Evaluations of sagittal and vertical changes induced by surgically assisted rapid palatal expansion

Three-dimensional assessment of the maxilla after modified surgically assisted rapid expansion: a retrospective study

OBJECTIVE

This retrospective study aims to assess the three-dimensional dentoskeletal effects and median palatal suture opening pattern in patients undergoing modified surgically assisted maxillary rapid expansion (SARME) without pterygoid plate detachment.

METHODS

Twenty-eight patients submitted to modified SARME between 2009 and 2016 were retrospectively evaluated through cone-beam computed tomography (CBCT). Dental and skeletal measurements were taken at three different operative periods (before the expansion - T0; at the end of the activation of the Hyrax device - T1; and six months after the immobilization of the device - T2). Statistical analyses, including ANOVA and Pearson's correlation coefficient, were performed using SPSS software.

RESULTS

SARME demonstrated significant transverse maxillary expansion (with an average of 6.05 mm) with a greater impact in the anterior region. Dental measurements, including canine and molar distances, exhibited significant changes over the operative periods. Bone measurements (ANS and PNS) presented small but significant alterations, including a slight inferior displacement of ANS during device activation. The nasal floor width increased, followed by a width reduction after immobilization. The median palatal suture predominantly exhibited a Type II (V-shaped) opening.

CONCLUSION

The modified SARME presented a transversal direction increase and a super-lower skeletal displacement, with the anterior region being more affected than the posterior region. There was no change in the anteroposterior direction of the maxilla. Additionally, there was an increase in the linear dental measurements and a decrease in the angular measurement, with a positive correlation between the amount of posterior bone expansion and molar expansion as a result of the treatment in the analyzed period.

Magneto-dynamic tool for full arch immediate loading in post-traumatic restoration with narrow implants: A case report

New surgical techniques using narrow, tilted implants positioned through a magneto-dynamic tool in guided surgery for a Toronto restoration. A 69-year-old woman wanted fixed rehabilitation to replace her removable complete dentures. A cone-beam computed tomography showed significant bone resorption in both the maxillary and mandibular regions. The plan was to load the entire upper arch with six implants immediately, while removable partial dentures were recommended for the lower jaw. The guided surgery project was aligned with the new dentures, and the laboratory created a printed cast with dental implant analogues in planned positions. A metal-reinforced denture was constructed, and surgery was performed to place six narrow implants using the magneto-dynamic instrument. The denture was directly screwed onto multi-unit abutments. Final rehabilitation was completed after 6 months. Narrow implants can be a good option for fixed, full-arch rehabilitations. Further research is needed to confirm these findings on a larger scale.

Can different osteotomies have an influence on surgically assisted rapid maxillary expansion? A systematic review

The purpose of this study was to systematically review the randomized and non-randomized clinical trials (RCT; nRCT) concerning the different available osteotomies for surgically assisted rapid maxillary expansion (SARME): pterygomaxillary disjunction (SARME + PD vs SARME-PD) and segmental Le Fort I osteotomy (2-piece vs 3-piece). Outcomes focused on skeletal, dental, upper airway changes, complications, and relapse. Two authors investigated five databases (PubMed, Cochrane Library, Google Scholar, Scopus, Web of Science) until August 2023. The Cochrane Collaboration Tool and the Newcastle-Ottawa scale were used for the quality assessment of the included RCTs and nRCTs, respectively. A total of 554 articles were retrieved and after duplicates removing and full-text reading, 40 studies were included. Two RCTs showed a low risk of bias, one an unclear risk and one a high risk. Among the non-RCTs, 15 studies showed a good quality, while 21 exhibited a fair quality score. SARME + PD resulted in more homogeneous posterior bone expansion, with minimal dental effects. No difference between 2-piece and 3-piece in asymmetric expansion was observed, although 3SO showed 1-2 mm of more transverse increase. The oropharynx minimum cross-sectional area, the nasopharynx and the oropharynx volume were greater in SARME + PD. Both dental and bone relapse can occur but no differences between the groups were observed. All osteotomies guaranteed a correction of transverse maxillary deficiency. Lower side effects were described in SARME + PD. Two-piece and 3-piece segmental Le Fort I osteotomies did not show any differences in the symmetry and amount of expansion.

