Opening of circumaxillary sutures by alternate rapid maxillary expansions and constrictions

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.

Class III treatment with mini-implants anchorage in young adult patients: short and long-term results

INTRODUCTION

Class III malocclusion should be intercepted and treated at early age, to prevent the necessity of future complex and expensive procedures. The orthopedic facemask therapy has the goal to achieve skeletal changes, minimizing side effects on dentition. The use of skeletal anchorage, combined with Alternate Rapid Maxillary Expansion and Constriction (Alt-RAMEC) protocol, may be effective in treating a greater number of growing Class III patients.

OBJECTIVE

To summarize the existing evidence-based literature on Class III malocclusion treatment in young adult patients, and to illustrate its application and effectiveness, by presenting an emblematic case report.

CONCLUSION

The resolution of the present case, its long-term follow up, along with the studies conducted on a larger sample, demonstrate the effectiveness of the strategic combination of orthopedic and orthodontic treatments by using an hybrid rapid palatal expander and Alt-RAMEC protocol for treating Class III malocclusions in adult patients.

Analysis of the Frequency and Correlated Factors of Midpalatal Suture Maturation Stages in Young Adults, Based on Cone Beam Computed Tomography Imaging

BACKGROUND

The choice of whether to perform a palatal disjunction in constricted maxilla has traditionally been decided based on the age of the patients, although there are gradually increasing references to the fact that this is not a determining factor. The main goal of this study was to evaluate the frequency of the different stages of midpalatal suture maturation in a sample of young adults between 15 and 30 years of age. Other objectives also included analyzing the possible correlation the maturation stages could maintain with sex and age groups.

METHODS

142 Cone Beam Computed Tomography (CBCT) scans of young adults were performed. The images were divided into four age groups based on age ranges of 15-18, 19-22, 23-26, and 27-30 years. Each group consisted of 26, 41, 39, and 36 patients, respectively, which were classified using Angelieri's method. In addition, sex and age groups were considered as variables, and the possible correlation of the prevalence of each one, according to age and sex, was studied.

RESULTS

the sample was classified into 4.9% stage B; 52.1% stage C; 27.5% stage D; and 15.5% stage E. In addition, no statistically significant correlation between sex and the maturation stages was found, but more advanced stages did appear to be related to the chronological age of the subjects.

CONCLUSIONS

The frequency of maturational stages where the suture is shown to be consolidated did not appear to be as high as expected; therefore, the idea of rejecting transverse plane treatment in a conventional manner in an out-of-growth patient should be discarded.

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

BACKGROUND

Regardless 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 METHODS

27 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.

RESULTS

Point 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.

CONCLUSION

Despite 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.

Management of skeletal Cl III malocclusion using simultaneous alternate rapid maxillary expansion and constriction (Alt-RAMEC) and facemask protraction in adolescence

Cl III malocclusion with a significant skeletal component presents a therapeutic challenge during adolescence. This article presents the encouraging results of an individualized two-stage treatment approach adopted for successful nonsurgical correction of severe skeletal Cl III malocclusion in an adolescent girl after the onset of puberty. An orthopedic approach involving simultaneous alternate rapid maxillary expansion and constriction (Alt-RAMEC) protocol and protraction facemask (PFM) therapy was adopted in phase 1 to correct the sagittal skeletal discrepancy. In phase 2, fixed orthodontic therapy aided by the interim use of a modified occlusal settling appliance was undertaken to obtain well-interdigitated occlusion. Meticulously planned and well-executed orthopedic and orthodontic approach, combined with good patient compliance and favorable growth pattern, helped establish well-balanced facial harmony with a proper maxillomandibular relationship and satisfactory overjet and overbite. The results remained stable during the 4-year follow-up. Alt-RAMEC-PFM therapy accompanied by fixed mechanotherapy is a viable option to treat severe skeletal Cl III malocclusion in adolescents.

[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.

Parathyroid hormone promotes maxillary expansion and reduces relapse in the repeated activation maxillary expansion rat model by regulating Wnt/β-catenin pathway

Background

Constricted maxillary bone is a common skeletal deformity, which may lead to crowding and posterior crossbite. Mid-palatal suture expansion is often used to increase the maxillary width, but its skeletal effects are limited and tend to relapse, even with prolonged retention. We hypothesized that parathyroid hormone (PTH) may reduce the relapse of maxillary expansion.

Methods

We established a novel rat maxillary expansion model using palatal tubes with an insertable “W”-shaped spring which can be repeatedly activated. A total of 32 male healthy Wistar rats were randomly divided into six groups: the control group, the PTH group, the expansion group, the expansion + PTH group, the expansion + relapse group and the expansion + PTH + relapse group. All animals in the first 4 groups were killed after 10 days and the 2 relapse groups were killed after 15 days. The maxillary arch widths and histological staining were used to assess the expansion and relapse effects. The immunohistochemical staining, micro-CT, RT-qPCR and Western blot were used to evaluate the bone remodeling during expansion.

Results

The suture width was increased by the expansion device, and the repeated activation maxillary expansion rat model showed better expansion effects than the conventional model. PTH significantly promoted the expansion width and reduced the relapse ratio. Meanwhile, in the expansion + PTH group, histological and immunohistochemical staining showed that osteoblasts, osteoclasts, new cartilage and osteoid were significantly increased, micro-CT showed increased bone mass, and PCR and Western blot results confirmed up-regulation of RANKL, β-catenin, type II collagen and OCN.

