion Combined with Protraction Facemask Therapy: A Prospective Magnetic Resonance Imaging Study

3D Printed Customized Facemask for Maxillary Protraction in the Early Treatment of a Class III Malocclusion: Proof-of-Concept Clinical Case.

In order to improve fit and comfort, a maxillary protraction facemask customized to the patient’s anatomy was produced by means of 3D face scanning, digital design and additive manufacturing. An 8-year-old patient in need of early treatment for the Class III malocclusion received a rapid palatal expander and a Petit-type facemask, whose components were digitally designed on a 3D scan of the patient’s face. For face scanning, the iPad Pro 2018 tablet (Apple, Cupertino, CA, USA) with the Bellus3D DentalPro application (Bellus3D, Campbell, CA, USA) was used. Facemask components were modelled with 3D Blender software. The rests were 3D printed in BioMed Clear biocompatible resin (Formlabs, Somerville, MA, USA), and the bar in stainless steel. For greater comfort, the internal surface of the rests was lined with a polymer gel pad (Silipos, Niagara Falls, NY, USA). The manufacturing procedure of the customized facemask is patented. The patient wore the facemask at night for a period of 9 months. The patient’s experience was evaluated with a questionnaire at 1 week, 3, 6, and 10 months of treatment. The customized facemask was well accepted by the patient and obtained the expected treatment outcome. Furthermore, 3D face scanning, 3D modelling and 3D printing allow for the manufacturing of customized facemasks with improved fit and comfort, favoring patient compliance and treatment success.

Different Treatment Modalities of Maxillary Protraction in Cleft Lip and Palate Patients: A Literature Review

Cleft lip and palate is the most common cranio-facial defect with patients displaying unfavorable growth pattern of the cranio-facial complex. When such a deficiency in growing subjects, is left untreated, can lead to severe functional, aesthetic, breathing and psychological problems. To treat patients with cleft lip and palate, early orthopedic correction is considered to be advantageous. This can be applied through a tooth-anchored protraction facemask, bone-anchored protraction facemask or even the application of direct force via intra-oral inter-maxillary elastics anchored in mini-plates between the maxilla and the mandible.

Maxillary Skeletal Changes Concomitant With Different Levels of Force Application for Maxillary Protraction in Growing Class 3 Patients

Objective: to evaluate maxillary skeletal changes concomitant with different three levels of force application for maxillary protraction in growing orthodontiv patients with skeletal class 3 malocclusion. subjets and Methods: The current study was conducted on 30 class 3 patients (19 boys and 11 girls) with maxillary difficieny. The age of the recrutted sample ranged from 7-10 years. The patients were randomely allocated into three equal groups. The point of protraction force application varied among the three groups; groupA at the occlusal plane, group B 20 mm above the occlusal plane and group C at the infraorbital foramen. The duration of the treatment laste for 8 months, the patients were instructed to werethe appliance 16 hour/day with the applied 550gs protraction force. The analysis of the outcomes of this study was doneusing CBCT images were taken before and after maxillary protraction. Results: The average amount of maxillary advancement in the three groups 2.5mm with non-significant difference. The pattern of rotation accompanied with maxillary advancement as demonstrated by PP-TVP; in group A it was counterclockwise rotation (2.8 )in group B it was minimum (0.35 ) and in group C it was clockwise rotation (-1.8 ). Conclusions: Varying the point of force application was an efficient tool in order to control the rotation of the maxilla during protraction facemask therapy without affecting the amount of maxillary advancement.

