Long-term evaluation of the molar movements following Pendulum and fixed appliances

Efficacy of clear aligner therapy over conventional fixed appliances in controlling orthodontic movement: A systematic review

OBJECTIVE

The purpose of the current systematic review was to answer the clinical research question "Is Clear Aligner Therapy (CAT) effective in controlling the orthodontic movement?" by bringing together the most up-to-date information about the available evidence for CAT.

METHODOLOGY

On January 1, 2023, a search was conducted in PubMed, ERIC, Embase, and CINHAL for any research papers published in the previous 10 years that provided an overview of the PICO questions. Both the titles and abstracts of the selected studies were evaluated independently by two different authors, and if there was any disagreement between the two review authors, a third reviewer was brought in to settle it.

RESULTS

Among included studies, three were retrospective non-randomized and two studies were prospective randomized clinical trials. Various authors reported better outcome for fixed orthodontic appliances than for clear aligner treatment (CAT) in relation to mandibular incisor proclination. The mean objective grading system score was better for braces (17) than for CAT (12) with no clinically significant difference, while staging had a significant impact on treatment efficacy.

CONCLUSION

The results of this study suggest that clear aligners may be an effective alternative to traditional braces, but more research is needed to confirm these findings and determine the optimal size of future prospective studies evaluating this treatment.

Effect of Different Anchorage Reinforcement Methods on Long-Term Maxillary Whole Arch Distalization with Clear Aligner: A 4D Finite Element Study with Staging Simulation

The objective of this study was to examine how various anchorage methods impact long-term maxillary whole arch distalization using clear aligners (CAs) through an automated staging simulation. Three different anchorage reinforcement methods, namely, Class II elastics, buccal temporary anchorage device (TAD), and palatal TAD, were designed. Orthodontic tooth movement induced by orthodontic forces was simulated using an iterative computation method. Additionally, the automatic adjustment of the CA was simulated through the application of the thermal expansion method. The results indicated that the palatal TAD group had the largest retraction of incisors, followed by the buccal TAD group and the Class II elastic group, while the least was in the control group. The largest distal displacements and efficiency of molar distalization for the first and the second molars were noticed in the palatal TAD group. Arch width increased at the molar and premolar levels in all groups. The FEM results suggested palatal TAD had the best performance considering anterior teeth anchorage maintenance, both sagittally and vertically. However, attention should be paid to the possible increasement of arch width.

Vertical effects of distalization protocol with Clear aligners in Class II patients: a prospective study

BACKGROUND

The aim of the present prospective study was to detect the effects on vertical dentoskeletal dimension produced by molar distalization with Clear Aligners in a group of subjects with Class II malocclusion.

METHODS

The Clear Aligners Group (CAG) comprised 20 patients (13 females, seven males) with a mean age of 17.2±3.2 years. The same standardized protocol of sequential distalization was applied in all subjects. For each patient lateral cephalograms have been analyzed before treatment (T1) and at the end of the therapy (T2).

RESULTS

At the end of treatment, clear aligners were effective in the correction of Class II dental relationship with the correction of the overjet (-1.3 mm). The treated group showed statistically significant reduction in FMA angle (-1.3°) associated with a counterclockwise rotation of the occlusal plane (POccl^PF -3.1°; SN^POccl -4.2°) and a slight intrusion of maxillary first molars to palatal plane (-0.9 mm). Finally, statistically significant differences were detected in anterior facial height (N-Me) and in the ArGo^GoMe angle (-1.2 mm and -3.4°, respectively).

CONCLUSIONS

Upper molar distalization with clear aligners represents a valid alternative to non-extraction treatment of Class II malocclusion, reducing the extrusion of maxillary first molars and improving the control of the occlusal plane and of the vertical dimension.

Effects of pendulum appliance versus clear aligners in the vertical dimension during Class II malocclusion treatment: a randomized prospective clinical trial

Background

The aim of the present study was to compare the effects on vertical dentoskeletal dimension produced by Pendulum appliance and Clear Aligners in patients with Class II malocclusion.

Trial design

This is a prospective two-arm parallel group randomized clinical trial with 1:1 allocation ratio.

Methods

The Pendulum Group (PG) consisted of 20 patients (15F, 5 M) with a mean age of 17.2 ± 4.3 years. The Clear Aligners Group (CAG) comprised 20 patients (13F, 7 M) with a mean age of 17.2 ± 3.2 years. Distalization’s protocol in PG involved the activation of TMA wires till the achievement of Class I molar relationship. A protocol of sequential distalization was applied in the CAG. For each subject lateral cephalograms have been analyzed before treatment (T1) and at the end of the therapy (T2). Descriptive statistics and statistical between-group comparisons (PG vs CAG) were calculated for the craniofacial starting forms at T1 and for the T2–T1 changes. Statistical between-group comparisons for the T2–T1 changes were performed with independent samples t-tests (P < 0.05).

Results

The PG showed significantly greater increases in SN^GoGn° when compared with CAG (+ 2.1 and − 0.3 degrees, respectively). Clockwise rotation of the occlusal plane with significantly greater increase of SN^POccl angle was observed in PG (+ 2.8 degrees) when compared with CAG (− 4.2 degrees).

