Evaluation of miniscrew-supported rapid maxillary expansion in adolescents: A prospective randomized clinical trial

Why does maxillary skeletal expansion work with some adults and fail with Others?: A narrative review

Maxillary skeletal expansion is considered a challenging treatment modality in adult ages. Mini-screw-assisted rapid palatal expansion (MARPE) is considered a pioneer in providing a solution for maxillary deficiency in adults away from any surgical interventions. If we consider patient cooperation and motivation, together with operator skills, as constant factors during MARPE, and exclude all hygiene and soft tissue complications that jeopardise the appliance's stability, there is a percentage of expansion failure recorded in different studies with no emphasis on what makes mid-facial diastema appear in some, rather than others. Electronic databases including PubMed, Scopus, Google Scholar, and Web of Science, were searched for literature published in English till 2023. Failure was related in some literature to different criteria, as of yet, no verifiable indicators would allow us to determine success or failure in advance. This review highlighted the most common reasons for failure discussed in different literature: Chronological Age, Mid-palatal suture maturation, Bone density, Sex, Race, Appliance design, and Expansion technique used. This study could be considered an attempt to make candidate selection for non-surgical maxillary skeletal expansion at this old age easier, time-saving, and cost less.

Dentoalveolar, periodontal and skeletal effects of maxillary expansion techniques assisted by temporary anchorage devices compared with conventional protocols in growing patients with transverse maxillary deficiency: A systematic review and meta-analysis

OBJECTIVES

To synthesise the dentoalveolar, periodontal and skeletal changes that occur when using maxillary expansion techniques assisted by temporary anchorage devices compared to conventional protocols.

METHODS

Five databases and grey literature were consulted, up to December 2023, focusing on intervention designs and excluding other type of studies. The quality assessment was conducted by using the adaptation for orthodontics of the CONSORT statement, the guidelines for reporting non-randomised studies, the RoB-2 tool, and the ROBINS-I tool. A descriptive summary and meta-analysis using RevMan 5.4 were performed.

RESULTS

Nine clinical trials were included (n=377 patients, mean age 13.2±0.6) with a diagnosis of transverse maxillary deficiency. The analysed studies showed qualitative dentoalveolar and periodontal changes after expansion, which were greater on the maxillary first premolars in tooth-borne appliances. Meta-analyses for some effects were included from two studies (n=64); patients who used tooth-borne appliances had greater effects of buccal intercoronal width between the premolars with statistically significant differences (Std Mean difference 2.34; 95% CI: 0.04-4.65 p=0.05). Conversely, those patients who used bone-borne or hybrid appliances had greater effects of buccal intercoronal width between molars with statistically significant differences (Std Mean difference -0.64; 95% CI: -1.38-0.10; p=0.09).

CONCLUSIONS

According to the studies analysed, all measurements increased in the intervention groups after expansion. Quantitative analyses show different findings at dentoalveolar level when tooth-borne, bone-borne or hybrid appliances are considered. Nevertheless, the results should be taken with caution due to the heterogeneity of the studies. The protocol was registered at PROSPERO (CRD42021283170), with no funding to report.

Evolution, current status, and future trends of maxillary skeletal expansion: a bibliometric analysis

OBJECTIVES

The study aims to conduct a bibliometric analysis on maxillary skeletal expansion to elucidate the evolution and current status and predict future research hotspots and trends.

MATERIAL AND METHODS

A search was conducted in the Web of Science Core Collection at the University of Hong Kong's electronic library using the query "(TS = maxillary expansion) AND (TS = skeletal expansion)." The resulting literature data were imported into CiteSpace 6.2.R4 and VOS viewer software to analyze authorship, countries, institutions, keywords, etc. RESULTS: A total of 923 articles were analyzed. The research in this field has shown a steady growth, with a significant increase since 2019. The USA and Italy have played prominent roles in contributing to the publication volume and strengthening collaborative exchanges. Clustering labels provide directions for in-depth analysis of the literature.

CONCLUSIONS

(1) MARPE (miniscrew-assisted rapid palatal expansion) and SARME (surgically assisted rapid maxillary expansion) have gained widespread attention and become research hotspots due to their applicability in adults whose growth and development have ceased, while still producing favorable skeletal effects. (2) In addition to widening the maxillary arch, maxillary expansion techniques have shown significant effects on increasing nasal cavity width and volume. However, there is still controversy regarding whether they can effectively improve the deviated nasal septum. (3) Maxillary skeletal expansion techniques have been shown to increase upper airway volume and improve breathing, making them potentially valuable in the treatment of obstructive sleep apnea (OSA).

CLINICAL RELEVANCE

This study can provide cutting-edge clinical recommendations for healthcare professionals to better formulate clinical strategies.

Vertical changes in the hard tissues after space closure by miniscrew sliding mechanics: a three-dimensional modality analysis

OBJECTIVES

This study aimed to investigate vertical changes in the maxillary central incisor and the maxillary first molar, along with alterations in the mandibular plane angle during space closure using miniscrew sliding mechanics.

METHODS

Twenty adult patients treated at Peking University Hospital of Stomatology between 2008 and 2013 were included. Digital dental models and craniofacial cone-beam computed tomography (CBCT) scans were obtained at the start of treatment (T0) and immediately after space closure (T1). Stable miniscrews were used for superimposing maxillary digital dental models (T0 and T1), and vertical changes in the maxillary first molar and the maxillary central incisor were measured. Three-dimensional changes in the mandibular plane were assessed through CBCT superimposition.

RESULTS

The maxillary central incisor exhibited an average extrusion of 2.56 ± 0.18 mm, while the maxillary first molar showed an average intrusion of 1.25 ± 1.11 mm with a distal movement of 0.97 ± 0.99 mm. Additionally, the mandibular plane angle decreased by an average of 0.83 ± 1.65°. All three indices exhibited statistically significant differences.

CONCLUSION

During space closure using the miniscrew sliding technique, significant changes occurred in both the sagittal and vertical dimensions of the upper dentition. This included extrusion of the maxillary central incisors, intrusion of the maxillary first molars, and a slight counterclockwise rotation of the mandibular plane.

Stress distribution and displacement with four different types of MARPE on craniofacial complex: A three-dimensional finite element analysis

BACKGROUND

Various designs of mini-implants assisted rapid palatal expander (MARPE) appliances can impact treatment effectiveness through their biomechanical effects. The purpose of the study was to study the stress distribution and displacement with four different designs of the MARPE appliance on the craniofacial complex.

METHODS

A 3D finite element model of the craniofacial complex was created from CBCT DICOM data, comprising four distinct groups. Each group consisted of one 4-hole expansion screw positioned between the second premolar and first molar in all models. Group 1 used four single-cortical mini-implants (1.5×8mm) engaging only the palatal cortex. Group 2 employed four mini-implants (1.5×11mm) engaging both the palatal and nasal cortices. Group 3 had monocortical implants on the palatal slopes, while Group 4 was similar to group 3 with implants in the acrylic wings. Comparisons between groups were made for anchorage (groups 1 and 2), mini-implant position (groups 1 and 3) and surface effect (groups 3 and 4). Von Mises stresses and displacements at various skeletal and dental points were evaluated using ANSYS software.

RESULTS

The highest stresses were observed in the maxillary, pterygoid and zygomatic bones, as well as in the mid- palatal suture in all four groups. Downward and forward rotation of the craniofacial complex was noted. Group 2 showed greater skeletal expansion than group 1. Among groups 1 and 3, group 3 showed a better stress distribution. Group 4 showed less dentoalveolar rotation than group 3.

CONCLUSIONS

The MARPE appliances had an impact on the craniofacial complex with stresses on the mid-palatal suture, maxillary bone, pterygoid bones and anterior teeth. Clockwise rotation of the maxilla, zygomatic bones and dentition was noted, while the pterygoid bones and pterygoid suture were displaced backwards. MARPE with bicortical anchorage produces better skeletal expansion. Placing implants on the palatal slopes with acrylic wings results in better skeletal expansion with less clockwise rotation of the dentition.

Effects of rapid maxillary expansion on anchorage alveolar bone meta-analysis

PURPOSE

Rapid maxillary expansion (RME) is a routine method for correcting transverse maxillary deficiency. This paper investigated the effect of RME on anchorage alveolar bone and examined the differences between micro-implant-assisted RME and conventional RME.

METHODS

Relevant articles were selected from the PubMed, EMBASE and Cochrane Central Register of Controlled Trials databases. Review Manager software (v.5.3) was used for the pooled analysis and Cochran Q and I2 statistic tests were used to assess the heterogeneity.

RESULTS

Following conventional RME, the distal buccal alveolar bone thickness and the mesiobuccal alveolar thickness of the maxillary first molars were significantly reduced. Hyrax (standard mean difference [SMD]: -0.93, 95% confidence interval [CI]: -1.20-0.66) and Haas procedures (SMD: -0.88, 95% CI: -1.40-0.36) significantly reduced the buccal vertical alveolar height of the maxillary first molars. Similar results were obtained for the maxillary first premolars following RME. The thickness of the buccal alveolar bone decreased with conventional RME compared to when using the method assisted by micro-implants.

CONCLUSIONS

Conventional RME can reduce the thickness and vertical height of maxillary alveolar bone, and there is less loss of alveolar bone when using micro-implant-assisted RME. Further research is needed to validate the findings.

Temporary anchorage devices in orthodontics: a bibliometric analysis of the 50 most-cited articles from 2012 to 2022

OBJECTIVES

To identify and analyze the 50 most cited articles on temporary anchorage devices (TADs) and investigate the achievement and development of scientific research about the topic through a bibliometric analysis.