Conclusion

The novel repeated activation maxillary expansion rat model has better effects than the conventional model. PTH enhances the maxillary expansion and reduces its relapse by regulating Wnt/β-catenin and RANKL pathways. PTH administration may serve as an adjunctive therapy in addition to mechanical expansion for treatment of maxillary constriction.

Short-term effects of microimplant-assisted rapid palatal expansion on the circummaxillary sutures in skeletally mature patients: A cone-beam computed tomography study

INTRODUCTION

This study aimed to investigate the short-term effects on the circummaxillary sutures induced by microimplant-assisted rapid palatal expansion (MARPE) in skeletally mature patients.

METHODS

Cone-beam computed tomography (CBCT) images of preexpansion (T0) and postexpansion (T1) of 23 patients (mean age, 20.9 ± 3.65 years) treated with MARPE were evaluated. The T0 and T1 CBCT images were reoriented and superimposed on the basis of the anterior cranial base, using OnDemand3D software (Cybermed, Seoul, Korea). Then, width changes of 9 circummaxillary sutures (frontonasal, frontomaxillary, frontozygomatic, nasomaxillary, zygomaticomaxillary, intermaxillary, midpalatal, zygomaticotemporal, and pterygopalatine sutures) were measured on 1 section of each patient's T0 and T1 CBCT images. In addition, correlation coefficients between changes in the midpalatal sutures, the amount of appliance activation, age, and the changes in other circummaxillary sutural widths were also calculated.

RESULTS

Statistically significant (P <0.05) width increases were found in all 9 circummaxillary sutures. The changes in midpalatal suture at the maxillary central incisor level positively correlated with the intermaxillary sutures at the anterior nasal spine level, midpalatal sutures at the posterior nasal spine level, and frontomaxillary sutures (P <0.05). In addition, the changes in the midpalatal sutures at the posterior nasal spine level also positively correlated with the changes in the intermaxillary sutures at the anterior nasal spine level, frontomaxillary sutures, and medial pterygopalatine sutures (P <0.05).

CONCLUSIONS

All 9 circummaxillary sutural widths increased in skeletally mature patients immediately after MARPE. The greatest increases in width were measured in the midpalatal sutures and the intermaxillary sutures, followed by the frontomaxillary sutures.

Long-term follow-up of late maxillary orthopedic advancement with the Liou-Alternate rapid maxillary expansion-constriction technique in patients with skeletal Class III malocclusion

INTRODUCTION

The objective of this study was to evaluate short and long-term results of the application of the alternate rapid maxillary expansion/constriction (Alt-RAMEC) technique in patients with skeletal Class III malocclusion.

METHODS

Forty-two white patients were consecutively treated with the Alt-RAMEC technique. The average age of the patients was 12.7 ± 1.6 years (range, 9.4-15.9 years) before protraction. The average age at long-term follow-up was 19.4 ± 2.8 years (range, 17.2-26.9 years). A sample of nontreated patients with Class III malocclusion from the archives of orthognatic surgery in our hospital was used as a control group. The initial records were matched for sex, the severity of Class III malocclusion, and age (mean, 12.1 ± 1.4 years; range, 9.7-14.1 years) with the old records available in the archive. The control sample had records presurgery (mean, 19.8 ± 2.2 years; range, 16.6-21.6 years).

RESULTS

The sagittal advancement of A-point, after the application of the technique, was 5.43 ± 2.71 mm. Some mandibular dentoalveolar adaptation was noted. The position of the maxilla was stable in the long term. In contrast, the control group showed limited growth at the maxillary level during the long-term follow-up period.

CONCLUSIONS

Our results showed that the Alt-RAMEC technique, performed at the correct time, with a double-hinged expander, followed by Class III spring or elastic traction, 24 h/d, allows for satisfactory maxillary protraction, with stable long-term results. The comparison with a sample of matched nontreated patients with Class III malocclusion allowed to suggest the positive effect of the treatment on the maxillary position vs the natural evolution of the Class III skeletal discrepancy.

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

OBJECTIVE

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

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.

Deformation of the circummaxillary sutures during acute micro-implant assisted rapid palatal expansion and tooth-supported expansion: An ex vivo study

INTRODUCTION

This study aimed to assess and compare the deformation that develops in the circummaxillary sutures during activation of micro-implant assisted rapid palatal expander (MARPE) and tooth-supported expander (Hyrax) s, in the rapid maxillary expansion.

SETTINGS AND SAMPLE

7 pigs Sus Scrofa received custom-made MARPE (n = 3) and Hyrax (n = 4) appliances.

MATERIAL AND METHODS

The devices were activated 25 times with strain readings captured by strain gauges attached to the following regions: posterior midpalatal suture (MPS), maxilla-premaxilla suture (MPM), maxilla-zygomatic suture (MZ) and maxilla pterygoid-process suture (MPP). The intermolar distance and suture width were measured immediately before activation and at the 20th and 25th activation. ANOVA and Kruskal-Wallis test was applied.

