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Introduction: The use of arch models is essential in diagnosis and planning in orthodontics. The demand for digital and printed models has increased among professionals., Objective: The aim of the study was to assess the agreement of horizontal and vertical linear measurements obtained from digital models, printed models, and direct measurements., Materials and Methods: Intraoral scans of 30 individuals were obtained. Digital measurements were performed using the STL files. From printed models, the measurements were done using a digital caliper, and the real measurements were done directly to the mouth of respective patients., Results: The one-sample t test showed no discrepancy between the paired sets of measurements, with the value of 0 (p>0.05). The evaluation of the measurements was done using Bland-Altman analysis in pairs. The three methods showed agreement in horizontal and vertical measurements. Linear regression analyses showed no proportional bias in the data (p>0.05)., Conclusion: The horizontal and vertical measurements evaluated showed agreement when measured on digital models, printed models and directly in the individuals' mouths.

Background: This study aims to verify Bolton's values for tooth size ratios and to evaluate possible relationships to different occlusal traits using precise digital measurement methods., Materials and Methods: Including 1000 consecutively selected patients from three study centres a digital, partially automated model analysis was performed utilizing the software OnyxCeph. The measurements comprised tooth width for calculation of anterior (AR) and overall ratio (OR) as a percentage, arch width, length, perimeter, overjet, overbite, space analysis in millimetre and the assessment of the angle classification., Results: AR and OR were significantly increased compared to Bolton's ratios of 77.2% (AR) and 91.3% (OR). In the gender comparison, male patients showed larger tooth size ratios, especially in the OR. Patients with Angle Class II/1 and II/2 had smaller tooth size ratios than patients with Angle Class III and I. Thus, patients with Angle Class II/1 had the largest tooth diameters in all maxillary teeth and with Angle Class II/2 the smallest tooth sizes in the mandible. The largest tooth widths in the lower jaw were observed in the Angle Class III patient group. Furthermore, a negative correlation from AR/OR to overjet, overbite, and available space in lower jaw as well as a positive correlation to available space in upper jaw was detected., Conclusions: There is a clear correlation between the tooth size ratios and the present dysgnathia as well as other orthodontically relevant occlusal traits. This prior knowledge about our patients is extremely important to create an individualized treatment plan and enable sufficient occlusion. To achieve a functionally good occlusion with correct overjet and overbite, it is essential that the maxillary and mandibular teeth are proportional in size. Any deviation from the ideal patient in terms of tooth size, number, shape, or arch must be considered in the pre-therapeutic treatment plan in combination with the existing dysgnathia in order to be able to achieve a stable anterior and posterior occlusion with appropriate adjustments to the therapy post-therapeutically., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: This study aimed to investigate the differences in the buccolingual inclination and transverse width of maxillary and mandibular first molars among different vertical facial types., Methods: In all, 78 samples were divided into three groups based on the GoGn-SN angle: the low-angle group (n = 26, mean age=24.21±5.11), average-angle group (n = 26, mean age=22.66±3.72), and high-angle group (n = 26, mean age=22.23±2.43). Cone beam computed tomography (CBCT) measurements were used to assess the buccolingual inclination of the axis of the maxillary and mandibular first molars, as well as the buccolingual inclination of the alveolar bone, the dental arch width, and the basal bone width. One-way ANOVA, the LSD test, and Pearson correlation analysis were performed., Results: The high-angle group showed significantly greater lingual inclination of the maxillary alveolar bone than the low-angle group and average-angle group (p < 0.001; p < 0.05). The difference in buccolingual inclination of the axis of the maxillary first molar and the alveolar bone was significantly greater in the high-angle group than in the low-angle group (p < 0.05). Both the maxillary and mandibular dental arch were significantly narrower in the high-angle group than in the other two groups. The mandibular basal bone was also significantly narrower in the high-angle group than in the low-angle group and average-angle group (p < 0.001; p < 0.01)., Conclusions: The alveolar bone of maxillary first molar in the high-angle group was more palatal inclined than that the low-angle group and the average-angle group, which suggests that orthodontists should pay more attention to the root-bone relationship in the high-angle group during expansion treatment to prevent bone fenestration and dehiscense., Competing Interests: Declaration of competing interest None., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Objectives: This study compared the accuracy of seven intraoral scanners (IOS) by the virtual-fit method., Methods: Four maxillary arches with tooth abutments were scanned with an industrial reference scanner (n=1) and by Aoralscan3, EmeraldS, Helios600, Lumina, Mediti700, Primescan, and Trios5 IOSs (each n=12). Two complete-arch fixed frameworks were designed on each IOS scan with a 70 µm (group 70) and a 90 µm internal cement space (group 70+20, additional 20 µm at the margin). The virtual-fit method was comprised of superimposing the framework designs onto the reference scan using a non-penetrating algorithm simulating the clinical try-in. Internal and marginal gaps were measured. Precision was estimated by the mean absolute errors (MAE)., Results: In group 70, Mediti700 (43 µm), Primescan (42 µm), and EmeraldS were in the best homogenous subset for the marginal gap, followed by the Lumina (67 µm), Aoralscan3 (70 µm), and Trios5 (70 µm), whereas Helios600 (118 µm) was in the third subset. Based on the MAE at the margin, Mediti700, Trios5, and EmeraldS were in the first-best homogenous subset, followed by Primescan. Lumina and Helios600 were in the third subset, and Aoralscan3 was in the fourth subset. In group 70+20, the marginal gap was significantly decreased for Lumina and Aoralscan3, whereas MAE significantly decreased for EmeraldS and Aoralscan3. The rank of IOSs was similar for the internal gap., Conclusion: EmeraldS, Mediti700, Primescan, and Trios5 meet the marginal and internal fit criteria for fixed tooth-borne complete arch restorations. Increasing the cement space during design could enhance restoration fit., Clinical Significance: The virtual-fit alignment method can effectively evaluate the accuracy of different intraoral scanners, offering valuable clinical guidance for distinguishing among them. Recent software and hardware versions of long-standing IOS manufacturers are suitable for fabricating complete arch restoration., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Statement of Problem: Scan path length and the presence of edentulous alveolar ridge sections have a negative influence on scanning accuracy. How different artificial landmarks combined with an adapted scanning method affect accuracy is unclear., Purpose: The purpose of this in vitro study was to determine the influence of 2 different artificial landmarks combined with an adapted scanning method on the scanning accuracy of a partially edentulous maxillary model., Material and Methods: The model simulated a maxilla with 6 prepared teeth to accommodate a complete arch fixed partial denture. Five ceramic precision balls (ball center P 1 -P 5 ), distributed buccally to the dental arch, were used to detect the dimensional and angular changes between the reference model and the intraoral scans. One intraoral scanner (Primescan) was used to make 30 scans each with either the scanning strategy recommended by the manufacturer (M) or with an adapted scanning strategy and the use of a bar (B) or 4 plates (P) as artificial landmarks in the dorsal palate. Data were statistically analyzed using a generalized least squares regression model (α=.05)., Results: Scanning with artificial landmarks reduced the maximum absolute distance deviations (M: 249 μm, B: 190 μm, P: 238 μm) and the maximum angle deviations (M: 0.31 degrees, B: 0.28 degrees, P: 0.26 degrees). Vertical distance deviations were improved by 10 to 50% with the use of artificial landmarks. Absolute mean distance deviations were significantly lower for group M (P<.001). In contrast, with artificial landmarks, mean angle (P<.001) and mean vertical distance deviations (P<.014) improved significantly., Conclusions: Scanning with artificial landmarks in the dorsal palate combined with an adapted scanning method improved the scanning accuracy and reliability of vertical distance deviations., (Copyright © 2022 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Introduction: Symmetry is balance, some correspondence in the size, form, and arrangements of parts on opposite sides of a plane, line, or point. The opposite of this concept is asymmetry, or imbalance., Objective: This retrospective study compared two methods for assessing arch symmetry with linear measurements based on triangles, to determine their applicability and efficiency., Methods: Two groups were enrolled: children (n=20) and adults (n=20), and the arch symmetry was assessed from linear measurements. Method 1: the incisor-canine (INC), canine-molar (CM), and incisor-molar (INM) distances (paired t-test and Pearson correlation). Method 2: a mathematical equation between the cusps measurements of the canines and the distobuccal of the first molars leading to result 1 (t-test for one sample and bootstrapping analysis). Dental casts were digitized and analyzed using a software program. The Bland-Altman test compared the methods (α=0.05)., Results: The Bland-Altman test revealed concordance between the methods; however, separately the results were different: In method 1, the mandibular arch did not demonstrate correlation (children, INC r=0.33; CM r=0.45; INM r=0.51; adults, CM r=0.46; INM r=0.35), however, the maxilla revealed a strong correlation in children and a strong/moderate correlation in adults. In method 2, both arches were symmetrical (p>0.05)., Conclusion: Method 1 may be appropriate during orthodontic treatment, and method 2 may be indicated for final treatment. These methods are useful; however, only method 1 identified the side of asymmetry. The methods can contribute to future studies in syndromic and non-syndromic patients, before and after orthognathic surgeries and orthodontic treatment, comparing results.