The PG revealed a significant increase in the N-Me variable with a mean change of + 4.4 mm compared to the CAG with mean values of − 1.2 mm. The PG showed an increase in the ArGo^GoMe angle (+ 0.7° degrees) compared to the CAG (− 3.4° degrees). The PG showed significantly greater increases in both maxillary and mandibular first molar to palatal plane (+ 1.3 and + 2.1 mm, respectively) when compared with CAG (− 0.9 and − 0.2 mm, respectively).

Conclusions

Upper molar distalization with clear aligners represents a valid alternative to non-extraction treatment of Class II malocclusion, reducing the extrusion of maxillary first molars and improving the management of the occlusal plane and vertical dimension.

Trial registration: ClinicalTrials.gov, NCT05298280. Registered 28 March 2022—Retrospectively registered, https://clinicaltrials.gov.

Efficiency of maxillary total arch distalization using temporary anchorage devices (TADs) for treatment of Class II-malocclusions: A systematic review and meta-analysis

OBJECTIVES

To evaluate the treatment effects and post-treatment stability of the maxillary total arch distalization using TADs during the non-extraction treatment of class II malocclusions.

MATERIALS AND METHODS

Study involved an electronic search followed by hand searching for randomized and non-randomized clinical studies about maxillary total arch distalization using TADs. After data extraction and risk of bias assessment, meta-analysis was performed for dental, skeletal and soft tissue changes using the Generic-inverse variance approach by use of the mean difference and random-effect model.

RESULTS

In total, 1788 articles were identified, 88 full texts were screened and 22 studies were found eligible; 17 of them were included in the quantitative analysis. The means of distalization/distal tipping of the maxillary first molar were 4mm/3.17° in adults, 3.95mm/1.61° in adolescents after treatment with the Modified C-Palatal plate (MCPP), while they were 2.44mm/2.91° with the inter-radicular mini-screws. Both MCPP's treatment in adults and inter-radicular mini-screws resulted in significant intrusion of U6 (1.64 and 0.75mm, respectively), while insignificant extrusion of U6 was resulted in adolescents treated by MCPP. MCPP appliances resulted in palatal inclination/extrusion of maxillary incisors U1 (6.77°/2mm in adults, 7.46°/3.14mm in adolescents). In contrast, inter-radicular mini-screws resulted in less palatal less amount of palatal inclination/insignificant intrusion of U1 (2.42°/0.14mm). MCPP treatment also resulted in significant changes in the skeletal measurements (SNA, ANB, occlusal and mandibular planes). Insignificant differences were found between subgroups in the retraction amount of maxillary incisors, as well as the upper and lower lips. In the follow-up of adolescents treated with MCPP, a significant amount of mesial movement, mesial tipping, and extrusion (2.94mm, 2.84°, and 3.94mm, respectively) was found. However, skeletal and occlusal corrections of the Class II relationship were maintained.

CONCLUSIONS

Maxillary total arch distalization using TADs can be an effective and stable treatment procedure. However, RCTs or prospective cohort studies are highly recommended to establish a clinical evidence regarding their efficiency.

Skeletal, Dental and Soft Tissue Cephalometric Changes after Orthodontic Treatment of Dental Class II Malocclusion with Maxillary First Molar or First Premolar Extractions

The aim of the present retrospective study was evaluating skeletal, dental and soft tissue changes of two groups of Class II patients orthodontically treated with extractions of upper first premolars (U4 group) and upper first molars (U6 group). In total, 21 patient records (9M and 12F; mean age 12.5 ± 1.2 years) were selected for the U4 group, and 38 patient records (17M and 21F; mean age 13.2 ± 1.3 years) were recruited for the U6 group. Twenty cephalometric variables were analysed on standardised lateral cephalograms at baseline (T0) and at the end of orthodontic treatment (T1). Means and standard deviations (SDs) were calculated for both groups and increments were calculated. After revealing the normal distribution of data with the Shapiro–Wilk test, Student’s t-test was used to compare variables at T0 between groups. A paired t-test was used to analyse changes between time points within each group, and Student’s t-test to compare differences between groups at T1. Both groups showed a significant increase in the distance among upper second molars and the vertical pterygoid line (PTV-maxillary second molar centroid U6 group: 6.66 ± 5.00 mm; U4 group: 3.66 ± 2.20 mm). Moreover, the distance of upper incisors to the palatal plane significantly increased (PP-maxillary incisor tip U6 group: 1.09 ± 1.52 mm; U4 group: 0.20 ± 2.00 mm; p = 0.061). Significant changes were found for overjet (U6 group: −4.86 ± 1.62 mm; U4 group: −3.27 ± 1.90 mm; p = 0.001). The distance between upper lip and esthetic plane showed a significantly reduction in both groups (ULip-E Plane U6 group: −2.98 ± 1.65 mm; U4 group: −1.93 ± 1.57 mm). No statistically significant changes were found in sagittal or vertical skeletal values. The significantly larger reduction of upper lip protrusion and overjet in the U6 group compared to the U4 group suggests preferring molar extraction treatment for severe Class II with protrusive soft tissues’ profile and increased overjet. Since no differences on vertical values were found, an increased SN^GoGn angle should not be considered a discriminating factor for choosing molar extraction treatment.

Efficacy of clear aligners in producing molar distalization: Systematic review

Objectives:

The aim of this review is to systematically analyze the efficacy of molar distalization using clear aligners in non-growing Class II patients.

