Search Results (24)

Miniscrew-assisted rapid palatal expansion (MARPE) is increasingly used to manage transverse maxillary deficiency; however, three-dimensional evidence comparing bone-borne appliance designs remains limited. This retrospective cone-beam computed tomography (CBCT) study evaluated the dentoskeletal outcomes of two digitally planned MARPE approaches using Superscrew- and Hyrax-type expansion screw systems. Because activation regimen was associated with the screw system, the groups were interpreted as two clinical approaches rather than isolated screw-design comparisons. Twenty-seven individuals were divided into Superscrew-type (n = 15) and Hyrax-type (n = 12) groups. Pretreatment and post-expansion CBCT records were used to assess midpalatal and pterygopalatine suture opening, nasal and maxillary width changes, and buccal and palatal intermolar distances. Both approaches produced significant increases in nasal, maxillary, and intermolar widths. No significant intergroup differences were observed in sutural opening, PNS/ANS ratio, pterygopalatine suture separation, nasal width, maxillary width, or buccal intermolar distance changes. A borderline unadjusted difference was observed for palatal intermolar distance (6.08 ± 2.48 mm vs. 4.29 ± 1.97 mm; unadjusted p = 0.047), but it did not remain significant after correction for multiple comparisons. Therefore, this finding should be interpreted as exploratory rather than clinically confirmatory. Full article

(1) Background: Posterior crossbite associated with maxillary transverse deficiency is commonly managed with maxillary expansion, yet the correspondence between laboratory activation behavior and the clinical response of nickel–titanium leaf-spring expanders remains insufficiently defined; therefore, this study aimed to compare in vitro and in vivo performance of the Leaf Expander^® and to assess their agreement. (2) Methods: A retrospective sample of 15 mixed-dentition patients (7–10 years) treated at two university centers with a Leaf Expander^® (6 mm screw; 900 g) was evaluated; interpremolar (E–E), intermolar (6–6), and intercanine (C–C) distances were recorded at baseline (T0, digital models) and at follow-up visits (T1–T5, caliper measurements), while mechanical compression testing (Instron 3365) quantified force release across the activation sequence; normality (Shapiro–Wilk), parametric analyses, and Pearson correlation were used. (3) Results Posterior crossbite correction was achieved in all completed cases, with mean total increases (T0–T5) of 5.4 mm (E–E), 4.4 mm (6–6), and 6.0 mm (C–C); early expansion (T1–T0) averaged 2.5 mm at E–E, and laboratory curves showed an activation peak followed by sustained force release (~6.5–9 N) and a residual-load phase. Agreement between declared activation and clinical response was higher for E–E and 6–6 than for C–C, which showed greater variability. (4) Conclusions: These findings support the Leaf Expander^® as an effective compliance-free slow expansion device and indicate that laboratory force behavior can help interpret the clinical expansion timeline, including delayed expression after activation. Full article

Background/Objectives: Transverse maxillary deficiency in growing patients can be treated using rapid maxillary expansion (RME) or slow maxillary expansion (SME) with spring-based appliances, such as the Leaf Expander (LE), but their comparative dentoskeletal effects remain debated. This study evaluated the transverse dentoskeletal outcomes of LE-based SME versus conventional RME. Methods: A systematic review was conducted in accordance with PRISMA 2020 guidelines and registered in PROSPERO. Electronic searches were performed in PubMed, Scopus, Embase, Web of Science, and Cochrane Library up to 9 January 2026. Randomized controlled trials (RCTs) comparing LE-based SME and RME in skeletally immature patients were included. Primary outcomes were transverse maxillary change; secondary outcomes included dentoalveolar side effects. Risk of bias was assessed using the RoB 2 tool, and certainty of evidence was evaluated using the GRADE framework. When possible, a meta-analysis was performed using standardized mean differences and a random-effects model. Results: Four RCTs met the inclusion criteria. Both SME and RME achieved significant transverse expansion. Meta-analysis showed no statistically significant differences between protocols for inter-canine distance, inter-second deciduous molar distance, inter-first permanent molar distance, or basal maxillary width. Intergroup differences varied by anatomical site and measurement method: RME showed greater anterior dental and skeletal transverse gains, whereas SME achieved comparable intermolar expansion with greater molar distorotation. Three-dimensional analyses indicated similar morphological enlargement. Risk of bias ranged from low to high; the certainty of evidence was low to very low for most transverse parameters and moderate only for molar distorotation. Conclusions: Both LE-based SME and RME effectively correct transverse maxillary deficiency. Quantitative synthesis showed comparable overall transverse expansion, with differences mainly related to the distribution and biomechanical pattern of dentoskeletal effects rather than the absolute amount of expansion achieved. Appliance selection should be guided by biomechanical features and individual treatment objectives. Further high-quality RCTs with standardized three-dimensional protocols and longer follow-up are needed. Full article

