Effect of maxillary protraction with alternating rapid palatal expansion and constriction vs expansion alone in maxillary retrusive patients: a single-center, randomized controlled trial

Impact of tonsillectomy on the efficacy of Alt-RAMEC/PFM treatment protocols in children with class III malocclusion and tonsillar hypertrophy: protocol for a cluster randomised controlled trial

INTRODUCTION

Orthodontic treatment using face mask protraction combined with an alternate rapid maxillary expansion and constriction/protraction face mask (Alt-RAMEC/PFM) protocol is effective in the early treatment of patients with class III malocclusion, but the stability of treatment outcomes represents a major concern. Previous studies have suggested that tonsillar hypertrophy can be a risk factor for class III malocclusion and tonsillectomy may prompt the normalisation of dentofacial growth. However, these studies had a low-to-moderate level of evidence. This study was designed to identify the impact of tonsillectomy before orthodontic treatment on the efficacy and stability of Alt-RAMEC/PFM protocols and the sleep quality and oral health in children with anterior crossbite and tonsillar hypertrophy.

METHODS AND ANALYSIS

This is a two-arm, parallel-group, superiority cluster randomised controlled trial, with four clinics randomly assigned to the surgery-first arm and the orthodontic-first arm in a 1:1 ratio. The Alt-RAMEC protocol involves alternate activation and deactivation of the expander's jet screw over 6 weeks to stimulate maxillary suture distraction. Patients will be instructed to wear the PFM for a minimum of 14 hours per day. The primary outcomes are changes in Wits appraisal and the degree of maxillary advancement from baseline to the end of orthodontic treatment. Lateral cephalometric radiographs, polysomnography, Obstructive Sleep Apnoea-18 questionnaire and Oral Health Impact Profile-14 questionnaire will be traced, collected and measured. We will recruit 96 patients intofor the study. To assess differences, repeated multilevel linear mixed modelling analyses will be used.

ETHICS AND DISSEMINATION

This study has been granted ethical approval by the Ethics Committee of the School & Hospital of Stomatology, Wuhan University (approval No. 2023-D10). Written informed consent will be obtained from the participants and their guardians. The results of the trial will be disseminated through academic conferences and journal publications.

TRIAL REGISTRATION NUMBER

ChiCTR2300078833.

Orthodontic treatment for prominent lower front teeth (Class III malocclusion) in children

BACKGROUND

Prominent lower front teeth (Class III malocclusion) may be due to jaw or tooth position or both. The upper jaw (maxilla) can be too far back or the lower jaw (mandible) too far forward; the upper front teeth (incisors) may be tipped back or the lower front teeth tipped forwards. Orthodontic treatment uses different types of braces (appliances) fitted inside or outside the mouth (or both) and fixed to the teeth. A facemask is the most commonly reported non-surgical intervention used to correct Class III malocclusion. The facemask rests on the forehead and chin, and is connected to the upper teeth via an expansion appliance (known as 'rapid maxillary expansion' (RME)). Using elastic bands placed by the wearer, a force is applied to the top teeth and jaw to pull them forwards and downward. Some orthodontic interventions involve a surgical component; these go through the gum into the bone (e.g. miniplates). In severe cases, or if orthodontic treatment is unsuccessful, people may need jaw (orthognathic) surgery as adults. This review updates one published in 2013.

OBJECTIVES

To assess the effects of orthodontic treatment for prominent lower front teeth in children and adolescents.

SEARCH METHODS

An information specialist searched four bibliographic databases and two trial registries up to 16 January 2023. Review authors screened reference lists.

SELECTION CRITERIA

We looked for randomised controlled trials (RCTs) involving children and adolescents (16 years of age or under) randomised to receive orthodontic treatment to correct prominent lower front teeth (Class III malocclusion), or no (or delayed) treatment.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcome was overjet (i.e. prominence of the lower front teeth); our secondary outcomes included ANB (A point, nasion, B point) angle (which measures the relative position of the maxilla to the mandible).

MAIN RESULTS

We identified 29 RCTs that randomised 1169 children (1102 analysed). The children were five to 13 years old at the start of treatment. Most studies measured outcomes directly after treatment; only one study provided long-term follow-up. All studies were at high risk of bias as participant and personnel blinding was not possible. Non-surgical orthodontic treatment versus untreated control We found moderate-certainty evidence that non-surgical orthodontic treatments provided a substantial improvement in overjet (mean difference (MD) 5.03 mm, 95% confidence interval (CI) 3.81 to 6.25; 4 studies, 184 participants) and ANB (MD 3.05°, 95% CI 2.40 to 3.71; 8 studies, 345 participants), compared to an untreated control group, when measured immediately after treatment. There was high heterogeneity in the analyses, but the effects were consistently in favour of the orthodontic treatment groups rather than the untreated control groups (studies tested facemask (with or without RME), chin cup, orthodontic removable traction appliance, tandem traction bow appliance, reverse Twin Block with lip pads and RME, Reverse Forsus and mandibular headgear). Longer-term outcomes were measured in only one study, which evaluated facemask. It presented low-certainty evidence that improvements in overjet and ANB were smaller at 3-year follow-up than just after treatment (overjet MD 2.5 mm, 95% CI 1.21 to 3.79; ANB MD 1.4°, 95% CI 0.43 to 2.37; 63 participants), and were not found at 6-year follow-up (overjet MD 1.30 mm, 95% CI -0.16 to 2.76; ANB MD 0.7°, 95% CI -0.74 to 2.14; 65 participants). In the same study, at the 6-year follow-up, clinicians made an assessment of whether surgical correction of participants' jaw position was likely to be needed in the future. A perceived need for surgical correction was observed more often in participants who had not received facemask treatment (odds ratio (OR) 3.34, 95% CI 1.21 to 9.24; 65 participants; low-certainty evidence). Surgical orthodontic treatment versus untreated control One study of 30 participants evaluated surgical miniplates, with facemask or Class III elastics, against no treatment, and found a substantial improvement in overjet (MD 7.96 mm, 95% CI 6.99 to 8.40) and ANB (MD 5.20°, 95% CI 4.48 to 5.92; 30 participants). However, the evidence was of low certainty, and there was no follow-up beyond the end of treatment. Facemask versus another non-surgical orthodontic treatment Eight studies compared facemask or modified facemask (with or without RME) to another non-surgical orthodontic treatment. Meta-analysis did not suggest that other treatments were superior; however, there was high heterogeneity, with mixed, uncertain findings (very low-certainty evidence). Facemask versus surgically-anchored appliance There may be no advantage of adding surgical anchorage to facemasks for ANB (MD -0.35, 95% CI -0.78 to 0.07; 4 studies, 143 participants; low-certainty evidence). The evidence for overjet was of very low certainty (MD -0.40 mm, 95% CI -1.30 to 0.50; 1 study, 43 participants). Facemask variations Adding RME to facemask treatment may have no additional benefit for ANB (MD -0.15°, 95% CI -0.94 to 0.64; 2 studies, 60 participants; low-certainty evidence). The evidence for overjet was of low certainty (MD 1.86 mm, 95% CI 0.39 to 3.33; 1 study, 31 participants). There may be no benefit in terms of effect on ANB of alternating rapid maxillary expansion and constriction compared to using expansion alone (MD -0.46°, 95% CI -1.03 to 0.10; 4 studies, 131 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

Moderate-certainty evidence showed that non-surgical orthodontic treatments (which included facemask, reverse Twin Block, orthodontic removable traction appliance, chin cup, tandem traction bow appliance and mandibular headgear) improved the bite and jaw relationship immediately post-treatment. Low-certainty evidence showed surgical orthodontic treatments were also effective. One study measured longer-term outcomes and found that the benefit from facemask was reduced three years after treatment, and appeared to be lost by six years. However, participants receiving facemask treatment were judged by clinicians to be less likely to need jaw surgery in adulthood. We have low confidence in these findings and more studies are required to reach reliable conclusions. Orthodontic treatment for Class III malocclusion can be invasive, expensive and time-consuming, so future trials should include measurement of adverse effects and patient satisfaction, and should last long enough to evaluate whether orthodontic treatment in childhood avoids the need for jaw surgery in adulthood.

