Transverse Maxillary Deficiency Research Articles

Risk of Maxillary Canine Impaction in Pediatric Patients with Maxillary Constriction: Retrospective Study on Panoramic Dental Images

The maxillary canine is the second most commonly impacted tooth after the maxillary third molar. Identifying risk factors for impaction is crucial for timely intervention; panoramic radiographs are particularly valuable for screening and identification purposes. This study aims to explore the association between transverse maxillary deficiency with bilateral crossbite, and the risk of maxillary canine impaction. A cross-sectional retrospective study was conducted on records of pediatric patients (7–13 years old) undergoing orthodontic evaluations. Panoramic radiographs were analyzed to assess the risk of canine impaction using the sectorial method, distance from the occlusal plane, and the alpha angle. Results from 48 canines of patients with transverse maxillary deficiency and bilateral crossbite were compared to canines of sex- and age-matched patients without these malocclusions. Statistical analysis was performed by the Shapiro–Wilk test, Levene’s test, or a t-test. There were no significant differences in high-risk canine impaction between groups when considering sector classification or distance from the occlusal plane. However, the control group showed a significantly higher risk according to the alpha angle (≥25°). No overall significant difference in risk was observed, suggesting that transverse maxillary deficiency with bilateral crossbite may not increase the risk of maxillary canine impaction.

Effects of Hyrax Maxillary Expander on Nasal Cavity and Upper Airway in Adolescents: A Systematic Review and Meta-Analysis.

Whether Hyrax maxillary expander is an effective treatment for maxillary transverse deficiency as well as expansion of the upper airway is still controversial. The study's purpose was to evaluate 3D changes in upper airway dimensions of adolescent patients measured primarily by cone-beam computed tomography (CBCT) after rapid maxillary expansion (RME) with the Hyrax maxillary expander. Studies up to 1 April 2024 were searched in the following databases: PubMed/MEDICINE, Web of Science, Cochrane Library, and Embase. Inclusion criteria were clinical trials and cohort studies that assessed the effect of RME in adolescent patients with upper airway stenosis using CBCT-based three-dimensional analysis. The risk of bias in the study outcomes was assessed using the Cochrane Collaboration's risk of bias tool, the GRADE method, and a tool for evaluating non-randomized controlled study (non-RCT) literature from a previous systematic review, depending on the types of articles. The study was reported in accordance with PRISMA guidelines. The study conducted a random effects meta-analysis of mean differences and 95% confidence intervals for changes in upper airway volumes, including the nasal cavity (NC), in the outcomes of 16 included studies, followed by subgroup analyses. A significant increase in nasopharynx volume was observed after rapid maxillary expansion (RME) by Hyrax maxillary expander (MD = 0.69, 95% CI (0.09~1.28), p = 0.02).

The Success of Miniscrew-Assisted Rapid Palatal Expansion (MARPE) in Adult Orthodontics: A Literature Review

This literature review examines the success and effectiveness of Miniscrew-Assisted Rapid Palatal Expansion (MARPE) in adult orthodontics. Traditional methods like Surgically Assisted Rapid Palatal Expansion (SARPE) have been commonly used for treating transverse maxillary deficiencies in adults, but they come with significant drawbacks, including higher biological and financial costs. MARPE, which utilizes mini screws to apply controlled forces for palatal expansion, offers a less invasive and more precise alternative. The review analyzes several studies and reports on MARPE's success in expanding skeletal and dental structures, improving respiratory function in obstructive sleep apnea (OSA) patients, and minimizing complications like unwanted tooth movement. Despite some challenges, such as asymmetrical expansion, MARPE has demonstrated a high success rate in adult orthodontics and presents a promising treatment option. Further high-quality, long-term studies are recommended to optimize treatment protocols and evaluate potential risks.