Sagittal and Vertical Changes of the Maxilla after Surgically Assisted Rapid Palatal Expansion: A Systematic Review and Meta-Analysis

Surgically assisted rapid palatal expansion (SARPE) is often performed to correct the transverse deficiency in the maxilla for skeletally mature patients. However, there is little consensus on the sagittal and vertical displacement of the maxilla after SARPE. This systematic review aims to analyze the position changes of the maxilla in the sagittal and vertical dimensions after the completion of SARPE. Registered with PROSPERO (registration number: CRD42022312103), this study complied with the 2020 PRISMA guideline and was conducted on 21 January 2023. Original studies were screened from MEDLINE (PubMed), Elsevier (SCOPUS), and Cochrane, and supplemented by hand-searching. Cephalometric changes of skeletal vertical and sagittal measurements were the focus. A fixed-effects model was applied in R for meta-analysis. After applying inclusion and exclusion criteria, seven articles were included in the final review. Four studies had a high risk of bias, and the other three had a medium risk of bias. Meta-analysis revealed that the SNA angle increased by 0.50° ± 0.08° (95% confidence interval, 0.33° to 0.66°), and the SN-PP angle increased by 0.60° ± 0.09° (95% confidence interval, 0.41° to 0.79°) after SARPE. In summary, the maxilla displayed statistically significant forward and clockwise downward movement after SARPE. However, the amounts were small and might not be clinically significant. Due to the high risk of bias of included studies, our results must be taken cautiously. Future studies are needed to discern the effects of direction and angulation of the osteotomies of SARPE on the displacement of the maxilla.

Comparison of 3 different bone-borne type expansion appliances used in surgically-assisted rapid palatal expansion: A finite element analysis

INTRODUCTION

This study aimed to compare the effects of 3 different bone-borne type expansion appliances used in the surgically-assisted rapid palatal expansion (SARPE) by finite element analysis.

METHODS

Three different miniscrew-supported palatal expansion appliances were modeled. Median and lateral osteotomies were performed without pterygomaxillary suture separation. Model I consisted of a palatal expander with 2 miniscrews placed 4 mm far from the midpalatal suture. In model II, 2 miniscrews were located at the alveolar ridge between the first molar and the second premolar. In model III, 4 miniscrews were placed as a combination of the first and second models. Stress distributions and amount of displacements were evaluated with Ansys software (version 19.2; Ansys, Canonsburg, Pa) for 5-mm expansion in a symmetrical finite element analysis model to reflect the clinical situation.

RESULTS

SARPE simulation using miniscrew-assisted maxillary expanders for all models showed a rotation and tipping of the maxilla. The largest displacement was found for the anterior part of the palate in model II and the posterior part in model III. Although a wedge-shaped expansion pattern was observed in all models, this form was more prominent in model II. The highest stress value (0.91 MPa) was measured in model I, and the lowest value (0.004 MPa) was measured in model II for the anterior nasal spine region. The highest stress value (0.51 MPa) was measured in model III, and the lowest value (0.12 MPa) was measured in model II for the posterior nasal spine region. The lowest stress values were measured in model II for all the craniofacial and maxillofacial structures.

CONCLUSIONS

Among the models, the lowest stress distribution conditions for craniofacial and maxillofacial structures were found in model II. The largest displacement was found at the incisors and anterior part of the maxilla for model II. The greatest displacement was found at the posterior region for model III.

Surgically assisted maxillary expansion with or without pterygoid disjunction alters maxillomandibular positioning

PURPOSE

This study aimed to analyze alterations in mandibular positioning after surgically assisted maxillary expansion (SARME) with and without pterygoid disjunction (PD).

METHODS

Cone-beam computed tomography scans of 24 healthy individuals (18-45 years old) with transverse deficiency, superior to 5 mm, underwent SARME with or without PD. The aspects prospectively assessed were (1) alignment and position of the head (ITK-Snap and 3D Slicer software); (2) McNamara's and Steiner-Tweed-Wits' cephalometric analysis (Dolphin Imaging®); and (3) colorimetric evaluation based on 3D correspondence analysis (3D Slicer software).

RESULTS

A decrease in 1-NA and 1-SN angles as well as an increased occlusal plane in both groups was observed. Superior-inferior and anteroposterior spatial displacements of the chin were statistically significant in the PD group. Altered colorimetric patterns were also observed in the PD group.

CONCLUSIONS

This study found more evident tooth inclination in the group without PD; mandibular alterations were more evident in the PD group. Further studies with 3D analysis are strongly recommended for more comprehensive results.