Statement of Problem: The effect of different surface locking patterns on the trueness of a digital implant scan of a completely edentulous arch remains uncertain., Purpose: The purpose of this in vitro study was to evaluate whether locking surfaces with different patterns affected the trueness of complete arch implant digital scans., Material and Methods: An edentulous maxillary cast with 4 implants (2 anterior implants parallel and 2 posterior implants tilted at 17 degrees) was fabricated. Four implant-level scan bodies were fixed onto the implants, and the cast was scanned with a desktop scanner to create the reference file. Four groups (L0, L1, L2, and L3) were formed, each with a distinct locking surface configuration, and all scans were made using the same intraoral scanner. L0 kept all 4 implant-level scan bodies during scanning. L1 involved removing the right first premolar (RPM) scan body, scanning the other 3 implant scan bodies, then reattaching the RPM's scan body, and continuing scanning. In L2, the RPM and right lateral incisor (RIC) scan bodies were removed, followed by scanning the left implants to create a locking surface, and scanning the right implants. In L3, only the left posterior molar's (LPM) scan body was retained and scanned; then a locking surface was generated, and then the remaining implants were scanned. A metrology software program (Geomagic Control X) was used for comparison. Statistical analyses were performed using the Kruskal-Wallis, the 1-way ANOVA, the Welch ANOVA, the Friedman test, the repeated-measures ANOVA, the Bonferroni post hoc test, and the Games-Howell post hoc test (α=.05)., Results: Significant 3D surface deviations were observed in the coronal bevel (CB) region and in the entire scan bodies when assessing trueness in the L0, L1, L2, and L3 groups (P<.001). L2 exhibited the highest discrepancies in 3D surface deviation for CB (0.030 ±0.002 mm) and implant scan bodies (0.357 ±0.052 mm) and distance deviation, while the highest mean angular deviation values were found in L0 (0.924 ±0.131 degrees)., Conclusions: Locking half of the arch showed the highest trueness discrepancies when performing digital scans for complete arch implant-supported prostheses., (Copyright © 2024 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Objectives: To compare the trueness of maxillomandibular relationship between articulated 3D-printed and conventional diagnostic casts in maximum intercuspation (MIP)., Methods: Reference casts were articulated in MIP, and scanned using a Coordinate Measurement Machine (CMM, n = 1). Digital scans were made from the reference casts by using an intraoral scanner (IOS, n = 10) (Trios 4; 3Shape A/S). IOS scans were processed to create 3D-printed casts by using MAX UV385 (Asiga) and NextDent 5100 (3DSystems) 3D-printers. The conventional workflow implemented vinylpolysiloxane (VPS) impressions and Type IV stone. Stone and 3D-printed casts were articulated and digitized with a laboratory scanner (E4; 3Shape A/S). The 3D-printed casts were scanned on two occasions: with and without positioning pins. Inter-arch distances and 3D-contact area were measured and compared. Statistical tests used were Shapiro-Wilk, Levene's, Welch's t-test, and 2-way ANOVA (α=0.05)., Results: IOS group showed similar or better maxillomandibular relationship trueness than stone casts and 3D-printed casts (p < 0.05). 3D-contact area analysis showed similar deviations between 3D-printed and stone casts (p > 0.05). The choice of 3D-printer and presence of positioning pins on the casts significantly influenced maxillomandibular relationship trueness (p < 0.05)., Conclusions: Articulated 3D-printed and stone casts exhibited similar maxillomandibular relationship trueness., Clinical Significance: Although 3D-printing methods can introduce a considerable amount of deviations, the maxillomandibular relationship trueness of articulated 3D-printed and stone casts in MIP can be considered similar., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Background: Cranial, facial, nasal, and maxillary widths have been shown to be significantly affected by the individual's sex. The present study aims to use measurements of dental arch and maxillary skeletal base to determine sex, employing supervised machine learning., Materials and Methods: Maxillary and mandibular tomographic examinations from 100 patients were analyzed to investigate the inter-premolar width, inter-molar width, maxillary width, inter-pterygoid width, nasal cavity width, nostril width, and maxillary length, obtained through Cone Beam Computed Tomography scans. The following machine learning algorithms were used to build the predictive models: Logistic Regression, Gradient Boosting Classifier, K-Nearest Neighbors (KNN), Support Vector Machine (SVM), Multi-Layer Perceptron Classifier (MLP), Decision Tree, and Random Forest Classifier. A 10-fold cross-validation approach was adopted to validate each model. Metrics such as area under the curve (AUC), accuracy, recall, precision, and F1 Score were calculated for each model, and Receiver Operating Characteristic (ROC) curves were constructed., Results: Univariate analysis showed statistical significance (p < 0.10) for all skeletal and dental variables. Nostril width showed greater importance in two models, while Inter-molar width stood out among dental measurements. The models achieved accuracy values ranging from 0.75 to 0.85 on the test data. Logistic Regression, Random Forest, Decision Tree, and SVM models had the highest AUC values, with SVM showing the smallest disparity between cross-validation and test data for accuracy metrics., Conclusion: Transverse dental arch and maxillary skeletal base measurements exhibited strong predictive capability, achieving high accuracy with machine learning methods. Among the evaluated models, the SVM algorithm exhibited the best performance. This indicates potential usefulness in forensic sex determination., (© 2024. The Author(s).)

