Transverse Maxillary Deficiency Research Articles

Midpalatal suture maturation in 15- to 35-year-olds: morphological assessment in the coronal plane using CBCT-an exploratory study.

Rapid maxillary expansion (RME) is used in patients presenting transverse maxillary deficiency. However, RME may be unpredictable after late adolescence if the midpalatal sutural maturation stage (MPMS) is in late stage. Since MPMS evaluation is influenced by the expertise of the operator and image quality, this classification method could be complemented. Therefore, this study aimed to analyze the morphology of the midpalatal suture (MPS) and its surrounding bone in the coronal plane using cone beam computed tomography (CBCT) images of adolescents and young adults and to correlate the findings with their respective MPMS status. CBCT scans of 200 patients aged 15-35years of both sexes were evaluated. MPS and surrounding bone tissue characteristics in the coronal and axial sections were analyzed, and MPMS was evaluated (A to E). Six categories were identified for the coronal evaluation, analyzing it in 2 standardized locations. Sutural morphology: I, hypodense sutural line limited by 2 hyper-dense para-sutural lines; II, hypodense sutural line; and III, suture not visible. The presence of para-sutural cancellous bone: CB0, compact bone; CB1, dense cancellous tissue; CB2, spaced cancellous bone. Midpalatal bone thickness (MBTh) was also measured. ANOVA-Bonferroni, chi-square, logistic regression and t-tests were used. MPMS increased with age. Sutural morphology I and CB0 bone were the most prevalent. Here we show that sutural morphology, para-sutural bone characteristics, and MPSM were significantly associated. The coronal evaluation of the MPS can complement the information from the MPSM assessment, allowing the identification of patent MPS even in the presence of late MPSM.

Main clinical and surgical outcomes of crossbite treatment: a concise systematic review

Introduction: In the crossbite scenario, the prevalence of malocclusion is 56%, with 10% of crossbites in the primary dentition, 11% in the mixed dentition, and 5% in the permanent dentition. The etiology is multifactorial and early diagnosis of crossbite is essential to reduce the risk of dental, alveolar, and skeletal malocclusions. In this sense, malocclusions are a disorder that is increasingly present in the population. Objective: It was to carry out a concise systematic review of the main considerations of crossbite and malocclusions. Methods: The PRISMA Platform systematic review rules were followed. The search was carried out from June to September 2023 in the Scopus, PubMed, Science Direct, Scielo, and Google Scholar databases. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed according to the Cochrane instrument. Results and Conclusion: A total 117 articles were found, and 22 articles were evaluated in full and 13 were included and developed in the present systematic review study. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 7 studies with a high risk of bias and 43 studies that did not meet GRADE. Early bite correction will provide benefits, restoring the normal redirection of the eruption of permanent teeth, providing correction of asymmetries in condylar positioning, and favoring ideal occlusion. Furthermore, early expansion with a removable expansion plate is a successful method for correcting crossbites and increasing intermolar width in the early phase of mixed dentition. Results remain stable until comprehensive treatment of the permanent dentition begins. Rapid maxillary expansion is a resource of great value to the orthodontist that can be used to treat maxillary transverse deficiencies.

Assessment of early dental arch growth modification with removable maxillary expansion by cone-beam computed tomography and lateral cephalometric radiographs: a retrospective study