Miniscrew-assisted Rapid Palatal Expansion Before Orthognathic Surgery for a Patient With Laterognathia

In this case report, a 19-year-old male patient with maxillary transverse deficiency, concave profile, and facial asymmetry is presented. In the case of transversal insufficiency, nonsurgical maxillary expansion was performed with the miniscrew-assisted rapid palatal expansion (MARPE) appliance to reduce the number of surgeries and provide both dentoalveolar and skeletal expansion. The periodontal soundness and short-term stability of the maxillary expansion were confirmed both clinically and radiologically. Mandibular prognathism was later corrected with orthognathic surgery. MARPE is an effective approach to the treatment of maxillary transverse deficiencies in adult patients.

Transverse dentoalveolar development in Chinese children and adolescents: A cross-sectional study using revised Andrews’ Element III analysis

This study investigated the prevalence of maxillary transverse deficiency (MTD) in Chinese children and adolescents using revised Andrews' Element III analysis and studied transverse developmental characteristics of the maxillomandibular complex. Plaster or digital casts of 794 participants aged 7-18 years were evaluated. MTD was diagnosed when the maxilla-mandible width difference, represented by the decompensated maxillary and mandibular first molars, exceeded 4 mm. The average prevalence of MTD among patients aged 7-18 years was 31.1%. Patients with MTD exhibited narrower maxillary and/or wider mandibular arches. Strikingly, 32.3% of participants with posterior crossbite because of local crowding or mandibular deviation were not diagnosed with MTD. Dental compensation, such as a greater buccolingual inclination of the first molars, was common in patients with MTD. Transverse growth of the maxillomandibular complex was completed by 17 years old, with the maxilla undergoing greater transverse growth than the mandible. The physiological buccolingual inclination of first molars was observed in patients without MTD. The 95% reference value of the palatal arch width was 31.9-42.3 mm. The prevalence of MTD is 31.1% among Chinese children and adolescents. However, it is often camouflaged by dental compensation and sagittal discrepancy. The etiology of MTD is uncoordinated width in the maxillomandibular complex, which is not solely attributed to a narrow maxilla but also to an excessively wide mandible. To enhance diagnostic accuracy, individualized measurements of the maxillomandibular complex and a revised dental decompensation formula, rather than posterior crossbite alone, are recommended for transverse diagnosis. A potential presence of MTD is indicated when the palatal arch width is<31.9 mm.

Piezo1 Promotes Osteogenesis Through CaMKII Signalling in a Rat Maxillary Expansion Model.

Rapid maxillary expansion (RME) is a widely used technique to treat maxillary transverse deficiency. Piezo1 is a cation channel that is activated by mechanical force and regulates bone formation. This study aims to elucidate the role of Piezo1 in bone remodelling during the RME process. In this study, the periosteal-derived stem cells (PDSCs) were cultured and stretched by the Flexcell system. The effects of Piezo1 on osteogenesis were assessed via RNA sequencing, real-time quantitative PCR, and western blot analyses. Moreover, for invivo analyses, the rat RME model was established. The function of Piezo1 in mid-palatal suture bone remodelling was evaluated using micro-CT, haematoxylin-eosin (HE) staining, and immunohistochemistry analyses. It was revealed that under tension force, the osteogenic factors (Runt-related transcription factor 2, Osterix, and Alkaline Phosphatase) and Ca2+/calmodulin -dependent protein kinase (CaMKII) were significantly enhanced in PDSCs over time. Furthermore, these were also upregulated in the RME model with the expansion of the mid-palatal suture. However, Piezo1 inhibition by Grammostola spatulata mechanotoxin 4 downregulated the levels of these factors in the RME model. This study indicated that Piezo1 is associated with the osteogenesis of PDSCs and bone remodelling in the RME process. CaMKII might also participate in this process.