Although dental patterns are unique, the use of bitemark analysis in personal identification remains controversial. To accurately reproduce and compare three-dimensional models of bitemarks and dental arches, intraoral three-dimensional scans, commonly utilized in clinical dental practice for precise and stable digital impressions, are recommended. This study aims to compare two different techniques for bitemark analysis: a digital method based on the superimposition of digital scans of dental patterns and lesions, and a visual method based on the physical superimposition of impressions and resin casts produced by 3D printing. A sample of 12 volunteers (6 males and 6 females) with a mean age of 26 years was collected as biters. Each subject was asked to bite on custom supports made from semi-rigid water bottles covered with imprintable dental wax. The dental arches and bitemarks were then recorded using an intraoral scanner and dental impressions. Scan superimposition analysis was conducted using CloudCompare software, while resin casts were printed using a 3D printer and physically superimposed on the bitemark impressions by a blind operator, who was not involved in sample collection, bite test execution, prior cast acquisition, or CloudCompare analysis. Both superimposition techniques relied on the selection of 10 corresponding landmarks (on canines and central and lateral incisors of the upper and lower arches) between the dental arches and impressions. The digital superimposition showed an average concordance of 92.5% for the upper arch landmarks and 85% for the lower arch landmarks, with an overall average concordance of 88.8% for both arches combined. In contrast, the visual analysis of resin casts showed an average concordance of 77.5% for the upper arch and 76.7% for the lower arch, with an overall average of 77.1% for both arches combined. In the analysis performed using CloudCompare, the maxillary arch demonstrated the best superimposition, with 4 landmarks (R0, R1, R2, R5) consistently overlapping. The digital analysis outperformed the visual analysis in all four quadrants, particularly in the upper right arch compared to the lower left arch, thereby supporting the integration of digital techniques in forensic applications. Further studies are necessary to validate the digital technique on a larger sample, including subjects with different dental characteristics, bite dynamics, and varying types of supports and substrates., Competing Interests: The authors report no conflicts of interest in this work., (Copyright© 2024 IOFOS This work is published and licensed by International Organization for Forensic Odonto-Stomatology.)

Background: Many indices have been suggested to help orthodontists in predicting the ideal dental arch width. One of these was Pont's index which was established by Pont. He suggested equations to predict the ideal maxillary dental arch width (interpremolar and intermolar) from the combined mesiodistal width of the maxillary incisors. This study aimed to test the applicability of Pont's index as an orthodontic diagnostic tool in Egyptian population and to compare the results with those obtained from studies of different ethnic subjects., Methods: This study was performed using dental casts of 184 Egyptian individuals (82 males and 102 females; age range, 19-24 years). The casts were divided into 46 casts with normal occlusion, 46 casts with class I, 46 casts with class II and 46 casts with class III malocclusion, according to Angle's classification. Alginate impressions were taken for all patients and poured immediately using dental plaster. The real models were transformed into digital models using three-dimensional laser scanner to allow digital model analysis. Predicted arch widths were calculated using Pont's equations. The predicted values were compared to the measured values., Results: Intra class correlation coefficient (ICC) (absolute agreement) between measured and predicted arch widths was determined. Poor absolute agreement was found between measured arch width values and the corresponding values calculated according to Pont's index., Conclusion: According to the results of this study, Pont's index is not a reliable method for predicting the ideal dental arch widths in Egyptian populations., (© 2024. The Author(s).)

The objective of this study was to assess the relative contributions of genetic and environmental factors to variation in palatal parameters in twins with completed maxillary growth. The subjects of this study comprised digital dental casts of 50 monozygotic and 35 dizygotic twin pairs. The subjects' average age was 17.95 ± 2.83 years. Zygosity determination was carried out using 15 specific DNA markers and an amel fragment of the amelogenin gene. The interdental distances were measured between selected dental landmarks at the occlusal and gingival planes. The palatal height, surface area and volume were measured between the gingival plane and the midpalate suture. High heritability estimates were observed for all transverse intra-arch measurements. The palate height (a 2  = 0.8), dental arch width in the molar area (a 2  = 0.86), palatal surface area (a 2  = 0.61) and palate volume (a 2  = 0.69) were under strong additive genetic control. Moderate genetic dominance was observed for dental arch widths at the gingival line in the canine (d 2  = 0.5) and premolar regions (d 2  = 0.78-0.81). Sexual dimorphism was shown, with males exhibiting a greater arch width, palate surface area and volume than females (p < 0.01). The majority of palate parameters variation in twins was controlled by genetic effects, and most were highly heritable., (© 2024. The Author(s).)

Purpose: To investigate the biomechanical expression of different shapes of attachments on the maxillary anterior teeth during the lingual tooth movement process using clear aligners, providing new insights for orthodontists to improve the clinical design., Methods: In this study, CBCT data were simulated using the three-dimensional finite element technique. Attachments of various shapes, including no attachment(A1), rectangular attachment(A2), wedge-shaped attachment(A3), and curved arc attachment(A4), were designed on the lateral incisors. Ansys software was employed to calculate the three-dimensional changes in the lateral incisors, dental arch, and clear aligners and the distribution of equivalent stress on the periodontal ligament(von Mises) under the same load conditions., Results: The coronal displacement of the lateral incisors showed the following variations: A1＞A4＞A3＞A2. The sagittal displacement exhibited the following variations: A3＞A4＞A1＞A2. The vertical elongation demonstrated the following variations: A4＞A3＞ A1＞A2. The overall displacement of each dental arch displayed an arch-shaped trend. Different regions of the clear aligners exhibited variations in deformation. The von Mises distribution of the periodontal ligament in A1 and A2 group showed similarities, while A3 group exhibited stress concentration only in the lingual area of the root's one-third region. Group A4 experienced significantly higher stress in the cervical region compared to A1 and A2 group., Conclusions: Rectangular attachments and curved arc attachments possess advantages in coronal control, with rectangular attachments exhibiting the best control effect in vertical control. The area of attachment force and actual displacement efficiency do not have an absolute correlation, as the shape of the force-bearing surface can significantly affect its specific biomechanical expression.

