Skeletal and dentoalveolar changes in the transverse dimension using microimplant-assisted rapid palatal expansion (MARPE) appliances

MISMARPE protocol: minimally invasive surgical and miniscrew-assisted rapid palatal expansion

OBJECTIVE

The purpose of this article is to present the MISMARPE technique, a new minimally invasive surgical procedure to treat maxillary transverse atresia in adult patients under local anesthesia and on an outpatient basis.

TECHNIQUE DESCRIPTION

The technique consists of miniscrew-assisted rapid palatal expansion (MARPE) associated with a minimally invasive approach using maxillary osteotomies, latency and activation periods until the desired expansion is achieved. The present MISMARPE technique was performed in 25 consecutive cases with a success rate of 96%, yielding good skeletal outcomes with minimal trauma. The expander appliances, with their anchorage types, and a description of the surgical steps of the MISMARPE technique are presented.

CONCLUSION

MISMARPE is a new and effective alternative for less invasive treatment of maxillary transverse deficiency in adults, compared to conventional surgery. Emphasis is placed on the importance of systematic and well-established protocols, for executing the procedures safely and predictably.

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.

Monitoring the Opening of Rapid Palatal Expansion (RPE) in a 3D-Printed Skull Model Using Fiber Optic F-P Sensors

We present a novel method for the online measurement of multi-point opening distances of midpalatal sutures during a rapid palatal expansion (RPE) using fiber optic Fabry-Perot (F-P) sensors. The sensor consists of an optical fiber with a cut flat end face and an optical reflector, which are implanted into the palatal base structure of an expander and is capable of measuring the precise distance between two optical reflective surfaces. As a demonstration, a 3D-printed skull model containing the maxilla and zygomaticomaxillary complex (ZMC) was produced and a miniscrew-assisted rapid palatal expander (MARPE) with two guide rods was used to generate the midpalatal suture expansion. The reflected spectrums of the sensors were used to dynamically extract cavity length information for full process monitoring of expansion. The dynamic opening of the midpalatal suture during the gradual activation of the expander was measured, and a displacement resolution of 2.5 μm was demonstrated. The angle of expansion was derived and the results suggested that the midpalatal suture was opened with a slight V-type expansion of 0.03 rad at the first loading and subsequently expanded in parallel. This finding might be useful for understanding the mechanical mechanisms that lead to different types of expansion. The use of a fiber optic sensor for mounting the rapid palatal expander facilitates biomechanical studies and experimental and clinical evaluation of the effects of RPE.

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.

Changes in the nasal and pharyngeal airway volume with miniscrew-assisted rapid palatal expansion appliances

Objectives:

The purpose of this study was to assess the volumetric changes in the nasal and pharyngeal airway volume in patients with maxillary transverse deficiency treated with miniscrew-assisted rapid palatal expansion (MARPE) appliances.

Material and Methods:

The pre- and post-treatment cone-beam computed tomography scans of 20 subjects who underwent treatment with the MARPE appliance as part of their orthodontic treatment were included in the study. Pre- and post-expansion airway volume measurements of the nasal cavity, nasopharynx, and oropharynx were measured. Linear measurements of the skeletal structures surrounding the nasal cavity were taken to assess the pattern of airway expansion. Paired t-tests were used to evaluate nasal and pharyngeal airway volume changes with expansion. Pearson correlation test was utilized to assess the relationship between nasal and pharyngeal volume changes.

Results:

A total of 17 out of 20 samples had a successful split of the mid-palatal sutures. A significant increase in nasal airway volume (12.0%) was found post-expansion. In addition, a significant increase in linear measurements of the nasal cavity base width in the frontal plane (7.1%) and both the anterior and posterior widths in the transverse dimension (9.4% and 3.4%, respectively) were found. Significant positive correlations were found between airway volumes and increase in width of the maxillary expansion appliance.

Conclusion:

The effects of maxillary expansion with a MARPE appliance include an increase in nasal cavity volume, but not the nasopharyngeal and the oropharyngeal airway volume. The nasal cavity expands in a triangular pattern in both the frontal and transverse dimensions following orthopedic expansion with the MARPE appliance. Increase in airway volume is a result of the increase in width of the maxillary expansion appliance.

Three-dimensional craniofacial changes with maxillary expansion in young adult patients with different craniofacial morphology

Objectives:

Skeletally mature patients with transverse deficiency are best treated with surgically assisted rapid palatal expansion (RPE) procedure. Recent studies have shown that microimplant-assisted RPE (MARPE) appliances can be effective in achieving skeletal expansion in young adults. This retrospective study aimed to evaluate the skeletal and dental alveolar changes in response to treatment with MARPE appliances in three types of anteroposterior skeletal malocclusions using cone-beam computed tomography (CBCT) scans.

Material and Methods:

Seventy-eight subjects diagnosed with maxillary transverse deficiency and treated with the MARPE appliance (mean age of 22.9 ± 4.2 years) were divided into skeletal Class I, II, and III malocclusions with 26 subjects in each group. Pre- and post-treatment CBCT scans were used for superimposition to examine the skeletal and dentoalveolar changes following maxillary expansion treatment.

Results:

Significant lateral separation of the maxilla was found at the levels of the nasal floor, interzygomatic bones, and the inferior palatine margin of the alveolar process (P < 0.05) in the whole sample. Most of the sagittal and vertical variables change significantly in the whole sample and each studied group separately. Intergroup comparisons revealed no significant differences among the three skeletal classes except for the left frontozygomatic angle, left maxillary inclination angle, and torque in the first and second premolars. In Class III patients, the maxilla moved forward significantly in most of the cases (eight of 26 cases) (0.88°, P < 0.05) and the mandible moved downward and backward improving the anteroposterior skeletal relationship. Significant differences were also found in the vertical measurements (N-Me, MMP, and MP/SN, P < 0.05) in all three types of anteroposterior malocclusions.

