Bone density of the midpalatal suture 7 months after surgically assisted rapid palatal expansion in adults

Bone Density of the Midpalatal Suture After Surgically Assisted Rapid Maxillary Expansion: A Retrospective Cohort Study

OBJECTIVES

To evaluate the bone density in the midpalatal suture after 10 months of surgically assisted rapid maxillary expansion (SARME) with the separation of the maxilla into 2 segments.

METHODS

Sixty multislice computed tomography (MCT) from 20 patients undergoing SARME were analyzed in 3 periods of time (1 MCT per patient on each occasion): (1) 1 week before surgery, (2) postsurgery immediately after completing the expander activation, and (3) 10 months after the expander activation. On all occasions, the bone density was measured in Hounsfield units on MCT scans in axial and coronal sections, in the anterior (A1), middle (A2), and posterior (A3) regions of the midpalatal suture.

RESULTS

The mean percentage values of bone density in Hounsfield units, from the 10-month postactivation period to preoperative in the A1, A2, and A3 regions were 68.38%, 38.21%, and 55.90%, respectively, in the axial norm, and 64.06%, 36.81%, and 55.50% in coronal norm (A1 = A3>A2), with no significant difference in the tomographic cuts (P >0.05). There was no correlation between patient age or amount of expansion in the expander and bone density.

CONCLUSIONS

The bone density in the midpalatal suture 10 months after SARME is lower than preexpansion. A denser new bone formation along the suture concentrates closer to the extremities rather than in the central region. Although the maturation of the new bone formation in the midpalatal suture is lower 10 months after SARME, it appears to be sufficient for satisfactory clinical results, regardless of patient age or the amount of expansion in the expander.

Ultrasonic mapping of midpalatal suture - An ex-vivo study

OBJECTIVE

Rapid maxillary expansion is a common orthodontic procedure to correct maxillary constriction. Assessing the midpalatal suture (MPS) expansion plays a crucial role in treatment planning to determine its effectiveness. The objectives of this preliminary investigation are to demonstrate a proof of concept that the palatal bone underlying the rugae can be clearly imaged by ultrasound (US) and the reconstructed axial view of the US image accurately maps the MPS patency.

METHODS

An ex-vivo US scanning was conducted on the upper jawbones of two piglet's carcasses before and after the creation of bone defects, which simulated the suture opening. The planar images were processed to enhance bone intensity distribution before being orderly stacked to fuse into a volume. Graph-cut segmentation was applied to delineate the palatal bone to generate a bone volume. The accuracy of the reconstructed bone volume and the suture opening was validated by the micro-computed tomography (µCT) data used as the ground truth and compared with cone beam computed tomography (CBCT) data as the clinical standard. Also included in the comparison is the rugae thickness. Correlation and Bland-Altman plots were used to test the agreement between the two methods: US versus µCT/CBCT.

RESULTS

The reconstruction of the US palatal bone volumes was accurate based on surface topography comparison with a mean error of 0.19 mm for pre-defect and 0.15 mm and 0.09 mm for post-defect models of the two samples, respectively when compared with µCT volumes. A strong correlation (R2 ≥ 0.99) in measuring MPS expansion was found between US and µCT/CBCT with MADs of less than 0.05 mm, 0.11 mm and 0.23 mm for US, µCT and CBCT, respectively.

CONCLUSIONS

It was possible to axially image the MPS opening and rugae thickness accurately using high-frequency ultrasound.

CLINICAL SIGNIFICANCE

This study introduces an ionizing radiation-free, low-cost, and portable technique to accurately image a difficult part of oral cavity anatomy. The advantages of conceivable visualization could promise a successful clinical examination of MPS to support the predictable treatment outcome of maxillary transverse deficiency.