Background: Three-dimensional (3D) printing technologies have become popular in orthodontics. The aim of this study is to determine the effect of printing technology, orientation, and layer height on the accuracy of 3D-printed dental models., Methods: The maxillary arch of a post-treatment patient was scanned and printed at different orientations (0°, 90°) and layer thicknesses (25 µm, 50 µm, 100 µm, and 175 µm) using two different printing technologies (digital light processing and stereolithography). The 120 models were digitally scanned, and their average deviation from the initial model was analyzed using 3D algorithm. A multivariable linear regression analysis was used to estimate the effect of all variables on the average deviation from the initial model for the common layer thicknesses (50/100 µm). Finally, one-way ANOVA and Tukey posthoc test was used to compare the stereolithography (SLA) 25 µm and digital light processing (DLP) 175 µm groups with the groups that showed the least average deviation in the former analysis., Results: The multivariable linear regression analysis showed that the DLP 50 µm (mean ± SD: -0.022 ± 0.012 mm) and 100 µm (mean ± SD: -0.02 ± 0.009 mm) horizontally printed models showed the least average deviation from the initial model. Finally, the DLP 175 µm horizontally printed models (mean ± SD: 0.015 ± 0.005 mm) and the SLA 25 µm horizontally (mean ± SD: 0.011 ± 0.005 mm) printed models were more accurate., Conclusions: All the models showed dimensional accuracy within the reported clinically acceptable limits. The highest accuracy was observed with DLP printer, 175 µm layer thickness, and horizontal orientation followed by SLA printer, 25 µm layer thickness, and horizontal orientation., (Copyright © 2024 World Federation of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Objectives: To measure the impact of the superimposition methods on accuracy analyses in digital implant research using an ISO-recommended 3-dimensional (3D) metrology-grade inspection software., Materials and Methods: A six-implant edentulous maxillary model was scanned using a desktop scanner (7Series; DentalWings; Montreal, Canada) and an intraoral scanner (TRIOS 4; 3Shape; Copenhagen, Denmark) to generate a reference and an experimental mesh, respectively. Thirty experimental standard tesselletion language (STL) files were superimposed onto the reference model's STL using the core features of six superimposition methods, creating the following groups: initial automated pre-alignment (GI), landmark-based alignment (G1), partial area-based alignment (G2), entire area-based alignment (G3), and double alignment combining landmark-based alignment with entire model area-based alignment (G4 ) or the scan bodies' surface (G5). The groups underwent various alignment variations, resulting in sixteen subgroups (n = 30). The alignment accuracy between experimental and reference meshes was quantified by using the root mean square (RMS) error as trueness and its fluctuation as precision. The Kruskal-Wallis test with a subsequent adjusted post-hoc Dunn's pairwise comparison test was used to analyze the data (α = 0.05). The reliability of the measurements was assessed using the intraclass correlation coefficient (ICC)., Results: A total of 480 superimpositions were performed. No significant differences were found in trueness and precision among the groups (p > 0.05), except for partial area-based alignment (p < 0.001). Subgroup analysis showed significant differences for partial area-based alignment considering only one scan body (p < 0.001). Initial automated alignment was as accurate as landmark-based, partial, or entire area-based alignments (p > 0.05). Double alignments did not improve alignment accuracy (p > 0.05). The entire area-based alignment of the scan bodies' surface had the least effect on accuracy analyses., Conclusions: Digital oral implant investigation remains unaffected by the superimposition method when ISO-recommended 3D metrology-grade inspection software is used. At least two scan bodies are needed when considering partial area-based alignments., Clinical Significance: The superimposition method choice within the tested ISO-recommended 3D inspection software did not impact accuracy analyses in digital implant investigation., Competing Interests: Declaration of competing interest The authors have no conflict of interest to report pertaining to the conduction of this study., (Copyright © 2024. Published by Elsevier Ltd.)

Introduction: Extraction vs. non-extraction is a crucial decision in orthodontic therapy., Objective: The aim of the present study was to investigate the changes in the dental arch width and buccal corridor after orthodontic treatment using extraction and non-extraction therapy with Damon self-ligating system., Material and Methods: This retrospective study consisted of 35 patients (20 female and 15 male patients with median age of 12.5 years), treated by extracting 4 or 2 premolars, and 37 patients (16 female and 21 male patients with the median age of 12.8 years), treated without premolar extraction. Both groups were treated with Damon self-ligating system. Plaster models before (T0) and after (T1) treatment were measured, and the arch width values were determined at the level of the first molars, second premolars, canines and palatal rugae. Buccal corridor width was measured using the extraoral images at T0 and T1. Paired t-test was used for the analysis of the normally distributed data, and Wilcoxon Mann-Whitney U test was used for the data with non-normal distribution. Values of p<0.05 were set as statistically significant., Results: The upper intercanine width increased significantly in both groups (p<0.01). In the non-extraction group, the arch width increased significantly in the maxillary second premolar and first molar region (p<0.01) as well as in the region of the canines (p=0.04), second premolars (p=0.01) and first molars (p<0.01) of the mandible. The buccal corridor decreased significantly in the non-extraction group (p<0.01)., Conclusion: Premolar extraction in combination with Damon self-ligating system did not lead to reduction of the dental arch width in the maxilla, nor did it increase the size of the buccal corridors.

Objectives: The objective of this study was to use in vitro models to examine the bite registration accuracy of four different intraoral scanners (IOS) for edentulous maxillary and mandibular arches. The objective was to assess the trueness and precision of the IOS and determine if there were significant differences between them., Methods: An Asiga Max UV 3D printer was used to print maxillary and mandibular edentulous models based on the shape of Frasaco models (artificial dental arch models). Four dental implants were placed symmetrically in both models using Straumann BLT RC implants. Digital impressions were taken with Primescan, Trios 3, Trios 4, and Medit i500 intraoral scanners (n = 10 for each IOS). Digital bite registrations were made, and scanning data was exported in STL format. The accuracy of the interarch distance (the distance between the metrological spheres attached to the mandibular and maxillary models) was estimated for each IOS., Results: The results showed significant differences in trueness and precision between different IOS (p <.05), except Medit i500 and Trios 3 (p >.05). Primescan provided the most accurate results, followed by Medit i500, Trios 3, and Trios 4, respectively., Conclusions: within the limitations of this study, the IOS type affects the accuracy of interocclusal bite registration in in vitro design. Only Primescan achieved clinically acceptable accuracy for the interocclusal recording of edentulous arches., Clinical Relevance: The comparison of the accuracy of bite registration between different intraoral scanners will help increase the efficiency of the clinical application of digitalized interarch registration., Competing Interests: Declaration of competing interest The authors had no commercial interest in any materials used in this study., (Copyright © 2024. Published by Elsevier Ltd.)