MATERIALS AND METHODS

On August 22, 2022, a computerized database search was performed to detect papers published in the scientific literature about TADs from 2012 to 2022. Metrics data were identified using the Incites Journal Citation Reports (Clarivate Analytics) data set. The Scopus database was used to obtain information on the authors' affiliations, country of origin, and h-index. Key words were automatically harvested from the selected articles to implement the visualized analysis.

RESULTS

From a total of 1858 papers screened by searching the database, a list of the top 50 most cited articles was created. The total number of citations collected by the 50 most cited articles in TADs was 2380. Among the 50 most cited articles on TADs, 38 were original research papers (76.0%) and 12 were reviews (24.0%). As shown by the key word-network analysis, Orthodontic anchorage procedure was identified as the larger node.

CONCLUSIONS

Findings of this bibliometric study showed an increasing number of citations for papers on TADs, accompanied by a simultaneous rise in scientific interest in this topic in the past decade. The present work identifies the most influential articles, emphasizing the journals, the authors, and the topics addressed.

External root resorption and rapid maxillary expansion in the short-term: a CBCT comparative study between tooth-borne and bone-borne appliances, using 3D imaging digital technology

BACKGROUND

The aim of the study was to analyze and compare external root resorption (ERR) in patients treated with tooth-borne (TB) and bone-borne (BB) rapid maxillary expansion (RME).

METHODS

The sample included 40 subjects who received tooth-borne RME (TB group, average age: 13.1 ± 1.08 years) or bone-borne RME (BB group, average age: 14.5 ± 1.11 years) and Cone-beam computed tomography (CBCT) scans before treatment (T0) and after 3-month of retention (T1). A specific 3D Imaging technology was used to generate 3D models of posterior dentition (M1 = maxillary first molars, P2 = second premolars, P1 = first premolar) and calculate volumetric data (mean and percentage values) and shape changes, the latter obtained from deviation analysis between the radicular models at different time points. Evaluation of radicular length changes was performed for each tooth. Data were statistically analysed to perform intra-timing and inter-groups comparisons.

RESULTS

A significant reduction of radicular volume and length was found in posterior dentition in both groups (p < 0.05), and the M1 (volume) and its palatal root (length) were mostly involved in this response. No differences were found between M1, P1 and P2 (p > 0.05) when volumetric changes were calculated as percentage of the total volume. Deviation analysis revealed that the radicular areas mostly affected by shape change were the apex and bucco-medial side. The amount of ERR was significantly greater in TB group compared to BB group.

CONCLUSIONS

BB-RME treatment could reduce the amount of ERR at the post-expansion stage.

The effects of miniscrew-assisted rapid palatal expansion on the upper airway of adults with midpalatal suture in the last two degrees of ossification

BACKGROUND

Transverse deficiencies of the maxillary basal bone have been treated in adult patients using miniscrew-assisted rapid palatal expansion (MARPE) therapy. However, the midpalatal suture's degree of ossification may affect the upper airway dimensions. This study compared the volumetric changes of the total upper, retropalatal, retroglossal airways, and the minimal transverse airway constriction after MARPE therapy in patients with midpalatal suture in the last stages of ossification.

METHODS

This controlled clinical trial included a total of 20 adult patients (mean age 24.5 ± 6.2 years) with maxillary atresia treated with MARPE. Preoperative (T0) cone-beam computed tomography scans were used to determine the degree of midpalatal suture ossification. Two groups were formed considering the last two stages of sutural ossification "D" or "E" (n = 10 per group). After 120 days of the therapy (T1), cone-beam computed tomography assessments were performed to compare the pre and post-treatment outcomes. The total upper, retropalatal, and retroglossal airways and the minimal transverse airway constriction were evaluated. The three-dimensional reconstruction was performed with OsiriX MD software. The comparisons were carried out using mixed models for repeated measures at fixed time points (α = 0.05).

RESULTS

Groups D and E showed no significant difference for any of the analyzed parameters (P > 0.05). Both groups showed a statistically significant increase for all airway segments after the treatment with MARPE (P < 0.05). The total upper airway increased (11.6% and 16.1%) for groups D and E, respectively (P = 0.3356).

CONCLUSIONS

MARPE therapy resulted in dimensional gains of the upper airway for adult patients, irrespective of the intermaxillary sutural degree of ossification.

Maxillary expansion in nongrowing patients. Conventional, surgical, or miniscrew-assisted, an update

Maxillary transverse deficiency can occur in various clinical dentoskeletal deformities and include unilateral or bilateral posterior crossbite, narrow, tapering, or high palatal arch. The development of temporary anchorage devices led to a new generation of tooth-bone-borne expansion appliance using two or four screws to apply the mechanical forces to the bone and reduce the stress to the anchored teeth. The aim of these new devices is to reduce the adverse dentoalveolar effect and achieve more skeletal expansion than conventional tooth-borne rapid palatal expansion. This article reviews the age limitation and complication and soft tissue change of nonsurgical maxillary expansion. We discuss the approach of surgical maxillary expansion with maxillary skeletal expander device. The clinical case will show the benefit of nonsurgical and surgical tooth-bone-borne rapid palatal expansion.

Comparison of Different Types of Palatal Expanders: Scoping Review

Maxillary bone contraction is caused by genetics or ambiental factors and is often accompanied by dental crowding, with the possibility of canine inclusion, crossbite, class II and III malocclusion, temporomandibular joint disorder, and obstructive sleep apnea (OSAS). Transverse maxillary deficits, in which the maxillary growth is unusually modest, are frequently treated with maxillary expansion. The purpose of this study is to compare the dental and skeletal effects of different types of expanders, particularly the Leaf Expander, rapid and slow dental-anchored or skeletal-anchored maxillary expanders.

METHODS

We chose studies that compared effects determined by palatal expansion using a rapid palatal expander, expander on palatal screws, and leaf expander.

RESULTS

Reports assessed for eligibility are 26 and the reports excluded were 11. A final number of 15 studies were included in the review for qualitative analysis.

CONCLUSIONS

Clinically and radiographically, the outcomes are similar to those obtained with RME and SME appliances; Therefore, it might be a useful treatment choice as an alternative to RME/SME equipment in cases of poor patient compliance or specific situations. Finally, all of the devices studied produce meaningful skeletal growth of the palate. The use of skeletally anchored devices does, without a doubt, promote larger and more successful growth in adolescent patients.

Do the miniscrews of the prefabricated systems for the "appliance first" protocol of miniscrew-assisted rapid palatal expansion have lengths that meet the palatal thickness of patients?

INTRODUCTION

In the "appliance first" protocol of miniscrew-assisted rapid palatal expansion, the prefabricated shape of the expanders limits the potential locations for miniscrew placement. Considering the influence of palatal thickness on the selection of the optimal length of miniscrews, this study aimed to evaluate the thickness of both bone and mucosa of the palate of patients aged 6-65 years and suggest optimal lengths of miniscrews for this approach.

METHODS

Two hundred and eighty-two cone-beam computed tomography of patients of both sexes were divided into 3 groups according to age. The thicknesses of bone and mucosa were measured in the anterior and posterior regions of the palate.

RESULTS

Males showed a greater thickness of palatal bone than females. The thickness of both bone and mucosa was greater in the anterior region of the palate. The young patients showed greater bone thickness than adults and mature adults. The mature adults showed thinner bone thickness in the posterior region of the palate and greater mucosal thickness along the palate than young patients and adults. Development of miniscrews with longer thread lengths is necessary. Miniscrews with a 3-mm thread length would prevent excessive extravasation in the posterior region of the palate.

CONCLUSIONS

The thickness of both bone and mucosa of the palate is variable and influenced by sex and age. Manufacturing additional miniscrews with different lengths of thread is suggested to achieve bicortical anchorage in patients undergoing the "appliance first" protocol of miniscrew-assisted rapid palatal expansion.

Comparison of palatal volume and surface changes between bone-borne and tooth-tissue-borne maxillary expansion on cone beam computed tomography digital cast models

OBJECTIVES

To compare the changes of palatal volume and area in patients treated with tooth-tissue-borne palatal expanders (conventional Haas) and miniscrew-supported palatal expanders (modified Haas).

MATERIALS AND METHODS

The sample included casts of 22 patients treated as part of a clinical study at the Department of Orthodontics, Al-Azhar University, to correct their crossbite malocclusion. Patients were divided equally into two groups upon arrival. The first group, with a mean age of 12 years and 6 months, received the miniscrew-supported palatal expander. The second group, with a mean age of 12 years and 2 months, received the Haas design-palatal expansion appliance. Pre- and post-expansion dental casts were cone beam computed tomography scanned and the slices were constructed into 3D volumes. Fully automated superimposition was done for pre- and post-expansion 3D models. Palatal volume and area were determined, and all measurements were carried out blindly. Paired t-test was used to assess the mean differences within each group and Welch's t-test was applied to assess the mean changes between the two groups. Shapiro-Wilk test was used to test for the normality of the data.

RESULTS

There were no statistical differences in volume changes either within each group or between the groups. Although area changes were statistically significant within each group, the difference between the groups was not significant.

CONCLUSIONS

Changes that result from the use of either method to expand the upper arch occur primarily in the shape of the palate, but not in its size.