RESULTS

The MARPE group presented greater MPS displacement in all measured regions, and one of the devices produced a significant opening (1.7 mm) in the posterior region. The accumulated tension in the MPS was higher compared to the other sutures (P < .05). A MARPE animal presented higher median tension in the MPS region (294.77με) compared to all other animals except one Hyrax animal (P < .05). Regarding the median tensions of the different activation intervals, the median tension measured during the 16th to 25th activation interval in the Hyrax group was lower than that measured during the first 8 activations, in both the MPS and MZ (P < .05).

CONCLUSIONS

MARPE expanders developed more constant tensions during all activations (MPS and MZ), while Hyrax showed lower tension in the 16th to 25th activation.

Three-dimensional evaluation of treatment results of the Alt-RAMEC and facemask protocol in growing patients

PURPOSE

The aim of this retrospective study was to evaluate the skeletal, dental, and soft tissue effects of the alternating rapid maxillary expansions and constrictions (Alt-RAMEC) protocol combined with a facemask in prepubertal patients.

METHODS

The study group (mean age 9.74 ± 1.46 years) consisted of 20 patients with class III malocclusion characterized by maxillary retrognathism. They were treated with a facemask for 7 months following a 9‑week Alt-RAMEC protocol. Cone-beam computed tomography (CBCT) records and three-dimensional (3D) photographs taken before (T0) and after the protraction and retention period (T1) were evaluated. The study group was compared with a well-matched control group of 16 untreated patients (mean age 9.44 ± 0.79 years) with the same malocclusion. The records for the control group included cephalometric radiographs and 3D photographs.

RESULTS

In the study group, significant forward movements of A point (3.49 mm), nasal (2.91 mm) and zygomatic bones were achieved. Intermolar, internasal, and interzygomatic widths increased. Soft tissue points followed the hard tissue movements, apart from b and pog. In the control group, A (0.97 mm), B (1.69 mm), Pog, and b points presented forward movement. Significant differences were found regarding the forward movement of the maxilla between the groups.

CONCLUSION

The Alt-RAMEC/facemask protocol was effective not only in the maxillary region but also in the midface.

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.

Comparison of skeletal anchorage and tooth-borne maxillary protraction followed by fixed appliance in Class III malocclusion

Objectives

The purpose of this study was to compare the results of skeletal anchorage (SAMP) and tooth- borne (TBMP) maxillary protraction followed by fixed appliance in growing skeletal Class III patients.

Materials and methods

Patients treated with maxillary protraction were selected and classified into two groups (SAMP: n = 19, mean age = 11.19 years; TBMP: n = 27, mean age = 11.21 years). Lateral cephalograms taken before treatment (T0), after the maxillary protraction (T1), and after the fixed appliance treatment (T2) were analysed and all variables were statistically tested to find difference between the two groups.

Results

Compared to the TBMP, the SAMP showed significant forward growth of maxilla (Co-A point and SN-Orbitale) and improvement in intermaxillary relationship (ANB, AB to mandible plane, and APDI) after the overall treatment (T0–T2), with no significant sagittal changes in maxilla or mandible throughout the fixed appliance treatment (T1–T2).

Limitations

In maxillary protraction, effects of skeletal anchorage were retrospectively compared with those of dental anchorage, not with Class I or III control.

Conclusions and implications

After maxillary protraction, skeletal and tooth-borne anchorage did not cause significant differences in the residual growth of maxilla throughout the phase II treatment. Orthopaedic effects with skeletal anchorage showed appropriate stability in maxilla and intermaxillary relationship even after fixed appliance treatment.

Dentofacial Effects of Modified Alt-RAMEC Protocol Combined with the Facial Mask for Treatment of Preadolescent Caucasian Class III Patients

Introduction

In this study we analyzed dentoskeletal effects of orthopedic therapy with rapid palatal expander (RME), used according to modified Alt-RAMEC protocol, followed by facial mask in preadolescent patients with class III malocclusion.

Materials and methods

The sample consisted of 10 patients treated consecutively with the alternate rapid maxillary expansions and constrictions (Alt-RAMEC) protocol and facial mask before the pubertal growth spur the patients were re-evaluated after about one year of treatment. We compared the cephalometric analyses at T0 (before the treatment) and T1 (just after the end of the treatment—about 1 year), evaluating 18 parameters. The normality of each distribution was assessed with D’Agostino-Pearson normality test and significative differences between T0 and T1 were assessed with paired t test (p < 0.05).

Results

Sagittal measurements of the maxilla (SNpSNa distance) showed significant improvements (p < 0.0001) with protraction effect at point A. Significant improvements were recorded also at Wits appraisal and overjet. Measures of the mandibular growth (Co-Gn) showed increased values at T1, as well as vertical dimension (SNpSNa-GoGn). No significant variations were recorded at the dental parameters.

Conclusion

This protocol induces important skeletal effects, like advancement of the maxilla, also in preadolescent patients, while dental changes are minimal. Alt-RAMEC protocol seem to modulate maxillary development in patients near the pubertal growth spurt.

How to cite this article

Rota E, Ferrari M, et al. Dentofacial Effects of Modified Alt-RAMEC Protocol Combined with the Facial Mask for Treatment of Preadolescent Caucasian Class III Patients. Int J Clin Pediatr Dent 2019;12(3):222–228.