The Effect Of Different Force Levels for Maxillary Protraction on The Upper Inciosrs’ Position in Growing Class 3 Patients

Objective: To evaluate changes in the anterior maxillary dentoalveolar segment concomitant with different levels of force application for maxillary protraction in growing skeletal class3 patients. Subjects and Methods: The current study was conducted on 30 class 3 patients (19 boys and 11 girls) with maxillary difficieny. The age of the recrutted sample ranged from 7-10 years. The patients were randomely allocated into three equal groups. The point of protraction force application varied among the three groups; group A at the occlusal plane, group B 20 mm above the occlusal plane and group C at the infraorbital foramen. The duration of the treatment laste for 8 months, the patients were instructed to werethe appliance 16 hour/day with the applied 550gs protraction force. The analysis of the outcomes of this study was doneusing CBCT images were taken before and after maxillary protraction. Results: The average amount the upper midface projection varied significantly (p˂ 0.05) among the three studied groups as demonstrated by L&R IOF –TVP. The maximum amount of the upper midface anterior displacement was observed in group C (2.65 mm) followed by group B (1.77 mm) . the least amount of displacement was observed in group A (0.93 mm) . Conclusions: The application of the protraction force in a level higher than the occlusal plane is an efficient tool to maximized the amount of upper midface projection after protraction facemask without affecting the amount of maxillary advancement.

Protraction Facemask Followed by Mandibular Cervical Headgear: an Alternative in the Treatment of Class III Malocclusion with Severe Anterior Open-Bite

The present case report describes a conservative and uncommon treatment for class III malocclusion in a woman growing patient with aged eight years and four months. An unconventional treatment modality was used for the treatment of this malocclusion, reverse-pull headgear and distalisation of lower teeth using mandibular cervical headgear in the lower arch. At the end of the treatment (after 33 months), there was correction of the transversal and sagittal occlusal relationship between maxilla and mandible and correct dental intercuspation. Keywords Class III malocclusion; Open-bite; Orthodontics.

Evaluation of Alt-RAMEC With Facemask in Patients With Unilateral Cleft lip and Palate (UCLP) Using Cone Beam Computed Tomography (CBCT) and Finite Element Modeling-A Clinical Prospective Study.

Evaluate the effects of alternate rapid maxillary expansion and constriction (Alt-RAMEC) protocol on patients with unilateral cleft lip and palate (UCLP) along with maxillary protraction using cone beam computed tomography (CBCT) records and a finite element modeling (FEM) model. Twenty-five patients (aged 9-13 years) with UCLP having a GOSLON score 3 were selected for this prospective single-arm cohort study after obtaining necessary informed consent. A 9-week Alt-RAMEC protocol using a custom-made fan-shaped expansion screw was initiated, which was followed by 6-month facemask wear. Pre (T1) and posttreatment (T2) records including CBCT were taken and were evaluated for treatment changes in all 3 dimensions using paired t test. Additionally, a FEM model (ANSYS 15.0) using the Alt-RAMEC protocol was also analyzed for the displacement and stress on various craniofacial structures. Significant forward movement of the maxilla along with clockwise rotation of mandible along with statistically significant increase in lower molar height and upper incisor proclination (P < .05) was observed. CBCT evaluation showed a statistical significant decrease in buccal alveolar bone thickness and increase in molar inclination (P < .05). Finite element modeling analysis highlighted that the maximum displacement occurred at the anterior region with stresses radiating till the anterior nasal spine, zygomatic arch, and sphenoid bone. Alt- RAMEC protocol combined with facemask protraction can lead to significant maxillary advancement, with some transient decrease in buccal bone thickness noted thereby warranting long-term studies to further assess its effect on the dentofacial apparatus.

Long-term maxillary anteroposterior changes following maxillary protraction with or without expansion: A meta-analysis and meta-regression.