Objectives: This study examines the relationship between maxillary morphology and the severity of obstructive sleep apnea (OSA) in adults, with a focus on intermolar distance (IMD) and palatal height (PH) as predictive factors. Methods: A retrospective observational study was conducted at private orthodontic practices in Sydney, Australia. A total of 100 adults (50 OSA patients and 50 controls) were included. OSA diagnosis and severity were confirmed via hospital-based polysomnography. Digital maxillary models were analyzed using the Medit Link software (version 3.2.0; Medit Corp., Seoul, Republic of Korea), and IMD and PH were measured. Statistical analyses included one-way ANOVA and linear regression modeling, with adjustments for age and sex. Results: The OSA group exhibited significantly narrower IMD (28.96–35.01 mm) and higher PH (21.68–29.56 mm) compared to the control group (IMD: 36.35–41.50 mm; PH: 18.57–23.51 mm). A negative correlation was observed between IMD and PH across all groups. Linear regression analysis demonstrated a strong association between these craniofacial parameters and OSA severity (R² = 0.76, p < 0.001). IMD was negatively correlated with the Apnea-Hypopnea Index (AHI) (p = 0.003), while PH was positively correlated (p < 0.001). The inclusion of demographic variables did not significantly enhance the predictive model. Conclusions: Maxillary morphology associates with OSA severity, with narrower IMD and greater PH linked to higher AHI. Full article

Objective: The Staub™ Cranial system is based on defined anatomical reference points of edentulous casts that can guide the reconstruction of artificial teeth on the edentulous jaw. The aim of this study was to evaluate the validity of the Staub™ Cranial system in reconstructing the position of natural teeth in edentulous maxillae. Materials and methods: To reconstruct the original position of natural teeth, 20 fully dentate maxillary casts were produced, and 20 duplicates had all teeth eliminated. Subsequently, following the Staub™ Cranial system guidelines, an artificial teeth set-up was completed. The measured distances included the intermolar width #16–26, the intercanine width #13–23, and the incisocervical length #11. Measurements were made using the principle of stripe projection with specially developed software. Original and reproduced casts were then compared. The reproduced casts with measured distances deviating less than 5% from the mean values of control models were considered successful reconstructions. Results: The ability of the system to reconstruct the original position of lost teeth in the edentulous jaw was precise. With a narrow tolerance range of 5%, 80% of the models could be reproduced with zero or a deviation in one dimension only. Conclusions: The results of this study confirmed the efficacy of the Staub™ Cranial system to provide guidance for the customized arrangement of artificial teeth in edentulous jaws. Full article