Clinical advances in maxillary skeletal expansion and introduction of a new MARPE concept

BACKGROUND

Transverse maxillary deficiency, typically characterized by the clinical manifestations of unilateral or bilateral crossbite, is a common orthodontic discrepancy. The primary goal of maxillary expansion should be to obtain a nearly maximum width increase in the basal bone of the constricted maxilla and to avoid the dental expansion of the anchor teeth. The introduction of miniscrew anchorage-supported rapid maxillary expansion (MARPE) devices has helped increase the feasibility of obtaining nonsurgical transverse correction in late adolescents and young adults with optimum orthopedic effects. However, the success rate of MARPE shows a negative correlation with age. Although MARPE offers an effective method for correcting a transverse skeletal deficiency, given the appliance cost and increased risk for complications, it could present challenges for adult patients and practitioners in daily practice.

AIMS

In this article, current advances in maxillary skeletal expansion are summarized, and a new MARPE concept is introduced.

CONCLUSION

The new MARPE design offers several advantages to other existing methods: (1) it can be installed directly to the patient in the clinical setting with no additional laboratory waiting times. (2) It is purely a bone-borne appliance. (3) The appliance is designed to be placed in the thickest part of the anterior palate to maximize the cortical and trabecular bone support. (4) Allows for bicortical placement of the miniscrews with no perforations in the nasal floor. Finally, (5) offers an esthetic and minimalistic approach to maxillary skeletal expansion in late adolescent and adult patients.

External root resorption (ERR) and rapid maxillary expansion (RME) at post-retention stage: a comparison between tooth-borne and bone-borne RME

BACKGROUND

The study aimed to compare external root resorption (ERR) three-dimensionally in subjects treated with tooth-borne (TB) versus bone-borne (BB) rapid maxillary expansion (RME). Forty subjects who received tooth-borne RME (TB group, average age 13.3 years ± 1.10 years) or bone-borne RME (BB group, average age 14.7 ± 1.15 years) were assessed using CBCT imaging before treatment (T0) and after a 6-month retention period (T1). 3D reconstructions of the radicular anatomy of maxillary first molars (M1), first and second premolars (P1 and P2) were generated to calculate volumetric (mean and percentage values) and shape changes (deviation analysis of the radicular models) obtained at each time point. 2D assessment of radicular length changes was also performed for each tooth. Data were statistically analyzed to perform intra-group (different teeth) and inter-group comparisons.

RESULTS

In both groups, all the investigated teeth showed a significant reduction in radicular volume and length (p < 0.05), with the first molars being the teeth most affected by the resorption process (volume and palatal root length). When volumetric radicular changes were calculated as a percentage of the pre-treatment volumes, no differences were found among the investigated teeth (p > 0.05). Based on the deviation analysis from radicular models superimposition, the areas most affected by shape change were the apex and bucco-medial root surface. Overall, the amount of ERR was significantly greater in the TB group (mm³: M1 = 17.03, P1 = 6.42, P2 = 5.26) compared to the BB group (mm³: M1 = 3.11, P1 = 1.04, P2 = 1.24).

CONCLUSIONS

Despite the statistical significance, the difference in the amount of ERR of the posterior maxillary dentition between TB-RME and BB-RME remains clinically questionable.

Non-Surgical Transversal Dentoalveolar Compensation with Completely Customized Lingual Appliances versus Surgically Assisted Rapid Palatal Expansion in Adults-The Amount of Posterior Crossbite Correction

The aim of this study was to compare the crossbite correction of a group (n = 43; f/m 19/24; mean age 27.6 ± 9.5 years) with surgically assisted rapid palatal expansion (SARPE) versus a non-surgical transversal dentoalveolar compensation (DC) group (n = 38; f/m 25/13; mean age 30.4 ± 12.9 years) with completely customized lingual appliances (CCLA). Arch width was measured on digital models at the canines (C), second premolars (P2), first molars (M1) and second molars (M2). Measurements were obtained before treatment (T0) and at the end of lingual treatment (T1) or after orthodontic alignment prior to a second surgical intervention for three-dimensional bite correction. There was no statistically significant difference (p > 0.05) in the amount of total crossbite correction between the SARPE and DC-CCLA group at C, P2, M1 and M2. Maxillary expansion was greater in the SARPE group and mandibular compression was greater in the DC-CCLA group. Crossbite correction in the DC-CCLA group was mainly a combination of maxillary expansion and mandibular compression. Dentoalveolar compensation with CCLAs as a combination of maxillary expansion and mandibular compression seems to be a clinically effective procedure to correct a transverse maxillo-mandibular discrepancy without the need for surgical assistance.

Dentoskeletal changes due to rapid maxillary expansion in growing patients with tooth-borne and tooth-bone-borne expanders: A randomized clinical trial

OBJECTIVES

To compare, using cone-beam computed tomography, the dentoskeletal changes in rapid maxillary expansion with tooth-bone-borne (Hybrid Hyrax) and tooth-borne (Hyrax) appliances.

SETTING AND SAMPLE POPULATION

Forty-two patients who met the eligibility criteria (aged 11-14 years; transverse maxillary deficiency, posterior crossbite, and presence of upper first premolars and molars) were screened and allocated into two groups: HHG (treatment with Hybrid Hyrax) and HG (treatment with Hyrax).

MAIN OUTCOME MEASURES

The primary outcomes included nasomaxillary dimensional changes. CBCT was performed before and 3 months after the activation phase. Measurements were performed using Dolphin® . Baseline data were compared using one-way ANOVA. For intergroup comparison, ANCOVA was used to analyze the initial age, appliance activations (mm), and mid-palatal suture maturation data as covariates. Statistical significance was set at 5%.

RESULTS

The premolar region in HHG showed increased skeletal changes than in HG, with the difference being 1.5 mm (0.5; 2.6) in the nasal cavity (P = .004), 1.4 mm (0.3; 2.5) in the nasal floor (P = .019), and 1.1 mm (0.2; 2.1) in the maxilla (P = .022). The molar region in HHG showed increased skeletal changes with the difference being 0.9 mm (0.2; 1.5) in the nasal cavity (P = .005), and 0.9 mm (0; 1.8) in the maxilla (P = .042) than in HG. Premolar inclination was higher in HG.

CONCLUSION

Hybrid Hyrax showed more skeletal changes and fewer dental side effects, especially in the first premolar region. The amount of activation influenced the higher nasal skeletal changes in the Hybrid hyrax group.

Patient-reported outcomes of slow vs rapid miniscrew-supported maxillary expansion in adolescents: secondary outcomes of a randomized clinical trial

OBJECTIVES

To compare patient-reported experience between a Penn expander activated every other day vs twice daily.

MATERIALS AND METHODS

A total of 30 patients aged 12-16 years with transverse maxillary deficiency were recruited from the outpatient clinic, Faculty of Dentistry, Alexandria University (February 2019-December 2020). They were randomly allocated to two groups using block randomization (block size of six) and an allocation ratio of 1:1, which was concealed using opaque, sealed, sequentially numbered envelopes. Both groups received Penn expanders anchored by four palatal miniscrews. The slow maxillary expansion (SME) group activated the appliance once every other day. The rapid maxillary expansion (RME) group activated the appliance twice daily. Outcome measures were pain, pressure, headache, dizziness, speech difficulty, chewing difficulty, and swallowing difficulty scores rated by the participants on an 11-point numeric rating scale (NRS) at the following four time points: before appliance insertion (t1), after first activation (t2), after 1 week of activation (t3), and after last activation (t4).

RESULTS

Data of 24 patients in the SME group (n = 12, mean age = 14.30 ± 1.37 years) and RME group (n = 12, mean age = 15.07 ± 1.59 years) were analyzed. Median scores for all outcomes were in the bottom quartiles of the NRS. No difference was found between the two groups at t1 or t2. Significantly higher scores for all variables, except dizziness and headache, were reported in the RME group at t4.

CONCLUSIONS

Activation of miniscrew-supported expanders resulted in mild to moderate discomfort and functional limitation. Slow activation resulted in a better overall patient experience compared with rapid activation.

Effect and stability of miniscrew-assisted rapid palatal expansion: A systematic review and meta-analysis

Objective

This study aimed to systematically analyze the effect and stability of miniscrew-assisted rapid palatal expansion (MARPE) to provide a reference for the clinical treatment of patients with maxillary transverse deficiency (MTD).

Methods

We searched PubMed, Science Direct, Web of Science, Embase, Cochrane Library, CNKI, and Wanfang Database for relevant studies published before February 18, 2021 and selected them according to the eligibility criteria. The Cochrane Handbook for Systematic Reviews (version 5.1.0) criteria were used for the quality assessment of randomized controlled trials, while the scoring protocol of the methodological index for non-randomized studies was used for non-randomized controlled trials. Statistical analysis was performed using the RevMan5.3 software.

Results

All the included studies showed a relatively high success rate of expansion. The changes in both the intermolar and alveolar widths after MARPE were statistically significant. MARPE exhibited greater skeletal expansion effects than did conventional RPE. The midpalatal suture was opened in parallel after MARPE. A small amount of relapse was observed 1 year after expansion. MARPE caused tooth inclination and a decrease in alveolar height, but it was less significant than in conventional RPE.

Conclusions

MARPE may be an effective treatment modality for patients with MTD. It causes great transverse skeletal expansion in late adolescence. In comparison to conventional RPE, MARPE has lower detrimental periodontal effects and has certain clinical advantages.

Rapid Maxillary Expansion on the Adolescent Patient: Systematic Review and Case Report

Aim: In the literature, many studies and articles are investigating new devices and approaches to achieve rapid palate expansion through the opening of the palatal suture, and evaluating the skeletal, dental, and soft tissue effects. The purpose of this review was to assess how palatal expansion is performed in adolescent patients with permanent dentition. Furthermore, it was reported as an example of successful orthodontic treatment of an 11-year-old female patient affected by maxillary skeletal transverse deficiency, in permanent dentition. Methods: A search of the literature was conducted on PubMed, Cochrane, Scopus, Embase, and Web of Science databases. Inclusion criteria were the year of publication between 2017 and 2022, patients aged 10 to 16 years in permanent dentition, with transversal discrepancy, treated with tooth-borne, bone-borne, hybrid palatal expanders. Results: A total of 619 articles were identified by the electronic search, and finally, a total of 16 papers were included in the qualitative analysis. Conclusions: From this study, it was assessed that MARPE is more predictable, and it determines a more significant expansion of the suture than the Hyrax expander, with fewer side effects.