Comparison of the short-term effects of facemask therapy preceded by conventional rapid maxillary expansion or by an alternate rapid maxillary expansions and constrictions protocol : A retrospective study

PURPOSE

We aimed to compare the short-term effects of alternate rapid maxillary expansion and constriction (Alt-RAMEC) with conventional rapid maxillary expansion (RME) followed by facemask (FM) therapy.

METHODS

A total of 30 patients who had received facemask therapy after RME or Alt-RAMEC protocols were included in the study. The Alt-RAMEC/FM and RME/FM groups were created to be well-matched regarding cervical vertebral maturation stage and sex. In the Alt-RAMEC group (10 males and 5 females, 10.99 ± 1.80 years), expansion screws were activated for a week (two turns/day), then deactivated in the following week (two turns/day). The activation-deactivation protocol continued for 6 or 7 weeks. In the RME/FM group (10 males and 5 females, 11.61 ± 1.20 years), screw activation was performed according to the patients' requirements. Lateral cephalograms which had been taken at the beginning of treatment and at the end of the facemask therapy were analyzed. Intragroup and intergroup differences were statistically analyzed.

RESULTS

Both groups showed a significant sagittal advancement of the maxilla. However, the Alt-RAMEC/FM group showed statistically greater improvements than the RME/FM group for SNA (3.11 ± 1.79 vs. 1.45 ± 1.34, p = 0.008), ANB (4.29 ± 1.80 vs. 2.95 ± 1.19, p = 0.023), convexity (8.91 ± 4.29 vs. 5.61 ± 2.51, p = 0.016), and overjet (5.86 ± 2.29 vs. 4.61 ± 2.10, p < 0.001). The sagittal mandibular, vertical skeletal, dental, and soft tissue changes were similar between the groups (p > 0.05).

CONCLUSION

The Alt-RAMEC protocol was found to be more effective in the correction of skeletal class III malocclusion in the short term.

Effects of Alt-RAMEC protocol with facemask therapy in cleft lip palate patients in a sample of Pakistani population

OBJECTIVE

The objective of the study is to evaluate the skeletal, dentoalveolar and soft tissue changes before and after treatment with Alt-RAMEC protocol and protraction headgear in comparison to the controls.

MATERIAL AND METHODS

A quasi experimental study was conducted in the orthodontic department on 60 patients of cleft lip and palate. These patients were divided into two groups. Group I was the Alt-RAMEC group that underwent Alt-RAMEC protocol followed by facemask therapy while group II was the control group that underwent RME and facemask therapy. Total treatment time in both the groups was approximately 6 to 7 months. Mean and standard deviation was calculated for all the quantitative variables. Pre and post treatment changes between treatment and control groups were made using paired t-test. Intergroup comparison between treatment and control group was analyzed using independent t-test. Significance for all tests was predetermined at a P-value of  ≤ 0.05.

RESULTS

The Alt-RAMEC group showed significant forward movement of maxilla and improvement in the maxillary base. A remarkable improvement in SNA was seen. The overall outcome was better maxillo-mandibular relationship as shown by positive ANB values and angle of convexity. More effect on maxilla and least effect on mandible was notified with Alt-RAMEC protocol and facemask therapy. Improvement in transverse relationship was also evident in the Alt-RAMEC group.

CONCLUSION

Alt-RAMEC protocol in combination with protraction headgear is a better alternative to treat cleft lip and palate patients in comparison to the conventional protocol.

Accuracy and eligibility of Bonwill⁃Hawley arch form established by CBCT image for dental crowding measurement: a comparative study with the conventional brass wire and caliper methods

OBJECTIVES

The purpose of this study was to develop a novel Bonwill⁃Hawley method (Bonwill⁃Hawley arch form based on CBCT image) for the assessment of dental crowding, and to investigate and compare the accuracy and eligibility with the conventional brass wire and caliper methods under different crowding conditions.

MATERIAL AND METHODS

Sixty patients with the pair of plaster casts and CBCT data were collected. All the casts were marked and transformed into digital models using iTero scanner, and imported into OrthoCAD software to measure the required space. Using the conventional brass wire (M1) and caliper methods (M2), the available space and dental crowding were measured and calculated basing on digital models, respectively. Correspondingly, the axial planes in the level of dental arches were oriented and captured from the CBCT images to draw the Bonwill⁃Hawley arch forms (M3), which were used to measure and calculate the available space and dental crowding. For each method, intra and inter-examiner reliabilities were evaluated with intra-class correlation coefficients (ICCs). Wilcoxon test and Kruskal-Wallis test were performed for statistically analyzing the discrepancy among different groups.

RESULTS

Both intra- and inter-examiner reliability were generally excellent for all parameters obtained by the three methods, except for the dental crowding measured using M1(ICC: 0.473/0.261). The dental crowding measured using M2 were significantly increased in mild, moderate and severe-crowding groups compared with M1. However, no significant difference was detected between M1 and M3 in severe-crowding group (maxilla, p = 0.108 > 0.05; mandible, p = 0.074 > 0.05). With the deterioration of crowding condition, the discrepancy of dental crowding between M1 and M2, or M1 and M3 were significantly decreased (maxilla, M2-M1, mild VS serve, p = 0.003 < 0.05; maxilla, M3-M1, mild VS serve, p = 0.003 < 0.05; mandible, M2-M1, mild VS serve, p = 0.000 < 0.001; mandible, M3-M1, mild VS serve, p = 0.043 < 0.05).

CONCLUSION

Dental crowding measured using the novel Bonwill⁃Hawley method was relatively greater than the caliper method, but not exceeding the brass wire method, which wound gradually come close to the brass wire method with the deterioration of crowding condition.

CLINICAL RELEVANCE

The Bonwill⁃Hawley method basing on CBCT image proved to be a reliable and acceptable choice for orthodontists to analyze the dental crowding.

X-Ray Cephalometric Analysis of the Effects of Angle Class II and III Malocclusion on the Upper Airway Width and Hyoid Position between Parents and Children of Uygur Nationality

Objective

The objective of this paper is to analyze the effect of angle class II and III malocclusion on the sagittal diameter of the upper airway between parents and children of Uygur nationality and to compare the degree of influence.

Methods

29 Uygur adolescents with malocclusion and their fathers (mothers) were selected as our subjects via X-ray cephalometric radiograph to analyze the difference between the upper airway sagittal dimension and normal occlusion and compare the influence of malocclusion on the upper airway between parents and children.