Materials and Methods:

A complete search across the electronic database through PubMed, Cochrane, Google scholar, LILACS, and manual search of orthodontic journals were done till 2019. Studies were selected on the basis of PRISMA guidelines.

Results:

A total of four articles were included in this review. The amount of molar distalization reported was 2–3 mm.

Conclusion:

Out of the four studies included. In all the studies a significant amount of distalization was reported. Three retrospective studies concluded that distalization with aligners is the most effective of all tooth movements. One study concluded that aligners effectively achieved distalization with an efficacy of 87%, other two studies concluded that aligners effectively distalized the molars with good control over vertical dimension and mesiodistal tipping.

The effect of third molars on maxillary molar distalisation using a miniscrew-supported 3D® maxillary bimetric distalising arch

Objectives: The aim of the present study was to investigate the effect of third molars on the efficiency and biomechanics of a novel miniscrew-supported 3D® Maxillary Bimetric Distalising Arch (3D-MBDA).

Methods: Twenty-three patients, whose third molars were either extracted at the beginning of treatment (Group 1, n =11) or retained (Group 2, n =12), were included in the study. Lateral cephalometric films and dental casts, taken at the beginning (T0) and at the end of upper molar distalisation (T1), were analysed to study the differences between groups.

Results: Crown distalisation of the first molars was similar between the groups; however, root distalisation, both at the trifurcation and apex levels, intrusion at the mesiobuccal cusp tip, and the distalisation rate were significantly higher in Group 1. The resultant tipping of the first molars in both groups was mesially-directed, unlike the usual distal tipping. The second molars distalised more, displaced less vestibularly and rotated mesiobuccally in Group 1, whereas they demonstrated a significantly higher vestibular displacement and distobuccal rotation in Group 2. The mean distalisation time was significantly shorter in Group 1 when compared to Group 2. The miniscrew success rate was 95.5% for Group 1 and 91.7% for Group 2.

Conclusion: The miniscrew-supported 3D-MBDA was found to have greater effects on root distalisation and the final inclination of the molars. The third molars were associated with limited root movement, unfavourable displacement of the second molars, as well as a slower distalisation rate. Therefore, the extraction of third molars prior to distalisation is recommended, especially when the miniscrew-supported 3D-MBDA is the appliance choice.

Total maxillary arch distalization with modified C-palatal plates in adolescents: A long-term study using cone-beam computed tomography

INTRODUCTION

The aims of this study were to evaluate the long-term skeletodental effects, the volume of maxillary tuberosity, and airway space changes after maxillary molar distalization using modified C-palatal plate (MCPP) in adolescents with Class II malocclusion.

METHODS

The sample consisted of 20 adolescent patients (MCPP group; mean age, 12.9 ± 1.0 year) who underwent bilateral distalization of their maxillary dentition and 20 subjects as a control group. In the MCPP group, cone-beam computed tomography images were taken before distalization, at the end of the treatment, and during retention with a minimum of a 3-year posttreatment follow up period. Repeated measures ANOVA followed by post-hoc analysis with the Bonferroni test were used to identify significant differences between time points.

RESULTS

After the long-term observation period, sagittal skeletal and dental relationships were maintained (there were no significant changes in ANB, occlusal plane angle, and overjet postretention). The vertical skeletal dimension did not change during treatment and was stable at the long-term follow-up (the mandibular plane angle and ANS-Me were relatively well maintained). The volume of the maxillary tuberosity showed no significant change during long-term retention. However, the volume was significantly smaller in the treatment group than in the control group (P <0.0001). There were no significant airway space changes after distalization and the postretention period. In addition, there was no significant difference between the MCPP and control groups.

CONCLUSIONS

Improved sagittal skeletal and dental relationships because of treatment were maintained in the long-term evaluation. There was no negative long-term effect on airway space associated with the maxillary arch distalization. Therefore, these findings might be beneficial for clinicians in diagnosis and treatment planning for Class II malocclusion in adolescents.

Stability of class II treatment with Pendulum and Jones jig followed by fixed appliances

INTRODUCTION

The present study aimed to evaluate and compare the long-term stability of Class II correction with the Pendulum or Jones jig followed by fixed appliances.

SETTINGS AND SAMPLE POPULATION

Group 1 comprised 20 Class II malocclusion patients with a mean initial age of 13.97 years (SD = 1.57), treated with Pendulum and fixed appliances for a mean period of 4.72 years (SD = 0.98), and mean long-term post-treatment evaluation of 4.72 years (SD = 0.97). Group 2 consisted of 18 Class II patients with a mean initial age of 13.19 years (SD = 1.26), treated with Jones jig and fixed appliances for a mean period of 3.96 years (SD = 0.92). Mean long-term post-treatment time was 5.50 years (SD = 1.57).

METHODS

Lateral cephalograms were evaluated at three stages: initial (T1), final (T2) and long-term post-treatment (T3). Intragroup comparisons were performed with repeated measures ANOVA and Tukey's test and intergroup comparisons with independent t test.

RESULTS

Many treatment changes were observed in both groups. From the long-term post-treatment periods, there was stability for most of the variables. Maxillary second molars and mandibular first molars extruded in the Jones jig group and slightly intruded in the Pendulum appliance group. The nasolabial angle decreased in the Pendulum group and increased in the Jones jig group.