Dental, Skeletal, and Soft Tissue Changes after Bone-Borne Surgically Assisted Rapid Maxillary Expansion: A Systematic Review and Meta-Analysis

(1) Background: For non-growing patients with marked transverse maxillary deficiency, bone-borne surgically assisted rapid maxillary expansion (SARME) has been proposed as an effective treatment option. Objective: To evaluate the dental, skeletal, and soft tissue changes following bone-borne SARME. (2) Methods: An unrestricted systematic electronic search of six databases, supplemented by manual searches, was performed up to April 2023. The eligibility criteria included prospective/retrospective clinical studies with outcomes pertaining to objective measurements of dental/skeletal/soft tissue effects of bone-borne SARME in healthy patients. (3) Results: Overall, 27 studies satisfied the inclusion criteria. The risk of bias of the non-randomized trials ranged between moderate (20) and serious (4). For the two RCTs, there were some concerns of bias. Trials with outcomes measured at the same landmarks within the scope of the prespecified timeframe were deemed eligible for quantitative synthesis. Eventually, five trials were included in the meta-analysis. SARME was associated with a statistically significant lengthening of the dental arch perimeter immediately after expansion, along with a marginally significant decrease in palatal depth during the post-SARME retention period. Post-treatment SNA values exhibited no statistically significant change. (4) Conclusion: Current evidence indicates that bone-borne SARME constitutes an effective treatment option for adult patients with maxillary transverse deficiency. Further long-term randomized clinical trials with robust methodology, large sample sizes, and 3D evaluation of the outcomes are needed.

Midpalatal suture bone repair after miniscrew-assisted rapid palatal expansion in adults

Background

Midpalatal suture (MPS) repair in growing patients after RPE has been previously reported. However, differences between young and adult patients for timing and pattern of MPS repair after rapid maxillary expansion are expected. The aim of this study was to evaluate the midpalatal suture repair pattern after miniscrew-assisted rapid palatal expansion (MARPE) in adult patients.

Materials and methods

The study included 21 patients (six males, 15 females) successfully treated with MARPE with a mean initial age of 29.1 years of age (SD = 8.0; range = 20.1–45.1). MPS repair was evaluated using maxillary axial and coronal sections derived from CBCT exams taken 16 months after the expansion (SD = 5.9). Objective and subjective assessments of MPS repair were performed. Objective assessments were performed measuring MPS bone density at anterior, median and posterior region of hard palate. Pre-expansion and post-retention bone density changes were evaluated using paired t tests (p < 0.05). Midpalatal suture bone repair was scored 0 to 3 considering, respectively, the complete absence of bone repair in the MPS, the repair of less than 50% of the MPS, the repair of more than 50% of the MPS and the complete repair of the MPS. Intra- and interexaminer reliability evaluation were assessed using Kappa coefficient.

Results

The objective evaluation showed a significant higher bone density at the pre-expansion stage in all palatal regions. The reliability of the subjective method was adequate with intra- and interexaminer agreements varying from 0.807 to 0.904. Scores 1, 2 and 3 were found in 19.05%, 38.09% and 42.86% of the sample, respectively. The most common region demonstrating absence of bone repair was the middle third. The anterior third of the midpalatal suture was repaired in all patients.

Conclusions

A decreased bone density was observed after the retention period when compared to pre-expansion stage. Most adult patients demonstrated incomplete repair of the midpalatal suture 16 months after MARPE. However, adequate bone repair covering more than half of the hard palate extension was observed in 80.95% of the patients.

The 27 Facial Sutures: Timing and Clinical Consequences of Closure

SUMMARY

Facial sutures contribute significantly to postnatal facial development, but their potential role in craniofacial disease is understudied. Since interest in their development and physiology peaked in the mid-twentieth century, facial sutures have not garnered nearly the same clinical research interest as calvarial sutures or cranial base endochondral articulations. In addition to reinforcing the complex structure of the facial skeleton, facial sutures absorb mechanical stress and generally remain patent into and beyond adolescence, as they mediate growth and refine the shape of facial bones. However, premature closure of these sites of postnatal osteogenesis leads to disrupted growth vectors and consequent dysmorphologies. Although abnormality in individual sutures results in isolated facial deformities, we posit that generalized abnormality across multiple sutures may be involved in complex craniofacial conditions such as syndromic craniosynostosis. In this work, the authors comprehensively review 27 key facial sutures, including physiologic maturation and closure, contributions to postnatal facial development, and clinical consequences of premature closure.