Maxillary protraction with or without expansion is a widely known orthopedic treatment modality in growing skeletal Class III patients. However, limited data are available regarding the outcomes of long-term changes in the maxilla. Aim of this meta-analysis was to assess the effectiveness of the long-term maxillary anteroposterior changes following a facemask therapy with or without rapid maxillary expansion in growing skeletal Class III patients. A comprehensive literature search was conducted using the databases of PubMed, Science Direct, Web of Science, and Embase. Randomized controlled trials and cohort studies, published up to Sep. 2020, with maxillary protraction and/or expansion as keywords were included in this meta-analysis. Risk of bias within and across studies were assessed using the Cochrane tools (RoB2.0 and ROBINS-I) and GRADE approach. Overall and subgroup comparisons with the random-effect model were performed in this meta-analysis. Meta-regression models were designed to determine potential heterogeneity. There was a statistically significant increase (Mean difference, 2.29°; 95% confidence interval, 1.86-2.73; and p < 0.001 after facemask (FM) protraction. Mean difference, 1.73°; 95% confidence interval, 1.36-2.11; and p < 0.001 after rapid maxillary expansion(RME) and facemask protraction) in the Sella-Nasion-A point (SNA) angle in the treatment groups as compared with the control groups, when measured during the less than 3-year follow-up period. However, no statistically significant changes (Mean difference, 0.28°; 95% confidence interval, -0.57-1.13; and p = 0.52 after facemask protraction. Mean difference, 0.34°; 95% confidence interval, -0.64-1.33; and p = 0.50 after rapid maxillary expansion and facemask protraction) were observed in the SNA angle in the groups, when measured after 3 years of follow-up. Meta-regression analysis also showed that with increased follow-up duration, the effectiveness of maxillary protraction decreased. This meta-analysis revealed that maxillary protraction therapy could be effective for a short-term in correcting maxillary hypoplasia and the treatment result was not affected by mean age and sex. However, with increased follow-up duration, the sagittal maxillary changes gradually decreased. Limitations on this review were only the SNA angle was used and clinical heterogeneity was not discussed. The quality of evidence was moderate. Further long-term observational studies are necessary for a comprehensive evaluation of the effects on maxillary skeletal changes.

Pediatric Obstructive Sleep Apnea: The Role of Orthodontic Management - Review Article

Pediatric obstructive sleep apnea (OSA) is a common breathing-related sleep disorder affecting 1% to 5% of children. It often presents with less recognized signs and symptoms compared to adult OSA. Consequently, many patients with pediatric OSA remain undiagnosed. Risk factors include adenotonsillar hypertrophy, craniofacial anomalies, retrognathia, nasal obstruction, macroglossia, nasal septal deviation, and obesity. Orthodontist as a healthcare provider could have a significant role in screening, diagnostic referral, and treatment. The management approach for pediatric OSA requires multidisciplinary collaboration to obtain an optimal treatment outcome. Currently, adenotonsillectomy is recommended as first-line therapy. However, the treatment success varies considerably among patients. Children with OSA are often found to have narrow and constricted maxilla, mandibular retrognathia, and posterior rotation of mandible. Therefore, orthodontic treatment such as rapid maxillary expansion (RME), functional jaw orthopedic appliances, and protraction facemask could improve pediatric OSA with proper case selections. Additional maxillary expansion can also be performed in conjunction with adenotonsillectomy regardless of treatment sequence. The present article reviewed the currently available literature on the efficacy of various orthodontic treatments on pediatric OSA. Additional high-quality evidence is required to further substantiate the effectiveness of these orthodontic therapy. Keywords: Pediatric OSA, Orthodontic treatment, Rapid Maxillary Expansion (RME), Functional jaw orthopedic appliances, Protraction facemask

Effects of the long-term use of maxillary protraction facemasks with skeletal anchorage on pharyngeal airway dimensions in growing patients with cleft lip and palate.