Background: to evaluate the predictability of expansion achieved in patients in early mixed dentition treated with Clear Aligners (CA), analyzing the efficiency of the expansion at the end of the first set of aligners and at the end of the therapy in the upper and lower arch., Methods: 36 patients (20 F, 16 M; mean age 8.3 ± 1.5 years) were selected retrospectively from the Department of Orthodontics of the Hospital of Rome "Tor Vergata". All subjects were treated with CA with no other auxiliaries than attachments. For each patient a standardized sequential expansion protocol was planned for both arches. Digital dental casts were created at three observation periods from an intraoral scanner: prior to treatment (T0), at the end of the first set of aligners (T1), at the end of treatment (T2). The 3D models in planned position determined by the first Clincheck (CC) were obtained for comparison with T1 and T2. Six linear transversal measurements were used to evaluate the dimensional changes and the predictability of expansion movements, comparing T1-CC and T2-CC., Results: a statistically significant increase within the pre-treatment and the final outcomes for all the variables examined was found. In the upper arch, the greatest level of predictability was detected at the level of the first (46.44%) and second deciduous molar width (44.95%) at T1. The analysis of T2-CC changes showed a significant increase in the percentage of predictability of expansion at the level of the first permanent molars, at mesial (54.86%) and distal (58.92%) width. In the lower arch, a higher percentage of predictability than the upper arch was reported at T1-CC and T2-CC, with the greatest values at the level of second (T1-CC: 48.70%; T2-CC: 75.32%) and first deciduous molar width (T1-CC: 45.71%; T2-CC: 72.75%)., Conclusions: CA can induce significant transversal increments. The predictability of expansion is variable, but it did not exceed the 50% during the first set of aligners. It was necessary to apply refinement set to achieve a good predictability for expansion of about 70%. The expansion in the lower arch was observed to be more predictable than in the upper arch., (© 2024. The Author(s).)

Objective: This in-vitro study assessed the influence of two intraoral scanning (IOS) protocols on the accuracy (trueness and precision) of digital scans performed in edentulous arches., Methods: Twenty-two abutment-level master casts of edentulous arches with at least four implants were scanned repeatedly five times, each with two different scanning protocols. Protocol A (IOS-A) consisted of scanning the edentulous arch before inserting the implant scan bodies, followed by their insertion and its subsequent digital acquisition. Protocol B (IOS-B) consisted of scanning the edentulous arch with the scan bodies inserted from the outset. A reference scan from each edentulous cast was obtained using a laboratory scanner. Trueness and precision were calculated using the spatial fit analysis, cross-arch distance, and virtual Sheffield test. Statistical analysis was performed using generalized estimating equations (GEEs). Statistical significance was set at α = .05., Results: In the spatial fit test, the precision of average 3D distances was 45 μm (±23 μm) with protocol IOS-A and 25 μm (±10 μm) for IOS-B (p < .001), and the trueness of average 3D distances was 44 μm (±24 μm) with protocol IOS-A and 24 μm (±7 μm) for IOS-B (p < .001). Cross-arch distance precision was 59 μm (±53 μm) for IOS-A and 41 μm (±43 μm) for IOS-B (p = .0035), and trueness was 64 μm (±47 μm) for IOS-A and 50 μm (±40 μm) for IOS-B (p = .0021). Virtual Sheffield precision was 286 μm (±198 μm) for IOS-A and 146 μm (±92 μm) for IOS-B (p < .001), and trueness was 228 μm (±171 μm) for IOS-A and 139 μm (±92 μm) for IOS-B (p < .001)., Conclusions: The IOS-B protocol demonstrated significantly superior accuracy. Placement of scan bodies before scanning the edentulous arch is recommended to improve the accuracy of complete-arch intraoral scanning., (© 2024 The Authors. Clinical Oral Implants Research published by John Wiley & Sons Ltd.)

Purpose: This study aimed to measure and analyze the transverse indicators of normodivergent patients with different sagittal skeletal malocclusions, to explore the transverse characteristics of different sagittal skeletal malocclusions., Methods: Lateral cephalograms and CBCT of 90 normodivergent patients with skeletal Class Ⅰ, Ⅱ and Ⅲ in their permanent dentition were collected. Dolphin software was applied to measure the widths of the basal bone, alveolar bone, dental arch and buccolingual inclination angle of the corresponding teeth in the maxillary and mandibular canine, premolar and molar areas. SPSS 22.0 software package was applied for statistical analysis of the data., Results: The widths of the mandibular basal bone in canine, premolar and molar areas of skeletal Class Ⅲ were (27.15±2.74), (39.30±2.82) and (59.97±2.93) mm, respectively. The widths of the mandibular alveolar bone of skeletal Class Ⅲ were (25.38±1.78), (34.51±2.28) and (47.72±2.73) mm, respectively. The dental arch widths of the maxillary premolar and mandibular canine areas of skeletal Class Ⅲ were (48.70±2.35) and (30.69±2.31)mm, respectively. The above data of skeletal Class Ⅲ were significantly larger than those of skeletal Class Ⅰ and Ⅱ(P＜0.01). The dental arch widths of the maxillary canine, maxillary molar and mandibular molar areas of skeletal Class Ⅲ were (38.88±1.90), (59.51±3.40) and (56.01±2.86)mm, respectively, which were significantly larger than those of skeletal Class Ⅱ(P＜0.05). The maxillomandibular width difference of basal bone in the canine, premolar and molar areas of skeletal Class Ⅲ were (4.69±2.84), (2.31±2.39) and (3.27±2.05) mm, respectively, which were significantly less than that of skeletal Class Ⅰ and Ⅱ(P＜0.01). Compared with skeletal Class Ⅰ, the maxillary canines and first molars of skeletal Class Ⅱ had larger lingual inclination level, while the maxillary first premolars and first molars of skeletal Class Ⅲ had larger buccal inclination level, the mandibular canines and the mandibular first premolars of skeletal Class Ⅲ had larger lingual inclination level(P＜0.01)., Conclusions: For normodivergent patients, the width of the mandibular base bone, alveolar bone, and maxillary and mandibular dental arch in skeletal Class Ⅲ is the widest, which is more likely to have width discrepancy in basal bone. In skeletal Class Ⅲ, the maxillary teeth are buccally inclined, and the mandibular teeth are ingually inclined. In skeletal Class Ⅱ, the maxillary teeth are lingually inclined, and the mandibular teeth are compensatory upright.