Results

Compared with normal group, the vertical distance from the hyoid point to orbital-ear plane (H-FH) and vertical distance from hyoid point to the mandibular plane (H-MP) in angle class II malocclusion elevated signally, while the vertical distance from hyoid point to anterior cervical plane (H-VL), PNS-UPW, H-FH, and H-MP decreased significantly; compared with normal group: the distance between the posterior nasal spine and the upper pharynx wall (PNS-UPW), H-FH, and H-MP in angle class III malocclusion visually reduced, while PAS, and horizontal distance from the hyoid point and center point of sella turcica to orbital-ear foot (H-S), increased markedly. The impact of class II malocclusion on parents' U-MPM was greater than their children.

Conclusion

The oropharyngeal space of upper airway becomes smaller and hyoid shifts downwards due to class II malocclusion. Class III malocclusion results in decreased nasopharyngeal gap with hyoid to shift upward. The influence of class II malocclusion on the upper pharyngeal tract of parents was greater than their children.

Very early orthodontic treatment: when, why and how?

Introduction:

Several orthodontic problems should already be treated at an early age to prevent the necessity of future complex and expensive procedures. Scientific evidence suggests that posterior crossbites, mild to moderate Class III, as well as certain Class II malocclusions, open bites and arch length discrepancies can benefit from simple, but efficient interceptive therapy.

Objective:

To summarize the existing evidence-based literature on early orthodontic treatment, and to illustrate its application and effectiveness by showcasing multiple clinical examples.

Conclusion:

Early short-term interceptive orthodontic treatment with simple appliances, in the deciduous or early mixed dentition phase, can efficiently correct certain malocclusions and help to either reduce the complexity or even avoid the necessity of complex and expensive procedures during puberty. For certain patients with significant arch length discrepancy the concept of serial extractions should be part of the orthodontic armamentarium.

[A cone-beam computed tomography evaluation of three-dimensional changes of circummaxillary sutures following maxillary protraction with alternate rapid palatal expansions and constrictions]

OBJECTIVE

To assess three-dimensional (3D) changes of circummaxillary sutures following maxillary protraction with alternate rapid palatal expansions and constrictions (RPE/C) facemask protocol in maxillary retrusive children, and to investigate the relationship between the changes of circum-maxillary sutures and zygomaticomaxillary suture (ZMS) maturation, and to explore the factors of maxilla forward movement with RPE/C and facemask.

METHODS

In the study (clinical trial registration No: ChiCTR2000034909), 36 maxillary retrusive patients were recruited and block randomized to either the rapid palatal expansion (RPE) group or the RPE/C group. Patients aged 7 to 13 years, Class Ⅲ malocclusion, anterior crossbite, ANB less than 0°, Wits appraisal less than -2 mm, and A-Np less than 0 mm were included in the study. The RPE group received rapid palatal expansion, whereas the RPE/C group received alternate rapid palatal expansions and constrictions, and both with facemask protraction. Head orientations of cone-beam computed tomography (CBCT) images were implemented by Dolphin 11.7. 3D measurements of circummaxillary sutures on CBCT images were evaluated using Mimics 10.01 before (T0) and after treatment (T1). The changes were analyzed with independent t test, two-way ANOVA, Pearson correlation and regression analysis.

RESULTS

Two subjects in the RPE/C group were lost to follow-up. A total of 34 patients reached the completion criteria and were analyzed. Compared with the RPE group, sagittal changes of circummaxillary sutures were significantly increased in the RPE/C group with 1.21 mm advancement of zygomaticotemporal suture, 2.20 mm of ZMS, 1.43 mm of zygoma-ticofrontal suture (P < 0.05, respectively). Except for the zygomaticotemporal suture, the rest forward sagittal changes of other circummaxillary sutures showed no major difference in terms of the ZMS maturation. The Spearman's correlation in RPE/C indicated a strong positive correlation of sagittal changes between ZMS and point A (P < 0.01) with a regression analysis R²=42.5%.

CONCLUSION

RPE/C might be more effective on the treatment of maxillary retrusive children. As one of the major mechanical loading sutures during orthopedic therapy, ZMS showed a strong positive correlation with point A on sagittal changes.

Bite Force Changes in Bilateral Cleft Lip and Palate Patients Before and After ALT-RAMEC Protocol

To evaluate the bite force (BF) changes in bilateral cleft lip and palate (BCLP) in contrast to the non BCLP children after ALT-RAMEC Facemask therapy.

The prospective study was carried out on a total of 60 subjects of age 6 to 13 years in a tertiary care hospital; treatment group, 30 children with BCLP and control group, 30 children without cleft lip and palate. Each cleft patient was received ALT-RAMEC Facemask treatment and their BF assessed at 4 different stages. Bite force taken before treatment, immediately, 3 months and 6 months after treatment. Bite force of the control group was taken at baseline to compare with the treatment group to demonstrate the difference in BF values. Independent t test and analysis of variance were used to perform statistical analysis.

There was a significant difference in BF between the treatment group (BCLP) 122.53 ± 8.64 N and the control group (non BCLP) 181.38 ± 18.84 N at baseline. After the Alt RAMEC protocol, changes in BF recorded over 3 and 6 months of therapy showed significant improvement. The mean values of BF at 3months and 6 months were 106.7 ± 9.3 N and 137.4 ± 9.5 N, respectively.

Bite force was significantly improved after ALT-RAMEC protocol followed by facemask therapy in BCLP patients.

Protraction Headgear Compliance and Orthognathic Surgery in Patients With Cleft Lip and Palate

Assess cephalometric parameters and the need for orthognathic surgery (OS) and its relationship with compliance in protraction headgear (PHG).

Retrospective case series.

Hospital cleft-craniofacial center.

23 patients with nonsyndromic cleft lip and palate and history of lip and palate repair.

Patients received PHG and orthodontic treatment. Compliant patients were compared to patients that were not. Protraction was applied with 170-gram elastics and patients were instructed to wear for at least 12 hours daily.

Cephalometric measurements at initial (T1), post-PHG (T2), and pre-surgical or post-orthodontic treatment (T3) of at least age 15 for females and 17 for males and the presence of OS were compared.

83% (19) of patients reported compliance with therapy. Of those compliant, 68% (13) had OS and 32% (6) did not (P = .99). Inter-group comparisons at T1 between compliant and noncompliant showed no significant differences and the non-OS patients started with larger nasolabial angles (P < .05). At T2, there were no significant cephalometric differences between groups. At T3, compliant patients showed significantly more upper incisor proclination than noncompliant patients. Between OS and non-OS, OS patients had significantly decreased ANB, Wits, convexity, overjet, and FMA and larger nasolabial angles (P < .05).

Patients compliant with PHG showed no difference in the need for OS. However, after orthodontic treatment, compliant patients showed more upper incisor proclination and OS patients with decreased ANB, Wits, convexity, overjet, FMA, and larger nasolabial angles.

The variation in crown-root morphology of anterior teeth assessed with cone-beam computed tomography

Objective:

To determine the discrepancy of crown-root morphology of anterior teeth, using cone-beam computed tomography (CBCT), and to provide a guidance for proper torque expression.

Methods:

A total of eligible 200 CBCT were imported into Invivo v. 5.4 software, to obtain the middle labio-lingual sections of anterior teeth. AutoCAD 2007 software was applied to measure the crown-root angulation (Collum angle) and the angle formed by a tangent to the center of the labial surface and the long axis of the crown (labial surface angle). SPSS 18.0 was used for statistical comparisons of the two measurements, at the level of p< 0.05, and the Pearson correlation analysis was applied to investigate the association between the two measurements.