Cone-beam CT landmark detection for measuring basal bone width: a retrospective validation study

BackgroundAccurate assessment of basal bone width is essential for distinguishing individuals with normal occlusion from patients with maxillary transverse deficiency who may require maxillary expansion. Herein, we evaluated the effectiveness of a deep learning (DL) model in measuring landmarks of basal bone width and assessed the consistency of automated measurements compared to manual measurements.MethodsBased on the U-Net algorithm, a coarse-to-fine DL model was developed and trained using 80 cone-beam computed tomography (CBCT) images. The model’s prediction capabilities were validated on 10 CBCT scans and tested on an additional 34. To evaluate the performance of the DL model, its measurements were compared with those taken manually by one junior orthodontist using the concordance correlation coefficient (CCC).ResultsIt took approximately 1.5 s for the DL model to perform the measurement task in only CBCT images. This framework showed a mean radial error of 1.22 ± 1.93 mm and achieved successful detection rates of 71.34%, 81.37%, 86.77%, and 91.18% in the 2.0-, 2.5-, 3.0-, and 4.0-mm ranges, respectively. The CCCs (95% confidence interval) of the maxillary basal bone width and mandibular basal bone width distance between the DL model and manual measurement for the 34 cases were 0.96 (0.94–0.97) and 0.98 (0.97–0.99), respectively.ConclusionThe novel DL framework developed in this study improved the diagnostic accuracy of the individual assessment of maxillary width. These results emphasize the potential applicability of this framework as a computer-aided diagnostic tool in orthodontic practice.

Effect of treatment of transverse maxillary deficiency using rapid palatal expansion on oral health-related quality of life in children: complementary results for a controlled clinical trial.

To evaluate the effect of rapid palatal expansion (RPE) using Haas-type expanders on children's oral health-related quality of life (OHRQOL) and compare said effect with that previously reported for the use of Hyrax-type expanders. Forty participants aged 8-10 years with transverse maxillary deficiency were treated using Haas appliances. OHRQOL was measured using the CPQ8 - 10 before RPE, during RPE (T1), at the end of RPE (T2), and 1 month after appliance removal (T3). Generalized mixed models were fitted to assess the effect of the Haas-type expander compared to previously collected data (a nontreated and a Hyrax-type expander-treated group). RPE with Haas-type appliances had a negative impact on overall OHRQOL at T1 and T2 (P = 0.001), and a positive impact at T3 (P = 0.001). The Haas-type expander had a significantly greater negative impact on OHRQOL than the Hyrax-type appliance during RPE. At T1, overall scores using the Haas-type expander were 1.08 times the scores using the Hyrax-type expander (i.e., 8% increase; 95% CI, 1.01-1.17; P = 0.033). Patients using the Haas appliance had 1.24 times the scores of those using Hyrax-type devices for the oral symptoms domain at T1 (i.e., 24% increase; 95% CI, 1.06-1.46; P = 0.009). Correction of the transverse maxillary deficiency by RPE using the Haas appliance in children 8-10 years improves OHRQOL. The Haas- and Hyrax-type devices temporarily worsen OHRQOL during treatment, however, the negative impact is less with the Hyrax-type expander than with the Haas-type expander, because it causes fewer negative oral symptoms. From a patient-centered perspective, the use of the Hyrax over the Haas appliance may be suggested as it causes less negative oral symptoms during use.

Treatment of maxillary transverse deficiency combined with crossbite and severe crowding using maxillary skeletal expander: a case report

Treatment of maxillary transverse deficiency combined with crossbite and severe crowding using maxillary skeletal expander: a case report

Three-dimensional assessment on digital cast of spontaneous upper first molar distorotation after Ni-ti leaf springs expander and rapid maxillary expander: A two-centre randomized controlled trial.