Skeletal and dentoalveolar effects of slow vs rapid activation protocols of miniscrew-supported maxillary expanders in adolescents: A randomized clinical trial

OBJECTIVES

To compare between skeletal and dentoalveolar effects of slow and rapid activation of miniscrew-supported expanders.

MATERIALS AND METHODS

A total of 30 patients were randomly allocated to two groups using block randomization and the allocation ratio 1:1. Both groups received maxillary expanders anchored using four miniscrews. Activation protocol was once every other day in the slow expansion (SME) group and twice daily in the rapid expansion (RME) group. Cone-beam computed tomography (CBCT) scans were obtained before expansion and after removal of the expanders. Transverse skeletal and dentoalveolar changes were measured using CBCT.

RESULTS

A total of 12 patients in the SME group (mean age, 14.30 ± 1.37 years) and 12 patients in the RME group (mean age, 15.07 ± 1.59 years) were analyzed. RME showed significantly greater widening of the mid-palatal suture at the level of first molars (mean difference [SME - RME] = -0.61 mm), and a greater increase in right and left molar buccal inclination (mean difference= -3.83° and -2.03°, respectively). Percentage of skeletal expansion relative to the jackscrew opening was not significantly different between the groups. Palatal inflammation was evident following appliance removal. Miniscrew mobility and bending were observed with RME.

CONCLUSIONS

Both SME and RME were effective in correcting skeletal transverse maxillary deficiency. However, RME resulted in more buccal tipping of maxillary molars and in miniscrew failures and bending.

Evaluation of bone depth, cortical bone, and mucosa thickness of palatal posterior supra-alveolar insertion site for miniscrew placement

BACKGROUND

The use of palatal miniscrew offers the possibility to improve the effectiveness of orthodontic expansion devices. Palatal expanders supported by miniscrew can be applied with different clinical protocols. Some authors proposed the use of four palatal miniscrews during miniscrew-supported palatal expansion to maximize skeletal effects in young adults' treatment. However, bone availability decreases in the posterior paramedian palatal regions, making the positioning of the two-posterior paramedian palatal miniscrews challenging, when it is performed avoiding nasal cavities invasion. Some authors proposed miniscrews insertion in a specific region located laterally to the palatal process of the maxillary bone, and apically relatively to the dento-alveolar process. The aim of this study was to evaluate the bone thickness, cortical bone thickness, and mucosae depth of this anatomical site that, in this study, was defined as palatal posterior supra-alveolar insertion site.

RESULTS

The evaluation of bone availability of palatal posterior supra-alveolar insertion site at different antero-posterior levels showed that the maximum amount of total bone thickness was found between the second premolar and the first molar. At this level total bone, thickness is significantly (p < .05) greater compared to the other sagittal sites and it offers on average around 2 mm of extra bone depth for miniscrew placement. Cortical bone thickness is adequate for primary miniscrew stability. Overall, cortical bone thickness considered at different insertion sites showed significant statistically (p < .05) differences. The findings of this study showed that palatal mucosa is particularly thick with average values ranging from 4 to 7 mm, and its extension ultimately affects miniscrew length selection. Palatal mucosa thickness showed no clinically significant differences comparing different sagittal and vertical insertion sites. Data also showed that palatal mucosal thickness slightly significantly increases (p < .05) with the inclination of the insertion axis relative to the occlusal plane. Finally, study findings showed that vertical growth pattern can significantly affect considered outcomes (p < .05).

CONCLUSIONS

Palatal posterior supra-alveolar insertion site is an appropriate site for posterior insertion of palatal miniscrews. Considering high anatomical variation preliminary CBCT evaluation is important to achieve optimal miniscrew placement.

Three-dimensional evaluation of skeletal and dental effects of treatment with maxillary skeletal expansion

INTRODUCTION

The objective was to determine the skeletal and dental changes with microimplant assisted rapid palatal expansion (MARPE) appliances in growing (GR) and nongrowing (NG) patients using cone-beam computed tomography and 3-dimensional imaging analysis.

METHODS

The sample consisted of 25 patients with transverse maxillary discrepancy treated with a maxillary skeletal expander, a type of MARPE appliance. Cone-beam computed tomography scans were taken before and after maxillary expansion; the interval was 6.0 ± 4.3 months. The sample was divided into GR and NG groups using cervical vertebral and midpalatal suture maturation. Linear and angular 3-dimensional dentoskeletal changes were assessed after cranial base superimposition. Groups were compared with independent-samples t test (P <0.05).

RESULTS

Both groups displayed marked transverse changes with a similar ratio of skeletal to dental transverse changes and parallel sutural opening from the posterior nasal spine-anterior nasal spine; a similar amount of expansion occurred in the anterior and the posterior regions of the maxilla. The maxilla expanded skeletally without rotational displacements in both groups. The small downward-forward displacements were similar in both groups, except that the GR group had a significantly greater vertical displacement of the canines (GR, 1.7 ±1.0 mm; NG, 0.6 ± 0.8 mm; P = 0.02) and anterior nasal spine (GR, 1.1 ± 0.6 mm; NG, 0.5 ± 0.5 mm; P = 0.004).

CONCLUSIONS

Treatment of patients with MARPE appliance is effective in GR and NG patients. Although greater skeletal and dental changes were observed in GR patients, a similar ratio of skeletal to dental transverse changes was observed in both groups.

Short-Term and Long-Term Changes of Nasal Soft Tissue after Rapid Maxillary Expansion (RME) with Tooth-Borne and Bone-Borne Devices. A CBCT Retrospective Study

The objective of the study was to assess the changes in nasal soft tissues after RME was performed with tooth-borne (TB) and bone-borne (BB) appliances. Methods. This study included 40 subjects with a diagnosis of posterior cross-bite who received tooth-borne RME (TB, average age: 11.75 ± 1.13 years) or bone-borne RME (BB, average age: 12.68 ± 1.31 years). Cone-beam computed tomography (CBCT) was taken before treatment (T0), after a 6-month retention period (T1), and one year after retention (T2). Specific linear measurements of the skeletal components and of the soft-tissue region of the nose were performed. All data were statistically analyzed. Results. Concerning skeletal measurements, the BB group showed a greater skeletal expansion of the anterior and posterior region of the nose compared to the TB group (p < 0.05) immediately after RME. Both TB and BB RME induce a small increment (>1 mm) of the alar base and alar width, without significant differences between the two expansion methods (p > 0.05). A high correlation was found between skeletal and soft-tissue expansion in the TB group; instead, a weaker correlation was found in the BB group. Conclusion. A similar slight increment of the alar width and alar base width was found in both TB and BB groups. However, the clinical relevance of these differences, in terms of facial appearance, remains questionable.

Comparison of changes in skeletal, dentoalveolar, periodontal, and nasal structures after tooth-borne or bone-borne rapid maxillary expansion: A parallel cohort study

INTRODUCTION

This parallel cohort study aimed to assess the dentoalveolar, skeletal, periodontal, and airway effects of tooth-borne (hyrax) and computer-guided miniscrew-supported rapid palatal expansion appliances.

METHODS

Thirty-six subjects were randomly allocated into 2 groups. Eighteen subjects (mean age, 12.2 years; male-to-female ratio, 10:8) were assigned to receive treatment with the hyrax appliance (group A), and 18 subjects were treated with the computer-guided miniscrew-supported appliance (group B). The same type of expansion screw and expansion protocol was used in both groups. Linear and angular measurements of skeletal, dentoalveolar, periodontal, and nasal floor changes were performed on the pretreatment and posttreatment cone-beam computed tomography images (6-month follow-up). Descriptive statistics and the independent Student t test were used for the statistical analysis. Intraoperator reliability was evaluated using a 2 sample t test. The level of significance was P ≤0.05.

RESULTS

Ten subjects were censured because posttreatment cone-beam computed tomography imaging was not performed because of the coronavirus disease 2019 pandemic. In the remaining 26 subjects, increases in linear measurements were observed in both groups. The transversal skeletal increase was greater and statistically significant in the group treated with the bone-borne expander (P ≤0.05). The dentoalveolar transverse diameters were greater in the tooth-supported expander group, with no statistically significant difference between the groups. The buccal inclination of the maxillary first molar was observed in the group with the tooth-borne expander, with a statistically significant difference between the 2 groups. A slight reduction of buccal and palatal thicknesses at the level of the maxillary first molars was observed in both groups, smaller in the skeletal expander group, with a statistically significant difference between the 2 groups only on the right buccal cortical plate. The width of the nasal floor increased more in the group with skeletal expander with a statistically significant difference of 2 mm.

CONCLUSIONS

Computer-guided miniscrew-supported maxillary expanders allowed a greater transversal increase of the nasal-maxillary skeletal structures by reducing the dentoalveolar side effects of the tooth-supported devices.

Short-term skeletal and dentoalveolar effects of overexpansion

OBJECTIVES

To evaluate whether the amount of rapid maxillary expansion differentially affects the skeletal and dentoalveolar changes that occur.