Results:

The value of Collum angle in maxillary central incisor was close to 0°. Significantly negative Collum angle in lateral incisors and maxillary canine, and positive value in mandibular canine were detected (p < 0.001). The labial surface angle in canine was significantly greater than the intra-arch incisors (p< 0.001), and no significant difference was detected between the central and lateral incisors (p > 0.05). Notably, there was also a significant positive correlation between the two measurements.

Conclusions:

The crown-root angulations were greatly different among anterior teeth. Accompanying the obvious crown-root angulations, the canines both in maxillary and mandibular arches presented considerable labial surface curvatures. Hence, equivalent deviation during bracket bonding might cause greater torque expression error and increase the risk of alveolar fenestration and dehiscence.

A retrospective long-term comparison of early RME-facemask versus late Hybrid-Hyrax, alt-RAMEC and miniscrew-supported intraoral elastics in growing Class III patients

OBJECTIVE

To compare the long-term dentoskeletal effects of early treatment with banded or bonded RME (Rapid Maxillary Expansion)-Face Mask (RME-FM) versus late treatment with bonded Hybrid-Hyrax, alt-RAMEC (Alternate Rapid Maxillary Expansion and Contraction) and intraoral Class III elastics anchored to miniscrew-reinforced-Lower-lingual-Arch (alt-RAMEC-HH-LLA) in growing, maxillary retrognathic patients.

MATERIALS AND METHODS

Two groups were matched at long-term follow-up retrospectively. Patients received either early RME-FM (n=16, 5 males, 11 females, age T1: 6.5±0.9 years, age T2: 15.8±2.5 years) or late alt-RAMEC-HH-LLA (n=15, 7 males, 8 females, age T1: 12.52±0.94 years, age T2: 16.8±0.9 years). Total follow-up was 9.2±2.3 years and 4.2±0.2 years respectively, including fixed appliances to compete treatment.

RESULTS

Both treatments resulted in Class III correction except one unsuccessful case of alt-RAMEC-HH-LLA. Active maxillary protraction was 1.6±0.5years with RME-FM and 0.5 years with alt-RAMEC-HH-LLA being significantly shorter (P<0.001). Values at T2 estimation with multivariate linear regression for correlated multiple outcomes, conditional on baseline estimates, age and sex showed alt-RAMEC-HH-LLA inducing significantly more retroclined lower incisors (mean: -6.11°; 95%CI: -10.66, -1.57; P=0.01), less overbite (mean: -1.28mm; 95%CI: -1.79, -0.761; P<0.001), less maxillo (Co-A)- (mean: -4.54mm; 95%CI: -7.91, -1.16; P=0.01) mandibular (Co-Gn) (mean: -10.5mm; 95%CI: -17.45, -3.55; P=0.003) projections/size, more open gonial angle (mean: 4.93°; 95%CI: 2.27, 7.59; P<0.001), and less S-N length (mean: -5.04mm; 95%CI: -6.57, -3.51; P<0.001).

CONCLUSIONS

Patients treated with either early RME-FM or late Alt-RAMEC-HH-LLA had comparable overall post-pubertal skeletal and overjet corrections. However, the late Alt-RAMEC-HH-LLA showed less correction of dentoalveolar compensations and in particular of the mandibular incisors. The overbite, maxillary and mandibular projection and size were lower and the gonial angle was more open.

Post-pubertal effects of the Alt-RAMEC/FM and RME/FM protocols for the early treatment of Class III malocclusion: a retrospective controlled study

OBJECTIVE

To assess the stability of the effects of the modified Alt-RAMEC and facial mask (FM) protocol at a post-pubertal observation.

METHODS

Twenty-one Class III patients (11 males and 10 females, 6.5 ± 0.7 years) treated consecutively with the Alt-RAMEC/FM approach and presenting with lateral cephalograms taken before treatment (T1), after treatment (T2), and at post-pubertal observations (T3) were compared with 22 Class III patients (9 males and 13 females, 6.9 ± 1.2 years) treated with the rapid maxillary expansion (RME) and FM protocol and with 15 Class III untreated subjects (7 males and 8 females, 6.2 ± 2.2 years). At T3, all patients showed a post-pubertal skeletal maturation stage (CS4-CS6). Descriptive statistics and statistical comparisons between the three groups at T1 and for the T3-T1, T2-T1, and T3-T2 changes were assessed by means of the ANOVA or Kruskal-Wallis test.

RESULTS

During the overall observation period, Alt-RAMEC/FM and RME/FM protocols produced statistically significant favourable effects when compared with the Control group (ANB + 2.8° and +2.2°, respectively; Wits appraisal +4.4 mm and +2.7 mm, respectively). No statistically significant differences were found between the outcomes of the Alt-RAMEC/FM and RME/FM protocols neither at the post-pubertal or short-term observations.

LIMITATIONS

Retrospective study and the comparison with an historical control sample of subjects with untreated Class III malocclusion.

CONCLUSIONS

The Alt-RAMEC/FM protocol cannot be recommended as the approach of choice for the therapy of Class III dentoskeletal disharmony in very young subjects compared to the conventional RME/FM protocol.

Relative effectiveness of facemask therapy with alternate maxillary expansion and constriction in the early treatment of Class III malocclusion

INTRODUCTION

This study aimed to investigate the relative efficacy of maxillary protraction combined with a modified alternate rapid maxillary expansion and constriction (Alt-RAMEC) protocol compared with conventional protocols in the early orthopedic treatment of skeletal Class III malocclusion.

METHODS

A sample of 39 patients was divided into 3 groups on the basis of different interventions. Conventional facemask (FM) with splint-type intraoral devices was performed in the FM group (7 males and 5 females; mean age, 9.53 ± 1.37 years). Maxillary expansion with an activation rate of 0.5 mm/d (twice a day) followed by FM therapy was applied in the rapid maxillary expansion group (RME/FM) (6 males and 6 females; mean age, 9.31 ± 1.60 years). In the Alt-RAMEC/FM group (7 males and 8 females; mean age, 10.01 ± 1.31 years), Alt-RAMEC was started simultaneously and throughout the entire course of maxillary protraction, with repetitive alternations between activation and deactivation of expanders (0.5 mm/d for 7 days). The patients in all groups were instructed to wear FMs for a minimum of 12 h/d. Pretreatment and posttreatment lateral cephalograms were all traced and measured.

RESULTS

The Alt-RAMEC group showed statistically more significant maxillary advancement than other groups (A-VRP, 3.87 mm vs 3.04 mm [RME/FM], vs 2.04 mm [FM]; P <0.05). Analysis of variance did not reveal significant intergroup differences in palatal plane angulation changes (P >0.05). No pronounced mandibular clockwise rotations were noted in the Alt-RAMEC/FM group with distinct intergroup differences (P <0.05). There were more skeletal effects (88.7%) during overjet correction in the Alt-RAMEC/FM protocol.

CONCLUSIONS

A combination of the modified Alt-RAMEC protocol with FM revealed more favorable skeletal effects compared with FM and RME/FM protocols in treating prepubertal patients with maxillary deficiency.

Importance of orthodontic intervention of the Class III malocclusion in mixed dentition

INTRODUCTION

Supervising the development of occlusion, managing problems during the transition from mixed to permanent dentition, as well as controlling environmental factors that contribute to establishing malocclusion, are important actions to achieve a Class I occlusion with facial balance. Among these problems, the malocclusions associated with dysfunctions such as mouth breathing or obstructive sleep apnea syndrome (OSAS), atypical swallowing and abnormal tongue position, open bites, crossbites and maxillomandibular discrepancies, and especially the Class III malocclusion can be listed.