BackgroundThis study evaluated the skeletal and dental changes of patients brought by early removable maxillary expansion (ERME) treatment to explore the clinical treatment effect of ERME on early dental arch growth modification.MethodsSubject children aged 6–10 years with a maxillary transverse deficiency received ERME treatment, cone-beam computed tomography (CBCT) and lateral cephalometric radiographs were measured before and after treatment, and statistical differences in the measured items were evaluated with corresponding statistical methods to explore the skeletal and dental changes.ResultsAfter ERME treatment, there was a statistical increase in the maxillary basal bone arch width, nasal cavity width, maxillary alveolar bone arch width, and maxillary dental arch width. A buccal inclination of the maxillary alveolar bone and a buccal inclination and buccal movement in the alveolar bone of maxillary first molars were found. The maxillary skeletal expansion was statistically greater than the dental expansion. Increases in the mandibular alveolar bone arch width and dental arch width happened after treatment. A decrease in angle ANB and an increase in Ptm-A, U1-SN, U1-PP, L1-MP, and L6-MP were found after treatment. No statistical changes in the growth pattern-related measured items were observed.ConclusionsERME could expand the maxillary basal bone arch width, nasal cavity width, maxillary alveolar bone arch width, and maxillary dental arch width. The maxillary skeletal expansion was greater than the dental expansion. Secondary increases in the mandibular alveolar bone and dental arch widths would happen after ERME. ERME would result in a mandibular advancement, a labial inclination of maxillary anterior teeth, and an increase of maxillary sagittal length, and would not change the patient’s growth pattern.Trial registrationThis study was approved by the Institutional Review Board of the West China Hospital of Stomatology, Sichuan University. (WCHSIRB-D-2020–446).

Short-term outcomes in the upper airway with tooth-bone-borne vs bone-borne rapid maxillary expanders

BackgroundThis study compared the area and minimal section of the nasal cavity, nasopharynx, oropharynx, and hypopharynx in cases treated with different methods of microimplant-assisted expansion.MethodsBased on a pilot study to calculate the sample size, 30 patients with transverse maxillary deficiency over 14 years of age were retrospectively selected. These patients had received two different types of microimplant-assisted maxillary expansion treatment (MARPE and BAME). The patient underwent Cone-Beam computed tomography (CBCT) before and after treatment (mean time 1.5 months) with MARPE or BAME and upper airway measurements (volume and minimum cross-sectional area) were taken to assess upper airways changes and compare changes between the groups. A paired sample t-test was performed to evaluate the T0-T1 change of airway measurements obtained with MARPE and BAME, and a student t-test to compare changes in airway measurements between MARPE and BAME.ResultsThis investigation shows a statistically significant increase in total nasopharyngeal airway volume (0.59 ± 1.42 cm3; p < 0.01), total oropharyngeal airway volume (3.83 ± 7.53 cm3; p < 0.01) and minimum oropharyngeal cross-section (53.23 ± 126.46 mm2; p < 0.05) in all cases treated with micro-screw assisted expansion. The minimal cross-sectional area of the oropharynx ((79.12 ± 142.28 mm2; p < 0.05) and hypopharynx (59.87 ± 89.79 mm2; p < 0.05) showed significant changes for cases treated with BAME. As for the comparison between cases treated with MARPE and BAME, no differences in upper airway changes have been observed, except for the minimum cross-sectional area of the nasal cavity, which increases for MARPE (52.05 ± 132.91 mm2) and decreases for BAME (-34.10 ± 90.85 mm2).ConclusionsA significant increase in total area and minimal section at the level of nasopharynx and oropharynx was observed in cases treated with BAME. Regarding the comparison of MARPE and BAME treatments, no differences were found in the total airway volume and minimal section in upper airway except for the minimum cross section of the nasal cavity that increases for MARPE and decreases for BAME.

Posterior Palatal Expansion via Subnasal Endoscopy (2PENN) for Maxillary Deficiency: A Pilot Study.