CONCLUSION

The correction of a Class II malocclusion was shown to be stable with similar long-term post-treatment results with Pendulum or Jones jig followed by fixed orthodontic appliances.

Stability of Class II malocclusion treatment with the distal jet followed by fixed appliances

INTRODUCTION

This retrospective study aimed to assess the stability of Class II malocclusion treatment with the distal jet, followed by fixed appliances.

METHODS

Seventy-five cephalograms of 30 subjects were divided into 2 groups. The treated group consisted of 15 patients who were evaluated at the pretreatment, posttreatment, and long-term posttreatment stages. The control group consisted of 15 subjects with normal occlusion, comparable to the experimental group at the long-term posttreatment period. Intergroup comparison of posttreatment changes was evaluated with t tests.

RESULTS

In the long-term posttreatment period, there was no significant change in the anteroposterior position of the maxilla and mandible to the cranial base. The lower anterior face height had a significantly smaller increase in the treated than in the control group. The maxillary molars in the treated group had significantly smaller vertical development, and the mandibular incisors had significantly greater labial tipping and protrusion than the control group. The treatment produced significant improvement in molar relationship and reduction of overbite and overjet, which remained stable in the long-term posttreatment period. There was greater upper lip protrusion in the experimental than in the control group in the long-term posttreatment period.

CONCLUSIONS

Treatment of Class II malocclusions with the distal jet, followed by fixed appliances, showed good long-term stability in molar relationship, overbite, and overjet.

Transverse stability of Class II malocclusion correction with the pendulum appliance

INTRODUCTION

This study aimed to evaluate the stability of transverse changes after Class II malocclusion correction with the pendulum fixed distalizer, followed by preadjusted edgewise fixed orthodontic appliances.

METHODS

This longitudinal study was conducted in the maxillary dental casts of 20 Class II malocclusion subjects (mean age, 12.5 years; 14 females and 6 males). Eighty 3-dimensional maxillary dental casts were analyzed; 20 at the beginning of treatment, 20 after distalization, 20 after edgewise appliance debonding, and 20 at 5 years posttreatment. Maxillary transverse distances between canines, first premolars, second premolars, first molars, and second molars were analyzed using Geomagic Studio 5 (3D Systems, Rock Hill, SC).

RESULTS

There were no significant changes in intercanine distance during and after treatment. There were significant interfirst and intersecond premolar distance increases during treatment. There were significant interfirst and intersecond molar distance increases during the distalization phase. However, there were significant decreases in these distances at the end of treatment. There were no significant long-term posttreatment changes.

CONCLUSIONS

The intercanine distance remains stable during and after treatment. The interfirst and intersecond premolar distances significantly increase during treatment and remain stable after treatment. The interfirst and intersecond molar distances increase during the distalization phase, decrease at the end of treatment, and remain stable after treatment.

Long-term stability of miniscrew anchored maxillary molar distalization in Class II treatment

OBJECTIVE

To investigate treatment stability of miniscrew-anchored maxillary distalization in Class II malocclusion.

MATERIALS AND METHODS

This retrospective study included a distalization (n = 19) and a control (n = 19) group; a patient group with minor corrections served the control. Lateral cephalograms of 38 adult patients were taken before (T0), immediately after (T1), and 3-4 years after (T2) treatment. Horizontal and vertical movement and tipping of the maxillary first molars (U6) and central incisors (U1) were measured along with skeletal craniofacial parameters at three time points to compare the two groups regarding the achieved treatment effects and their stability.

RESULTS

Total arch distalization therapy led to 4.2 mm of distal movement of U6 without distal crown tipping (0.6° of axis change) and 3.3° of occlusal plane steepening. Over an average retention period of 42 months, maxillary total arch distalization provided high stability of treatment results, showing the same amount of mesial movement (0.7 mm) as the control group.

CONCLUSIONS

In Class II treatment, miniscrew-anchored maxillary total arch distalization can provide stable distal movement of the maxillary first molars and central incisors.

Three-dimensional comparison of the skeletal and dentoalveolar effects of the Herbst and Pendulum appliances followed by fixed appliances: A CBCT study

OBJECTIVES

To compare three-dimensional (3D) skeletal and dentoalveolar effects of the Herbst and Pendulum appliances followed by fixed orthodontic treatment in growing patients.

SETTING AND SAMPLE POPULATION

A sample of 35 adolescents with cone-beam computed tomography scans obtained prior to Herbst and Pendulum treatment (T1) and immediately after fixed appliance treatment (T2).

MATERIALS AND METHODS

Patients with Class II malocclusion was assessed retrospectively and divided into two treatment groups: Herbst group (n = 17, age: 12.0 ± 1.6 years) and Pendulum group (n = 18, age: 12.1 ± 1.5 years), with a mean treatment duration of 2.8 ± 0.8 years and 2.5 ± 0.7 years, respectively. Reconstructions of the maxillomandibular and dentoalveolar regions and data in 3D were obtained relative to cranial base, maxillary and mandibular regional superimpositions. Treatment outcomes (T2-T1) were compared between both groups using t tests for independent samples (P<.05).