The effect of subspinal Le Fort 1 corticotomy on nasal morphology in surgically assisted rapid palatal expansion

The purpose of this retrospective study was to evaluate the influence of subspinal Le Fort 1 corticotomy (SLF1C) on nasal morphology in patients treated with surgically assisted rapid palatal expansion (SARPE) using three-dimensional (3D) stereophotogrammetry images. A total of 64 patients were enrolled in the study and divided into two groups according to the surgical approach that was used: in group 1 (n = 32) SARPE was performed using a conventional Le Fort 1 corticotomy (CLF1C), and in group 2 (n = 32) SARPE was performed using a subspinal Le Fort 1 corticotomy (SLF1C). Measurements of alar and columellar width, and nasolabial angle were taken on 3D stereophotogrammetry images before and after SARPE using Vectra 3D camera system. Both surgical groups showed a statistically significant increase in alar and columellar width, and nasolabial angle postoperatively (p<0.05). SLF1C resulted in significantly smaller changes of the columellar base postoperatively (p=0.0456). The datasuggests that SARPE with an osteotomy of the anterior nasal spine as an additional step to the conventional Le Fort 1 corticotomy results in a smaller increase of the columellar base.

Effect of Rapid Maxillary Expansion on Mandibular Rotation—A Systematic Review

Objective: To evaluate the effect of rapid maxillary expansion (RME) on mandibular rotation.

Materials and Method: A systematic review of articles selected from 4 electronic databases—PUBMED, Cochrane Central Register of Controlled Trials, Clinical Trials Registry, and Google Scholar—was carried out. Additional studies were hand-searched and retrieved from the reference lists of relevant articles. Studies published till August, 2019, were included in this study.

Results: A total of 28 articles were identified through electronic database searching. 16 articles were obtained after elimination of duplicates which were then screened. Full-text articles were assessed according to the eligibility criteria. 2 randomized controlled trials (RCTs) and 14 clinical trials (CTs) were identified for inclusion in the review. These studies effectively highlighted the effect of RME on mandibular rotation, primarily in the clockwise direction.

Conclusion: There is a moderate sum of evidence to illustrate the effect of RME on mandibular rotation. It can be concluded that RME brings about clockwise rotation of the mandible, ie in downward and backward directions, thereby increasing the lower anterior facial height. This effect could be attributed to the vertical maxillary movement and the extrusion of the maxillary molars.

Effects of surgically assisted rapid maxillary expansion on mandibular position: a three-dimensional study

Background

This study aimed to evaluate three-dimensional changes in mandibular position after surgically assisted rapid maxillary expansion (SARME).

Methods

A retrospective study was carried out with tomographic records of 30 adult patients with maxillary transverse deficiency who underwent SARME. Cone beam computed tomography scans were obtained preoperatively (T1), after expansion (T2) and 6 months after expansion (T3). Mandibular landmarks were measured with respect to axial, sagittal, and coronal planes. Repeated measures ANOVA was used for statistical analysis.

Results

Clockwise rotation and lateral displacement of the mandible were observed immediately after SARME. However, mandibular displacements tended to return close to their initial values at T3.

Conclusions

Clockwise rotation and lateral shift of the mandible are transient effects of SARME.

Evaluation of Changes in Lip Closing Force After Surgically Assisted Rapid Maxillary Expansion

OBJECTIVE

Morphological changes in patients subjected to surgical treatment to correct occlusal discrepancies may lead to various functional changes. The aim of the present study was to evaluate changes in lip closing force after surgically assisted rapid maxillary expansion in skeletally mature patients.

METHODS

The study involved 7 female and 7 male patients treated with surgically assisted rapid maxillary expansion. Maximum and minimum lip pressures of patients were measured with Lip De CumLDC-110R. The intercanine distance and incisors angulations were measured preoperatively (T0), at the end of the expansion (T1), at the end of the third month of retention (T2), and at the end of the sixth month of retention (T3).

RESULTS

The greatest values of maximum and the minimum lip closing force were observed at the end of the expansion period significantly. The intercanine distance and inclinations of incisors measured at the third and sixth months showed a significant decrease.

CONCLUSIONS

The present study demonstrated that, following surgically assisted rapid palatal expansion, both the maximum and the minimum lip closing force increases had a tendency to revert to their initial values 6 months after surgery.