ObjectiveTo investigate the effects of the long-term use of a maxillary protraction facemask with miniplate (FM-MP) on pharyngeal airway dimensions in growing patients with cleft lip and palate (CLP).MethodsThe study included 24 boys with CLP (mean age, 12.2 years; mean duration of FM-MP therapy, 4.9 years), divided into two groups according to the amount of A point advancement to the vertical reference plane (VRP): Group 1, > 4 mm; Group 2, < 2 mm; n = 12/group. After evaluating the skeletodental and airway variables using lateral cephalograms acquired before and after FM-MP therapy, statistical analyses were performed.ResultsGroup 1 showed greater forward and downward displacements of the posterior maxilla (posterior nasal spine [PNS]-horizontal reference plane [HRP]; PNS-VRP), greater increase in ANB, more forward tongue position (tongue tip-Pt vertical line to Frankfort horizontal plane), and greater increase in the oropharynx (superior posterior airway space [SPAS]; middle airway space [MAS]) and upper nasopharynx (PNS-adenoid2) than did Group 2. While maxillary advancement (A-VRP and PNS-VRP) correlated with increases in SPAS, MAS, and PNS-adenoid2, downward displacement of the PNS (PNS-HRP) correlated with increases in SPAS, MAS, PNS-adenoid1, and PNS-adenoid2, and with a decrease in vertical airway length (VAL). Mandibular forward displacement and decrease in mandibular plane correlated with increases in MAS.ConclusionsFM-MP therapy had positive effects on the oropharyngeal and nasopharyngeal airway spaces without increases in VAL in Group 1 rather than in Group 2. However, further validation using an untreated control group is necessary.

Comparison of treatment effects of different maxillary protraction methods in skeletal class III patients.

The aim of this study was to compare treatment outcomes with different maxillary protraction methods in patients with skeletal Class III malocclusion resulting from maxillary retrognathia. A total of 55 individuals consisting of 29 females and 26 males with a mean age of 11.4±1.06years were included in this study. Fifty-five treated maxillary retrognathic patients who underwent different protraction facemask methods were evaluated. Eighteen patients treated with RME were in the first group, and 19 patients treated with a modified Alt-RAMEC protocol were in the second group; eighteen patients on whom face masks with miniplates were applied were included in the skeletal anchorage (SA) group. Thirty measurements were made on lateral cephalometric radiographs before and after treatment. Differences between the groups were assessed with the ANOVA test. The mean age was higher in the SA group (11.96±0.92years) compared with the other groups. The mean ANB angle increased by 2.96°, 4.91° and 3.86° in the RME, Alt-RAMEC and SA groups, respectively. The forward movement of the maxilla was similar between the groups. However, while the rate of protraction was higher in the modified Alt-RAMEC group, a greater skeletal effect was found in the SA group. The most effective method in terms of skeletal effect is the application of the face mask with skeletal anchorage; the modified Alt-RAMEC protocol can be applied before face mask to obtain faster protraction.

Meta-analysis of the efficacy of bone anchorage and maxillary facemask protraction devices in treating skeletal class Ⅲ malocclusion in adolescents

To assess the efficacy of bone anchorage and maxillary facemask protraction devices in treating skeletal class Ⅲ malocclusion in adolescents. Articles relating to the use of bone anchorage and maxillary facemask protraction devices for treating skeletal class Ⅲ malocclusion in adolescents were searched from the databases of Cochrane Library, PubMed, EmBase, CNKI, and Wanfang database. Several inclusion and exclusion criteria were developed for the article screening. The clinical data were extracted, and the quality of the selected articles was evaluated. A Meta-analysis of SNA, SNB, ANB, ANS-Me, Wits, and U1-PP change was performed by using RevMan 5.3. Seven studies (264 patients) were included in the Meta-analysis. Among these studies, three were randomized controlled trials, and four were non-randomized controlled trials. Compared with the maxillary facemask protraction device group, the bone ancho-rage device group had higher SNA changes and lower ANS-Me, Wits, and U1-PP changes (P<0.05). No significant differences were observed in the SNB and ANB changes between these two groups. Compared with the maxillary facemask protraction device, the bone anchorage device can increase the extent of protraction of the maxilla and has better controls for the labial inclination of the maxillary anterior teeth in treating skeletal class Ⅲ malocclusion among adolescents. However, additional high-quality randomized controlled trials must be performed to verify the results.

Effect of facemask protraction on the development of impacted maxillary canines: a retrospective study.