Background: Presurgical nasoalveolar molding (NAM) improves outcomes in infants with cleft lip and palate by guiding alveolar segment alignment and enhancing nasal symmetry prior to primary lip repair. However, traditional NAM protocols require frequent clinical visits and specialized expertise, limiting access for families in rural and low-resource settings. Objective: This retrospective clinical study evaluated the feasibility and clinical outcomes of a digitally guided NAM approach using thermoformed clear aligners in infants with unilateral complete cleft lip and palate. Material and Methods: Twenty-five neonates residing in rural regions were treated over a 20-week pre-surgical period using a digital workflow that included intraoral scanning, 3D model design, and sequential aligner fabrication. The protocol minimized the number of in-office visits while engaging caregivers in home-based appliance management. Anatomical changes were assessed using 3D models at baseline and at treatment completion. Results: Significant reductions were observed in anterior cleft width (mean decrease: 5.38 mm, 95% CI: –7.58 to –3.18, p < 0.001) and posterior cleft width (mean decrease: 3.39 mm, 95% CI: –4.79 to –1.99, p < 0.001). Intermolar distance increased by 1.23 mm (p = 0.036), while intercanine width remained stable (p = 0.515), indicating preservation of maxillary arch form. Surgeons reported improved nasal symmetry and tissue alignment at the time of lip repair. Conclusions: This digitally planned NAM clear aligner protocol demonstrated clinical feasibility and effectiveness in reducing cleft width during the pre-surgical period. Findings should be interpreted with caution, given the retrospective design, lack of a control group, and absence of objective nasal outcome measures. Further studies are recommended to assess long-term outcomes and broader implementation potential. Full article

Background/Objectives: Accurate full-arch impressions are crucial for predictable prosthodontic outcomes. While intraoral scanners (IOSs) are increasingly adopted, evidence comparing their accuracy with conventional analog impressions across full mandibular arches—particularly under both laboratory and clinical conditions using an objective intraoral reference—is limited. Our study aims to evaluate the in vitro and in vivo accuracy of digital impressions compared to conventional methods in full-arch scans using an intraoral reference tool. Methods: In this study, a custom stainless steel transfer aid carrying four 5 mm steel spheres in a trapezoidal configuration, provided with known reference distances, was used. Ten mandibular Frasaco models (in vitro) and ten healthy young adults (18–30 yrs) with intact lower arches (in vivo) received the bonded spheres. Six inter-sphere distances were defined: intermolar (BL-BR), interpremolar (FL-FR), diagonals (BL-FR, FL-BR), and lateral spans (BL-FL, BR-FR). Each arch underwent a digital scan (Medit i700) and a conventional monophase PVS impression, which was poured in Type IV stone and digitized (GOM Scan 1). The inter-sphere linear distances were measured in GOM Inspect, and trueness (deviation from reference) and precision (SD) were calculated. Data normality and homogeneity were verified; parametric t-tests and one-sample tests (α = 0.05) assessed differences between workflows and against reference values. Results: In vitro, analog impressions closely matched reference distances, with only the long-span BL-BR showing minor deviation (0.053 mm, p < 0.001). Digital scans showed significantly greater deviations across all spans (max 0.117 mm), particularly over long distances. In vivo, both workflows demonstrated comparable accuracy: only BL-BR (analog) and BR-FR (digital) differed significantly from the reference, and all AMEs remained within clinical thresholds (≤0.10 mm), except for BL-BR and BL-FL spans. ICC values ranged from moderate to high. Direct paired comparisons revealed statistically equivalent performance across most spans. Conclusions: Analog impressions outperformed digital scans in vitro, particularly across longer spans, confirming their superior dimensional fidelity under controlled conditions. However, in vivo, both workflows delivered statistically comparable and clinically acceptable accuracy. These findings suggest that while analog impressions remain the gold standard for precision-demanding contexts, modern intraoral scanners—when used correctly—can offer reliable full-arch mandibular impressions. The four-sphere reference system proved valuable for objective, anatomy-independent measurement. Full article

(1) Aim: To compare transverse dimensions measured on AI-generated intra-oral models and conventional digital intra-oral models. (2) Methods: A group of 38 patients treated with clear aligners was selected retrospectively from those whose records featured both AI-generated and conventional digital intra-oral models taken at the same timepoint. Transverse dimensions (inter-canine, inter-premolar, and inter-molar distances) on both upper and lower arches were evaluated and compared. Intra-class correlation index and paired t-test were applied to test the repeatability of measurements and statistically significant differences, respectively. Statistical significance was set at 0.05. (3) Results: Intra-class correlation index showed good repeatability. Paired t-test showed differences in measurements of the distances between the thicket area of gingiva on the palatal side of the upper first molar (p = 0.002), the gingival margin of the lower first molar (p = 0.014), and the mesio-vestibular cusps of the lower first molars (p = 0.019). (4) Conclusions: Transverse measurements were similar on AI-generated and conventional intra-oral .stl renderings. Statistical differences were found on posterior areas of both upper and lower dental arches, but are unlikely to be clinically significant. Full article