Effect of mesenchymal stem cells with platelet-rich plasma carriers on bone formation after rapid maxillary expansion: An Animal Study

OBJECTIVE

To evaluate the effect of bone mesenchymal stem cells (BMSCs) with or without platelet-rich plasma (PRP) carriers on sutural new bone formation after rapid palatal expansion (RPE).

SETTINGS AND SAMPLE POPULATION

Sixty male Wistar rats were used in this study.

MATERIAL AND METHODS

All samples were subjected to 50cN of palatal expansion force for 7 days followed by 3 weeks of the retention period. The experimental groups received a single-dose injection of the specified solution at the time of retainer placement (BMSCs, PRP, BMSCs+PRP, normal saline). BMSCs used in this study were marked with the green fluorescent protein (GFP). New bone formation (NBF) in the sutural area was evaluated by µCT and occlusal radiography. In addition, semi-quantitative analyses were performed on histology images to analyse the quality of sutural bone, connective tissue and vascularization. Immunohistochemistry analyses were conducted for osteocalcin and collagen type I proteins.

RESULTS

After the 21-day retention period, limited GFP marked cells were detected around the sutural area. Samples treated with BMSCs + PRP had the highest NBF and showed higher expression of collagen type I and osteocalcin.

CONCLUSION

Injecting BMSCs + PRP may increase sutural bone density significantly. However, injecting BMSCs or PRP carriers alone did not affect sutural bone density.

Hydroxyapatite Nanoparticles Facilitate Osteoblast Differentiation and Bone Formation Within Sagittal Suture During Expansion in Rats

Background

The potential of relapse of craniofacial disharmony after trans-sutural distraction osteogenesis is high due to the failure to produce a stable bone bridge in the suture gap. The aim of this study is to evaluate whether hydroxyapatite nanoparticles (nHAP) have the effect of promoting osteoblast differentiation of suture-derived stem cells (SuSCs) and bone formation in sagittal suture during expansion.

Methods

SuSCs were isolated from sagittal sutures and exposed to various concentrations of nHAP (0, 25, 50, and 100 μg mL⁻¹) to determine the optimal concentration of nHAP in osteoblast differentiation via performing Western Blotting and RT-qPCR. Twenty 4-week-old male Sprague–Dawley rats were randomly assigned into 4 groups: SHAM (sham-surgery), distraction, ACS (absorbable collagen sponge) and ACS+nHAP groups. In the ACS and ACS+nHAP groups, saline solution and nHAP suspended in a saline solution were delivered by ACS placed across the sagittal suture, respectively. In the latter three groups, the suture was expanded for 14 days by 50 g of constant force via a W shape expansion device. Suture gap area, bone volume fraction (BV/TV) and bone mineral density (BMD) of sagittal sutures were assessed via micro-CT, while the mechanical properties of sagittal sutures were evaluated via nanoindentation test. The efficacy of nHAP on bone formation in sagittal suture was also evaluated via BMP-2 immunohistochemistry staining.

Results

The expression of osteoblast related genes and proteins induced by 25μg mL⁻¹ nHAP were significantly higher than the other groups in vitro (p<0.05). Furthermore, treating with 25μg mL⁻¹ nHAP in vivo, the suture gap area was significantly reduced when compared with the distraction group. Correspondingly, the BV/TV, BMD, hardness and modulus of sagittal sutures were significantly increased in the ACS+nHAP group (p<0.05).

Conclusion

The 25μg mL⁻¹ dose of nHAP delivered by ACS can facilitate bone formation into the sagittal suture during expansion via inducing osteoblast differentiation of SuSCs.

Influence of surgically assisted rapid maxillary expansion on the interdental papilla height of maxillary central incisors

PURPOSE

To evaluate the influence of orthodontic treatment with surgically assisted rapid maxillary expansion (SARME) on the interdental papilla height of maxillary central incisors.