The aim of this randomized controlled trial (RCT) was to evaluate the spontaneous distorotation of upper first permanent molars and the transverse dentoalveolar changes on digital casts in growing patients following maxillary expansion treatment using either the Leaf Expander® or the rapid maxillary expander (RME), both anchored to the deciduous second molar. This study was a two-arm, parallel-assignment, RCT with a dual-centre design conducted at two teaching hospitals in Italy. Inclusion criteria included maxillary transverse deficiency, prepubertal development stage (cervical vertebra maturation stage [CVMS] 1-2) and early mixed dentition with fully erupted upper first permanent molars. Exclusion criteria were systemic diseases or syndromes, CVMS 3-6, agenesis of upper second premolars, unavailability of the second deciduous molar for anchorage and Class III malocclusion. Patients were randomly assigned to the Leaf Expander® or RME group using a computer-generated randomization list created by a central randomization centre. Randomization was conducted immediately before the start of treatment. The intervention involved treatment with either the Leaf Expander® or the RME. Both devices were anchored to the second deciduous molars. Following randomization, patients were further categorized based on the presence of no crossbite, unilateral crossbite or bilateral crossbite. The primary outcome measure was the distorotation of the upper first molar (U6). Secondary outcomes included measurements of interdental linear dimensions, specifically upper inter-canine width (53-63), upper inter-molar width (MV16-MV26) and upper inter-deciduous second molar width (55-65). The examiner analysing the digital casts was blinded to the treatment groups to prevent detection bias and ensure objective assessment. However, due to the nature of the intervention, blinding was not feasible for the patients and clinicians involved in administering the treatment. A total of 150 patients were enrolled and randomly assigned to two groups: 75 to the Leaf Expander® group and 75 to the RME group. Recruitment started in November 2021 and was completed in November 2022. At the time of analysis, the trial was complete with no ongoing follow-ups. ANOVA tests revealed no significant differences between the three subgroups (no-cross, unilateral-cross and bilateral-cross) within both the Leaf Expander® and RME groups at T0. The Leaf Expander® demonstrated significantly greater distorotation in the unilateral crossbite subgroup compared to the RME (p = .014). In terms of total molar distorotation, the Leaf Expander® appliance showed a significantly greater effect (12.66°) compared with conventional RME (7.83°). Linear regression analysis demonstrated a significant correlation between the extent of expansion and the degree of molar rotation. Maxillary expansion resulted in significant spontaneous molar distorotation when the appliance was bonded to the second deciduous molars. The Leaf Expander® exhibited significantly greater molar distorotation compared with conventional RME. The degree of molar distorotation was correlated with the extent of expansion obtained on the second deciduous molar. The trial was registered at ClinicalTrials.gov (ID: NCT05135962).

A skeletal Class III young adult with severe maxillary transverse deficiency treated with maxillary skeletal expander.

This case report describes correction of maxillary constriction using a maxillary skeletal expander (MSE) in a 15-year-old female with a skeletal Class III pattern and asymmetry. The maxillary expansion device with four mini-implants was used to correct the constricted maxilla, bilateral crossbite of the posterior teeth, and crowding of the dentition. Comparison of cone-beam computed tomography scans before and after treatment showed that the majority of maxillary expansion was orthopedic, with minimal alveolar bone bending and tooth tipping. Fixed appliances were used to correct the crowding and malocclusion. Stable and satisfactory maxillary expansion was obtained by using MSE non-urgically.

Evaluation of Treatment Protocols in Surgically Assisted Rapid Maxillary Expansion by Finite Element Analysis.

Background and Objectives: Transverse maxillary deficiency is an important maxillary anomaly that is very common in society and remains current in orthodontics. The maxillary expansion has been used in treatment for a long time. While maxillary expansion can be performed with rapid maxillary expansion in young adults, it is performed with surgically assisted rapid maxillary expansion (SARME) in individuals who have reached skeletal maturity. No consensus has been reached on the most successful surgical technique or the ideal appliance for treating transverse maxillary deficiency. Accordingly, we aimed to evaluate various surgical techniques and orthodontic appliances for treating transverse maxillary deficiency using the finite element method (FEM) to identify the treatment protocol that minimizes stress on the maxillary bone and teeth. Materials and Methods: On the virtual models obtained from the cone beam computed tomography of a patient, two different incisions (the pterygomaxillary junction is separated and not separated) were made and combined using three different orthodontic appliances (tooth, bone, and hybrid assisted). Then, stresses over the maxillary bone and maxillary teeth were calculated by FEM. Results: Our results showed that when the pterygomaxillary plates were separated, fewer stresses were observed on the bone and teeth. Although hybrid-supported appliances created less stress on the teeth than tooth-supported appliances and no difference was found between bone-supported appliances, it was found that hybrid-supported appliances created less stress on the bone than the other appliances. Conclusions: The separation of the pterygomaxillary junction in the SARME operation and the use of a bone-supported or hybrid-supported appliance would place less stress on the bone and teeth.