Background/Objectives: Currently, clear aligners are preferred to conventional appliances, especially among adult patients. However, the use of aligners for treating maxillary constriction is still debated in the literature. Therefore, the purpose of this study was to assess maxillary dentoalveolar expansion following clear aligner therapy in adults using CBCT scans. Methods: The study sample encompassed 50 non-growing patients (27 females and 23 males) aged 20 to 42 undergoing clear aligner orthodontics without dental extractions or auxiliaries. Transverse linear distances were measured on initial and final CBCTs and, subsequently, analysed through paired t-test and ANOVA. We considered alveolar bone measurements and interdental widths measured at the buccal apices and cusps from canines to second molars. Results: The buccal alveolar ridge width showed the greatest expansion (1.01 ± 0.38 mm), followed by the palatal alveolar ridge and maxillary alveolar bone. Statistically significant improvements were observed for all interdental measurements. The most considerable changes occurred in the interpremolar cusp distances, while the least changes were seen in the intermolar apex distances. At the cusp level, the average interpremolar widths increased by 3.44 ± 0.22 mm for the first premolars and 3.14 ± 0.27 mm for the second ones. Conclusions: Clear aligner treatment can effectively manage a constricted maxillary arch. We found significant changes in the maxillary alveolar bone. Both inter-apex and inter-cusp widths increased in all teeth, with the highest values in the premolars. Moreover, the increases in interdental distances at both apex and cusp levels were related to tooth position. Full article

Adjustments to the anatomy of the facial region, such as maxillary expansion, may impact the geometry of the nasal airway and may increase nasal airway volume. The purpose of this study was to investigate the possible effect of maxillary dentoalveolar expansion using clear aligners on the nasal airway’s volume and intermolar distance in pediatric patients. Before and after maxillary expansion treatment using clear aligners, cone-beam computed tomography (CBCT) radiographs were taken as part of the diagnostic and progress records of 11 children (6–13 years) with constricted maxilla (the experimental group). The CBCT scans of 7 children (7–12 years) who had no treatment were considered to be the control group. The changes in nasal airway volume and intermolar distance between the experimental and control groups were compared and analyzed. Correlation analysis between nasal airway volume and intermolar distance changes was also performed. Compared with the control group, the nasal airway volume of the patients in the experimental group showed a significant increase (1595.6 ± 804.1 mm³; p < 0.001), and the intermolar distance also increased significantly (2.4 ± 0.4 mm; p < 0.001). However, there was little correlation between the change in intermolar distance and the change in nasal airway volume in the experimental group (r = −0.029) and a negative correlation in the control group (r = −0.768). This study showed increased maxillary intermolar width and increased nasal airway volume in children with constricted maxilla who underwent orthodontic maxillary expansion using clear aligners. Further studies with larger sample sizes and long follow-ups are needed. Due to the study design and small sample size, the results should be interpreted with caution and no causal relationship can be drawn between maxillary expansion using clear aligners and obstructive sleep apnea. Full article