Objective: The aim of the present study was to evaluate if maxillary protraction with facemask increases the risk of maxillary canine impaction. Materials and method: The records of 76 skeletal Class III subjects with a cervical vertebral maturation stage between CS1 and CS3 and a displaced maxillary canine were retrospectively collected. Intraoral photographs, orthopantomography and lateral cephalograms were collected, and patients were divided into three groups depending on the type of treatment received – a Rapid Palatal Expander (RPE), a RPE in conjunction with a facemask (RPE-FM), or a Class III functional appliance (FA). The patient’s records were used to determine if the maxillary canines were correctly erupted after that phase of treatment. A binary logistic regression was used to evaluate the effect of treatment modality and skeletal maturation stage on the chance of maxillary canine impaction. Results: No effect of the three different treatment modalities and of the skeletal maturation stage on the risk of canine impaction was observed. Conclusions: The protraction facemask can be used in growing skeletal Class III subjects without increasing the risks of maxillary canine displacement.

Effect of protraction facemask on the temporomandibular joint: a systematic review

BackgroundThe aim of this study was to assess the influence of protraction facemask (PFM) on temporomandibular joint (TMJ) of skeletal Class III malocclusion patients.MethodLiterature searches were carried out electronically in five English and three Chinese databases (Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed, Embase, MEDLINE (via Ovid), Chinese Biomedical Literature Database, China National Knowledge Infrastructure, and VIP Database). The date of the most recent search was 22 March 2017. Randomized controlled trials, controlled clinical trials, cohort studies, and before-after studies comparing the effect of PFM and other treatments on TMJ were included. The data were collected and extracted by three authors. The risk of bias in the RCTs was assessed in accordance with the Cochrane Handbook for Systematic Reviews of Interventions. For the nonrandomized studies, the risk of bias was judged with Newcastle-Ottawa Scale.ResultsFor the 261 articles identified, 13 studies with 522 participants were included for the final qualitative analysis. Three studies were graded as high value of evidence, while seven studies and the other three studies were graded as moderate value and low value respectively. According to the available evidence, PFM contributed to the significant increase of CondAx-SBL and the significant decrease of CondAx-ML. Thin-plate spline (TPS) analysis showed a horizontal compression in condyles. Condyles tended to move superiorly and posteriorly. Concerning the occurrence of temporomandibular disorders (TMD), PFM was not involved in aggravating TMJ symptoms and signs.ConclusionsClinical evidence suggests that PFM might contribute to the morphologic adaptation of TMJs and displacement of condyles, and PFM may well be not a risk factor for the development of TMD.

Early treatment of class III malocclusion with facemask.

Data sourcesThe Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Embase, Medline and the ClinicalTrials.gov databases.Study selectionRandomised controlled trials (RCTs) and controlled clinical trials (CCTs) of children aged 7-12 years with class III malocclusion undergoing fixed or removable orthodontic treatment for early correction were included.Data extraction and synthesisTwo reviewers independently selected studies, abstracted data and assessed risk of bias. The Cochrane risk of bias tool was used for RCTs and the Downs and Black and the Newcastle-Ottawa scales for CCTs. The primary outcome was correction of reverse overjet. Mean differences (MD) with 95% confidence intervals were calculated and a random effects meta-analysis conducted.ResultsFifteen studies (nine RCTs, six CCTs) were included. Only three of the RCTs were considered to be at low risk of bias, all six CCTs were at high risk of bias.Three RCTs (141 patients) compared protraction facemask and untreated control. The results for reverse overjet (MD = 2.5 mm; 95% CI, 1.21-3.79) and ANB angle (MD = 3.90˚; 95% CI, 3.54-4.25) were statistically significant favouring the facemask group. All CCTs demonstrated a statistically significant benefit in favour of the use of each appliance. However, the studies had high risk of bias.ConclusionsThere is a moderate amount of evidence to show that early treatment with a facemask results in positive improvement for both skeletal and dental effects in the short term. However, there was lack of evidence on long-term benefits. There is some evidence with regard to the chincup, tandem traction bow appliance and removable mandibular retractor, but the studies had a high risk of bias. Further high-quality, long-term studies are required to evaluate the early treatment effects for Class III malocclusion patients.