METHODS

In this retrospective study, patients who completed orthodontic treatment including SARME at the Radboud University Medical Center Orthodontic Department before December 2019 were included. Frontal intraoral photographs taken before (T1) and after completion of treatment (T2) were examined to determine the papilla height between the maxillary central incisors using the Jemt classification. The difference between the Jemt classification at T1 and T2 (∆Jemt) was defined as the primary outcome variable. Secondary outcome variables were gender, age, treatment duration, type of expansion appliance, maximal central diastema during expansion, pretreatment overlapping between the central incisors, gingival biotype, crown morphology and the distance between the bone crest and incisal contact point. Kappa statistics and paired t‑tests were used to determine reliability of the measurements. Pearson's Χ² test and independent t‑tests were used to compare the variables between the groups of patients with and without papillary recession. Finally, multiple logistic regression analysis was performed.

RESULTS

In all, 93 patients fulfilled the inclusion criteria and were included in the study. The Jemt score worsened for 30 patients (32%) between T1 and T2, indicating the occurrence of papillary recession. Incisal overlapping, crown morphology, small width to length ratio, increasing age and an increasing distance between crestal bone and the incisal contact point were factors associated with papillary recession.

CONCLUSION

After orthodontic treatment including SARME, one third of patients exhibited recession of papilla height of the maxillary central incisors.

Surgically Assisted Rapid Palatal Expansion to Correct Maxillary Transverse Deficiency

Background

Transverse maxillomandibular discrepancies are widespread. Treatment is comprised of orthodontic expansion in patients younger than 15 years or by surgically assisted rapid palatal expansion (SARPE) in skeletally mature patients where the possibility of successful orthodontic maxillary expansion decreases as sutures close and resistance to mechanical forces increases.

Aim

To present our experience of treating transverse maxillary deficiency using a unique L-shaped osteotomy and to demonstrate stable results.

Patients and Methods

32 patients aged between 19 and 54 years exhibiting transverse maxillary deficiency. L-shaped osteotomy was performed laterally from the pterygoid plate posteriorly to above the roots of the second incisive anteriorly continuing with a vertical osteotomy between the lateral incisive and canine teeth toward the horizontal osteotomy. In 18 patients with dysgnathia, bimaxillary surgery was performed one year following the SARPE procedure.

Results

Mean transverse maxillary expansion of 6.2mm at the canine incisal and 6.4mm at the first molar occlusal regions were obtained. One year postoperatively results were relatively stable, 5.8mm and 6.2mm respectively. The SARPE procedure resulted in overcoming the maxillary buttress resistance, expansion of the anterior dental arch and bilateral distraction creating bone on both sides of the premaxilla contributing to better alignment of the anterior teeth and superior stability.

Conclusions

We conclude that SARPE is an effective and stable method for addressing severe maxillary transverse discrepancy in adults while the unique osteotomy performed allowed for maintaining proper position of the premaxilla and maxillary midline and allowing for division of the newly created bone bilaterally thus resulting in a more stable outcome.

Surgically-assisted rapid maxillary expansion (SARME): indications, planning and treatment of severe maxillary deficiency in an adult patient

Introduction:

Maxillary deficiency, also called transverse deficiency of the maxilla, may be associated with posterior crossbite, as well as with other functional changes, particularly respiratory. In adult patients, because of bone maturation and the midpalatal suture fusion, rapid maxillary expansion has to be combined with a previous surgical procedure to release the areas of resistance of the maxilla. This procedure is known as surgically-assisted rapid maxillary expansion (SARME).

Objective:

This study discusses the indications, characteristics and effects of SARME, and presents a clinical case of transverse and sagittal skeletal maxillary discrepancy treated using SARME and orthodontic camouflage.

Influence of interdigitation and expander type in the mechanical response of the midpalatal suture during maxillary expansion

BACKGROUND AND OBJECTIVE

The orthopedic Maxillary Expansion (ME) procedure is used for treating the transverse maxillary deficiency. This pathology consists in a smaller transverse dimension in the maxilla and leads to malocclusion. The treatment takes advantage of the existence of the midpalatal suture (MPS), which corresponds to the junction at the palatine bones of its horizontal portions. The technique employs a device, conventionally a palatal expander attached to the posterior teeth, to separate the two maxillary bones in the MPS. The objective of this study was to analyze, using the Finite Element Method, the biomechanical behavior of the MPS when an expansion is applied.