Conclusion:

Maxillary expansion with the MARPE appliance in young adult patients induced different skeletal and dentoalveolar changes in the anteroposterior and vertical dimensions in each skeletal malocclusion with no significant difference among the three skeletal classes.

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.

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.

Posterior crossbite with mandibular asymmetry treated with lingual appliances, maxillary skeletal expanders, and alveolar bone miniscrews

Posterior crossbite and mandibular asymmetry affect esthetics and function. We report treatment of 3 patients with posterior crossbite with mandibular asymmetry but different anteroposterior and vertical characteristics. Treatment methods included maxillary skeletal expander, miniscrews, and lingual appliances. The results show that by using these appliances, ideal transverse, anteroposterior, and vertical control is possible in patients who have concerns about the esthetics of buccal appliances. Lingual appliances can provide satisfying results when combined with a maxillary skeletal expander and miniscrews in complex patients.

Stress distribution and displacement of three different types of micro-implant assisted rapid maxillary expansion (MARME): a three-dimensional finite element study

Abstract

Background/objective

Until 2010, adults underwent surgical treatment for maxillary expansion; however, with the advent of micro-implant-assisted rapid maxillary expansion (MARME), the availability of less invasive treatment options has increased. Nevertheless, individuals with severe transverse maxillary deficiency do not benefit from this therapy. This has aroused interest in creating a new device that allows the benefit of maxillary expansion for these individuals. The aim of this study was to evaluate the efficacy of three MARME models according to tension points, force distribution, and areas of concentration in the craniofacial complex when transverse forces are applied using finite element analysis.

Materials and methods

Digital modeling of the three MARME models was performed. Model A comprised five components: one body screw expander and four adjustable arms with rings for mini-implant insertion. These arms have an individualized height adjustment that allows MARME positioning according to the patient’s palatal anatomy, thereby preventing body screw expander collision with the lateral mucosa in severe cases of maxillary deficiency. Model B was a maxillary expander with screw rings joined to the body, and model C was similar to model B, except that model C had open rings for the insertion of the mini-implants. Through the MEF (Ansys software), the stresses, distribution, and area of concentration of the stresses were evaluated when transverse forces of 7.85 N were applied.

Results

The three models maintained the following pattern: model C presented weak stress peaks with limited distribution and lower concentration area, model B obtained median stress peaks with better distribution when compared to that of model C, and model A showed better stress distribution and larger concentration area. In model A, tensions were located in the lateral lamina of the pterygoid process, which is an important site for maxillary expansion. The limitation of the present study was that it did not include the periodontal tissues and muscles in the finite element method evaluation.

Conclusions

Model A showed the best stress distribution conditions. In cases of severe atresia, model A seems to be an excellent option.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40510-021-00357-5.

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).

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.

The role of micro-implant-assisted rapid palatal expansion (MARPE) in clinical orthodontics — a literature review

A maxillary transverse deficiency is a common craniofacial problem. Rapid palatal expansion (RPE) has been traditionally considered for the treatment of children and young adolescents, but this is not applicable in late adolescents or adults due to the ossification of facial sutures. A surgically assisted rapid palatal expansion (SARPE) was initially advocated for this group of patients, but the surgical procedure is associated with morbidity. As temporary anchorage devices (TADs) have been recently and popularly applied in clinical orthodontics, micro-implant-assisted rapid palatal expansion (MARPE) has been employed to facilitate maxillary expansion in skeletally mature patients. There have been various proposed MARPE designs and the outcomes appear promising. The aim of the present article is to discuss the role of MARPE in clinical orthodontics by reviewing its background, design, indications, treatment effects, stability, and limitations in the current literature. The treatment effects of two types of MARPE, bone-borne and tooth-bone-borne (hybrid), will be individually assessed.

Short-term impact of microimplant-assisted rapid palatal expansion on the nasal soft tissues in adults: A three-dimensional stereophotogrammetry study

Objective

The aim of this study was to evaluate changes in the nasal soft tissues, including movements of landmarks, changes in linear distances, and volumetric changes, using three-dimensional (3D) stereophotogrammetry after microimplant-assisted rapid palatal expansion (MARPE) in adult patients.

Methods

Facial data were scanned using a white light scanner before and after MARPE in 30 patients. In total, 7 mm of expansion was achieved over a 4-week expansion period. We determined 10 soft tissue landmarks using reverse engineering software and measured 3D vector changes at those points. In addition, we calculated the distances between points to determine changes in the width of the nasal soft tissues. The volumetric change in the nose was also measured.

Results

All landmarks except pronasale and subnasale showed statistically significant movement on the x-axis. Pronasale, subnasale, alar right, and alar left showed significant movement on the y-axis, while all landmarks except subnasale showed significant movement on the z-axis. The alar base width, alar width, and alar curvature width increased by 1.214, 0.932, and 0.987 mm, respectively. The average volumetric change was 993.33 mm³, and the amount of increase relative to the average initial volume was 2.96%.

Conclusions

The majority of soft tissue landmarks around the nasal region show significant positional changes after MARPE in adults. The nose tends to widen and move forward and downward. The post-treatment nasal volume may also exhibit a significant increase relative to the initial volume. Clinicians should thoroughly explain the anticipated changes to patients before MARPE initiation.