Surgically assisted rapid palatal expansion (SARPE) addresses transverse maxillary deficiency, a known contributor to nasal obstruction. The purpose of this study was to assess the feasibility, preliminary outcomes, and safety of posterior palatal expansion via subnasal endoscopy (2PENN), a modified SARPE procedure, aimed at achieving anterior and posterior maxillary expansion. This prospective case series included consecutive adult patients with findings of transverse maxillary deficiency that underwent the 2PENN procedure from 4/2021 to 4/2022. Patients completed pre- and post-operative clinical evaluations, Nasal Obstruction and Septoplasty Effectiveness (NOSE) questionnaires, and computed tomography (CT), with measures including expansion at the level of the posterior nasal spine (PNS), first maxillary inter-molar distance (IMD), and anterior nasal spine (ANS). The cohort (N = 20) was middle-aged (39 ± 11 years), predominantly male (80%), and overweight (BMI 28 ± 4 kg/m2 ). The majority (85%) of patients had sleep breathing issues, of which 10 (59%) had polysomnography-confirmed obstructive sleep apnea (OSA). Full anterior-posterior separation of the mid-palatal suture line was evident on all post-operative CT scans, with mean expansion at the PNS of 3.6 ± 1.3 mm, IMD of 6.1 ± 1.6 mm and ANS of 7.0 ± 1.6 mm (p < 0.001). Following surgery, mean NOSE scores improved from 57 ± 23 to 14 ± 13 (p < 0.001). One patient required maxillary antrostomy for post-operative sinusitis. 2PENN is an effective and safe technique for achieving both anterior and posterior maxillary expansion in patients with transverse maxillary deficiency. Further study is warranted to better understand the effect of 2PENN in patients with OSA, particularly as it relates to improving pharyngeal patency. 4 Laryngoscope, 134:1970-1977, 2024.

Effects of SARPE and MISMARPE on correction of transverse maxillary deficiency: A preliminary comparative evaluation.

The present study was designed to compare, on cone-beam computed tomography imaging, the skeletal and dental effects of the SARPE (Surgically assisted rapid palatal expansion) and MISMARPE (Minimally Invasive Surgical and Miniscrew-Assisted Rapid Palatal Expansion) techniques. The sample of adult patients with transverse maxillary deficiency (TMD) was divided into two groups, and scans were obtained preoperatively (T0) and immediately after completion of expansion (T1). The posterior and anterior linear transverse distances of the maxilla and the angulation of the maxillary first molars were evaluated. The data were entered into a generalized estimating equations model to verify the postoperative effects of the different techniques. None of the techniques caused any appreciable change in the angulation of the molars. The skeletal changes were similar, with significantly greater gains in the nasal fossa and intermaxillary distance when using the MISMARPE. The technique can be an effective and lower morbidity alternative to SARPE.

Near-Infrared Light-Controlled MicroRNA-21-Loaded Upconversion Nanoparticles to Promote Bone Formation in the Midpalatal Suture.

Rapid maxillary expansion (RME) is a common therapy for maxillary transverse deficiency. However, relapses after RME usually occur because of insufficient bone formation. MicroRNA-21 (miR-21) was reported as an important post-transcriptional modulator for osteogenesis. Herein, a photocontrolled miR-21 (PC-miR-21)-loaded nanosystem using upconversion nanoparticles (UCNPs) modified with poly(ether imide) (PEI), i.e., UCNPs@PEI@PC-miR-21, was constructed to promote bone formation in the midpalatal suture. UCNPs@PEI was constructed as the light transducer and delivery carrier. The UCNPs@PEI@PC-miR-21 nanocomplexes have good aqueous dispersibility and biocompatibility. The in vitro cell experiment suggested that UCNPs@PEI could protect PC-miR-21 from biodegradation and release PC-miR-21 into the cytoplasm under near-infrared light (NIR) irradiation. Furthermore, UCNPs@PEI@PC-miR-21 upregulated the expression of the osteogenic key markers, ALP, RUNX2, and COL1A1, at the levels of both genes and proteins. Besides, the results of the in vivo RME mice models further corroborated that photocontrollable UCNPs@PEI@PC-miR-21 accelerated bone formation with upregulating osteogenic markers of ALP, RUNX2, and osteoprotegerin and inducing fewer osteoclasts formation. In conclusion, UCNPs@PEI@PC-miR-21 nanoparticles with a NIR light could facilitate the remote and precise delivery of exogenous miR-21 to the midpalatal suture to promote bone formation during RME. This work represents a cutting-edge approach of gene therapy to promote osteogenesis in the midpalatal suture during RME and provides a frontier scientific basis for later clinical treatment.