Surgical/Orthodontic Correction of Transverse Maxillary Discrepancies

The transverse dimension is a critical component of comprehensive treatment in orthognathic surgery. Several treatment approaches exist and the team must consider the patient's needs, desires, and limitations when working to correct the malocclusion. Treatment approaches may include only orthodontic expansion or rapid palatal orthodontic expansion; however, in adults, the orthodontist may require surgical assistance to expand the bony maxilla. Segmental maxillary expansion may be indicated in severe transverse deficiencies of the maxillary arch or dentofacial deformity patients also requiring vertical and sagittal corrections. The various treatment options, advantages, and disadvantages, and indications for each surgical approach are discussed.

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.

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.

The immediate effect of alternate rapid maxillary expansions and constrictions on the alveolus: a retrospective cone beam computed tomography study

Background

Rapid maxillary expansion reduced the expander’s anchor teeth buccal alveolar bone thickness. However, the effects of alternate rapid maxillary expansions and constrictions (Alt-RAMEC) on the expander’s anchor teeth alveolar thickness has not been assessed. The purpose of this retrospective study was to evaluate the effects of Alt-RAMEC on the alveolus surrounding the anchor teeth of a double-hinged expander.

Methods

Twenty-six individuals, including 12 males (11.5 ± 1.00 years) and 14 females (11.5 ± 0.90 years), who had double-hinged expander for 7 weeks of Alt-RAMEC and then 3 months of maxillary protraction, were included. Their cone beam computed tomography (CBCT) images taken 3–6 months before treatment (T0) and after 7 week of Alt-RAMEC (T1), were studied for the buccal alveolar bone thickness (BABT) and palatal alveolar bone thickness (PABT) of the expander’s anchor teeth (first molars and first and second premolars) in four axial sections. The intra-class correlation coefficient, Dahlberg’s formula, and paired t tests were used to analyze the method errors, and the intra-group changes of the BABT and PABT at T0-T1 were analyzed by paired t test (p < 0.05).

Results

The 7 weeks of Alt-RAMEC significantly reduced the BABT of the expander’s anterior anchor teeth (0.54~ 70 mm, p < 0.05) and at the cervical region (0.14~ 0.25 mm, p < 0.05), but not at the apical region of the expander’s posterior anchor teeth. The reduction of BABT by 7 weeks of Alt-RAMEC was within the scope of the initial BABT. On the opposite, the Alt-RAMEC significantly (p < 0.05) increased the PABT in the anterior anchor teeth and the cervical region of posterior anchor teeth.

Conclusions

A 7-week protocol of Alt-RAMEC with double-hinged expander for maxillary protraction might reduce the buccal alveolar bone thickness of the expander’s anchor teeth, although the reduction is within the scope of initial alveolar thickness of the expander’s anchor teeth.

Short- and Long-Term Effects of Late Maxillary Advancement With the Liou-Alt-RAMEC Protocol in Unilateral Cleft Lip and Palate

Objective:

The objective of this retrospective longitudinal study was to evaluate short- and long-term results of the application of the Liou Alt-RAMEC (alternate rapid maxillary expansion and constriction) technique, a late orthopedic maxillary protraction technique, with intraoral anchorage, in patients with cleft.

Materials and Methods:

Twenty-six patients with unilateral cleft lip and palate (UCLP) were consecutively treated with the Alt-RAMEC technique. The average age of the patients was 11.7 years (10.3-13.2 years) before protraction and 18.3 years (17.4-21.1 years) at long-term follow-up. A sample of nontreated patients with UCLP was used as a control group. It was matched for sex, skeletal class III, and age (11.3 years). The control sample had records at the end of growth (18.7 years).

Results:

The sagittal advancement of A-point, after the application of the technique, was 5.7 (2.17) mm. Some mandibular dentoalveolar and positional adaptation was noted. The position of the maxilla was stable in the long term. On the other hand, the UCLP control group showed hardly any growth at the maxillary level during the long-term follow-up period.

Conclusion:

Our results showed that the Alt-RAMEC technique, performed at the correct time, with a double-hinged expander, followed by class III spring or elastic traction, 24 hours per day, allows for satisfactory maxillary protraction, with, at this stage, apparently stable long-term results. Nevertheless, as only 50% of the patients had long-term follow-up data, we are still unable to predict the percentage of patients which will not eventually need orthognathic surgery.

[Not Available]

Le Pr Ravindra Nanda a obtenu une licence et une maîtrise en dentisterie et en orthodontie du King George's Medical College, Lucknow University. En 1967, il a intégré l'Université Catholique de Nimègue, aux Pays-Bas, où il a obtenu un doctorat en philosophie en 1969. Il a rejoint la nouvelle école dentaire de Loyola à Chicago en 1970, après avoir occupé le poste de Professeur assistant en orthodontie dans le service dirigé par Frans van der Linden. En 1972, il fut promu au Département d'Orthodontie de l'Université du Connecticut à Farmington, CT, et y reçu son certificat en orthodontie sous la direction de Charles Burstone. Professeur adjoint, puis professeur titulaire à partir de 1979, il a assumé le poste de Chef du Département d'Orthodontie à partir de 1992 et a été promu pour diriger le Département des Sciences Craniofaciales en 2004, dont les divisions de chirurgie orale et maxillo-faciale, de dentisterie pédiatrique, de l'enseignement supérieur en dentisterie générale et en orthodontie.