Investigation of bone remodeling in gingival crevicular fluid in patients treated with rapid maxillary expansion during pubertal period

Purpose: We aimed to evaluate bone remodeling following 3-month and 6-month retention periods of rapid maxillary expansion (RME) in gingival crevicular fluid (GCF). Materials and Methods: 23 pubertal participants (15 girls- 8 boys, 12-15 years) with maxillary transversal deficiency were enrolled in the study. Following banded-type RME appliance was introduced into the mouth, RME protocol was initiated by turning the Hyrax screw twice daily (morning/evening) with ¼ activation. GCF samples were taken from right maxillary first molars at four different time points (T0: before the appliance was deployed, T1: following active phase, T2: at the end of the 3-month retention period, T3: at the end of the 6-month retention period) using paper strips. Probing depth, gingival index, plaque index, and bleeding percentage at probing were recorded. BALP, OPG, RANKL, and TNF-α levels were measured in GCF samples using ELISA kits. Results: Our study revealed that GCF's BALP and OPG levels remained unchanged over time in tension and pressure regions, and there were no statistically significant differences among regions at each time point (p&gt;0.05). RANKL level was statistically significantly increased in the buccal region (the pressure region) at time T1 (p=0.042). The palatinal region's TNF-α level was statistically significantly higher than the buccal region at T0, T2, and T3 time points (p=0.005, p=0.042, and p=0.006, respectively). Our study showed no correlation between 3-month and 6-month retention periods and biomarkers indicating RME's bone metabolic activities. Conclusions: Further studies with different retention periods and larger sample sizes are suggested.

Periodontal evaluation after maxillary expansion with atooth-bone-borne expander in growing patients : Arandomized clinical trial.

This two-arm parallel randomized controlled trial aimed to evaluate and compare periodontal changes due to rapid maxillary expansion (RME) using tooth-bone-borne and tooth-borne devices in growing patients via clinical examinations and cone-beam computed tomography (CBCT). Forty-two eligible patients (aged 11-14years; transverse maxillary deficiency, posterior crossbite) were screened and divided into two groups based on the treatment received (randomization was performed using computer-generated numeric sequences): hybrid hyrax tooth-bone-borne group (TBB) and hyrax tooth-borne group (TB). The primary outcome was the change in cortical bone thickness (by CBCT). In addition, the clinical attachment level (CAL), gingival recession, and bleeding were assessed. Both examinations were performed before and 3months after the activation phase. Intergroup comparisons were performed using analysis of covariance (ANCOVA; P < 0.05). Twenty-one patients (12girls and 9boys; mean initial age, 13.3years) were included in the TBB group and 21 (5girls and 16boys; mean initial age, 13.2years) were included in the TB group. The TB group exhibited adecrease in buccal bone thickness in the first premolars and first molars at all three evaluated levels. Specifically, tooth 14 at 3 mm from the enamel-cement junction showed asignificant width reduction (0.7 mm; p < 0.001), accompanied by anotable increase in palatal cortical thickness at 6 mm of enamel-cement junction (1.13 mm; p < 0.001). RME resulted in buccal bone thickness reduction at the first premolar with hyrax treatment. In the molar region, both devices resulted in cortical bone alterations that were less pronounced in the TBB group.