RESULTS

Significant increase in mandibular length was observed in the Herbst group (7.3 ± 3.5 mm) relative to the Pendulum group (4.6 ± 4.5 mm). Inferior and anterior displacements of Pogonion were 2.2 mm and 1.6 mm greater in the Herbst group, respectively. The mesial displacement of the lower first molars was significantly greater in the Herbst group (1.9 mm). The upper first molars had contrasting results in sagittal displacement, with 0.6 ± 1.7 mm of distal displacement with the Pendulum and 1.4 ± 2.1 mm of mesial displacement with the Herbst. Lower incisor projection and proclination were similar between groups.

CONCLUSIONS

The Herbst and Pendulum appliances followed by comprehensive orthodontic treatment effectively corrected Class II malocclusion in growing patients, but with differing skeletal and dentoalveolar effects.

Impact of molar teeth distalization with clear aligners on occlusal vertical dimension: a retrospective study

Background

A common strategy in the non-extraction treatment of Class II molar relationship is maxillary molar distalization, which could increase lower face height and cause clockwise mandibular rotation. The aim of this retrospective study was to analyse the effects on vertical dentoskeletal dimension of young adults treated with sequential distalization with orthodontic aligners.

Methods

Lateral cephalometric radiographs of 10 subjects (8 females 2 males; mean age 22.7 ± 5.3 years) treated with upper molars sequential distalization with orthodontic aligners (Invisalign, Align Technology, San Josè, California, USA) were analyzed.

Results

No statistically significant difference was observed for the primary outcome SN-GoGn between T0 and T1 and it was recorded a mean variation of 0.1 ± 2.0 degrees. Statistically significant differences were found in the linear position of the upper molars (6-PP, 7-PP) the molar class relationship parameter (MR) and the upper incisive inclination (1^PP) with at least p < 0.01.

Conclusions

Upper molar distalization with orthodontic aligners guarantee an excellent control of the vertical dimension representing an ideal solution for the treatment of hyperdivergent or openbite subjects. It also allows an excellent control of the incisal torque without loss of anchorage during the orthodontic procedure.

Maxillary molar distalization using conventional versus skeletal anchorage devices: A systematic review and meta-analysis

INTRODUCTION

The purpose of this study was to systematically review the evidence regarding conventional versus skeletal anchorage devices for molar distalization.

METHOD

An electronic search was conducted. Hand searching was done in the reference lists of included studies and some journals. Studies comparing conventional and skeletal anchorage for molar distalization in Angle class I or II malocclusions were assessed. Presence of periodontal disease, second or third molar extraction and application of tooth accelerating methods led to exclusion of studies. Generic-inverse variance approach was used for meta-analysis by use of the mean difference and random-effect model. Risk of bias was evaluated in included studies.

RESULTS

A total of 1996 articles were found; of which, 1991 were excluded. The mean amounts of molar distalization/tipping in skeletal anchorage and conventional anchorage groups were 5.35mm/8.44° and 4.25mm/8.31°, respectively, which were not significantly different. The mean amounts of premolar movement in skeletal anchorage and conventional anchorage groups were -0.96mm and +2.21mm, respectively, which was statistically significant (P=0.004). Duration of treatment in skeletal anchorage and conventional anchorage groups was 8.23 months and 7.95 months, respectively, which were significantly different (P=0.0001). Risk of bias was assessed to be high.

CONCLUSION

The conventional and skeletal anchorage devices were not significantly different in terms of the amount of molar distalization/tipping. However, the anchorage loss was lower in the skeletal anchorage group. The treatment time was shorter in the conventional anchorage group. More studies with proper design are required.

Osteo-regeneration personalized for children by rapid maxillary expansion: an imaging study based on synchrotron radiation microtomography

Background

Personalized maxillary expansion procedure has been proposed to correct maxillary transversal deficiency; different protocols of stem cell activation have been suggested and rapid maxillary expansion (RME) is the most commonly used among clinicians. The present study aimed to quantify in three-dimensions (3D) the osteo-regeneration of the midpalatal suture in children submitted to RME.

Methods

Three patients (mean age 8.3 ± 0.9 years) were enrolled in the study to preform biopsy of midpalatal suture. Two patients (subjects 1 and 2) were subjected to RME before biopsy. The third patient did not need maxillary expansion treatment and was enrolled as control (subject 3). Midpalatal suture samples were harvested 7 days after RME in subject 1, and 30 days after RME in subject 2. The samples were harvested with the clinical aim to remove bone for the supernumerary tooth extraction. When possible, maxillary suture and bone margins were both included in the sample. All the biopsies were evaluated by complementary imaging techniques, namely Synchrotron Radiation-based X-ray microtomography (microCT) and comparative light and electron microscopy.

Results

In agreement with microscopy, it was detected by microCT a relevant amount of newly formed bone both 7 days and 30 days after RME, with bone growth and a progressive mineralization, even if still immature respect to the control, also 30 days after RME. Interestingly, the microCT showed that the new bone was strongly connected and cross-linked, without a preferential orientation perpendicular to the suture’s long axis (previously hypothesized by histology), but with well-organized and rather isotropic 3D trabeculae.

Conclusions

The microCT imaging revealed, for the first time to the authors’ knowledge, the 3D bone regeneration in children submitted to RME.

Electronic supplementary material

The online version of this article (10.1186/s12903-018-0590-7) contains supplementary material, which is available to authorized users.