MATERIALS AND METHODS

This randomized controlled trial included 23 patients who had rapid maxillary expansion (RME). Subjects were randomly assigned to a conventional expansion control group (n = 12) or an overexpansion group (n = 11), who started treatment at 13.2 ± 1.5 and 13.8 ± 1 years of age, respectively. Cone beam computed tomography scans (11 cm) were obtained prior to rapid maxillary expander (RME) delivery and approximately 3.7 months later. Initial hand-wrist radiographs were used to determine the participants' skeletal maturity.

RESULTS

The RME screws were activated 5.6 ± 1.2 mm and 10.1 ± 0.6 mm in the conventional and overexpansion groups, respectively. Overexpansion produced significantly greater expansion of the nasal cavity (2.1X-2.5X), maxillary base (2.3X), buccal alveolar crest (1.4X), and greater palatine foramina (1.9X). Significantly greater intermolar width increases (1.8X) and molar inclination (2.8X) changes were also produced. The nasal cavity and maxillary base expanded 23%-32% as much as the screws were activated. Skeletal expansion was positively correlated with RME screw activation (R = 0.61 to 0.70) and negatively correlated (R = -0.56 to -0.64) with the patients' skeletal maturation indicators (SMIs). Together, screw activation and the patients' SMI scores explained 48%-66% of the variation in skeletal expansion.

CONCLUSIONS

This pilot study shows that overexpansion produces greater changes than conventional expansion, with greater skeletal effects among less mature patients.

Skeletal, dentoalveolar, and buccal bone changes using hybrid and tooth-borne expanders for RME and SARME in different growth stages

Objective

To compare the skeletal, dentoalveolar and buccal bone thickness of tooth–bone-borne (Hybrid-H) and tooth-borne (TB) maxillary expanders used for rapid maxillary expansion (RME) in early and late adolescents and for surgically-assisted RME (SARME) in young adults.

Materials and methods:

This two-centre clinical study included initial and 6 months post-retention CBCT records of 60 patients (27 males, 33 females; mean age 15.7 ± 3.75 years). The cohort was divided into two groups according to the expander type (H or TB) and subdivided into a further three groups determined by cervical vertebrae maturation stages: early adolescents (EA), late adolescents (LA), and young adults (A). EA and LA patients underwent RME and young adults received a SARME.

Results:

The hybrid-designed appliance increased the internal skeletal maxillary width and nasal width more than the TB-designed appliance anteriorly in EA and posteriorly in SARME young adults. The TB expanders tipped and expanded the first premolars more than the Hybrid SARME expanders in young adults and caused a greater reduction in buccal alveolar bone thickness at the level of the first premolars and molars at the three growth stages.

Conclusion

The hybrid expanders, with relatively greater skeletal and nasal widening potential and fewer dentoalveolar side effects, were a favourable alternative to tooth-borne expanders for RME in the early and late adolescents, and for SARME in young adults.

Minimally invasive surgical and miniscrew-assisted rapid palatal expansion (MISMARPE) in adult patients

The purpose of this study was to evaluate maxillary expansion, operative time and pain associated with a new minimally invasive surgical technique to treat maxillary hypoplasia in adult patients. Consecutive patients were included and prospectively analyzed. The technique consists in miniscrew-assisted rapid palatal expansion (MARPE), minimally invasive approach to maxillary osteotomies, latency period and activation period until the desired expansion. The parameters evaluated included operative time, treatment-related pain by the visual analog scale (VAS), and transverse maxillary expansion. The Shapiro-Wilk test was used to assess the normality of data distribution. A paired t-test was used to compare the data between T0 (preoperative) and T1 (postoperative - end of activation). The significance level was set at 5%. Eleven patients were included. Mean operative time was 24.11 min (14.4-32 min) and overall postoperative VAS score was 2.81 (0-9). A comparative analysis showed significant increases in maxillary width at the skeletal, alveolar, and dental levels (p < 0.0001 for all), with a mean range of 1.8 (SD 0.3) mm to 4.7 (SD 0.5) mm. The present minimally invasive surgical MARPE (MISMARPE) technique appears to yield good skeletal outcomes with minimal trauma. It might have potential for clinical use, but larger comparative studies are needed to confirm the clinical relevance of the approach.

Orthodontic treatment for posterior crossbites

BACKGROUND

A posterior crossbite occurs when the top back teeth bite inside the bottom back teeth. The prevalence of posterior crossbite is around 4% and 17% of children and adolescents in Europe and America, respectively. Several treatments have been recommended to correct this problem, which is related to such dental issues as tooth attrition, abnormal development of the jaws, joint problems, and imbalanced facial appearance. Treatments involve expanding the upper jaw with an orthodontic appliance, which can be fixed (e.g. quad-helix) or removable (e.g. expansion plate). This is the third update of a Cochrane review first published in 2001.

OBJECTIVES

To assess the effects of different orthodontic treatments for posterior crossbites.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched four bibliographic databases up to 8 April 2021 and used additional search methods to identify published, unpublished and ongoing studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of orthodontic treatment for posterior crossbites in children and adults.

DATA COLLECTION AND ANALYSIS

Two review authors, independently and in duplicate, screened the results of the electronic searches, extracted data, and assessed the risk of bias of the included studies. A third review author participated to resolve disagreements. We used risk ratios (RR) and 95% confidence intervals (CIs) to summarise dichotomous data (event), unless there were zero values in trial arms, in which case we used odds ratios (ORs). We used mean differences (MD) with 95% CIs to summarise continuous data. We performed meta-analyses using fixed-effect models. We used the GRADE approach to assess the certainty of the evidence for the main outcomes.

MAIN RESULTS

We included 31 studies that randomised approximately 1410 participants. Eight studies were at low risk of bias, 15 were at high risk of bias, and eight were unclear. Intervention versus observation For children (age 7 to 11 years), quad-helix was beneficial for posterior crossbite correction compared to observation (OR 50.59, 95% CI 26.77 to 95.60; 3 studies, 149 participants; high-certainty evidence) and resulted in higher final inter-molar distances (MD 4.71 mm, 95% CI 4.31 to 5.10; 3 studies, 146 participants; moderate-certainty evidence). For children, expansion plates were also beneficial for posterior crossbite correction compared to observation (OR 25.26, 95% CI 13.08 to 48.77; 3 studies, 148 participants; high-certainty evidence) and resulted in higher final inter-molar distances (MD 3.30 mm, 95% CI 2.88 to 3.73; 3 studies, 145 participants, 3 studies; moderate-certainty evidence). In addition, expansion plates resulted in higher inter-canine distances (MD 2.59 mm, 95% CI 2.18 to 3.01; 3 studies, 145 participants; moderate-certainty evidence). The use of Hyrax is probably effective for correcting posterior crossbite compared to observation (OR 48.02, 95% CI 21.58 to 106.87; 93 participants, 3 studies; moderate-certainty evidence). Two of the studies focused on adolescents (age 12 to 16 years) and found that Hyrax increased the inter-molar distance compared with observation (MD 5.80, 95% CI 5.15 to 6.45; 2 studies, 72 participants; moderate-certainty evidence). Intervention A versus intervention B When comparing quad-helix with expansion plates in children, quad-helix was more effective for posterior crossbite correction (RR 1.29, 95% CI 1.13 to 1.46; 3 studies, 151 participants; moderate-certainty evidence), final inter-molar distance (MD 1.48 mm, 95% CI 0.91 mm to 2.04 mm; 3 studies, 151 participants; high-certainty evidence), inter-canine distance (0.59 mm higher (95% CI 0.09 mm  to 1.08 mm; 3 studies, 151 participants; low-certainty evidence) and length of treatment (MD -3.15 months, 95% CI -4.04 to -2.25; 3 studies, 148 participants; moderate-certainty evidence). There was no evidence of a difference between Hyrax and Haas for posterior crossbite correction (RR 1.05, 95% CI 0.94 to 1.18; 3 studies, 83 participants; moderate-certainty evidence) or inter-molar distance (MD -0.15 mm, 95% CI -0.86 mm to 0.56 mm; 2 studies of adolescents, 46 participants; moderate-certainty evidence). There was no evidence of a difference between Hyrax and tooth-bone-borne expansion for crossbite correction (RR 1.02, 95% CI 0.92 to 1.12; I² = 0%; 3 studies, 120 participants; low-certainty evidence) or inter-molar distance (MD -0.66 mm, 95% CI -1.36 mm to 0.04 mm; I² = 0%; 2 studies, 65 participants; low-certainty evidence).  There was no evidence of a difference between Hyrax with bone-borne expansion for posterior crossbite correction (RR 1.00, 95% CI 0.94 to 1.07; I² = 0%; 2 studies of adolescents, 81 participants; low-certainty evidence) or inter-molar distance (MD -0.14 mm, 95% CI -0.85 mm to 0.57 mm; I² = 0%; 2 studies, 81 participants; low-certainty evidence).  AUTHORS' CONCLUSIONS: For children in the early mixed dentition stage (age 7 to 11 years old), quad-helix and expansion plates are more beneficial than no treatment for correcting posterior crossbites. Expansion plates also increase the inter-canine distance. Quad-helix is more effective than expansion plates for correcting posterior crossbite and increasing inter-molar distance. Treatment duration is shorter with quad-helix than expansion plates. For adolescents in permanent dentition (age 12 to 16 years old), Hyrax and Haas are similar for posterior crossbite correction and increasing the inter-molar distance. The remaining evidence was insufficient to draw any robust conclusions for the efficacy of posterior crossbite correction.