Mechanically induced M2 macrophages are involved in bone remodeling of the midpalatal suture during palatal expansion

BackgroundPalatal expansion is a common way of treating maxillary transverse deficiency. Under mechanical force, the midpalatal suture is expanded, causing local immune responses. This study aimed to determine whether macrophages participate in bone remodeling of the midpalatal suture during palatal expansion and the effects on bone remodeling.MethodsPalatal expansion model and macrophage depletion model were established. Micro-CT, histological staining, and immunohistochemical staining were used to investigate the changes in the number and phenotype of macrophages during palatal expansion as well as the effects on bone remodeling of the midpalatal suture. Additionally, the effect of mechanically induced M2 macrophages on palatal osteoblasts was also elucidated in vitro.ResultsThe number of macrophages increased significantly and polarized toward M2 phenotype with the increase of the expansion time, which was consistent with the trend of bone remodeling. After macrophage depletion, the function of osteoblasts and bone formation at the midpalatal suture were impaired during palatal expansion. In vitro, conditioned medium derived from M2 macrophages facilitated osteogenic differentiation of osteoblasts and decreased the RANKL/OPG ratio.ConclusionsMacrophages through polarizing toward M2 phenotype participated in midpalatal suture bone remodeling during palatal expansion, which may provide a new idea for promoting bone remodeling from the perspective of regulating macrophage polarization.

Evaluation of palate morphology in patients treated with leaf expander and hyrax expander: A geometric morphometric analysis.

The aim of this study was to evaluate changes in shape of the palatal vault after maxillary expansion with hyrax expander (HE) and leaf expander (LE), using 3D Geometric Morphometric Analysis. Overall, 250 patients (110 M, 140 F) with maxillary transverse deficiency were selected for this study. In this study, 127 subjects were treated with HE, 123 with LE. Digital dental models were obtained pre-treatment (T0) and after 12 months from the cementation of the device (T1) and processed by means of a digital scanner. Linear and morphometric analyses were conducted to determine the effects of each appliance on dental measurements and palatal shape, and a multiple linear regression was performed to analyse the influence of anchorage and appliance type on final shape. Morphometric analysis showed that there was a lowering of the palatal vault in the HE group, while in the LE group it remained unchanged: the difference in palatal shape at time T0 and T1 was statistically significant in both treatments (HE vs. LE). In the HE group, the change in shape also included the upper part of the palatal vault in the vertical dimension, while in the LE group the change in shape interested mainly palatal shelves and the lower portion of the palate. Both LE and HE produce clinically significant changes in the morphology of the palatal vault.

Comparative evaluation of transverse width indices for diagnosing maxillary transverse deficiency

ObjectivesThis study aimed to compare and evaluate different transverse width indices for diagnosing maxillary transverse deficiency (MTD), a common malocclusion characterized by uncoordinated dental arches, crossbites, and tooth crowding.Materials and methodsSixty patients aged 7–12 years were included in the study, with 20 patients diagnosed with MTD and 40 normal controls. Transverse width indices, including maxillary width at the buccal alveolar crest and lingual midroot level, as well as at the jugal process width, were measured. Differences between these indices and their corresponding mandibular indices were used as standardized transverse width indices. The reference range of these indices was determined and evaluated. Receiver operating characteristic (ROC) analysis was performed to evaluate their diagnostic ability.ResultsThe transverse width indices and standardized transverse width indices of the MTD group were significantly smaller than those of the control group, except for the jugal process width. The evaluation of the reference range and ROC analysis revealed that the difference of the maxillomandibular width at buccal alveolar crest was the most accurate diagnostic method.ConclusionsThe jugal point analysis method may not be suitable for diagnosing MTD. Instead, measuring the difference in maxillomandibular width at the buccal alveolar crest proves to be a more reliable and accurate diagnostic method for MTD.

Research progress in the treatment of maxillary transverse deficiency with combined orthodontic-orthognathic approach

In combined orthodontic-orthognathic treatment, the maxillary palatine suture is closed in most patients with insufficient maxillary width, and bony expansion of the maxilla cannot be achieved by dental expansion or rapid palatal expansion (RPE) which causes buccal inclination of the maxillary posterior teeth leading to unstable results. Therefore, segmental LeFort Ⅰ osteotomy and surgically assisted RPE are often used in clinical practice. In recent years, with the application of implant anchorage technology, implant anchorage assisted RPE has been gradually applied in orthognathic treatment. This article reviewed the indications, contraindications, complications, efficacy and long-term stability in different treatment approaches including segmental LeFort Ⅰ osteotomy, surgically assisted RPE and implant-supported maxillary skeletal expansion.