OBJECTIVE

The purpose of this article is to present and discuss the main aspects relevant to the benefits of performing the treatment of Class III malocclusion in patients with growth.

Maxillary Protraction Therapy in Class III Patients With and Without Cleft Lip and Palate: An Interim Report of a Prospective Comparative Study

OBJECTIVE

To investigate and compare the effects of maxillary protraction therapy on Class III patients with unilateral cleft lip and palate (UCLP) and Class III patients with noncleft.

DESIGN

Prospective controlled clinical trial.

PATIENTS

Twenty-six Class III patients with UCLP (mean age: 10.32 ± 1.29 years) and 26 Class III patients with noncleft (mean age: 9.82 ± 1.03 years) were included and treated with maxillary protraction therapy.

INTERVENTIONS

Maxillary protraction therapy was performed with an intraoral Hyrax appliance and extraoral facemask. Cone beam computed tomography scans were taken before and after treatment. Pretreatment skeletal and dental characteristics and treatment changes were analyzed and compared.

RESULTS

The average treatment duration was 18.44 ± 4.16 months in the UCLP group, which was substantially longer than the 12.46 ± 4.03-month average treatment duration in the noncleft group (P < .001). No significant difference was found in the maxillary changes (length, advancement of point A, and SNA angle) and improvement of intermaxillary relationship (ANB angle) between the 2 groups. The UCLP group had 1.40° more mandibular clockwise rotation (P = .034). Regarding dental changes, the UCLP group had more upper incisor proclination (P = .006) and less lower incisor retroclination (P = .023).

CONCLUSIONS

Approximately extended maxillary protraction therapy in patients with UCLP could be as effective as in patients with noncleft. Further study is required to follow patients until completion of growth to elucidate the long-term stability of the treatment.

Dental root development associated with treatments by rapid maxillary expansion/reverse headgear and slow maxillary expansion

OBJECTIVES

To assess dental root development in two groups of paediatric patients who received treatments with reverse headgear and rapid maxillary expansion and slow maxillary dental arch expansion.

MATERIALS AND METHODS

The 20 subjects (13 girls, 7 boys; mean age: 8.9 ± 1.3 years) in the first group were treated with a Petit-type reverse headgear attached to a full-coverage bonded rapid maxillary expander via elastics (RME&RHg group). The 20 subjects included in the second group (9 girls, 11 boys; mean age: 9.1 ± 2.2 years) were selected among patients who were treated with Hawley appliances for slow maxillary expansion (SME group). Digitized panoramic radiographs were used. A total of 960 permanent teeth (maxillary-mandibular incisors, canines, premolars, and first molars) were measured quantitatively for pre-treatment and post-treatment.

RESULTS

No significant increase was found except for the right and left maxillary and mandibular second premolars and left mandibular and first premolar in the RME&RHg group (P < 0.05). Teeth length values increased significantly in all maxillary and mandibular teeth except maxillary first molars and mandibular incisors in the SME group (P < 0.05). Inter-group comparisons showed that statistically significant differences were observed in maxillary and mandibular incisors, left maxillary first premolar, and molar teeth (P > 0.05).

LIMITATION

A limitation of this study is the use of two-dimensional radiographic images for root length measurement. However, ethical obligations limit the dental cone beam computed tomography imaging application for protection of paediatric patients from harm.

CONCLUSIONS

RME&RHg therapy inhibits root development of maxillary and mandibular teeth in the early period. However, further studies should be performed to determine whether this effect on root development is reversible or irreversible.

Orthopaedic and orthodontic treatment with hyrax, Class III elastics on mandibular miniplates, maxillary mini-implants in a Class III adolescent: A case report

BACKGROUND

The treatment of Skeletal Class III malocclusion continues to be considered as one of the biggest challenges in orthodontics as the success of its correction is largely unpredictable. Early diagnosis and treatment are highly recommended to eliminate primary etiological factors and prevent an increase in severity of the existing malocclusion. However, if the diagnosis is delayed until adulthood, treatment becomes restricted to orthognathic surgery due to limited or no remaining growth potential left. The inherent risks involved with the surgical procedures often preclude the patients from opting for it, thus leaving the orthodontist with no option but to perform possible compensatory treatments to improve facial aesthetics and restore functional occlusion.

OBJECTIVE

To report the case of a 15-year old boy (adolescent) with Skeletal Class III malocclusion, a concave facial profile with an anterior crossbite and no incisor visibility during smile.

METHODS

Intra-oral skeletally anchored maxillary protraction (I-SAMP) and mini-implants associated with fixed appliance to aid in the correction of the skeletal bases and subsequently relieve the dental crowding.

RESULTS

After 36 months of treatment, functional normal occlusion with a Class I molar and canine relation was achieved. The consequential increase in upper lip thickness and decrease in lower lip fullness alongwith an increased exposure of maxillary incisors during smile resulted in a significant improvement of the patient's facial profile and an aesthetically pleasing smile.

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

OBJECTIVE

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.

SETTING AND SAMPLE POPULATION

A total of 55 individuals consisting of 29 females and 26 males with a mean age of 11.4 ± 1.06 years were included in this study.

MATERIAL AND METHODS

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.

RESULTS

The mean age was higher in the SA group (11.96 ± 0.92 years) 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.

CONCLUSION

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.

Maxillary protraction in patients with unilateral cleft lip and palate : Evaluation of soft and hard tissues using the Alt-RAMEC protocol

PURPOSE

The aim of this study was to evaluate the hard and soft tissue effects and differences of the Alt-RAMEC protocol to the facemask and conventional facemask protocols in patients with unilateral cleft lip and palate.

METHODS

This prospective study was carried out with 30 patients with unilateral cleft lip and palate with skeletal and dental class III malocclusions who were referred to a university department of orthodontics. The patients were evaluated with the cervical vertebral maturation method and divided into two groups, each consisting of 15 patients. The patients in group I (mean age 10.00 ± 0.73 years) were treated according to conventional facemask protocol, and the patients in group II (mean age 10.07 ± 2.43 years) were treated according to the Alt-RAMEC protocol before facemask application. Lateral cephalometric radiographs were evaluated by using the Dolphin Imaging Software version 11.7. The skeletal, dentoalveolar and soft tissue differences and treatment times were evaluated.

RESULTS

Group II demonstrated a 5.73° increase in SNA, which was statistically significant, while this increase was 3.13° in group I (p < 0.001). Results for Co‑A and A‑PTV showed a significant increase for group II only (group I: 1.02 mm, 1.06 mm, group II: 3.02 mm, 2.21 mm; p < 0.05 and p < 0.01, respectively). In addition, group II presented significant increase for the values of ANB, N‑A-Pg, SN/MP, Wits, U1-SN, U1-L1, U1-PTV, U1-FHP, U6-PTV, U6-FHP, overjet, Ss-PTV, UL-PTV and UL‑S line (p < 0.001). The treatment mean times were 7.3 months in group I and 4.7 months in group II (p < 0.01).

CONCLUSION

Applying the facemask after having followed the Alt-RAMEC protocol induced more skeletal, dentoalveolar and soft tissue changes in comparison to the conventional facemask protocol in patients with unilateral cleft lip and palate.