[Intramaxillary devices of molar distalization on fixed appliance and with aligners]

INTRODUCTION

Class II malocclusion is a dysmorphosis that can result from different skeletal and/or alveolar components of maxillary and/or mandibular origin. In dental class II cases due to mesial drift of the maxillary molars, it is sometimes interesting to retract the maxillary molars, in order to avoid in certain situations extractions of premolars. To this end, several devices have been described in the literature. The most recent intraoral devices allow a more controlled correction, and no longer require cooperation from the patient. In addition, in a number of cases of distalization, aligners now offer a useful therapeutic option since they are both esthetic and easy-to-use.

MATERIALS AND METHODS

In this study, we carried out a review of the various studies in the literature describing intra-oral distalization of the maxillary molars in the multi-bracket technique as well as using aligners, with a clinical illustration of a Class II case treated by aligners.

A comparison of treatment effects of total arch distalization using modified C-palatal plate vs buccal miniscrews

OBJECTIVE

The purpose of this study was to compare the treatment effects of palatally vs buccally placed temporary anchorage devices.

MATERIALS AND METHODS

Of 40 Class II division 1 malocclusion patients, 22 were treated with modified C-palatal plate (MCPP) appliances (age 21.9 ± 6.6 years), and 18 (age 24.2 ± 6.8 years) were treated with buccally placed miniscrews between the maxillary first molar and second premolar. A total of 26 linear and angular measurements were analyzed on pre- and posttreatment lateral cephalograms. Multivariate analysis of variance was performed to evaluate the treatment effects within each group and to compare the effects between groups.

RESULTS

Overall, the MCPP appliances showed 4.2 mm of distalization, 1.6 mm of intrusion of the first molar with 2° tipping, and 0.8 mm extrusion of incisors. The miniscrew group resulted in 2.0 mm of distalization, 0.1 mm intrusion of the first molar with 7.2° tipping, and 0.3 mm of incisor extrusion. Regarding soft tissue change, in the MCPP group, the upper lip was significantly retracted ( P < .001).

CONCLUSIONS

Comparing the treatment effects between MCPP appliances and buccal miniscrews, the MCPP appliances showed greater distalization and intrusion with less distal tipping of the first molar and less extrusion of the incisor compared to the buccal miniscrews.

Pendulum and modified pendulum appliances for maxillary molar distalization in Class II malocclusion - a systematic review

OBJECTIVE

The main purpose of the present systematic review was to evaluate the quantitative effects of the pendulum appliance and modified pendulum appliances for maxillary molar distalization in Class II malocclusion.

MATERIALS AND METHODS

Our systematic search included MEDLINE, EMBASE, CINAHL, PsychINFO, Scopus and key journals and review articles; the date of the last search was 30 January 2017. We graded the methodological quality of the studies by means of the Quality Assessment Tool for Quantitative Studies, developed for the Effective Public Health Practice Project (EPHPP).

RESULTS

In total, 203 studies were identified for screening, and 25 studies were eligible. The quality assessment rated four (16%) of the study as being of strong quality and 21 (84%) of these studies as being of moderate quality. The pendulum appliances showed mean molar distalization of 2-6.4 mm, distal tipping of molars from 6.67° to 14.50° and anchorage loss with mean premolar and incisor mesial movement of 1.63-3.6 mm and 0.9-6.5 mm, respectively. The bone anchored pendulum appliances (BAPAs) showed mean molar distalization of 4.8-6.4 mm, distal tipping of molars from 9° to 11.3° and mean premolar distalization of 2.7-5.4 mm.

CONCLUSIONS

Pendulum and modified pendulum appliances are effective in molar distalization. Pendulum appliance with K-loop modification, implant supported pendulum appliance and BAPA significantly reduced anchorage loss of the anterior teeth and distal tipping of the molar teeth.

Long-term stability of maxillary group distalization with interradicular miniscrews in a patient with a Class II Division 2 malocclusion

We successfully treated a Class II Division 2 patient with maxillary group distalization using interradicular miniscrews. A woman, aged 28 years 11 months, had a convex profile and an excessive overjet caused by a skeletal Class II jaw-base relationship. After leveling and alignment, titanium miniscrews were obliquely implanted between the maxillary second premolar and first molar. To distalize the maxillary dentition, nickel-titanium closing coil springs with a 2-N load were placed between the screws and the hooks on the archwire. After 28 months of active orthodontic treatment, a proper facial profile and an acceptable occlusion were achieved with a 4-mm distalization of the maxillary dentition. The resultant occlusion was stable throughout a 5-year retention period. Interradicular miniscrews were useful to distalize the maxillary dentition for correcting a Class II malocclusion. This new strategy, group distalization with miniscrews, can make the treatment simpler with greater predictability.

A New Orthodontic Appliance with a Mini Screw for Upper Molar Distalization

The aim of this study is to present a new upper molar distalization appliance called Cise distalizer designed as intraoral device supported with orthodontic mini screw for upper permanent molar distalization. The new appliance consists of eight main components. In order to understand the optimum force level, the appliance under static loading is tested by using strain gage measurement techniques. Results show that one of the open coils produces approximately 300 gr distalization force. Cise distalizer can provide totally 600 gr distalization force. This range of force level is enough for distalization of upper first and second molar teeth.

Bilateral en-masse distalization of maxillary posterior teeth with skeletal anchorage: a case report

Objective:

The aim of this study was to introduce a new method for bilateral distal movement of the entire maxillary posterior segment.