Maxillary and upper airway changes immediately after mini-screw assisted rapid maxillary expansion in class Ⅲ patients

Objective: To assess maxillary sagittal and vertical as well as upper airway changes immediately after mini-screw assisted rapid maxillary expansion (MARME) in class Ⅲ patients. Method: A consecutive sample of 48 class Ⅲ patients with maxillary transverse deficiency who visited the Department of Orthodontics, School & Hospital of Stomatology, Wuhan University between January 2013 and March 2023 was retrospectively collected. The sample was comprised of 24 growing patients (cervical vertebra maturation, CVM 1-4) and 24 nongrowing patients (CVM 5-6). Cone-beam CT scans before (T0) and immediately after MARME (T1) were imported into Dolphin Imaging software, and then voxel-based superimposition was conducted on the basis of the anterior cranial base. Sagittal and vertical changes of the maxillary landmarks (A, ANS, PNS, UI and Spr), as well as upper airway changes after MARME were measured on multiplanar reconstruction views. Wilcoxon signed-rank test was employed to analyze the changes after MARME. Mann-Whitney U test was employed to compare the changes between growing and non-growing patients. Results: Some class Ⅲ patients exhibited significant maxillary sagittal and vertical changes immediately after MARME. The amount of changes in midpalatal suture was 4.03 (2.99, 4.87) mm in growing patients, significantly larger than that in non-growing patients [2.27 (1.49, 3.64) mm] (U=3.18, P=0.001). In growing class Ⅲ patients, the forward changes of A, ANS, PNS, UI and Spr were 0.35 (0.06, 0.80), 0.48 (0.11, 0.88), 0.48 (0.13, 0.99), 0.53 (-0.33, 1.04) and 0.40 (0.03, 0.69) mm, respectively. Vertically, the downward changes of A, ANS, PNS, UI and Spr were 1.45 (0.99, 2.13), 1.18 (0.61, 1.95), 1.30 (0.91, 1.96), 1.20 (0.71, 1.83) and 1.30 (0.81, 1.73) mm, respectively. All changes were significantly different from 0 after treatment (P<0.05). In nongrowing patients, PNS moved forward by 0.18 (-0.08, 0.39) mm while other sagittal changes were statistically insignificant (P>0.05); vertically, the downward changes of A, ANS, PNS, UI and Spr were 0.90 (0.51, 1.39), 0.73 (0.41, 1.21), 0.70 (0.55, 1.08), 0.60 (0.36, 1.19) and 0.70 (0.55, 1.23) mm, respectively. Significant immediate increase of the nasopharynx volume and nasal width was obtained in both groups (P<0.05), and the changes of oropharynx volume and minimum cross-sectional area (MCA) presented as statistically insignificant (P>0.05). Conclusions: For growing class Ⅲ patients, besides transverse expansion, significant forward and downward changes of maxilla were obtained immediately after MARME. For non-growing patients, significant downward changes were observed, while sagittal changes were negligible. The nasopharynx volume increased in both growing and nongrowing class Ⅲ patients immediately after MARME, whereas, the changes of oropharynx volume and MCA presented as statistically insignificant.

Responsiveness of three measurements in cone-beam computed tomography transverse analyses during both tooth-supported and mini-screw-assisted rapid maxillary expansion.