METHODS

A Computer Tomography image of the maxilla was reconstructed, the suture geometry was modeled with different interdigitation levels and types of hyrax devices. A total of 12 geometric models (three levels for interdigitation and four types of hyrax devices) were prepared and analyzed taking into account the chewing forces and the expansion displacement. For each case, maximum principal stresses on the maxilla (bone), and equivalent stresses on the expander device (stainless steel) were observed. In the MPS, maximum principal stresses and directional displacement were evaluated.

RESULTS

The results showed that the interdigitation does not have an important influence on the deformation behavior of the maxilla but it affects the stress distribution. In addition, the type of expander device and anchorage have a direct relationship with the treatment effectiveness; larger deformation in the expansion direction was obtained with skeletal when compared to dental anchorage.

CONCLUSIONS

A study that allows a better understanding of the oral biomechanics during the application of ME was presented. To our knowledge, it is the first study based on computational simulations that takes into account bone structures, like maxilla and part of the skull, to analyze the interdigitation influence on the MPS behavior when exposed to a ME.

Surgically assisted rapid maxillary expansion in lingual orthodontics - optimizing of coupling and timing : Best oral presentation from the 21st Meeting of German Society of Lingual Orthodontics

Background

Surgically assisted rapid maxillary expansion (SARME) is primarily used in adult orthodontics. In many cases it is followed by further surgery to address further anteroposterior and/or vertical discrepancies. Treatment times in such cases are often long with adult patients usually requesting invisible appliances. Lingual appliances can provide the mechanical control required as well as fulfil the aesthetic demands in such cases. However lingual appliances are usually custom made and indirectly bonded. Due to tooth movement following surgery there is usually a long delay before impressions can be made for customized lingual appliances. This results in a long delay before alignement and leveling can be commenced post-surgery.

Case presentations

Three cases are presented here demonstrating the simultaneous placement of bone anchored expansion devices for surgically assisted rapid maxillary expansion with customized lingual appliances.

Conclusions

The combination of the two procedures allows the alignement and leveling to commence very soon after surgery significantly reducing treatment times. The design of the appliances and the clinical procedures are described and discussed.

The value of cone beam computed tomography imaging in surgically assisted rapid palatal expansion: a systematic review of the literature

This study aimed to evaluate the reliability of cone-beam computed tomography (CBCT) imaging of the maxillary structures and the postoperative dentoskeletal, nasal airway, periodontal, and facial soft tissue changes after surgically assisted rapid palatal expansion (SARPE). A systematic review of the literature on CBCT analysis of SARPE was performed. The PubMed, Embase, and Cochrane Library databases were searched. Nine articles were included, involving a total of 228 patients. The general trend was tooth-borne distraction with pterygomaxillary dysjunction. A systematic increase in all transverse dimensions at the dentoalveolar and dental levels, as well as a certain degree of tipping and extrusion of the anchorage teeth and tipping of the skeletal segments, was detected. Soft tissue findings reflected the underlying dentoalveolar changes. A decrease in the buccal alveolar bone thickness and alveolar crest level occurred. Results confirm that CBCT is an accurate and reliable method to assess anatomical changes after SARPE. Although this systematic review provides valuable preliminary information about the effects of SARPE, results should be interpreted with caution due to the low level of evidence of the publications, great heterogeneity among study groups regarding outcome variables and surgical-orthodontic protocols, and lack of long-term data.

Evaluation of opening pattern and bone neoformation at median palatal suture area in patients submitted to surgically assisted rapid maxillary expansion (SARME) through cone beam computed tomography

Surgically assisted rapid maxillary expansion (SARME) is the treatment of choice to adult patients even with severe transversal maxillary discrepancies. However, the adequate retention period to achieve the bone remodeling, thus assuring treatment stability, is controversial.Objective To evaluate the opening pattern and bone neoformation process at the midpalatal suture in patients submitted to surgically assisted (SARME) through cone beam computed tomography (CBCT).Material and Methods Fourteen patients were submitted to SARME through subtotal Le Fort I osteotomy. Both the opening pattern and the mean bone density at midpalatal suture area to evaluate bone formation were assessed pre- and post-operatively (15, 60 and 180 days) through CBCT.Results Type I opening pattern (from anterior to posterior nasal spine) occurred in 12 subjects while type II opening pattern (from anterior nasal spine to transverse palatine suture) occurred in 2 individuals. The 180-day postoperative mean (PO 180) of bone density value was 49.9% of the preoperative mean (Pre) value.Conclusions The opening pattern of midpalatal suture is more related to patients' age (23.9 years in type I and 33.5 years in type II) and surgical technique. It was not possible to observe complete bone formation at midpalatal suture area at the ending of the retention period studied (180 days).