Il est membre et ancien président de la composante Atlantique Nord de la Edward H. Angle Society of Orthodontists. Il occupe actuellement la fonction de rédacteur en chef de Progress in Orthodontics, de rédacteur associé du Journal of Clinical Orthodontics et est membre du comité éditorial de neuf revues d'orthodontie nationales et internationales. Il est membre de l'Association dentaire américaine, de l'Association dentaire de l'État du Connecticut, de la Hartford Dental Society, de l'Association américaine des orthodontistes, de la Société européenne d'orthodontie, de l'Association internationale de recherche dentaire et du College of Diplomates of American Board of Orthodontists.

Il a rédigé et publié sept manuels et plus de 200 articles dans des revues à comité de lecture. Il a donné des conférences magistrales dans plus de 40 pays et a reçu de nombreux prix et honneurs pour ses contributions en dentisterie et en orthodontie, aux États-Unis et de la part d'organisations internationales d'orthodontie. Il est membre d'honneur des Jordan Orthodontic Society, Czech Orthodontic Society, Taiwanese Orthodontic Society, Central American Orthodontics Society et membre d'honneur à vie de l'Indian Orthodontic Society.

Ravindra Nanda a été honoré du Life Time Achievement Award (University of Connecticut Foundation), et il est Senior Research Fellow (Japan Promotion for Science, Sendai, Japan − Tohoku University). Il a prononcé de nombreuses conférences d'honneur : la John Taylor Lecture, lors de la réunion annuelle de l'Australian Society of Orthodontics Foundation, la Sheldon Friel Memorial Lecture lors de la réunion annuelle de l'European Orthodontic Society, la Gordon Kirkness Memorial Lecture lors de la réunion annuelle de l'Australian Society of Orthodontics, la John Mershon Memorial Lecture, Boston, Massachusetts lors de la réunion annuelle de l'American Association of Orthodontics et la Wendell L. Wylie Memorial Lecture, à l'Université de San Francisco, Californie.

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[Effects of strontium ranelate on the rats' palatal suture after rapid maxillary expansion]

OBJECTIVE

This study investigated the effects of strontium ranelate (SrR) on the rats' palatal suture after rapid maxillary expansion (RME).

METHODS

Thirty-six male 6-week-old Wistar rats were randomly divided into three groups: control group (A), expansion only group (B), and expansion plus SrR group (C). Each group comprised 12 rats. Neither expansion nor SrR was given to group A. Each rat in groups B and C was set an orthodontic appliance with an initial expansive force of 1 N. The rats in group C were administered with SrR (600 mg·kg⁻¹ body weight) at the same time every day after RME. All the rats were then euthanized in batches on days 4, 7, and 10. The width of the rats' upper jaw was measured. Histological observation was used to section the rats and count the osteoblasts.

RESULTS

After the RME, no statistical difference was observed on the rats' upper jaw width in group A (P>0.05). However, the change of upper jaw width in groups B and C presented a statistical significance (P<0.05). By contrast, no statistical difference was observed between groups B and C (P>0.05). The rats' sections were placed under a microscope, and some red fibrous tissues, mesenchymal cells, chondrocytes, and osteoblasts were observed in group A. More red fibrous tissues, mesenchymal cells, and chondrocytes were observed in groups B and C. In addition, more osteoblasts were observed on the edge of mid-palatal suture of the rats. Group C contains more osteoblasts than group B.

CONCLUSIONS

RME can expand the mid-palatal suture of rats, which were in the growth development period, and increase the width of dental arch. SrR may promote osteoblast differentiation and hasten new bone formation in the expanded mid-palatal suture. Both conditions accelerate new bone formation and bone deposition calcification, which may be therapeutically beneficial to prevent relapse after RME.

Treatment Options for Class III Malocclusion in Growing Patients with Emphasis on Maxillary Protraction

It is very difficult to diagnose and treat Class III malocclusion. This type of malocclusion involves a number of cranial base and maxillary and mandibular skeletal and dental compensation components. In Class III malocclusion originating from mandibular prognathism, orthodontic treatment in growing patients is not a good choice and in most cases orthognathic surgery is recommended after the end of growth. Approximately 30-40% of Class III patients exhibit some degree of maxillary deficiency; therefore, devices can be used for maxillary protraction for orthodontic treatment in early mixed dentition. In cases in which dental components are primarily responsible for Class III malocclusion, early therapeutic intervention is recommended. An electronic search was conducted using the Medline database (Entrez PubMed), the Cochrane Collaboration Oral Health Group Database of Clinical Trials, Science Direct, and Scopus. In this review article, we described the treatment options for Class III malocclusion in growing patient with an emphasis on maxillary protraction. It seems that the most important factor for treatment of Class III malocclusion in growing patient is case selection.

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

INTRODUCTION

The objective of this randomized controlled trial was to investigate the effects of facemask protraction combined with alternating rapid palatal expansion and constriction (RPE/C) vs rapid palatal expansion (RPE) alone in the early treatment of maxillary retrusive patients.