To evaluate the responsiveness of three cone-beam computed tomography (CBCT) transverse analyses (University of the Pennsylvania [UPenn] analysis, Boston University analysis and Yonsei University [YU] analysis). A consecutive cohort sample of patients was retrospectively reviewed for eligibility. CBCT records before treatment (T0) and immediately after maxillary expansion (T1) of 71 patients receiving tooth-supported rapid maxillary expansion (RME) and 57 patients receiving mini-screw-assisted RME (MARME) were finally analyzed. Responsiveness was assessed by comparing changes of measures (T1-T0) to mid-palatal suture opening distance (MSOD) at T1. Correlational responsiveness was assessed by Pearson correlation coefficient (r). Absolute agreement responsiveness was assessed by Bland-Altman analysis. A specialized intraclass correlation coefficient (ICC) was selected to assess responsiveness combining correlation and absolute agreement. Changes of all three measures were moderately to strongly correlated to MSOD (r > 0.5). The highest correlation coefficient (0.79) was found between the YU analysis and MSOD. When exploring absolute agreement responsiveness, the smallest deviation (0.14 mm) was observed in the UPenn analysis. For ICC, the highest ICC value (0.63) was observed when the YU analysis was used. In addition, all three measurements were more responsive to MSOD in the MARME group than to those in RME group. All three transverse measurements responded well to true changes of maxillary transverse deficiency during both tooth-supported and mini-screw-assisted RME. Deviations of responsive properties of these measurements from true skeletal changes were below a clinically meaningful level (1 mm).

Treatment effects after maxillary expansion using invisalign first system vs. acrylic splint expander in mixed dentition: a prospective cohort study

BackgroundInvisalign First System (First) is a new type of orthodontic appliance for maxillary arch expansion in mixed dentition children. Till now, few studies have evaluated the expansion effects of First versus other appliances. What’s more, most studies of arch expansion did not include a natural group to rule out growth effects. This prospective cohort study aimed to evaluate the dental and dentoalveolar effects using First or acrylic splint rapid maxillary expander (RME) in adolescents excluding growth factors.Materials and methodsAfter screening by strict inclusion criteria and propensity score matching (PSM), fifty-one patients were included: First group (n = 17), RME group (n = 17), and natural growth (NG) group (n = 17). Nine indicators including dental arch width, dentoalveolar arch width, and inclination of the molars were measured on digital dental casts at baseline (T0) and six-month follow-up (T1). Paired t-tests were used for intra-group results, and two-sample independent t-tests were used for inter-group comparisons.ResultsThere was no significant increase in all indicators within six months in the NG group (p > 0.05). In the First group and RME group, all width indicators were significantly increased after treatment (p < 0.05). The RME group exhibited greater expansion than the First group in intercanine width, first interpremolar width, second interdeciduous molar width, first intermolar width, arch perimeter, intercanine dentoalveolar width, intermolar dentoalveolar width, and inclination of the molars (p < 0.05). Whereas, there was no significant difference in arch depth between the two treated groups.ConclusionsBoth First and RME can expand the maxillary arch in mixed dentition. In case of mild to moderate maxillary transverse deficiency (MTD), Invisalign First System could be a reasonable option. RME shows significant better efficiency of dental arch expansion than First, recommended for patients with severe MTD.Trial registrationThis prospective study was registered on ClinicalTrials.gov (01/02/2022, registration number: ChiCTR2200056220). The trial was approved by the Ethical Committee of the Hunan Xiangya Stomatological Hospital Central South University (20,200,088), and informed consent was obtained from all subjects and their legal guardian(s).

Skeletal and dentoalveolar modifications in adults with different sagittal facial patterns after personalized miniscrew-assisted rapid palatal expansion: A prospective cone-beam computed tomography study

This study aimed to compare the skeletal and dental modifications in adults with different sagittal facial patterns by a personalized miniscrew-assisted rapid palatal expander (pMARPE). Forty subjects (aged 18-28 years; 15 females and 25 males) with maxillary transverse deficiency were assigned to 1 of 3 groups (Class I, II, and III relationship) on the basis of their sagittal facial patterns. Each patient was treated with an individually customized expander. A similar expansion protocol was used for all patients. Cone-beam computed tomography scans were obtained before and after expansion. One-way analysis of variance was used to analyze differences among 3 groups in skeletal, dentoalveolar, and periodontal changes (P<0.05). The success rates of expansion were higher in patients with a Class I or II relationship than those with a Class III relationship. Patients with a Class I or II relationship had greater changes in the anterior nasal spine and maxillary basal bone widths. A more parallel sutural opening in the anteroposterior direction was seen in those with a Class II relationship. The tipping of the maxillary first molar increased, and the buccal alveolar bone thickness decreased in all groups after expansion, especially in patients with a Class III relationship. The pMARPE effectively split the midpalatal suture among adults. However, midpalatal suture expansion was more difficult, and there were more dentoalveolar side effects and fewer orthopedic effects in patients with a Class III relationship than in those with Class I or II relationships.