Comparison of dentoskeletal and soft tissue changes between tooth-borne and tooth-bone-borne hybrid nonsurgical rapid maxillary expansions in adults: a retrospective observational study

BACKGROUND

Despite the gradual increase in the use of rapid maxillary expansion (RME), specifically RME with the aid of skeletal anchorage in adults, there have been no reports comparing dentoskeletal and soft tissue changes between nonsurgical tooth-borne and tooth-bone-borne RMEs in adults. This study aimed to analyse differences in dentoskeletal and soft tissue changes between tooth-borne and tooth-bone-borne RMEs using a similar appliance design and the same expansion protocol in adult patients.

METHODS

Twenty-one patients with tooth-borne expansion (a conventional expansion screw with two premolars and two molar bands for dental anchorage [T-RME]) and the same number of patients with tooth-bone-borne hybrid expansion (a conventional expansion screw with two premolar and two molar bands for dental anchorage and four mini-implants in the palate for skeletal anchorage [H-RME]) were included. Dentoskeletal and soft tissue variables at pretreatment (T1) and after expansion (T2) were measured using posteroanterior and lateral cephalograms and frontal photographs. The sex distribution of the two groups was analysed using the chi-square test, and the change after RME in each group was evaluated using the Wilcoxon signed-rank test. Differences in pretreatment age, expansion duration, post-expansion duration, and dentoskeletal and soft tissue changes after RME between the two groups were determined using the Mann-Whitney U test.

RESULTS

There were no significant differences in the expansion protocol, pretreatment conditions, and sex distribution between the two groups. Despite similar degrees of dental expansion at the crown level between the two groups, H-RME induced increased skeletal and parallel expansion of the maxilla compared to T-RME. After expansion, H-RME demonstrated increased forward displacement of the maxilla without significant changes in the vertical dimension, while T-RME exhibited increased backward displacement of the mandible, increased vertical dimension, and decreased overbite. Both groups showed significant retroclination and extrusion of the maxillary incisors without significant intergroup differences. There were no significant soft tissue changes between the two groups.

CONCLUSION

This study suggests that using skeletal anchorage in RME may induce increased skeletal and parallel expansion of the maxilla without significant effects on the vertical dimension.

Age-dependent effects of transverse maxillary deficiency treated by microimplant-assisted rapid palatal expansion: A prospective cone-beam computed tomography study

INTRODUCTION

This study investigated the results of maxillary discrepancy treated by microimplant-assisted rapid palatal expansion (MARPE) at different ages.

METHODS

Sixty patients (aged 11.0-34.1 years; 23 male and 37 female) were treated by MARPE. Cone-beam computed tomography scans and dental casts were taken before and after expansion. The data were compared among 4 age groups: early adolescents (aged 11-14 years), late adolescents (aged 15-19 years), young adults (aged 20-24 years), and old adults (aged 25-34.1 years).

RESULTS

The success rates of midpalatal suture separation were 100%, 100%, 88.2%, and 85.7% for early adolescents, late adolescents, young adults, and old adults, respectively. Palatal sutures at the level of the first molar were expanded by 4.02 mm, 3.48 mm, 2.63 mm, and 2.10 mm, corresponding to 66.7%, 58.1%, 42.0%, and 37.9% of the total dental expansion. Significant differences were found in the amounts of palatal suture expansion and the ratio of skeletal dental expansion between patients aged <20 years and patients aged ≥20 years (P <0.05). Skeletal expansion constituted 69.4%, 51.3%, 39.0%, and 29.8% of the total screw expansion. Except for the comparison between young adults and old adults, there were significant differences between groups for the ratio of skeletal screw expansion (P <0.05).

CONCLUSIONS

The midpalatal suture can be expanded by MARPE more easily in patients <20 years of age than in patients ≥20 years of age. The ratio of skeletal screw expansion decreases as age increases.

The 100 most-cited articles in orthodontic journals in the last 20 years

INTRODUCTION

This study aimed to identify and analyze the 100 most-cited articles published in orthodontic scientific journals in the past 21 years.

METHODS

The research was conducted in the Thomson Reuters Web of Science data citation index, considering articles from 2000 to 2020 and the category of dentistry, oral surgery, and medicine. Information about the number of citations, citations per year, title, authors, year of publication, the title of scientific journals, type of study, keywords, and thematic field were extracted for each article. Descriptive statistical analyses were performed to evaluate the collected data. The Pearson correlation analysis was used to explore the relationship between publication and the number of citations received. The VOSviewer software (Leiden University Center for Science and Technology Studies, Leiden, the Netherlands) was used to generate the keyword cooccurrence network.

RESULTS

The number of citations of the 100 selected articles ranged from 122 to 547. The journal with the largest number of cited articles was the American Journal of Orthodontics and Dentofacial Orthopedics. Most of the papers were cross-sectional and longitudinal studies, and the most frequent thematic fields among the selected articles were anchorage, root resorption, and rapid maxillary expansion. Orthodontic treatment, anchorage, and root resorption were the most frequent keywords.

CONCLUSIONS

Bibliometric analysis of citations revealed a greater centralization of orthodontic studies. Most of the articles were published in a single journal and by one country. Anchorage is a trending topic in orthodontics, and cross-sectional and longitudinal studies are the most-cited types of papers.

Periodontal effects of maxillary expansion in adults using non-surgical expanders with skeletal anchorage vs. surgically assisted maxillary expansion: a systematic review

OBJECTIVES

Describe and compare harmful periodontal effects as a consequence of maxillary expansion in adult patients with different types of anchorage devices in non-surgical expanders with skeletal anchorage and surgically assisted maxillary expansion.

MATERIALS AND METHODS

An exhaustive search was carried out on the electronic databases PubMed (MEDLINE), Embase, Cochrane and LILACS. Additionally, journal references and grey literature were searched without any restrictions. After the selection and extraction process; risk of bias was assessed by the ROB-1 Cochrane tool and Newcastle-Ottawa Scale (NOS) for randomized trials and cohort studies, respectively.

RESULTS

Of 621 studies retrieved from the searches, six were finally included in this review. One of them presented a low risk bias, while five were excellent respective to selection, comparability and outcomes. Results showed that maxillary expansion in adults using non-surgical expanders (bone-borne or tooth-bone-borne with bicortical skeletal anchorage) produce less harmful periodontal effects, such as: alveolar bending with an average range from 0.92° to 2.32°, compared to surgically assisted maxillary expansion (tooth-borne) of 6.4°; dental inclination with an average range from 0.07° to 2.4°, compared to surgically assisted maxillary expansion (tooth-borne) with a range from 2.01° to 5.56°.

CONCLUSIONS

Although limited, the current evidence seems to show that the bone-borne or tooth-bone-borne with bicortical skeletal anchorage produces fewer undesirable periodontal effects.

Quantitative cone-beam computed tomography evaluation of hard and soft tissue thicknesses in the midpalatal suture region to facilitate orthodontic mini-implant placement

Objective

To identify the most favorable sites that optimize the initial stability and survival rate of orthodontic mini-implants, this study measured hard and soft tissue thicknesses in the median and paramedian regions of the palate using cone-beam computed tomography (CBCT) and determined possible sexand age-related differences in these thicknesses.

Methods

The study sample comprised CBCT images of 189 healthy subjects. The sample was divided into four groups according to age. A grid area was set for the measurement of hard and soft tissue thicknesses in the palate. Vertical lines were marked at intervals of 0, 1.5, and 3.0 mm lateral to the midpalatal suture, while horizontal lines were marked at 2-mm intervals up to 24 mm from the posterior margin of the incisive foramen. Measurements were made at 65 points of intersection between the horizontal and vertical lines.

Results

The palatal hard tissue thickness decreased from the anterior to the posterior region, with a decrease in the medial-to-lateral direction in the middle and posterior regions. While the soft tissue was rather thick around the lateral aspects of the palatal arch, it formed a constant layer that was only 1-2-mm thick throughout the palate. Statistically significant differences were observed according to sex and age.

Conclusions

The anterolateral palate as well as the midpalatal suture seem to be the most favorable sites for insertion of orthodontic mini-implants. The thickness of the palate differed by age and sex; these differences should be considered while planning the placement of orthodontic mini-implants.

Skeletal and dentoalveolar effects using tooth-borne and tooth-bone-borne RME appliances: a randomized controlled trial with 1-year follow-up

OBJECTIVES

To evaluate and compare the skeletal and dentoalveolar effects of tooth-borne (TB) and tooth-bone-borne (TBB) rapid maxillary expansion (RME).

MATERIALS AND METHODS

Fifty-two consecutive patients who met the eligibility criteria were recruited and allocated to either the TB group, mean age 9.3 years [standard deviation (SD) 1.3], or the TBB group, mean age 9.5 years (SD 1.2). Cone-beam computed tomography (CBCT) records and plaster models were taken before (T0), directly after (T1), and 1 year after expansion (T2). Dentoalveolar and skeletal measurements were made on the CBCT images. The dental expansion was also measured on the plaster models.

RANDOMIZATION

Participants were randomly allocated in blocks of different sizes using the concealed allocation principle in a 1:1 ratio. The randomization list was also stratified by sex to ensure homogeneity between groups.

BLINDING

Due to clinical limitations, only the outcomes assessors were blinded to the groups to which the patients were allocated.

RESULTS

Skeletal expansion in the midpalatal suture and at the level of the nasal cavity was significantly higher in the TBB group. However, the magnitude of the expansion in the midpalatal suture was around 1 mm [95 per cent confidence interval (CI) 0.5-1.7, P = 0.001] more and perhaps not clinically significant. The magnitude of the expansion at the level of the nasal cavity was almost two times higher in the TBB group (95 per cent CI 0.7-2.6, P = 0.001). The dental expansion, alveolar bending, tipping of the molars, and stability 1 year post-expansion did not show any statistically significant differences between the groups. The actual direct cost of the treatment for the TBB group was approximately €300 higher than TB group.