METHODS

Patients with a midface deficiency were recruited and randomly allocated into either the control group (RPE) or the intervention group (RPE/C). Eligibility criteria included the following: age 7 to 13 years old, Class III malocclusion, anterior crossbite, ANB less than 0°, Wits appraisal less than -2 mm, A-Np less than 0 mm, and no cleft of lip or palate. The primary outcome was the degree of maxillary forward movement after treatment. The secondary outcomes were the changes of the other cephalometric variables after treatment and the treatment time. Simple randomization was carried out using a random number table at the beginning of the study. Envelopes containing the grouping information were used to ensure allocation concealment from the researchers. Blinding was applicable for cephalometric analysis only. Hyrax palatal expanders and facemask maxillary protraction were used in all patients. Patients in the RPE group were treated with rapid palatal expansion for 1 week. Patients in the RPE/C group were treated with RPE/C for 7 weeks. The expansion or constriction rate was 1 mm per day. Cephalometric analysis with traditional cephalometric measurements and an x-y coordinate system were used to compare the pretreatment and posttreatment cephalometric radiographs. Independent t tests were used to compare the data between the 2 groups.

RESULTS

A total of 44 patients were randomized to either the RPE group or the RPE/C group in a 1:1 ratio. One subject in the RPE group was lost to follow-up during the treatment. Per-protocol analysis was used. All the other 43 patients reached the treatment completion criteria and were analyzed (RPE group: n = 21; RPE/C group: n = 22). The average protraction time was 10.84 months in the RPE group, which was significantly longer than that in the RPE/C group (9.06 months) (effect size [ES], 1.78 [95% CI, 0.15, 3.42; P = 0.033]). Maxillary forward movement increased by 3.04 mm in the RPE/C group, which was significantly greater than that in the RPE group (2.11 mm) (ES, -0.93 [95% CI, -1.65, -0.20; P = 0.013]). The counterclockwise rotation of the palatal plane was 1.73° in the RPE/C group, which was significantly greater than that in the RPE group (0.83°) (ES, 0.90 [95% CI, 0.08, 1.73; P = 0.033]). The degree of mandibular downward and backward rotation was significantly smaller in the RPE/C group (P <0.05). No serious harm was observed during treatment and research.

CONCLUSIONS

Facemask maxillary protraction with RPE/C might positively affect the forward movement of the maxilla compared with facemask protraction with RPE alone in the early treatment of maxillary retrusive patients. Although the differences between the groups were statistically significant for forward movement of the maxilla and rotation of the palatal and mandibular planes, these may not be clinically relevant, since the differences were less than 1 mm and 1°, respectively.

REGISTRATION

This trial was not registered.

PROTOCOL

The protocol was not published before trial commencement.

FUNDING

This research was supported by Peking University Research Fund. No conflict of interest is declared.

Orthopaedic protraction of the maxilla with miniplates: treatment of midface deficiency

Class III malocclusion is a consequence of maxillary deficiency and/or mandibular prognathism, resulting in an anterior crossbite and a concave profile. Early class III malocclusion treatment with reverse pull headgear generally results in maxillary skeletal protraction but is frequently also accompanied by unfavourable dentoalveolar effects. Titanium miniplates used as temporary anchorage device might permit equivalent favourable skeletal changes without unwanted dentoalveolar effects. We report two cases having class III malocclusion with maxillary deficiency treated by using titanium miniplates. Cephalometric tracings were done pre and post treatment to determine the anatomic changes during the course of treatment.

Comparative characterization of maxillary expansion and alternate maxillary expansions and constrictions in rats

The purpose of this study was to evaluate whether the cranial and circumaxillary sutures react differently to maxillary expansion (ME) and alternate maxillary expansions and constrictions (Alt-MEC) in a rat model. Twenty-two male Sprague-Dawley rats (6 weeks old) were used and divided into three groups. In ME group (n=9), an expander was activated for 5 days. In Alt-MEC group (9 animals), an alternate expansion and constriction protocol (5-day expansion and 5-day constriction for one cycle) was conducted for 2.5 cycles (25 days total). The control group comprised 4 animals with no appliances used, each of two sacrificed on day 5 and day 25 respectively. Midpalatal suture expansion or constriction levels were assessed qualitatively and quantitatively by bite-wing X-rays and cast models. Distances between two central incisors and two maxillary first molars were measured on cast models after each activation. Circumaxillary sutures (midpalatal, maxillopalatine, premaxillary, zygomaticotemporal and frontonasal suture) in each group were characterized histologically. Results showed that midpalatal suture was widened and restored after each expansion and constriction. At the end of activation, the widths between both central incisors and first molars in Alt-MEC group were significantly larger than those in ME group (P<0.05). Histologically, all five circumaxillary sutures studied were widened in multiple zones in Alt-MEC group. However, only midpalatal suture was expanded with cellular fibrous tissue filling in ME group. Significant osteoclast hyperplasia was observed in all circumaxillary sutures after alternate expansions and constrictions, but osteoclast count increase was only observed in midpalatal suture in ME group. These results suggested that cranial and circumaxillary sutures were actively reconstructed after Alt-MEC, while only midpalatal suture had active reaction after ME.

Comparison of the effects of face mask treatment started simultaneously and after the completion of the alternate rapid maxillary expansion and constriction procedure

OBJECTIVE

To test the null hypothesis that there were significant differences for skeletal, dentoalveolar, and soft tissue changes induced by face mask (FM) started simultaneously and after an alternate rapid maxillary expansion and constriction (Alt-RAMEC) procedure.

MATERIALS AND METHODS

Thirty-six patients with Class III malocclusion due to maxillary deficiency were randomly assigned to Group I (FM started after the completion of the Alt-RAMEC) and Group II (FM started simultaneously with the Alt-RAMEC). The screw of the RME appliance was alternately activated and deactivated twice daily (0.20 mm per turn) for 1 week over the course of 8 weeks. The changes observed in both groups were assessed using the cephalometric lateral films and statistically evaluated using the paired t-test and Student's t-test.