Objectives: To assess the impact of including the palate and the number of images recorded during intraoral digital scanning procedure on the accuracy of complete arch scans., Methods: An experienced operator conducted 40 digital scans of a 3D printed maxillary model and divided them into two groups: 20 with inclusion of the palate (PAL) and 20 without (NPAL). Each set of scans was performed using an intraoral scanner (IOS) (Trios 5; 3Shape A/S; Copenhagen, Denmark). The resulting STL files were imported into the Geomagic Control X software (3D Systems, Rock Hill, SC, USA) for accuracy comparison. A reference STL file was created using a 3Shape E3 laboratory scanner (3Shape Scanlt Dental 2.2.1.0; Copenhagen, Denmark). The number of images captured was recorded during the scanning procedure., Results: In the case of the right side no statistically significant difference in trueness was detected (84 µm ± 45.6 for PAL and 80.4 ± 40.4 µm for NPAL). In the case of the left side no significant difference in trueness was observed (215.1 ± 70.2 µm for PAL and 233.9 ± 70.7 µm for NPAL). In the case of the arch distortion a statistically significant difference in trueness was seen between the two types of scans (135.3 ± 71.9 µm for PAL and 380.4 ± 255.1 µm for NPAL). The average number of images was 831.25, and 593.8 for PAL and NPAL, respectively., Conclusions: Scanning of the palatal area can significantly improve the accuracy of dental scans in cases of complete arches. In terms of the number of images, based on the current results, obvious conclusions could not be drawn, and further investigation is required., Clinical Significance: Scanning the palate may be beneficial for improving the accuracy of intraoral scans in dentate patients. Consequently, this should be linked to an appropriate scanning strategy that predicts palatal scanning., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Purpose: To measure the gingival phenotype-related features, gingival thickness (GT) and gingival width (GW), in healthy children and to investigate their association between them, with age, gender, tooth-type and arch., Methods: The gingival sites of 1029 teeth were included from 64 children (36 males and 28 females), with primary and mixed dentition, attending the paediatric dental clinic of Aristotle University, Thessaloniki. GT and GW were measured ultrasonically and with a periodontal probe, respectively. Mixed effects linear regression models were used to evaluate the association of gingival thickness and gingival width with the under-investigation parameters. Spearman's correlation coefficient was used to evaluate correlation between GT and GW., Results: Significantly thicker gingiva is found in posterior teeth compared to anterior teeth, in permanent teeth versus primary teeth and in maxillary teeth in comparison to mandibular teeth (p value < 0.001). Regarding GW, significantly wider gingiva is noted in posterior regions (p value = 0.022) and the maxilla (p value < 0.001). Gender-wise and concerning age GT and GW are not significantly affected. A weak and positive correlation between GT and GW is noted (rho 0.30, p < 0.001)., Conclusions: GT and GW present significant associations with arch and tooth-type. Findings from this study fulfil the further understanding of GT and GW of paediatric patients that are investigated sparsely throughout the literature and demonstrate an accurate, painless and simple method to map the gingiva., (© 2024. The Author(s), under exclusive licence to European Academy of Paediatric Dentistry.)

Objective: Aim: The aim of the article is a comparative analysis of the main aspects of existing medical and diagnostic measures in patients with abnormal types of occlusal relationships and methods of mathematical and graphic reproduction of the shape of the dental arches, taking into account the individual characteristics of the maxillofacial area., Patients and Methods: Materials and Methods: The search for relevant publications related to the objective topic was carried out through scientific databases: Scopus, PubMed, BVS and Scielo., Conclusion: Conclusions: The analysis of regression models of the reproduction of individual characteristics of the dental arch of the jaws will avoid errors that occur when comparing the actual sizes with their statistical norm, which will allow to correctly determine the proportionality and ratio of dif f erent departments of the dental and jaw system, the necessary amount of orthodontic measures in the treatment of anomalies of the dental arches.

Objectives: The study aimed to compare the trueness and precision of five intraoral scanners (Emerald S, iTero Element 5D, Medit i700, Primescan, and Trios 4) and two indirect digitization techniques for both teeth and soft tissues on fresh mandibular and maxillary cadaver jaws., Methods: The maxilla and mandible of a fully dentate cadaver were scanned by the ATOS industrial scanner to create a master model. Then, the specimens were scanned eight times by each intraoral scanner (IOS). In addition, 8 polyvinylsiloxane (PVS) impressions were made and digitized with a Medit T710 desktop scanner. Stone models were then poured and again scanned with the desktop scanner. All IOS, PVS, and stone models were compared to the master model to calculate the mean absolute surface deviation for mandibular teeth, maxillary teeth, and palate., Results: For mandibular teeth, the PVS trueness was only significantly better than the Medit i700 (p < 0.001) and Primescan (p < 0.05). In maxillary teeth, the PVS trueness was significantly better than all IOSs (p < 0.05-0.001); the stone trueness was significantly better than Emerald S (p < 0.01), Medit i700 (p < 0.001) and Primescan (p < 0.01). In the palate, PVS and stone trueness were significantly lower than the iTero Element 5D (p < 0.01) and Trios 4 (p < p < 0.01). Stone trueness was significantly lower than the Medit i700 (p < 0.05). The precision in the palate was significantly lower for PVS and stone than for Emerald S (p < 0.01, p < 0.05), iTero Element 5D (p < 0.01, p < 0.01), Primescan (p < 0.001, p < 0.001), and Trios 4 (p < 0.001, p < 0.01). Significant differences in trueness between the IOSs were observed only in the mandibular teeth. The Medit i700 performed worse than Emerald S (p < 0.01) and iTero Element 5D (p < 0.01). For mandibular teeth, the Medit i700 was significantly more precise than Primescan (p < 0.01) and the Emerald S (p < 0.05). The Trios 4 was significantly less precise than Emerald S (p < 0.05). The precision of Medit i700 was significantly worse than iTero Element 5D (p < 0.01) for maxillary teeth, as well as the Primescan (p < 0.01) and Trios 4 (p < 0.05) for the palate., Conclusions: In general, indirectly digitized models from PVS impressions had higher trueness than IOS for maxillary teeth; precision between the two methods was similar. IOS was more accurate for palatal tissues. The differences in trueness and precision for mandibular teeth between the various techniques were negligible., Clinical Significance: All investigated IOSs and indirect digitization could be used for complete arch scanning in mandibular and maxillary dentate arches. However, direct optical digitization is preferable for the palate due to the low accuracy of physical impression techniques for soft tissues., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: To evaluate the hypothesis that dental arch form and inter-canine, inter-premolar, and inter-molar widths differ between OSAS patients and non-snoring, non-apneic controls., Methods: Dental digital models from 64 OSAS patients and 64 control subjects were used to obtain dental arch forms and to compare them between the two groups. Arch forms were extracted from the lower arch models using a professional graphics program and an orthodontic digital template. Through an orthodontic software, inter-molar, inter-premolar, and inter-canine widths were measured for both upper and lower arches., Results: The dental arch forms distribution differed between OSAS patients and controls. OSAS patients had reduced inter-canine, inter-premolar, and inter-molar widths for both arches compared to controls., Discussion: These results suggest that OSAS patients have narrower and more tapered arches than controls. Dental arch morphology and interdental widths differ between OSAS and control groups, supporting the hypothesis that they are an etiological factor.