Randomized clinical trial of surgically assisted rapid maxillary expansion with two and three segments for nasal breathing.

To evaluate surgically assisted rapid maxillary expansion (SARME), with osteotomies separating the maxilla into two segments (SARME-2S) and three segments (SARME-3S), on obstruction symptoms and nasal cavity dimensions in patients with maxillary transverse skeletal deficiency (MTSD). Sixteen patients with MTSD of 7mm or above were evaluated in each group, for a total of 32 patients. All patients were evaluated pre- and postoperatively up to 10months after the expander activations. The minimum cross-sectional area (MCA) and the volume of the nasal cavities were identified by acoustic rhinometry. The Nasal Obstruction Symptom Evaluation (NOSE) scale questionnaire was applied. The palate surface area (PSA) was measured, via digitized maxillary models, as a criterion for comparison with the other variables studied. There was no difference between the groups (p = 0.370) and was verified a significant increase in PSA postoperatively. MCA showed a small increase without statistical significance, and together with the volume of the nasal cavities remained constant during the study. NOSE scale scores decreased significantly in the postoperative periods, implying a decrease in nasal obstruction symptoms in both groups. SARME with two and three segments show similar results, and both may improve nasal obstruction symptoms when present in patients with MTSD. SARME, regardless of the chosen surgical technique, should follow the recommendation to correct just the MTSD. While an improvement in nasal breathing is expected, this must be understood as likely, but not certain.

ОЦЕНКА ВЕРХНИХ ДЫХАТЕЛЬНЫХ ПУТЕЙ И ОКРУЖАЮЩИХ МЯГКИХ ТКАНЕЙ У ПАЦИЕНТОВ С АНОМАЛИЯМИ ОККЛЮЗИИ В САГИТТАЛЬНОЙ ПЛОСКОСТИ ПО ДАННЫМ КОНУСНО-ЛУЧЕВОЙ КОМПЬЮТЕРНОЙ ТОМОГРАФИИ

The relationship between facial morphology and upper airway (UA) dimensions is well established in scientific literature. Due to that, upper airway assessment is an important step of orthodontic treatment planning and diagnosis. Three-dimensional cone-beam computer tomography analysis (CBCT) of upper airway is simple and readily available method of measuring linear and angular parameters, cross-sectional area, and volume of the UA. &#x0D; The aim of the study is to measure the UA and surrounding tissue dimensions in patients with different types of sagittal malocclusion. 63 CBCT scans of adult patients without history of trauma, orthodontic treatment and congenital syndromes, diagnosed with distal, mesial, and normal occlusion have been studied using Materialise Mimics 21.0. Three-dimensional models of UA were created, and measurements of volume and cross-sectional area were taken using centerline and conventional cephalometric analysis. Non-parametric statistical correlational analysis was conducted.&#x0D; There were statistically significant differences between patients with mesial and distal occlusion. Moderate statistically significant correlations between facial morphology and UA dimensions have been found. In patients with distal occlusion, extended head position, posterior position of the hyoid bone, transverse maxillary and mandibular deficiency UA tend to have smaller size. The most predictive factor for minimal cross-sectional area of UA is the craniocervical angle and the distance between mandibular condyles.