Salvage rapid maxillary expansion for the relapse of maxillary transverse expansion after Le Fort I with parasagittal osteotomy

Maxillary transverse deficiency is one of the most common deformities among occlusal discrepancies. Typical surgical methods are segmental Le Fort I osteotomy and surgically-assisted rapid maxillary expansion (SARME). This patient underwent a parasagittal split with a Le Fort I osteotomy to correct transverse maxillary deficiency. During follow-up, early transverse relapse occurred and rapid maxillary expansion (RME) application with removal of the fixative plate on the constricted side was able to regain the dimension again. RME application may be appropriate salvage therapy for such a case.

Effect of heterologous bone marrow mononuclear cell transplantation on midpalatal expansion in rats

The aim of this study was to explore whether bone marrow mononuclear cell (BMMC) transplantation is able to accelerate the bone remodeling induced by midpalatal expansion in rats. A total of 48 male Sprague-Dawley rats (mean weight, 208.36±7.32 g) were divided into control and midpalatal expansion with or without BMMC transplantation groups. Histological and morphological changes were observed in each group. The osteogenic activities and differential potentials of the transplanted BMMCs labeled with bromodeoxyuridine in the midpalatal bone tissue were assessed by osteocalcin expression. The receptor activator of nuclear factor κB ligand (RANKL)/osteoprotegerin (OPG) ratio was determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to reflect the equilibrium between bone resorption and formation. The results demonstrated that the width of the maxillary dental arch increased distinctly within 2 weeks of midpalatal expansion with BMMC transplantation. The morphology of the midpalatal suture in this group changed significantly; the cartilage was completely replaced by fibrous-like tissue expressing osteocalcin. The palatal bone was reorganized from a cancellous form into a mature compact structure after an additional 2-week relapse period. Immunostaining results indicated that the heterologous transplanted BMMCs survived and differentiated into osteoblasts during the remodeling induced by midpalatal expansion. The RANKL/OPG expression ratio significantly decreased after 2 weeks of midpalatal expansion with BMMC transplantation due to the inhibition of RANKL expression. Heterologous BMMC transplantation appears to accelerate the midpalatal bone remodeling induced by expansion of the rats through increasing the number of osteoprogenitor cells and regulating the RANKL-OPG signaling pathway.

Stimulation of bone formation in the expanding premaxillary suture with a GSK-3β inhibitor

OBJECTIVES

Glycogen synthase kinase-3β (GSK-3β)/β-catenin signaling mediates osteogenesis in response to mechanical loading. We tested the hypothesis that local administration of a GSK-3β inhibitor could stimulate new bone formation in the expanding premaxillary suture.

MATERIALS AND METHODS

Thirty-five Sprague-Dawley rats were subjected to premaxillary suture expansion using a helix spring. The experimental rats were given one or two local injections of SB-415286, a small-molecule GSK-3β inhibitor. Animals were administered calcein and sacrificed on day 7 to quantify new bone formation. To evaluate the proliferation and differentiation of osteoblasts, rats were labeled with bromodeoxyuridine on day 1 and sacrificed on day 2 or 4. β-catenin expression was evaluated by immunohistochemical staining.

RESULTS

Two injections of SB-415286 led to an elevation of β-catenin expression and an increase in the number of proliferating osteoblasts in expanding sutures on day 2 and day 4. Consequently, new bone formation in the suture increased significantly on day 7.

CONCLUSIONS

These results suggest that local delivery of a GSK-3β inhibitor could stimulate bone formation in the expanding premaxillary suture by eliciting β-catenin signaling. GSK-3β could be a pharmaceutical target for improving the effect of orthodontic treatments such as rapid palatal expansion.