Objectives/hypothesis: The prevalence of tympanostomy tube surgery (TTS) in patients with a cleft deformity was investigated, in relation to cleft width and cleft type., Study Design: Retrospective review of medical health records., Methods: Retrospective review of medical health records. Seventy-eight patients with non-syndromic cleft deformity of the palate and/or alveolus and lip between 2003 and 2017 were investigated. All available medical documents were analyzed. The study group was divided into subgroups: 1) patients with isolated cleft palate (CP) and patients with a cleft palate with cleft lip and alveolus (CLP). 2) According to Veau's classification (I-IV), further subgroups were defined. Cleft width was measured using plaster cast models., Results: TTS was performed in 55% of the patients (n = 43). Considering Veau's classification, TTS was conducted as follows: Veau I 65.2% (n = 15/23), Veau II 55.0% (n = 11/20), Veau III 47.6% (n = 10/21), and Veau IV 50.0% (n = 7/14). Cleft classifications, maxillary arch width, and absolute/relative cleft width had no statistical impact on TTS occurrence. Although no significant correlation could be found, patients in our study group with CP (Veau I and II) underwent TTS more often (60.5%, n = 26/43) than patients with CPL (Veau III and IV; 48.6%, n = 17/35) during a three-year follow-up., Conclusion: None of the cleft characteristics examined had a significant impact on the proportion of patients who received TTS. Nevertheless, patients with lower Veau classification and CP received tympanostomy tubes more often. Therefore, otolaryngologists and pediatricians treating children with cleft palate should maintain a high level of suspicion for chronic middle ear effusion, even in patients with small clefts., Level of Evidence: 3 Laryngoscope, 131:E2764-E2769, 2021., (© 2021 The Authors. The Laryngoscope published by Wiley Periodicals LLC on behalf of The American Laryngological, Rhinological and Otological Society, Inc.)

Introduction: This study's goal was to determine normal maxillary development on fetal cadavers., Materials and Methods: This study was carried out on 45 fetuses aged between the 17th - 40th weeks of gestation (24 male, 21 female). The distance between the widest left and right points of the maxillary dental arch (MDA) on the transverse plane, the distance of the papilla incisiva (PI) to the widest left and right points of the maxillary dental arch (MDAW), and the PI and posterior nasal spine (PNS) were measured. The average arch forms of the MDA were created according to trimester groups using the MATLAB program. The one-way ANOVA test was used to make a comparison between trimester groups, and ANOVA followed by post hoc analysis using the Bonferroni test was applied for comparisons. Pearson's correlation analysis was used for correlation analysis., Results: The data in the present study did not differ between genders. In the comparison between trimester groups, we did not find any difference between the 3rd trimester and full-term groups only in the PI-MDAW measurement. Other parameters increased with age. In the correlation analysis, the measurement values by age showed a strong positive correlation. The MDAW exhibited the best correlation with age (r week  = 0.919). When the average MDA forms created using the MATLAB program were evaluated, it was observed that the PI-MDAW of the average MDA in the 3rd trimester and full-term intersected., Conclusions: This study provides a basis for a better understanding of fetal maxillary growth processes and can be useful to standardize the detection of malformations or intrauterine growth restrictions., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Objectives: This study aimed at finding out whether anterior teeth angulation and inclination have a relationship with the maxillary teeth and dental arch dimensions., Methods: Fifty study models with normal occlusion were selected from the archive of the Department of Orthodontics at Baghdad Dental Faculty. Maxillary dental arch width and length at different points were determined in addition to measuring anterior teeth angulation, inclination, crown thickness, overjet, overbite, and Bolton's ratios. The unpaired t -test and Pearson's correlation coefficient test were used for data analysis., Results: No statistical gender differences were reported in all measurements except the dental arch widths and length where males had significantly higher mean values. Only the maxillary incisor's inclination showed a direct weak significant correlation with the total arch length., Conclusions: The inclination of upper incisors had a minimal effect on increasing dental arch length., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2021 Sara M. Al-Mashhadany et al.)

Objective: To determine the relationship between AOB and factors such as dental arch dimensions and tongue position during swallowing and phonation., Material and Methods: A case-control study was performed in two groups: 132 children with Anterior Open Bite (AOB) and 132 with normal vertical overbite (NVO), aged 8-16 years selected from the records taken by a previous study from five public schools. Dental arch dimensions were assessed through digitalized study models. Swallowing was evaluated using the Payne technique, and phoniatric assessment included an adaptation of the articulation test used to describe phonemes., Statistical Analysis: Chi-Square or Fisher's exact test for comparisons between qualitative variables and the Mann Whitney or T-student were applied to compare the dental arch dimensions according to bite type. A logistic regression model was applied to control the effect of confusion between independent variables and to describe its simultaneous effect on the type of bite., Results: Intercanine, interpremolar and intermolar widths showed higher values in AOB patients with a mean deviation (MD) of 0.536 (P=0.031), 0.60 (P=0.043) and 1.15, (P<0.001) respectively. Distortions caused by tongue interposition and thrust, tongue protrusion during swallowing, mandibular arch intermolar width, total maxillary arch length, maxillary arch perimeter, and posterior arch depth accounted for 64.6% of AOB and allowed for correct predictions in 83.8% of the cases observed in the study population., Conclusions: A significant association between tongue position and function, as well as alterations such as tongue interposition and thrust during swallowing and phonation in individuals with AOB, were observed. There is a relationship between AOB and the presence of a wider mandibular arch and a narrower, longer, and deeper maxillary arch., (Copyright © 2021 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.)