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

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

Orthodontic Treatment Using MARPE and Mini-Implants in a Patient with Skeletal Class I Malocclusion, Anterior Open Bite, and Maxillary Transverse Deficiency

Orthodontic Treatment Using MARPE and Mini-Implants in a Patient with Skeletal Class I Malocclusion, Anterior Open Bite, and Maxillary Transverse Deficiency

Applicability of Fractal Analysis for Quantitative Evaluation of Midpalatal Suture Maturation.

The treatment of transversal maxillary deficiency usually aims at skeletal expansion. The treatment option highly depends on the maturation stage of the midpalatal suture (MPS), which may vary between individuals at the same chronological age. Therefore, the individual determination of the MPS maturation is crucial. Our aim was to investigate the applicability of fractal analysis for the quantitative evaluation of MPS maturation. Nine experienced orthodontists were asked to evaluate the MPS maturation on 51 cone beam computed tomography (CBCT) scans according to the Angelieri classification method. Intra- and inter-examiner reliability was measured using Cohen's Kappa coefficient. The stages were agreed upon according to the results of the examiners with the highest strength of agreement. Fractal analysis was then performed on the CBCTs and the correlation between the fractal dimension values and maturation stages was then evaluated. Optimal fractal dimension cut-off values were determined using a receiver operating characteristic curve. The cut-off point was found at 1.073, at which the use of fractal dimension for predicting MPS maturation showed 100% sensitivity, 93.7% specificity, 9.5% false positive, 0% false negative rate. Our results provided further evidence that fractal analysis is a reliable tool to determine MPS maturation stage.

Effects of novel microimplant-assisted rapid palatal expanders manufactured by 3-dimensional printing technology: A finite element study

The expansion effects of several new microimplant-assisted rapid palatal expanders (MARPEs) manufactured by 3-dimensional printing technology were evaluated by finite element analysis (FEA). The aim was to identify a novel MARPE suitable for treating maxillary transverse deficiency. The finite element model was established using MIMICS software (version 19.0; Materialise, Leuven, Belgium). First, the appropriate microimplant insertion characteristics were identified via FEA, and several MARPEs with the above insertion patterns were manufactured by 3-dimensional printing technology. Then, the stress distribution and displacement prediction of the 4 MARPEs and hyrax expander (model E) were evaluated via FEA: bone-borne (model A), bone-tooth-borne (model B), bone-mucous-borne (model C), bone-tooth-mucous-borne (model D). Monocortical microimplants perpendicular to the cortical bone on the coronal plane resulted in better expansion effects. Compared with a conventional hyrax expander, the orthopedic expansion of each of the 4 MARPEs was far larger, the parallelism was greater, and the posterior teeth tipping rate was lower. Among them, the expansion effects of models C and D were the best; the von Mises peak values on the surfaces of the microimplants were smaller than those of models A and B. This study may demonstrate that the 4 MARPEs obtained more advantageous orthopedic expansion effects than a hyrax expander. Models C and D obtained better biomechanical effects and had better primary stability. Overall, model D is the recommended expander for treating maxillary transverse deficiency because its structure acts like an implant guide and is beneficial for the accurate insertion of the microimplant.

Dento-skeletal effects of different rapid maxillary expanders for growing patients-which is better?