(1) The purpose of this study is to relate the bidimensional and tridimensional measures of the palate to the vertical facial pattern defined by the angle “SN-MP” between the mandibular plane and the anterior cranial base (Sella–Nasion/mandibular plane angle) in skeletal Class II untreated patients. Furthermore, the same palatal measures were used to compare Class II with Class I subjects. (2) A sample of 197 Class II Caucasian subjects (112 females and 85 males) with untreated skeletal Class II was collected retrospectively (from a private dental clinic specialized in orthodontics) and divided into two main groups according to the ANB angle: 74 Class I patients (0° ≤ ANB ≤ 4°) and 123 Class II patients (ANB > 4°). Class II subjects were furthermore divided into three groups depending on the angle SN-MP. Lateral cephalograms and digital 3D maxillary dental scans were available. Bidimensional and tridimensional measures were taken on each maxillary dental scan. The differences among the groups were analyzed for significance using a variance analysis. (3) A decrease in the posterior palatal height and an increase in the palatal surface area in Class I subjects were reported. The results showed a change in upper arch form, with a greater intermolar width in patients with a low SN-MP angle and a smaller one in high-angle patients. The more a Class II subject tended towards high-angle divergence, the narrower the palate was. (4) A greater posterior palatal height was found in Class II malocclusion, while greater surface area was noted in Class I malocclusion. In addition to this result, another statistical significance was detected in Class II malocclusion: the intermolar distance was greater in hypodivergent than in hyperdivergent patients. Similar volume values were noted across different malocclusions and vertical divergence groups. Palatal width seemed to be related to vertical facial pattern, while palatal height and area seemed to be related to sagittal malocclusions. These findings underscore the importance of considering palatal morphology variations in designing individualized orthodontic treatments, thereby improving patient-specific outcomes and broadening our understanding of skeletal Class II malocclusion. Full article

Background: Traditional methods for palatal expansion using fixed appliances often face limitations in comfort and aesthetics. In comparison, aligner therapy has limitations, particularly regarding maxillary expansion. The aim of this study is to examine the biomechanical properties regarding the wire diameter and bending of different stainless steel wires to evaluate their potential for incorporation into maxillary aligner therapy. Materials and Methods: Three rectangular stainless steel wires (0.016″ × 0.022″, 0.017″ × 0.025″, and 0.019″ × 0.025″) were tested for mechanical expansion forces in the intermolar region, comparing non-tooth-shaped bent wires (A groups) and tooth-shaped bent wires (B groups). Using a Z010 testing machine (ZwickRoell GmbH and Co. KG, Ulm, Germany), expansion forces were measured at 1 mm intervals over a 5 mm distance, with 15 samples analyzed per group. Statistical analyses included the Shapiro–Wilk test for normal distribution, the Mann–Whitney U test, which revealed significant results (U = 225, p < 0.001), and the Kruskal–Wallis test, which indicated significance (H = 39.130; df = 2; p < 0.001). Results: Tooth-shaped bent wires exhibited significantly lower expansion forces than non-tooth-shaped bent wires for all tested wire types. This difference was most notable in wires with larger transverse profiles (0.019″ × 0.025″), where the tooth-shaped bent wires displayed a marked reduction in mechanical load capacity. Specific force measurements for non-tooth-shaped wires ranged from 760.61 ± 79.51 mN at 1 mm of deformation to 2468.46 ± 66.27 mN at 5 mm of deformation, while tooth-shaped wires ranged from 116.80 ± 3.74 mN to 1979.49 ± 23.23 mN. Conclusions: These findings suggest that non-tooth-shaped bent wires offer a more efficient and uniform expansion potential for maxillary movements due to their stable elastic properties. Clinically, integrating non-tooth-shaped stainless steel wires into aligner therapy may provide a viable method for maxillary expansion, supporting both first- and second-order movements in orthodontic treatment. Further research is needed to explore the integration of such wires for effective maxillary expansion in aligner therapy. Full article

Purpose: The aim was to analyze the accuracy of digital models and 3D-printed casts from full-arch digital impressions using two intraoral scanners (iTero^TM and Primescan^TM). Materials and methods: A crossover reliability study was designed, scanning children and teenagers with iTero^TM and Primescan^TM. Accuracy was evaluated by measuring intercanine, intermolar, and ipsilateral canine–molar distances intraorally and comparing these measurements with those from plaster casts, digital models obtained with intraoral scanners, and 3D-printed casts. A paired comparison and a general linear model with a one-way repeated measures ANOVA procedure were carried out with a confidence level of 95% (p ≤ 0.05). Results: A total of 51 subjects were analyzed (mean age 12.35 ± 2.57). Statistical differences (p < 0.05) were found in the upper and lower arch regarding accuracy in comparison to intraoral measurements, except for the iTero^TM-printed cast and canine–molar upper right and intercanine lower distances (p > 0.05 for all comparisons). Regarding a comparison between reproduction methods, the plaster cast oversized the intercanine upper distance in comparison with both intraoral scanners’ digital models and the Primescan^TM-printed cast (p = 0.001), but there were no differences in the lower arch (p > 0.05 for all comparisons). Conclusion: Intraoral scanners reproduce tooth structures with similar accuracy to conventional methods. Full article