Case report:

A 17-year-old girl with Class I skeletal malocclusion (end-to-end molar relationships, deviated midline and space deficiency for left maxillary canine) was referred for orthodontic treatment. She did not accept maxillary first premolars extraction. A modified Hyrax appliance (Dentaurum Ispringen, Germany) was used for bilateral distalization of maxillary posterior teeth simultaneously. Expansion vector was set anteroposteriorly. Posterior legs of Hyrax were welded to first maxillary molar bands. All posterior teeth on each side consolidated with a segment of 0.017 × 0.025-in stainless steel wire from the buccal side. Anterior legs of Hyrax were bent into eyelet form and attached to the anterior palate with two mini-screws (2 × 10 mm) (Jeil Medical Corporation Seoul, South Korea). Hyrax opening rate was 0.8 mm per month. Lateral cephalometric radiographs were used to evaluate the extent of distal movement. 3.5-mm distalization of posterior maxillary teeth was achieved in five months.

Results:

A nearly bodily distal movement without anchorage loss was obtained.

Conclusion:

The mini-screw-supported modified Hyrax appliance was found to be helpful for achieving en-masse distal movement of maxillary posterior teeth.

Comparison between direct vs indirect anchorage in two miniscrew-supported distalizing devices

OBJECTIVE

To compare two distalizing devices supported by palatal miniscrews, the MGBM System (MGBM) and the Distal Screw appliance (DS), in dental Class II patients.

MATERIALS AND METHODS

Pretreatment (T1) and postdistalization (T2) lateral cephalograms of 53 Class II malocclusion subjects were examined. MGBM consisted of 29 patients (16 males, 13 females) with a mean pretreatment age of 12.3 ± 1.5 years; DS consisted of 24 patients (11 males, 13 females) with a mean pretreatment age of 11.3 ± 1.2 years. The mean distalization time was 6 ± 2 months for MGBM and 9 ± 2 months for DS. Initial and final measurements and treatment changes were compared by means of a Student's t-test.

RESULTS

Maxillary superimpositions showed that the maxillary first molar distalized an average of 5.5 mm in the MGBM and 3.2 mm in the DS between T1 and T2; distal molar tipping was greater in the MGBM (10.3°) than in the DS (3.0°). First premolar showed a mean mesial movement of 1.4 mm, with a mesial tipping of 4.4° in the MGBM; on the contrary, first premolar showed a distal movement of 2.2 mm, with a distal tipping of 6.2°, in the DS.

CONCLUSIONS

The MGBM system resulted in greater distal molar movement and less treatment time, resulting in more efficient movement than was associated with the DS; DS showed less molar tipping during distalization.

Evaluation of long-term stability of mesiodistal axial inclinations of maxillary molars through panoramic radiographs in subjects treated with Pendulum appliance

OBJECTIVE

To evaluate the stability of mesiodistal inclination of maxillary molars produced by a pendulum appliance, five years after completion of orthodontic treatment. Angulation changes were compared to an untreated sample.

METHODS

The sample consisted of 20 patients (14 females and 6 males) with Class II, Division 1 malocclusion that was treated through molar distalization with a pendulum appliance followed by cervical headgear and full fixed appliances. Maxillary molar inclination was evaluated through panoramic radiograph. The mean age at pretreatment was 14.3 ± 1.6 years, whereas at immediate post-treatment it was 18.6 ± 1.8 years, and at long-term post-treatment it was 23.8 ± 2.0 years. A control group of 16 untreated individuals with untreated normocclusion ranging in age from 12 to 17 years old were used as comparison group. Data were statistically analyzed with independent t-tests and ANOVA test followed by Tukey post-hoc tests.

RESULTS

Statistically significant differences were found between T1(94.50) and T2 (98.80) as well as between T2 and T3 (94.70) for maxillary first molars. Maxillary second molars did not show any statistically significant positional changes during the evaluated time periods T1 (107.50), T2 (109.30) and T3 (106.90).

CONCLUSION

Although maxillary first molars underwent distal crown inclination immediately after treatment, approximately five years thereafter their roots tended to upright close to the pretreatment positions.

Comparative evaluation of molar distalization therapy using pendulum and distal screw appliances

OBJECTIVE

To compare dentoalveolar and skeletal changes produced by the pendulum appliance (PA) and the distal screw appliance (DS) in Class II patients.

METHODS

Forty-three patients (19 men, 24 women) with Class II malocclusion were retrospectively selected for the study. Twenty-four patients (mean age, 12.2 ± 1.5 years) were treated with the PA, and 19 patients (mean age, 11.3 ± 1.9 years) were treated with the DS. The mean distalization time was 7 months for the PA group and 9 months for the DS group. Lateral cephalograms were obtained at T1, before treatment, and at T2, the end of distalization. A Mann-Whitney U test was used for statistical comparisons of the two groups between T1 and T2.

RESULTS

PA and DS were equally effective in distalizing maxillary molars (4.7 mm and 4.2 mm, respectively) between T1 and T2; however, the maxillary first molars showed less distal tipping in the DS group than in the PA group (3.2° vs. 9.0°, respectively). Moreover, significant premolar anchorage loss (2.7 mm) and incisor proclination (5.0°) were noted in the PA group, whereas premolar distal movement (1.9 mm) and no significant changes at the incisor (0.1°) were observed in the DS group. No significant sagittal or vertical skeletal changes were detected between the two groups during the distalization phase.