RESULTS

Thirty patients completed the present prospective study. No significant differences were observed between the groups. Class III malocclusion and negative overjet were improved by means of skeletal changes in conjunction with upper incisor proclination in both groups. Skeletal contribution to overjet correction in Groups I and II was 91.70% and 86.10%, respectively. Maxilla showed a forward movement of 3.84 mm and 3.02 mm in Groups I and II, respectively.

CONCLUSIONS

The null hypothesis was rejected. Both groups showed similar results, and, thus, waiting until completion of the Alt-RAMEC procedure for the FM treatment is not necessary.

Short-term effects of a modified Alt-RAMEC protocol for early treatment of Class III malocclusion: a controlled study

OBJECTIVES

To assess the effects of a modified alternate rapid maxillary expansion and constriction (Alt-RAMEC) protocol in combination with facemask (FM) in Class III growing patients.

SETTING AND SAMPLE POPULATION

Thirty one Class III patients (17 males, 14 females) were treated with a modified Alt-RAMEC/FM protocol at the Department of Orthodontics of the University of Florence.

MATERIAL AND METHODS

All patients were evaluated at the beginning (T1, mean age 6.4 ± 0.8 years) and at the end of orthopedic therapy (T2, mean age 8.1 ± 0.9 years), and they were compared to a matched sample of 31 Class III patients (16 males and 15 females) treated with rapid maxillary expansion and facemask (RME/FM) and to a matched control group of 21 subjects (9 males and 12 females) with untreated Class III malocclusion. The three groups were compared with anova with Benjamini-Hochberg correction for multiple tests.

RESULTS

Both the Alt-RAMEC/FM and the RME/FM protocols showed significantly favorable effects leading to correction of the Class III malocclusion. The Alt-RAMEC/FM protocol produced a more effective advancement of the maxilla (SNA +1.2°) and greater intermaxillary changes (ANB +1.7°) vs. the RME/FM protocol. No significant differences were recorded as for mandibular skeletal changes and vertical skeletal relationships.

CONCLUSION

The Alt-RAMEC/FM protocol induced more favorable skeletal short-term effects compared with RME/FM therapy in Class III growing patients.

Three-dimensional assessment of maxillary changes associated with bone anchored maxillary protraction

INTRODUCTION

Bone-anchored maxillary protraction has been shown to be an effective treatment modality for the correction of Class III malocclusions. The purpose of this study was to evaluate 3-dimensional changes in the maxilla, the surrounding hard and soft tissues, and the circummaxillary sutures after bone-anchored maxillary protraction treatment.

METHODS

Twenty-five consecutive skeletal Class III patients between the ages of 9 and 13 years (mean, 11.10 ± 1.1 years) were treated with Class III intermaxillary elastics and bilateral miniplates (2 in the infrazygomatic crests of the maxilla and 2 in the anterior mandible). Cone-beam computed tomographs were taken before initial loading and 1 year out. Three-dimensional models were generated from the tomographs, registered on the anterior cranial base, superimposed, and analyzed by using color maps.

RESULTS

The maxilla showed a mean forward displacement of 3.7 mm, and the zygomas and the maxillary incisors came forward 3.7 and 4.3 mm, respectively.

CONCLUSIONS

This treatment approach produced significant orthopedic changes in the maxilla and the zygomas in growing Class III patients.

Three-dimensional computerized tomographic orbital volume and aperture width evaluation: a study in patients treated with rapid maxillary expansion

OBJECTIVE

The purpose of this study was to assess the influence of rapid maxillary expansion (RME) on orbital volume and aperture width measurements by using freeware software with DICOM data from low-dose-protocol multidetector computerized tomography (MDCT).

STUDY DESIGN

The subjects consisted of 30 patients (12 male, 18 females) treated with a Hyrax Palatal Expander, activated 3 times per day (0.25 mm per turn of the screw) for an average of 18 days. Low-dose MDCT was performed immediately before (T1) and after (T2) treatment. DICOM data was exported into the open-source OsiriX Medical Imaging software (www.osirix-viewer.com), the data reoriented to a standard projection, and then orbital volumetric and maximum aperture measurements performed.

RESULTS

Orbital mean volumes increased significantly from 18.81 ± 1.23 cm(3) (T1) to 19.53 ± 1.26 cm(3) (T2). Orbital aperture width also increased significantly from 36.02 ± 1.24 mm (T1) to 37.11 ± 1.01 mm (T1).

CONCLUSIONS

RME produces small but significant increases in orbital dimensions. However, RME does not produce drastic changes of the normal architecture of the orbital bones and is unlikely to alter the normal anatomy of the face.

Effects of facemask treatment anchored with miniplates after alternate rapid maxillary expansions and constrictions; a pilot study

OBJECTIVE

To describe the dentoskeletal and soft tissue effects of facemask treatment anchored with miniplates after alternate rapid maxillary expansions and constrictions (Alt-RAMEC) in maxillary retrusion patients.

MATERIALS AND METHODS

The sample consisted of 15 patients with a mean skeletal age of 11.6 ± 1.59 years undergoing 8 weeks of Alt-RAMEC followed by maxillary protraction. Three hundred fifty to 400 g of force per side was applied to the facemask from the titanium miniplates inserted on the lateral nasal wall of the maxilla. Total treatment time was 9.9 ± 2.63 months. Treatment changes were evaluated cephalometrically and analyzed by means of the dependent t-test and the Wilcoxon signed rank test.