LIMITATIONS

Double blinding was not possible due to the clinical limitations.

CONCLUSIONS

In young preadolescents with constricted maxilla and no signs of upper airway obstruction, it seems that conventional TB RME achieves the same clinical results with good stability 1 year post-expansion at lower cost.

TRIAL REGISTRATION

The trial was not registered.

Nasal ventilation and rapid maxillary expansion (RME): a randomized trial

OBJECTIVE

To assess three rapid maxillary expansion (RME) appliances in nasal ventilation.

TRIAL DESIGN

Three-arm parallel randomized clinical trial.

METHODS

Sixty-six growing subjects (10-16 years old) needing RME as part of their orthodontic treatment were randomly allocated (1:1:1 ratio) to three groups of 22 patients receiving Hyrax (H), Hybrid-Hyrax (HH), or Keles keyless expander (K). The primary outcome of nasal ventilation (pressure and velocity) and secondary outcomes (skeletal, dental, soft tissue, and nasal obstruction changes) were blindly assessed on the initial (T0) and final (T1, 6 months at appliance removal) cone-beam computed tomography (CBCT) data by applying computational fluid dynamics (CFD) method. Differences across groups were assessed with crude and adjusted for baseline values and confounders (gender, age, skeletal maturation, expansion amount, mucosal/adenoid hypertrophy, nasal septum deviation) regression models with alpha = 5%.

RESULTS

Fifty-four patients were analysed (19H, 21HH, 14K). RME reduced both nasal pressure (H: -45.8%, HH: -75.5%, K: -63.2%) and velocity (H: -30%, HH: -58.5%, K: -35%) accompanied with nasal obstruction resolution (H: 26%, HH: 62%, K: 50%). Regressions accounting for baseline severity indicated HH expander performing better in terms of post-expansion maximum velocity (P = 0.03) and nasal obstruction resolution (P = 0.04), which was robust to confounders. Mucosal/adenoid hypertrophy and nasal septum deviation changes were variable, minimal, and similar across groups. The HH resulted in significantly greater increase in the nasal cross-sectional area (62.3%), anterior (14.6%), and posterior (10.5%) nasal widths. Nasal obstruction resolution was more probable among younger (P = 0.04), skeletally immature (P = 0.03), and male patients (P = 0.02) without pre-treatment mucosal hypertrophy (P = 0.04), while HH was associated with marginal greater probability for obstruction resolution.

CONCLUSIONS

RME resulted in improvement of nasal skeletal parameters and simulated ventilation with the former being in favour of the HH and the latter not showing significant differences among the three appliances.

LIMITATION

Attrition in the K group due to blocked activation rods possibly leading to limited sample to identify any existing group differences.

HARMS

Replacement of blocked Keles expanders for finalizing treatment.

PROTOCOL

The protocol was not published before the trial commencement.

REGISTRATION

Australian and New Zealand Clinical Trial Registry; ACTRN12617001136392.

Skeletal width changes after mini-implant-assisted rapid maxillary expansion (MARME) in young adults

OBJECTIVES

To observe skeletal width changes after mini-implant-assisted rapid maxillary expansion (MARME) and determine the possible factors that may affect the postexpansion changes using cone-beam computed tomography (CBCT) in young adults.

MATERIALS AND METHODS

Thirty-one patients (mean age 22.14 ± 4.76 years) who were treated with MARME over 1 year were enrolled. Four mini-implants were inserted in the midpalatal region, and the number of activations ranged from 40 to 60 turns (0.13 per turn). CBCT was performed before MARME (T0), after activation (T1), and after 1 year of retention (T2). The mean period between T1 and T0 was 6 ± 1.9 months and between T2 and T1 was 13 ± 2.18 months. A paired t-test was performed to compare T0, T1, and T2. The correlations between the postexpansion changes and possible contributing factors were analyzed by Pearson correlation analysis.

RESULTS

The widths increased significantly after T1. After T2, the palatal suture width decreased from 2.50 mm to 0.75 mm. From T1 to T2, decreases recorded among skeletal variables varied from 0.13 mm to 0.41 mm. This decrease accounted for 5.75% of the total expansion (2.26 mm) in nasal width (N-N) and 19.75% at the lateral pterygoid plate. A significant correlation was found between postexpansion change and palatal cortical bone thickness and inclination of the palatal plane (ANS-PNS/SN; P < .05).

CONCLUSIONS

Expanded skeletal width was generally stable after MARME. However, some amount of relapse occurred over time. Patients with thicker cortical bone of the palate and/or flatter palatal planes seemed to demonstrate better stability.

Treatment of maxillary transversal deficiency by using a mini-implant-borne rapid maxillary expander and aligners in combination

Bone-borne rapid maxillary expansion distraction devices are used to achieve a more skeletal expansion and to avoid dental side effects of conventional expanders such as tipping of anchorage teeth. In this article, we report the use of a prefabricated expander fixed on 2 mini-implants in the anterior palate. This allows for the insertion of the mini-implants and the expander to occur without the need for an impression or any laboratory procedures. Especially when aligners are going to be used, the use of a mini-implant-borne expander seems to be reasonable because the expander can be left in place as a skeletal retainer during the aligner finishing.

Comparison of skeletal and dentoalveolar changes between pure bone-borne and hybrid tooth-borne and bone-borne maxillary rapid palatal expanders using cone-beam computed tomography

Objectives:

The objectives of the study were to compare the skeletal, dentoalveolar, and periodontal changes between two types of microimplant-assisted rapid maxillary expansion appliances: The bone-anchored maxillary expanders (BAME) and the tooth-bone-anchored maxillary skeletal expander (MSE).

Materials and Methods:

Thirty-four patients with a transverse maxillary deficiency were divided into two groups; the first group (16 patients, average age 14.9 years) was treated with the MSE appliance, and the second group (18 patients, average age 13.8 years) was treated with the BAME appliance. Cone-beam computed tomography scans were taken at pre-treatment (T1) and immediately post-expansion (T2) to measure the changes in midpalatal suture opening, total expansion (TE), alveolar bone bending, dental tipping (DT), and buccal bone thickness. Data were analyzed using paired t-test and two-sample t-test.

Results:

Midpalatal suture separation was found in 100% of the patients in both groups. The TE at the first molar was 5.9 mm in the MSE group and 4.7 mm in the BAME group. The skeletal contributions were 56% and 83% of TE for the MSE and BAME groups, respectively. Significantly less dental buccal tipping and buccal bone loss were found with the BAME group. The midpalatal suture in both groups exhibited a parallel opening pattern in the axial plane.

Conclusion:

The use of BAME appliance resulted in greater skeletal effects, less dental tipping, and less buccal bone reduction compared to MSE appliance (immediately after maxillary expansion).

Evaluation of pulp cavity/chamber changes after tooth-borne and bone-borne rapid maxillary expansions: a CBCT study using surface-based superimposition and deviation analysis

OBJECTIVES

To compare volume and shape changes of pulp chamber of maxillary posterior teeth between tooth-borne and bone-borne maxillary expansions in adolescents.

MATERIALS AND METHODS

This study included 36 adolescents with bilateral maxillary crossbite who received tooth-borne rapid maxillary expansion (TB group, average age 14.4 years) or bone-borne rapid maxillary expansion (BB group, average age 14.7 years). Cone beam computed tomography (CBCT) was taken before treatment (T1) and after a 6-month retention period (T2). Volumetric and shape changes of pulp chamber of maxillary first molars and premolars were detected by referring to a specific 3D digital technology involving deviation analysis of T1/T2 CBCT-derived models of pulp chamber. Student's t tests were used to (1) compare T1 and T2 volumes of pulp chambers in TB and BB groups and (2) assess differences between the two groups in the post-treatment volumetric changes and in the percentage of matching of 3D pulp models.

RESULTS

All investigated teeth showed a reduction of pulp volume, being this difference significant in both TB (p < 0.0001) and BB (p < 0.0001) groups. The volumetric reduction was greater in the TB group; also, subjects in the TB group showed a lower percentage of matching between T1 and T2 pulp models (p < 0.0001). The area most affected by shape change was that of pulp horns.

CONCLUSIONS

TB expander could induce a higher volumetric reduction of pulp chamber of posterior teeth compared with BB expander, in the short term.

CLINICAL RELEVANCE

The present findings add new information concerning the effects of RME protocols on pulp tissue.

In-vitro trabecular bone damage following mono- and bicortical mini implants anchorage in mini-implant assisted rapid palatal expansion (MARPE)

OBJECTIVES

To assess in-vitro trabecular bone damage following mono- and bicortical mini-implant (MI) anchorage in mini-implant assisted rapid palatal expansion (MARPE).

MATERIAL AND METHODS

Sixteen self-drilling MI (four MARPE appliances) were distributed in two groups according to bone insertion (monocortical and bicortical) in bovine rib. The device was activated five times (0.5mm each). Trabecular bone damage was assessed using micro-CT scans made at baseline and after each activation by trabecular spacing parameter (Tb.Sp) (distance [mm] between the trabecular bone structure). These measurements were made in five different regions of interest (ROI) surrounding the screw (whole, superior, inferior, anterior and posterior). Two-way ANOVA with Tukey post-hoc analysis (α=0.05) was used to evaluate the effect of insertion type (monocortical vs. bicortical) and activation cycle (0-5) on trabecular damage. The time effect was evaluated using ANOVA-MR test effect with Bonferroni correction (α=0.003). The micro-CT images were also examined qualitatively.