Background: This study aimed to compare the clinical outcomes of using two different devices to treat upper palatal discrepancies evaluated with a digital intraoral scanner. Methods: A total of 64 patients were enrolled and treated with either an elastodontic expansion device (32 patient test group, 16 females and 16 males, mean age 7.08 ± 0.44) or Haas expander (32 patient control group, 16 females and 16 males, mean age 7.32 ± 0.50). The two groups exhibited similar orthodontic features. The orthodontic criteria were: skeletal class I relationship; molar class I relationship; complete eruption of upper sixths; presence of unilateral or bilateral cross bite. All dental casts were examined and subsequently scanned with an intraoral scanner (I-Tero) pre-treatment (T0) and 12 months after the onset of therapy (T1) to assess the distance between the decidous upper canines (ICW, intercanine width) and the distance between the mesiopalatal cusps of the upper first molars (IMW, intermolar width). For statistical analysis, the t-test for continous variables and the chi-square test for categorical variables were used, respectively. Results: There were no statistically significant differences between the mean and SD of the expansions that resulted from the Haas expander and the elastodontic devices (Haas expander vs. Eptamed: ICW_T1 (Haas) = 42.34 (3.09), ICW_T1 (Eptamed) = 42.69 (2.77); p = 0.743; IMW_T1 (Haas) = 34.22 (2.29), IMW_T1 (Eptamed) = 34.00 (2.56); p = 0.800). The two devices were similarly effective. Conclusions: Elastodontic devices and the Haas expander can successfully help the orthodontist to conduct upper arch expansion treatment. However, elastodontic devices are more comfortable during the resolution of palatal discrepancies compared to palatal expander devices. Full article

(1) Background: In the pursuit of enhancing diagnostic precision and treatment planning in orthodontics, accurate measurements in dental study casts of the different parameters of the dental arch stands as a critical element. Measurements such as dental arch perimetry, arch length or intermolar distance play a key role in achieving optimal results in orthodontics. Therefore, the aim of this study is to develop, calibrate and verify a new tool for determining dental arch measurements and to compare these measurements, carried out with the newly fabricated instrument, to two other conventional measurements used in orthodontics. (2) Methods: The study used 40 dental study casts for measuring the three mentioned arch parameters. The measurements were conducted following three methods: with the new instrument, with the help of a digital caliper and with the conventional method using a graduated ruler and metal wire. The difference between the values obtained by measuring with the new instrument and the other two methods was noted out in order to calculate the margin of error. Descriptive statistics, including mean, minimum, maximum, and standard deviation, were computed for all replicates, while normality was assessed using the Kolmogorov–Smirnov and Shapiro–Wilk tests; mean differences were examined using the Friedman test and the Wilcoxon signed-rank test, with statistical significance set at p-values < 0.05. Results: In the case of the arch perimeter measurement, the difference from the conventional measurement was −0.045 mm ± 0.006 and from the digital measurement was 0.025 ± 0.013. The measurement of the anterior arch length results shows that the difference from the conventional measurement was −0.0002 ± 0.014 and from the digital measurement 0.02 ± 0.0006. For the measurement of the intermolar distance of the upper permanent molars, the difference from the conventional measurement was −0.02 ± 0.01 and from the digital measurement −0.02 ± 0.001. The greatest differences were observed in the measurements of the parameter “Arch perimeter”, obtaining an average value of −0.045 ± 0.006 mm between the measurement with the new instrument and that with the conventional method using graduated rulers, as opposed to a value of 0.025 ± 0.013 for the difference from the digital measurement. Conclusions: the values obtained using the proposed instrument closely align with those obtained through traditional measuring methods like the graduated ruler and metal wire, demonstrating comparable results. Additionally, the measurements closely match those achieved through digital measurement using electronic calipers, showcasing the instrument’s accuracy in comparison to established techniques. Full article