Banded versus modified appliances for anchorage during maxillary protraction

INTRODUCTION

The aim of this study was to compare banded versus modified appliances for anchorage during maxillary protraction in Class III malocclusions.

PATIENTS AND METHODS

The sample size consisted of 40 growing patients with Class III maxillary deficiency: 20 patients received maxillary protraction with a modified appliance and 20 patients with a banded appliance. Pre- and posttreatment cephalometric radiographs of all subjects were obtained and analyzed. The paired t‑test and Wilcoxon ranks test were used for statistical analysis.

RESULTS

The patients in the modified appliance group needed fewer appointments and shorter treatment time than those in the banded appliance group. The modified appliance was superior to the banded appliance with respect to simple structure, comfort, retention, and convenience in maintaining oral hygiene. The modified appliance was as effective as the banded appliance in correcting the Class III malocclusion. However, a greater increase was found in mandibular plane angle, anterior facial height, total facial height, mesialization of maxillary molars, and proclination of maxillary incisors in the banded appliance group compared with that in the modified appliance group (P < 0.05).

CONCLUSIONS

The newly developed modified appliance may be a promising approach in treating growing Class III patients with maxillary deficiency, which could decrease treatment time, increase treatment efficiency, and reduce anchorage loss.

3D effects of a bone-anchored intra-oral protraction in treating class III growing patient: a pilot study

OBJECTIVES

The aim of this prospective case series study is to assess the three-dimensional (3D) skeletal and soft tissue effects of the alternate rapid maxillary expansion and constriction (Alt-RAMEC) protocol in conjunction with a miniscrew-supported class III elastic wear in class III growing patients.

MATERIALS AND METHODS

Fourteen consecutive participants (mean age 12.05 ± 1.09 years), who displayed class III malocclusions with retrognathic maxillae, were recruited. A cone beam computed tomography (CBCT) scan was acquired before commencing treatment (T1). All participants were treated with a tooth-bone-borne rapid maxillary expansion (hybrid MARME) appliance that was activated by the Alt-RAMEC protocol for 9 weeks. This was followed by full-time class III elastics, delivering 400 g/side, to protract the maxilla. When a positive overjet was achieved, protraction was ceased and a post-treatment CBCT scan (T2) was taken. The 3D analysis of pre- and post-treatment CBCT scans was blinded. The scans were registered on the anterior cranial base. The Euclidean distance between the two extracted surface models of the pre- and post-treatment scans was displayed as a color surface map.

RESULTS

All participants completed the intervention successfully. The majority of the participants showed protraction of the anterior maxillary region (71.4%) and in the zygomatic processes (64.2%). The maxilla significantly protracted (SNA 1.87° ± 1.06°; Vert.T-A 3.29 ± 1.54 mm), while the mandibular base significantly redirected posteriorly (SNB - 2.03° ± 0.85°, Vert.T-B - 3.43 ± 4.47 mm) and that was reflected on the ANB and Wits measurements. No adverse effects were observed.

CONCLUSION

Class III elastics combined with the Alt-RAMEC activation protocol of the hybrid MARME appliance is an effective treatment method for mild/moderate class III malocclusions. A long-term follow-up and comparisons with other treatment modalities are required.

A Bayesian network meta-analysis of orthopaedic treatment in Class III malocclusion: Maxillary protraction with skeletal anchorage or a rapid maxillary expander

To evaluate and compare the effectiveness of orthopaedic treatment for Class III malocclusions using skeletal anchorage or a rapid maxillary expander for maxillary protraction. Electronic databases, including PubMed, EMBASE, Cochrane Library and Web of Science, were searched for randomized controlled trials (RCTs) and non-randomized clinical trials (CCTs) for orthopaedic treatment of Class III malocclusions. Five interventions were studied: a facemask with a maxillary temporary anchorage device (MTAD), a bone-anchored rapid maxillary expansion (BARME), a rapid maxillary expansion (RME), an alternate rapid maxillary expansion and contraction (Alt-RAMEC), and a bone-anchored intermaxillary traction (BAIMT). Eight outcomes (SNA, SNB, ANB, overjet, SN-GoGn, ANS-Me, IMPA (L1-MP), and U1-PP) were statistically polled. We conducted network meta-analysis using R statistical software with the GeMTC package. Twenty-five studies met the inclusion criteria. Compared with the RME group, the Alt-RAMEC group (mean difference (MD): 1.3; 95% credibility interval (CrI): 0.26, 2.3) and MTAD group (MD: 0.85; 95% CrI: 0.065, 1.6) showed a better effect on ANB in CCTs. Regarding the vertical relationship, the BAIMT group (MD: -2.2; 95% CrI: -5.2, 0.73) showed a smaller effect regarding increasing the vertical dimension of ANS-Me. The RME, MTAD and Alt-RAMEC group showed a higher ability to decrease the angle of L1-MP. The Alt-RAMEC and MTAD protocol have a higher possibility to obtain a skeletal and tooth effect in sagittal relationships. The BAIMT protocol can acquire a better skeletal effect in sagittal relationships with less vertical and dental changes. More well-designed RCTs are needed to ensure that the conclusion is reliable.

Effect of face mask therapy on mandibular rotation considering initial and final vertical growth pattern: A longitudinal study

Objectives

To evaluate the effect of maxillary protraction with facemask therapy on mandibular rotation taking into account the initial and final vertical growth pattern of each participant in order to evaluate our null hypothesis: The use of facemask in these patients does not modify their initial vertical growth pattern.

Material and Methods

A prospective single cohort study included children with Class III malocclusion treated with rapid palatal expansion and maxillary protraction with facemask. Cephalograms were taken before commencement and after completion of the facemask therapy with standardized equipment and magnification. Intraindividual cephalometric measurements were compared, and the vertical growth patterns were classified according to cephalometric standards. Potential changes in vertical growth pattern before and after completion of the facemask therapy was assessed by measuring Pearson's chi‐square and by multiple correspondence analysis.

Results

Thirty‐eight study participants were recruited, aged between 5.2 to 9.5 years (mean 7.5) at the commencement of facemask therapy, which lasted on average 1.6 years. Differences on pretherapy and posttherapy cephalograms were seen for linear rotational and sagittal measurements (p < .01) as well as angular measurements of the cranial base, including an average palatal plane rotation of 0.45° (standard deviation: 1.78) and an average mandibular rotation of 0.39° (standard deviation: 2.19). The majority of participants maintained their initial vertical growth pattern after facemask therapy according to the multiple correspondence analysis (p < .001).

Conclusion

Facemask therapy does not modify vertical growth pattern. The observed changes suggest a trend of maintaining each patient's initial growth direction after therapy.

Effects of Different Timing of Alveolar Bone Graft on Craniofacial Morphology in Unilateral Cleft Lip and Palate

OBJECTIVE

To evaluate the effect of the timing of secondary alveolar bone graft (SABG) on craniofacial morphology in patients with complete unilateral cleft lip and palate (UCLP).

DESIGN

Single-center retrospective assessment of consecutively treated nonsyndromic patients with complete UCLP.

PARTICIPANTS

One hundred sixty-seven patients (108 males, 59 females) with complete UCLP in whom the cleft was repaired with 1-stage method at approximately 8 months of age. The age of 128 patients at SABG varied from 1.4 to 11.5 years (SABG group), while 39 patients still awaited SABG at the moment of cephalometric evaluation (no-SABG group).