Single-blind, two-arm parallel-group randomised controlled trial. Patients aged 11-14 years old attending for comprehensive orthodontic treatment between January and July 2018. All subjects needed to have the following: present upper first premolars and first permanent molars; transverse maxillary deficiency; unilateral or bilateral posterior crossbite. The exclusion criteria was: cleft lip or palate, previous orthodontic treatment; congenital deformity; absent permanent teeth. Rapid maxillary expansion via two techniques were used and placed by the same orthodontist. Group A were treated via the tooth-bone-borne Hybrid Hyrax expander, Group B had the tooth-borne (hyrax) expander. CBCT scans of the maxilla were taken before treatment and 3 months after the activation phase when the appliances had been removed. Analysis of the dental and skeletal changes was completed via measuring pre and post treatment CBCT scans using Dolphin software for Group A and Group B. Measurements included: specific naso-maxillary widths in the first premolar region (i.e. nasal cavity, nasal floor, maxilla, palate), naso-maxillary widths in the first molar region, premolar/molar inclination, buccal cusp distance, and apices distance, as well as suture maturation. Baseline characteristic data was compared using one-way ANOVA. Intergroup comparison of changes was analysed using ANCOVA. P < 0.05 (5%) was considered statistically significant. Inter-rater reliability was assessed using correlation coefficient. Skeletal effects: The Hybrid Hyrax patients (HHG) showed a significantly higher increase in dimensions in the nasal cavity, nasal floor and maxilla in the premolar region only, of 1.5 mm, 1.4 mm and 1.1 mm, respectively, compared to the Hyrax expander patients (HG), to a 5% significance level. The HHG showed a significantly higher increase in dimensions in the nasal cavity of 0.9 mm, in the molar region, compared to the HG. Dental effects: Premolar inclination was significantly higher in the HG, with the difference being -3.2 degrees on the right 1st premolar and -2.5 degrees on the left 1st premolar. The higher the amount of activation, the higher the nasal skeletal changes in the Hybrid Hyrax group. The Hybrid Hyrax (tooth-bone-borne expander) resulted in increased skeletal dimension changes (i.e. in the nasomaxillary structures in the first premolar region, and nasal cavity in the first molar and first premolar region) and only minimal premolar inclination/tipping compared to the Hyrax (tooth-borne expander). There were however no differences between the expanders for position of premolar or molar apices, or molar crowns.

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.

0808 Comparison of Maxillary Transverse Dimension with Pediatric Obstructive Sleep Apnea Presence and Severity

Abstract Introduction Obstructive Sleep Apnea (OSA) in children and adolescents is commonly discussed amongst dental specialists. Physical attributes such as a high and narrow palate, dolichofacial appearance, and retrognathic mandible are reported to increase pediatric risk for OSA. Previous research states rapid maxillary expansion decreases AHI in children with OSA and may be an effective treatment option. Current literature does not report a consistent method of measuring a maxillary transverse deficiency nor does it report a numerical maxillary threshold deficiency that requires expansion in pediatric patients with OSA. Our aims are to compare two different orthodontic diagnostic methods for measuring the maxillary transverse dimension and to assess whether patients diagnosed with mild, moderate, or severe OSA have a numerical threshold for maxillary deficiency. Methods Participants were ages 7-17 years old (average 11.7 years) with no history of orthodontic treatment, craniofacial syndromes, craniosynostosis forms, or nasal abnormalities. Those with and without adenoids and tonsils were included. Participants presented to the Mayo Clinic Sleep Center for their polysomnogram. Their dentition was scanned, and a digital model was rendered. The maxillary transverse dimension was measured via two different methods: McNamara’s Analysis and Andrew’s Six Elements of Orofacial Harmony. Results There were 65 participants: 31 diagnosed with OSA (13 Mild, 4 Moderate, 5 Severe, and 9 Other) and 34 without (controls). Patients in the Other category were diagnosed based on clinical findings. No statistical difference was found between the maxillary transverse measurements of patients with versus without OSA or between the OSA categories. Patients with OSA were more likely to have permanent teeth (61.3% vs 32.4%, p=0.019), tonsils removed (54.8% vs 26.5%, p=0.020), and to have snored during the PSG (83.9% vs 55.9%, p=0.048). Conclusion Conclusions based on this pilot study should be interpreted carefully due to limited sample sizes. No statistically significant differences of the maxillary transverse dimension were found between those with and without OSA using either diagnostic method. No numerical maxillary deficiency threshold was found. Maxillary expansion should not be recommended based on OSA diagnosis alone. Referral to a dental specialist is recommended based on dental needs. Support (if any) Support was provided by Mayo Clinic CTSA grant UL1TR002377.