RESULTS

The miniplates withstood the orthopedic forces exerted during the treatment. Cephalometric findings showed that the maxilla moved forward by 2 mm, with an 0.8° counterclockwise rotation and without maxillary incisor movement. The mandible moved slightly in a downward and backward direction (1.2°). The inclinations of the mandibular incisors decreased significantly (2°). Statistically significant increases were observed in the vertical dimension (1°-1.3°). Soft tissue changes were more marked in the upper lip and soft tissue pogonion than in the lower lip.

CONCLUSIONS

This treatment approach can offer an advantage for correcting mild/moderate maxillary retrusion in Class III patients.

Mechanical strain at alveolar bone and circummaxillary sutures during acute rapid palatal expansion

INTRODUCTION

Palatal expansion can potentially affect alveolar bone and circummaxillary sutures. In this study, we characterized their mechanical strain during acute expansion.

METHODS

Eight 3- and 6-month-old fresh pig heads received acute palatal expansion with hyrax expanders. Strain gauges were used to measure strain at the buccal alveolar bone of anchor and adjacent nonanchor teeth, and at maxillary-premaxillary, maxillary-zygomatic, and zygomatic-temporal sutures during expansion. Intermolar width changes were measured from dental casts.

RESULTS

Intermolar width increased less than expander activation, and the midpalatal sutures were only opened slightly. Alveolar bone strain increased linearly with expander activation and decayed by 20% to 30% during postactivation intervals. Compressive strain at anchor-tooth alveolar bone locations was directed occlusally and apically, related to tooth tipping, and significantly higher than that at nonanchor tooth locations. With expander activation, suture strains increased monotonically and tended to plateau. Suture strain magnitude was generally similar to physiologic (masticatory) strains reported in the literature. The dominant strain polarity was compression at the maxillary-zygomatic and zygomatic-temporal sutures, but there was tension at the maxillary-premaxillary suture.

CONCLUSIONS

In these pigs, palatal expansion can cause significant occlusal-apical compression at buccal alveolar bone and physiologic-level strains at circummaxillary sutures.

Early post-treatment changes of circumaxillary sutures in young patients treated with rapid maxillary expansion

OBJECTIVE

To test the null hypothesis that circumaxillary sutures do not show bony displacement in response to rapid maxillary expansion (RME) therapy.

MATERIALS AND METHODS

Subjects consisted of eight growing patients (two male and six female) with Angle Class I malocclusion, bilateral posterior crossbite, transverse maxillary deficiency, deep palatal vault, and dental crowding at the start of the treatment. A Hyrax palatal expander was used for each patient, and activation protocol required the screw to be turned three times per day (0.25 mm per turn) for an average of 18 days for all subjects. Multislice computed tomography (CT) scans were performed before rapid palatal expansion (time T0) and again at the end of the active expansion phase (time T1) without removing the expander. Measurements were carried out directly on the CT image using the OsiriX Imaging software program. Data were analyzed statistically by using the Wilcoxon signed rank test.

RESULTS

All linear measurements showed an increase between T0 and T1 and RME determined a widening of suture; however, sutures far from the maxilla showed a smaller degree of disarticulation.

CONCLUSIONS

The hypothesis is rejected. Early treatment with RME produced a significant bony displacement by circumaxillary suture opening. The amount of changes of sutures depends on different factors relating to the subjects and varies between different sutures, showing that sutures that articulate directly with the maxilla face a greater influence by the RME compared with those located further away.

Activation-deactivation rapid palatal expansion and reverse headgear in Class III cases

The aim of this study was to evaluate and compare the dentofacial effects of 1 week rapid palatal expansion (RPE) and activation-deactivation (A/D) RPE protocols with reverse headgear (RH). Two groups, each containing 15 subjects, were included in this study. In the RPE group (seven males and eight females, 11.94 ± 1.62 years), Hyrax screws were activated every 12 hours for 1 week. At the end of this period, RPE was stopped and the patients were instructed to wear the RH. In the A/D-RPE group (seven males and eight females, 11.34 ± 1.81 years), the screws were activated every 12 hours for 1 week. Subsequently, the screws were deactivated every 12 hours for 1 week followed by activation and deactivation for the following 2 weeks. After this protocol, the patients were instructed to use the RH. A total force of 700 g was applied to both groups for 16-18 hours/day for the first 3 months, for 12 hours/day for the second 3 months, and for 6 hours/day for the second 6 months. Lateral cephalometric films were taken before treatment (T1) and at the end of the first (T2) and second (T3) 6 months to evaluate the dentofacial changes. Intragroup differences of each landmark at T2-T1, T3-T2, and T3-T1 were analysed with a paired t-test (P < 0.016), and intergroup differences were compared with an independent t-test (P < 0.05). Anterior movement of point A (4.13 mm) for the A/D-RPE group was approximately twice of the RPE group (2.33 mm; P < 0.001). Backward movement of the mandible showed no significant difference between the groups. Anterior face height increases did not demonstrate significant differences between the groups. The pronounced anterior movement of point A demonstrates that the A/D-RPE procedure positively affects maxillary protraction.