METHODS

Craniofacial morphology was assessed on lateral cephalograms taken at 10 years of age (standard deviation = 0.8; range: 7.5-12.3) using linear and angular measurements. T tests and regression models were made to analyze data.

RESULTS

Regression models demonstrated that the effect of SABG on the craniofacial morphology was limited-cephalometric variables which were statistically significantly different between SABG and no-SABG groups showed no association with the timing of SABG when (1) age of primary repair of the cleft, (2) age of cephalometric evaluation, (3) cleft side, (4) gender, and (5) operator were controlled for. Only the length of the maxilla (Condylion-point A) was affected-1-year delay of SABG corresponded with an increase in Co-point A distance by 0.52 mm. However, adjusted R ² of the model was 0.11.

CONCLUSIONS

Our findings cautiously indicate that SABG performed before 8 years of age can have limited negative effect on craniofacial morphology. Nevertheless, our results should be confirmed by cleft centers practicing alternative surgical repairs of the cleft.

Alternate Rapid Maxillary Expansion and Constriction (Alt-RAMEC) protocol: A Comprehensive Literature Review

The aim of this comprehensive review is to introduce clinicians to the increasingly popularity Alt-RAMEC procedure, a method commonly used in the treatment of class III malocclusion in the last 15 years. Another application of the literature to enhance the skeletal effects of Class III treatment on the maxillae is the Alternative Rapid Maxillary Expansion and Constriction (Alt-RAMEC) procedure introduced by Liou, which improves the effectiveness of the maxillae relative to the surrounding sutures and the enhancement of the maxillae. In the Alt-RAMEC protocol, maxillae will be enlarged to be 1 mm per day, first enlarged to 7 mm, and then the 1 mm screw is closed. In other weeks, in this order the screw of the expansion device is turned on for one week and then closed for one week, completing the Alt-RAMEC protocol at the end of the 9-week process. In this review, we will discuss the advantages and disadvantages of the studies, which include successful treatments by applying this protocol, differences with other methods, its effect on the airway, and its advantages and disadvantages.

Treatment with facemask and removable upper appliance versus modified tandem traction bow appliance: the effects on mandibular space

Objective

The aim of this study was to evaluate and compare the mandibular arch posterior space changes in Class III patients treated with facemask (FM) with removable upper appliance or modified tandem traction bow appliance (MTTBA).

Methods

Pre- and post-treatment and pre- and post-observation lateral cephalograms of 76 subjects with skeletal and dental Class III malocclusion from the period 2000-10 years formed the materials of this study. In the first group, 25 patients (10 girls, 15 boys; mean age: 10 years, 1 month) were treated with MTTBA. The average treatment time was 12 months. In the second group, 26 patients were treated (13 girls, 13 boys; mean age: 10 years, 4 months) with a Delaire-type FM. The average treatment time was 13 months. The remaining 25 children (9 girls, 16 boys; mean age: 9 years, 8 months) were observed without treatment for 10 months. ANOVA, Duncan, and paired t-tests were used for statistical evaluation.

Results

Although ramus width and mandibular posterior space increased significantly in all groups, no significant differences were found among the groups. Significant increase in tipping of lower molar (L6/GoMe) in the MTTBA group showed a significant difference compared with the FM and control groups. Significant retroclination of the lower incisors (L1/NB) in the MTTBA and FM treatment groups was significantly different compared with the control group. Retroclination of lower incisors in the MTTBA group was significantly greater than that in the FM group.

Conclusions

FM and MTTBA treatment approaches did not affect the dimensions of posterior space.

Limitations

To generalize the results of this study, long term evaluation by considering the third molar position should be done.

Developing Class III malocclusions: challenges and solutions

Class III malocclusion represents a growth-related dentofacial deformity with mandibular prognathism in relation to the maxilla and/or cranial base. Its prevalence varies greatly among and within different races, ethnic groups, and geographic regions studied. Class III malocclusion has a multifactorial etiology, which is the expression of a moderate distortion of normal development as a result of interaction between innate factors or genetic hereditary with environmental factors. Various skeletal topographies of underlying Class III malocclusion are due to discrepancy in the maxillary and mandibular growth along with vertical and/or transverse problems apart from sagittal malformations. The spectrum of complications for Class III malocclusion ranges in gravity from dentoalveolar problems with functional anterior shift of the mandible to true skeletal problems with serious maxillomandibular discrepancies, which makes its diagnosis highly challenging in growing children. Concern regarding early treatment and the need for interceptive care in the case of Class III malocclusion has always been a dilemma, knowing that not all problems will be solved in these cases until maxillomandibular growth is further completed, and the long-term outcome of various treatment approaches may depend on the growth tendency of an individual. Interceptive treatment of Class III malocclusions should be undertaken if it prevents damage to the oral tissues and/or significantly reduces the amount or severity of future orthodontic and surgical interventions. This paper presents an overview of developing Class III malocclusion, with the emphasis on challenges and their solutions based on the best current available evidence.

Early class III protraction facemask treatment reduces the need for orthognathic surgery: a multi-centre, two-arm parallel randomized, controlled trial

Objective: To evaluate whether patients who had received early class III protraction facemask treatment were less likely to need orthognathic surgery compared with untreated controls. This paper is a 6-year follow-up of a previous clinical trial. Design: Multi-centre 2-arm parallel randomized controlled trial. Setting: Eight United Kingdom hospital orthodontic departments. Participants: Seventy three 7- to 9–year-old children. Method: Patients were randomly allocated, stratified for gender, into an early class III protraction facemask group (PFG) (n = 35) and a control/no treatment group (CG) (n = 38). The primary outcome, need for orthognathic surgery was assessed by panel consensus. Secondary outcomes were changed in skeletal pattern, overjet, Peer Assessment Rating (PAR), self-esteem and the oral aesthetic impact of malocclusion. The data were compared between baseline (DC1) and 6-year follow-up (DC4). A per-protocol analysis was carried out with n = 32 in the CG and n = 33 in the PFG. Results: Thirty six percent of the PFG needed orthognathic surgery, compared with 66% of the CG (P = 0.027). The odds of needing surgery was 3.5 times more likely when protraction facemask treatment was not used (odds ratio = 3.34 95% CI 1.21–9.24). The PFG exhibited a clockwise rotation and the CG an anti-clockwise rotation in the maxilla (regression coefficient 8.24 (SE 0.75); 95% CI 6.73–9.75; P < 0.001) and the mandible (regression coefficient 6.72 (SE 0.73); 95% CI 5.27–8.18; P < 0.001). Sixty eight per cent of the PFG maintained a positive overjet at 6-year follow-up. There were no statistically significant differences between the PFG and CG for skeletal/occlusal improvement, self-esteem or oral aesthetic impact. Conclusions: Early class III protraction facemask treatment reduces the need for orthognathic surgery. However, this effect cannot be explained by the maintenance of skeletal cephalometric change.

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.

A novel method for treatment of Class III malocclusion in growing patients

Background

Management of Class III malocclusion is one of the most challenging treatments in orthodontics, and several methods have been advocated for treatment of this condition. A new treatment protocol involves the use of an alternating rapid maxillary expansion and constriction (Alt-RAMEC) protocol, in conjunction with full-time Class III elastic wear and coupled with the use of temporary anchorage devices (TADs). The aim of this study was to evaluate the dento-skeletal and profile soft tissue effects of this novel protocol in growing participants with retrognathic maxilla.