CONCLUSIONS

PA and DS seem to be equally effective in distalizing maxillary molars; however, greater distal molar tipping and premolar anchorage loss can be expected using PA.

Maxillary molar distalization therapy in adult patients: a multicentre study

OBJECTIVES

To evaluate dento-skeletal changes following conventional anchorage molar distalization therapy in adult patients.

SETTING AND SAMPLE POPULATION

Thirty-three patients (25 women, mean age 23 years 1 months ± 3 months; 8 men, mean age 28 years 3 months ± 7 months) were recruited from 4 Board Certified specialists. All subjects underwent molar distalization therapy using intra-oral distalizing appliances.

SUBJECTS AND METHODS

Cephalometric headfilms were available for all subjects before (T1) and at the end of comprehensive treatment (T2). The initial and final measurements and treatment changes were compared by means of a paired t-test.

RESULTS

Mean total treatment time was 3 years 2 months ± 6 months. Maxillary first molar distalized 2.9 ± 0.6 mm contributing 64.4% to Class II molar correction, whereas mandibular first molar showed a concomitant mesial movement of 1.6 ± 0.5 mm. Maxillary incisors retroclined an average of 5.8° ± 3.9°, lower incisors proclined 4.1° ± 1.1° and the occlusal plane rotated downwards and backwards 1.8° ± 2.1°. Clockwise rotation of the mandible (1.7° ± 0.5°) and increase in lower facial height (2.5 ± 1.5 mm) were also observed.

CONCLUSIONS

Maxillary molar distalization therapy can be successfully performed in adult patients despite a slight increase in vertical facial dimension should be considered.

Comparative evaluation of molar distalization therapy with erupted second molar: Segmented versus Quad Pendulum appliance

Background

There are controversial opinions about the effect of erupted second molars on distalization of the first molars. Most of the distalizing devices are anchored on the first molars, without including second molars; so, differences between sequentially distalize maxillary molars (second molar followed by the first molar) or distalize second and first molars together are not clear. The aim of the study was to compare sequential versus simultaneous molar distalization therapy with erupted second molar using two different modified Pendulum appliances followed by fixed appliances.

Methods

The treatment sample consisted of 35 class II malocclusion subjects, divided in two groups: group 1 consisted of 24 patients (13 males and 11 females) with a mean pre-treatment age of 12.9 years, treated with the Segmented Pendulum (SP) and fixed appliances; group 2 consisted of 11 patients (6 males and 5 females) with a mean pre-treatment age of 13.2 years, treated with the Quad Pendulum (QP) and fixed appliances. Lateral cephalograms were obtained before treatment (T1), at the end of distalization (T2), and at the end of orthodontic fixed appliance therapy (T3). A Student t test was used to identify significant between-group differences between T1 to T2, T2 to T3, and T1 to T3.

Results

QP and SP were equally effective in distalizing maxillary molars (3.5 and 4 mm, respectively) between T1 and T2; however, the maxillary first molar showed less distal tipping (4.6° vs. 9.6°) and more extrusion (1.1 vs. 0.2 mm) in the QP group than in the SP group, as well as the vertical facial dimension, which increased more in the QP group (1.2°) than in the SP group (0.7°). At T3, the QP group maintained greater increase in lower anterior facial height and molar extrusion and decrease in overbite than the SP group.

Conclusion

Quad Pendulum seems to have greater increase in vertical dimension and molar extrusion than the Segmented Pendulum.

Skeletal versus conventional intraoral anchorage for the treatment of class II malocclusion: dentoalveolar and skeletal effects

BACKGROUND

The purpose of this retrospective study is to investigate the dentoalveolar and skeletal effects of two distalizing protocols featuring different anchorage systems used in patients with class II malocclusion: the MGBM system (skeletal anchorage) and Pendulum (intraoral anchorage).

METHODS

The sample comprised 57 patients who were assigned to one of the two treatments: the MGBM group (30 patients, mean age 13.3 ± 2.3 years) or the Pendulum group (27 patients, mean age 12.8 ± 1.7 years). Three serial cephalograms were obtained at baseline (T0), after molar distalization (T1), and after fixed appliance treatment (T2). Esthetic, skeletal, and dental parameters were considered. Pancherz's superimposition method was used to assess sagittal dental changes. The initial and final measurements and treatment changes were compared by means of a paired t test or a paired Wilcoxon test. Statistical significance was tested at p < 0.05, p < 0.01, and p < 0.001.

RESULTS

In the MGBM group, the upper molar distalization was achieved in 7 months and showed a mean value of 4.9 mm (ms-PLO); the amount of molar relationship correction was 5.9 mm. In the Pendulum group, the upper molar distalization was obtained in 9 months and showed a mean value of 2.5 mm (ms-PLO), while the molar relationship correction amounted to 4.9 mm. Anterior anchorage loss occurred in both groups, although in the MGBM group, there was less mesial movement of the premolars.

CONCLUSIONS

The MGBM system and the Pendulum appliance are both effective in the correction of class II malocclusions. The MGBM system was found to be more efficient than the Pendulum appliance, producing greater molar distalization in a shorter treatment time.