RESULTS

When analysing the individual ROIs, only the superior ROI had a significant difference (P<0.003) beginning at the fourth activation cycle. For the monocortical group, trabecular spacing was affected when the whole ROI was analysed beginning at the fourth activation cycle, while for the superior ROI, this difference became apparent beginning with the third activation cycle (P<0.003). For the qualitative analysis, it seems that only monocortical anchorage influences the trabecular bone in the superior area.

CONCLUSIONS

Monocortical anchorage is more susceptible to bone damage around the MIs, with the superior (cervical) region most strongly affected.

Effectiveness of Dental and Maxillary Transverse Changes in Tooth-Borne, Bone-Borne, and Hybrid Palatal Expansion through Cone-Beam Tomography: A Systematic Review of the Literature

Background and Objectives: Palatal expansion is a common orthodontic technique able to increase the transverse changes for subjects with constricted maxillary arches. The aim of the present investigation was to evaluate through a systematic review the tomography effectiveness of different palatal expander approaches. Materials and Methods: The database used to perform the screening and determine the eligibility of the clinical papers was PubMed (Medline). Results: The database search included a total of 284 results, while 271 articles were excluded. A total of 14 articles were included for the qualitative assessment. Conclusions: The effectiveness of the present studies reported that skeletal expansion was a useful approach to increase the transverse changes for subjects with constricted maxillary arches.

Tooth-Bone-Borne Vs. Bone-Borne Palatal Expanders: A Systematic Review

The aim of this review was to evaluate the current evidence regarding post-treatment effects of tooth-bone-borne vs. bone-borne expanders. A search was conducted in MEDLINE via PubMed, Web of Science, Scopus, Cochrane Library, Google Scholar, and Open Gray; in addition to a hand search in reference lists of selected articles and creating a search alert in electronic databases. Selection criteria included randomized and prospective clinical trials comparing post-expansion skeletal and/or dento-alveolar effects of tooth-bone-borne expanders to those of bone-borne expanders. Following study retrieval and selection, relevant data was extracted, and risk of bias was assessed using the revised RoB 2 tool for randomized clinical trials. After examining 10 full text articles, one randomized clinical trial was finally included. The study compared the dento-alveolar effects of tooth-bone-borne and bone-borne expanders, following expansion and after 6 months, using digital dental casts. Using the RoB 2 tool, the study was judged overall to show some concerns. A definitive conclusion could not be drawn from this systematic review due to the scarcity of clinical trials tackling the research question. A need for future well-conducted research was highlighted in this review.

Root Resorption of Maxillary Posterior Teeth after Rapid Maxillary Expansion: A Comprehensive Review of the Current Evidence from in-vitro and in-vivo Studies

Background:

The application of heavy forces to the dentition, as those produced during a Rapid Maxillary Expansion (RME), has been associated in the literature with the development of root resorption of maxillary posterior teeth.

Objective:

The aim of the present manuscript was to report the available data from in-vitro and in-vivo studies that can elucidate the biological processes of resorption and repair of radicular cementum after RME.

Methods:

Studies evaluating the occurrence of root resorption after RME by means of histological and radiographic methodology were included. We detailed the changes of the radicular anatomy after RME and provided a synthesis of the most valuable scientific evidence showing the biological processes behind the potential modifications of radicular anatomy. Results. Loss of cementum material and reduction of radicular volumes were seen after rapid maxillary expansion. A small radicular volumetric recovery of anchored teeth occurred after the retention period; this reparative phenomenon was caused by cementum deposition without the reattachment of periodontal fibers, supporting the detrimental effects associated with RR.

Conclusion:

Retention period and the timing of radiographic examination could influence the extension of radicular resorption detected after RME since root resorption and cementum repair may occur at the same time at this stage.

Orthopedic outcomes of hybrid and conventional Hyrax expanders

OBJECTIVES

To compare the effects of a hybrid miniscrew-supported expander versus a conventional Hyrax (CH) expander in growing patients.

MATERIALS AND METHODS

Forty patients were randomized into two groups: a hybrid Hyrax (HH) expander group using a Hyrax expander with two miniscrews and a CH expander group. The final sample had 18 subjects (8 female, 10 male; initial age of 10.8 years) in the HH group and 14 subjects (6 female, 8 male; initial age of 11.4 years) in the CH group. Cone-beam computed tomography examinations and digital dental models were obtained before expansion and 11 months postexpansion. The primary outcomes included the orthopedic transverse effects of expansion. Intergroup comparison was performed using analysis of covariance (P < .05).

RESULTS

Significantly greater increases in the nasal cavity width, maxillary width, and buccal alveolar crest width were found for the HH group. No intergroup differences were observed for dental arch width or shape changes.

CONCLUSIONS

The HH group showed greater increases in the nasal cavity width, maxillary width, and buccal alveolar crest width. No differences were observed for intermolar, interpremolar, or intercanine widths; arch length; or arch perimeter. Arch size and shape showed similar changes in both groups.

Comparison of skeletal maxillary transverse deficiency treated by microimplant-assisted rapid palatal expansion and tooth-borne expansion during the post-pubertal growth spurt stage

OBJECTIVE

To investigate the efficacy of microimplant-assisted rapid palatal expansion (MARPE) to treat skeletal maxillary discrepancies during the post-pubertal growth spurt stage.

MATERIALS AND METHODS

Sixty patients with skeletal maxillary transverse deficiency during the post-pubertal growth spurt stage were randomly divided into MARPE and Hyrax groups. Thirty patients (mean age: 15.1 ± 1.6 years) were treated using the four-point MARPE appliance; 30 patients (mean age, 14.8 ± 1.5 years) were treated using the Hyrax expander. Cone beam computed tomography scans and dental casts were obtained before and after expansion. The data were analyzed using paired t-tests and independent t-tests.

RESULTS

The success rates of midpalatal suture separation were 100% and 86.7% for MARPE and Hyrax groups, respectively. Palatal expansion and skeletal to dental ratio at the first molar level were greater in the MARPE group (3.82 mm and 61.4%, respectively) than in the Hyrax group (2.20 mm and 32.3%, respectively) (P < .01). Reductions in buccal alveolar bone height and buccal tipping of the first molars were less in the MARPE group than in the Hyrax group (P < .01).

CONCLUSIONS

MARPE enabled more predictable and greater skeletal expansion, as well as less buccal tipping and alveolar height loss on anchorage teeth. Thus, MARPE is a better alternative for patients with skeletal maxillary deficiency during the post-pubertal growth spurt stage.

Radiological evaluation of the bone and soft tissue thicknesses of the palate for using a miniscrew-supported maxillary skeletal expander

PURPOSE

The purpose of this study was to determine the palatal bone and soft tissue thicknesses using a miniscrew-supported maxillary skeletal expander (MSE) in Class III malocclusion.

METHODS

The thicknesses of the palatal bone and soft tissue were measured in cone-beam computed tomography images obtained from 58 patients. All 20 points were crossing points between five levels, which were defined at 3 mm intervals relative to the line connecting the central fossae of the first molar (Level 0), and 2 mm and 4 mm lateral to the anteroposterior reference line (AP line).

RESULTS

The palatal bone was significantly thicker in males than females in the anterior palate up to Level 0, while there was no significant sex-related difference in the posterior palate. There was a tendency for the thickness to decrease in the posterior direction, except in females at 2 mm lateral to the AP line. The palatal soft tissue was significantly thicker in males than females in all positions. At 2 mm lateral to the AP line, the palatal soft tissue thickness decreased in the posterior direction. A 4 mm lateral to the AP line, it initially decreased in the posterior direction, and then increasing again at Level - 6 (6 mm posterior of Level 0). As the lateral distance from the AP line increased, the palatal bone thickness decreased while the palatal soft tissue thickness increased.

CONCLUSIONS

These findings provide quantitative data on the palatal bone and soft tissue thicknesses for the miniscrew-supported MSE in the posterior palate.

CBCT and CAD-CAM technology to design a minimally invasive maxillary expander

Background

A large number of articles in recent years studying the effects of non-surgically assisted tooth- versus bone-borne maxillary expanders in growing patients have found no significant differences in mid-palatal suture disjunction or even dentoalveolar changes. This suggests the need for new criteria and better use of current technology to make more effective devices and enhance the benefits of conventional treatments. This article describes a titanium grade V computer-aided design/computer-aided manufacturing (CAD/CAM) maxillary expander supported by two miniscrews, along with a 3D printed surgical guide.

Methods

The first step was to obtain a digitized model of the patient’s upper maxilla. To simplify the process and ensure the placement of the device in a high-quality bone area, the patients’ digital dental cast was superimposed with a cone beam computed tomography (CBCT) scan. Improved resistance to expansion forces was secured through the use of 2 mm-wide miniscrews, long enough for bicortical anchorage. Placement site and direction were assessed individually in order to achieve primary stability. We chose a site between the second premolars and first molars, while the inclination followed the natural contour of the palate vault. A 3D-printed, polyamide surgical guide was designed to ensure the correct placement of the device with a manual straight driver.

Results

Favorable clinical results were presented with 3D images. We confirmed a mid-palatal suture parallel separation of 3.63 mm, along with a higher palatal volume, as well as increased intercanine and intermolar distance. Segmentation of the facial soft tissue showed an expansion of nasal airways and changes in nasal morphology.

Conclusions

Digital models, CBCT and CAD/CAM technology, are essential to accomplish the goals proposed in this article. Further studies are necessary to establish safer miniscrew placement sites and insertion angles so as to achieve greater in-treatment stability. Both the clinician and the patient can benefit from the use of current technology, creating new devices and updating traditional orthodontic procedures.