Assessing the Efficacy and Stability of Rapid Maxillary Expansion and the Delaire Appliance in Skeletal Class III Malocclusion: A Narrative Review

Background: A Class III skeletal malocclusion is a very complex condition in orthodontics practice, and its solution is often carried out orthopedically. The most used orthopedic devices include rapid maxillary expansion (RME) and the Delaire Appliances to treat not only maxillary deficiency but also to correct the position of the upper jaw. Even if these interventions become sustainable in the short term, their long-term stability remains questionable. Aim: reveal a pretty complicated relationship between orthopaedic and orthodontic surgeries and their influences on the volume of the upper respiratory tract and craniofacial correction. Methods: We searched multiple online databases including; Web of Science, Scopus, Google Scholar, PubMed, and Cochrane Library. We used the following search strategy; "Rapid maxillary expansion" OR RME AND ("sleep apnea" OR "sleep-disordered breathing" OR "sleep-related breathing disorders" OR "sleep apnea-hypopnea syndrome" OR SAHS) AND (children OR pediatric) AND ("orthodontic treatment" OR "orthopaedic treatment" OR "maxillary expansion") AND (oximetry OR polysomnography). Results: RME and the Delaire appliance were seen to be promising in the short term with an outcome of correction of maxillary transverse deficiency and skeletal relationships. Nevertheless, the issue of the long-term stability was spotted, including with regard to growth. But nevertheless both interventions exhibited some really valuable additions in general treatment of skeletal class III malocclusion. Scientific Novelty: This literature review synthesizes and summarizes the current knowledge on the effectiveness and durability of RME and the Delaire splint concerning skeletal class III malocclusion, presenting perspectives on their short-term impact and long-term performance. With its emphasis on poorly understood issues and new research, it greatly assists in updating our knowledge about orthopedic treatments. Conclusion: In a relatively short period of time, the rapid maxillary expansion method as well as the Delaire appliance can produce positive outcomes in terms of correcting the retroposition in cranial base class III malocclusion. Although, long lasting stability issues remain a worry and make the case for continued research and clinical monitoring for achieving better treatment outcomes and evidence-based practices in orthodontics.

Numerical study of the impact of osteotomies and distractor location in surgically assisted rapid palatal expansion for transverse maxillary deficiency

IntroductionThis paper employs finite element analysis to assess the biomechanical behavior of surgically assisted rapid palatal expansion (SARPE) with a bone-borne transpalatal distractor (TPD) by varying surgical parameters. Material and methodsNine models were constructed to scrutinize the effects of pterygomaxillary disjunction (PMD), lateral osteotomy positioning, and TPD placement on displacement profiles and Von Mises stresses. These models encompassed variations such as no, unilateral or bilateral PMD, asymmetrical lateral osteotomy, and five TPD locations. ResultsPerforming a PMD reduces posterior resistance to transverse expansion, resulting in 10–20 % stress reduction around the maxillofacial complex. No significant changes in horizontal tipping were observed post-PMD. The asymmetric lateral osteotomy model exhibited larger displacements on the side with a more superiorly positioned osteotomy. Reduced stresses were observed at the maxillary body and medial pterygoid plate (superiorly), while increased stresses were observed at the medial (inferiorly) and lateral pterygoid plates. More posterior TPD placement facilitated more parallel expansion thus less horizontal tipping, albeit with increased vertical tipping. DiscussionSARPE procedures (distractor and osteotomy positions) can be tailored based on desired outcomes. PMD reduces stress within the maxillofacial complex but doesn't significantly affect tipping. Higher lateral osteotomies lead to increased displacements, more posterior distractors to more parallel expansion.