Methods

Fourteen growing participants (7 males and 7 females; 12.05 ± 1.09 years), who displayed Class III malocclusions with retrognathic maxilla, were recruited. Pre-treatment records were taken before commencing treatment (T1). All participants had a hybrid mini-implant-supported rapid maxillary expansion (MARME) appliance that was activated by the Alt-RAMEC protocol for 9 weeks. Full-time bone-anchored Class III elastics, delivering 400 g/side, were then used for maxillary protraction. When positive overjet was achieved, protraction was ceased and post-treatment records were taken (T2). Linear and angular cephalometric variables were blindly measured by one investigator and repeated after 1 month. An error measurement (Dahlberg’s formula) study was performed to evaluate the intra-examiner reliability. A paired-sample t test (p < 0.05) was used to compare each variable from T1 to T2.

Results

Treatment objectives were achieved in all participants within 8.5 weeks of protraction. The maxilla significantly protracted (SNA 1.87°± 1.06°; Vert.T-A 3.29± 1.54 mm p < 0.001), while the mandibular base significantly redirected posteriorly (SNB −2.03° ± 0.85°, Vert.T-B − 3.43± 4.47 mm, p < 0.001 and p < 0.05 respectively), resulting in a significant improvement in the jaw relationship (ANB 3.95°± 0.57°, p < 0.001; Wits 5.15± 1.51 mm, p < 0.001). The Y-axis angle increased significantly (1.95° ± 1.11°, p < 0.001). The upper incisors were significantly proclined (+ 2.98°± 2.71°, p < 0.01), coupled with a significant retroclination of the lower incisors (− 3.2°± 3.4°, p < 0.05). The combined skeletal and dental effects significantly improved the overjet (5.62± 1.36 mm, p < 0.001) and the soft tissue Harmony angle (2.75° ± 1.8°, p < 0.001).

Conclusions

Class III elastics, combined with the Alt-RAMEC activation protocol of the MARPE appliance, is an efficient treatment method for mild/moderate Class III malocclusions. The long-term stability of these changes needs further evaluation.

Stretch force guides finger-like pattern of bone formation in suture

Mechanical tension is widely applied on the suture to modulate the growth of craniofacial bones. Deeply understanding the features of bone formation in expanding sutures could help us to improve the outcomes of clinical treatment and avoid some side effects. Although there are reports that have uncovered some biological characteristics, the regular pattern of sutural bone formation in response to expansion forces is still unknown. Our study was to investigate the shape, arrangement and orientation of new bone formation in expanding sutures and explore related clinical implications. The premaxillary sutures of rat, which histologically resembles the sutures of human beings, became wider progressively under stretch force. Micro-CT detected new bones at day 3. Morphologically, these bones were forming in a finger-like pattern, projecting from the maxillae into the expanded sutures. There were about 4 finger-like bones appearing on the selected micro-CT sections at day 3 and this number increased to about 18 at day 7. The average length of these projections increased from 0.14 mm at day 3 to 0.81 mm at day 7. The volume of these bony protuberances increased to the highest level of 0.12 mm³ at day 7. HE staining demonstrated that these finger-like bones had thick bases connecting with the maxillae and thin fronts stretching into the expanded suture. Nasal sections had a higher frequency of finger-like bones occuring than the oral sections at day 3 and day 5. Masson-stained sections showed stretched fibers embedding into maxillary margins. Osteocalcin-positive osteoblasts changed their shapes from cuboidal to spindle and covered the surfaces of finger-like bones continuously. Alizarin red S and calcein deposited in the inner and outer layers of finger-like bones respectively, which showed that longer and larger bones formed on the nasal side of expanded sutures compared with the oral side. Interestingly, these finger-like bones were almost paralleling with the direction of stretch force. Inclined force led to inclined finger-like bones formation and deflection of bilateral maxillae. Additionally, heavily compressive force caused fracture of finger-like bones in the sutures. These data together proposed the special finger-like pattern of bone formation in sutures guided by stretch force, providing important implications for maxillary expansion.

Effects of hybrid-Hyrax, Alt-RAMEC and miniscrew reinforced heavy Class III elastics in growing maxillary retrusive patients. A four-year follow-up pilot study

Introduction

The aim of this study was to evaluate the short- and long-term effects of hybrid-Hyrax, Alt-RAMEC and applied, miniscrew reinforced, heavy intermaxillary elastics on a modified lingual arch in growing skeletal Class III patients.

Methods

Fifteen subjects (seven male, eight female) were included, with an average age of 12.52 ± 0.94 years, of cervical vertebrae maturation (CVM) stage CS2-CS4 and skeletal Class III malocclusions due to a retrognathic maxilla. Nine weeks of Alt-RAMEC were followed by eight to nine weeks of maxillary protraction with heavy 400 gm Class III elastics worn 24 h/day. Treatment was finalised with orthodontic fixed appliances. Cone beam computed tomographic (CBCT) scans were taken initially (T1), at the end of maxillary protraction (T2) and four years after active orthopaedic treatment (T3). Cephalometric measurements were performed on reconstructed lateral cephalograms and the differences between time intervals were calculated using an analysis of variance (ANOVA).

Results

A positive overjet was achieved in all but one subject. From T1 to T2, A point advanced 3.12 ± 3.42 mm and from T2 to T3 advanced a further 2.21 ± 3.49 mm. Significant initial increases in SNA of 1.05° ± 1.10° (p = 0.004), ANB of 2.71° ± 1.01° (p = 0.00), Wits of 4.49 ± 2.21 mm (p = 0.00) and overjet of 4.90 ± 1.66 mm (p = 0.00) were accomplished and maintained without significant changes in the vertical dimension. Upper and lower incisor inclinations were not affected by the protraction protocol but significantly increased (U1-PP: 8.39° ± 5.59°) between T2 and T3. SNB decreased initially by 1.67° ± 1.34° (p = 0.00) but relapsed due to residual mandibular growth and a counterclockwise rotation of the mandibular plane.

Conclusion

The hybrid-Hyrax Alt-RAMEC combined with miniscrew reinforced heavy Class III elastics resulted in a favourable and stable Class III correction.

Evaluation of the stiffness characteristics of rapid palatal expander screws

Background

The aim of this study is to evaluate the mechanical properties of the screws used for rapid expansion of the upper jaw.

Methods

Ten types of expansion screw were assessed, seven with four arms: Lancer Philosophy 1, Dentaurum Hyrax Click Medium, Forestadent Anatomic Expander type “S”, Forestadent Anatomic Expander type “S” for narrow palates, Forestadent Memory, Leone A 2620-10 with telescopic guide, and Leone A 0630-10 with orthogonal arms; and three with two arms: Dentaurum Variety S.P., Target Baby REP Veltri, and Leone A 362113. A test expander with the mean dimensions taken from measurements on a sample of 100 expanders was constructed for each screw. The test expanders were connected to the supports of an Instron 4467 (Instron Corp., USA) mechanical testing machine equipped with a 500 N load cell, and the compression force exerted after each activation was measured. The mean forces expressed by the two- and four-arm expanders were then compared.

Results

After five activations, the forces expressed by the two-arm devices were double than those expressed by the four-arm devices on average (224 ± 59.9 N vs. 103 ± 32.9 N), and such values remained high after subsequent activations.

Conclusions

The expanders tested demonstrated stiffness characteristics compatible with opening of the palatine sutures in pre-adolescent patients. The stiffness of such devices can be further increased during the construction phase.