The current study aimed to find a prediction equation to estimate the arch perimeter (AP) depending on various arch dimensions including intercanine width (ICW), intermolar width (IMW), interpremolar width (IPMW), and arch length (AL) in a sample of the Kurdish population in Sulaimani City. The study sample was 100 pairs of preorthodontic dental casts. Calculations of dental arch dimensions and perimeter were performed by a digital vernier. Statistical analysis was performed via using the SPSS version 25 software. The developed prediction equation for the upper arch was Y = +1.3 × (arch length) + 1 × (intermolar width), whereas the equation for the lower arch was Y = +0.9 × (intermolar width) + 0.92 × (intercanine width). Paired t -test revealed no statistical difference between predicted and real arch perimeters. Two separate prediction equations for upper and lower arches were developed based on the arch length (AL) and intermolar width (IMW) for the maxillary arch, intermolar (IMW), and inter canine widths (ICW) for the lower arch. The developed equations could have further beneficial impacts on orthodontic diagnosis and treatment planning., Competing Interests: The authors declare that they have no competing interests., (Copyright © 2020 Fadil Abdullah Kareem et al.)

Objectives: To evaluate and compare the skeletal changes during the retention period after expansion with "Transforce Transverse lingual or palatal Appliance®" (TTA) and "NiTi Palatal Expander®" (NPE) in growing subjects with class II division 1 malocclusion and to compare these changes with a matched historical control., Subjects and Methods: A unicentric two arm, parallel randomized clinical trial with additional historical control group was conducted over a period of six years. The subjects in the age group of 9-13 years were screened and recruited as they reported. The inclusion criteria were: late mixed/early permanent dentition, class II or end on molar relationship, posterior transverse inter-arch discrepancy 4-8mm, overjet≥5mm, cephalometrically ANB>4° and CVMI stage CS2-CS3. Subjects were randomly allocated to two study groups (SG), TTA and NPE using block randomization. Appliances in both SG were managed and followed by a single clinician with equal standards of care. The lateral cephalograms in digital form were obtained at the beginning of the treatment (T1), post-expansion (T2) and after ten months retention period (T3). Linear positional change>1mm and angular change>0.75° were considered as a clinically significant change. Due to the ethical reasons a historical control of ten patients (CG) comparable to the SG for age and inclusion criteria was used to rule out the growth changes on serial lateral cephalograms. All Cephalometric measurements were done by a single operator blinded for the group allocation. Operator's measurement error was estimated. The study was single-blinded in regard to statistical analysis. Inter-group comparisons between SG were made by using an unpaired Student's t-test. ANOVA with post-hoc analysis was used for comparison among the study and control groups., Results: A total of 36 subjects were recruited, 18 in each SG. Average time required to achieve the desired expansion in the TTA and NPE group was 13.6 weeks and 9.8 weeks respectively. The TTA group showed significant increase in SNB (1.54±0.33°) when compared with the control group (0.53±0.37°) and with the NPE group (0.74±0.29°) (P<0.0001). Significant differences were observed when post-retention changes in SNB, ANB, Wits appraisal, and N perpendicular to Pogonion, were compared among the three groups (ANOVA, P<0.0001). Tukey's multiple comparison showed that these mandibular sagittal changes were significantly greater in the TTA group than in NPE and the control group (P=<0.007, Bonferroni corrected value)., Conclusion: Cephalometrically significant sagittal advancement of mandible took place after expansion with TTA and NPE compared to untreated control. TTA appears to be more efficient for the sagittal positional changes than the NPE. Additional studies with larger samples are warranted to elucidate individual variations in skeletal response to the expansion protocol with these appliances., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Age at lower first molar (M 1 ) emergence is a commonly used proxy for inferring life-history scheduling in fossil primates, but its utility is dependent on knowing to what extent extant populations vary in this datum and how this variation correlates with the scheduling of life-history variables. Here, we address the first of these issues among extant chimpanzees. While age at M 1 emergence has been documented in several live individuals from the Kanyawara population of Pan troglodytes schweinfurthii in Uganda, it has been estimated for only one individual of Pan troglodytes verus, based on a deceased animal from the Taï Forest in Côte d'Ivoire. To further explore interpopulation variation in this variable in chimpanzees, and using dental histology, we calculated ages at death for two wild-shot individuals of P. t. verus with erupting M 1 , both collected in Liberia during the mid-1950s, and estimated ages at M 1 emergence from the ages at death. The overall range for these two individuals is ∼4.2-4.6 yr, compared with an age of ∼3.7 yr for the individual from the Taï Forest, and <2.5-3.3 yr for the several individuals of P. t. schweinfurthii. While the absolute range of ∼2 yr in these samples combined is little greater than in captive chimpanzees, the disparity between the samples of P. t. schweinfurthii and P. t. verus is striking, although it cannot be determined if this disparity represents a subspecies difference or simply population differences expressed in two different subspecies. While life-history data are unavailable for the population to which the Liberian chimpanzees belonged, the difference in M 1 emergence ages between these individuals and those from Kanyawara still suggests caution when attempting even broad life-history inference in fossil apes and hominins based on age at M 1 emergence., Competing Interests: Conflict of interest The authors declare no conflicts of interest in the research., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: Dental arch dimensions are important considerations in orthodontic treatment planning and monitoring., Objective: This study aimed to compare the dental arch dimensions in wind and non-wind instrument players (WIP and non-WIP)., Methods: This was a cross-sectional study which compared a group of 50 male subjects aged 18-45 years that had been playing wind instruments for a minimum of 2 years with a control group matched for age in the same environment. The arch dimensions were assessed for both groups by measuring their dental casts using a digital caliper. Data was analyzed using statistical Software Package for Social Sciences (SPSS Inc, Chicago, IL) version 17. Statistical significance level was set at P < 0.05., Results: The mean number of years of playing wind instrument among the WIP was 9.26 ± 6.21 years. All the maxillary arch dimensions were larger in the WIP group except for the palatal depth while the mandibular arch parameters in the non-WIP group were larger than the WIP group except the mandibular arch length. The differences were not statistically significant (P > 0.05). The mean maxillary inter-canine width (37.48 ± 1.12 mm), inter-molar width (57.27 ± 1.99 mm), arch length (29.80 ± 2.2.09 mm), and palatal depth (22.21 ± 2.33 mm) for class B instrument (Saxophone and clarinet) players were larger than either the class A instrument (Trumpet and trombone) players or the non-WIP group. These differences were not statistically significant (P > 0.05)., Conclusions: Playing a wind instrument as well as the type of instrument played, duration, and frequency of play did not significantly affect dental arch dimensions., Competing Interests: None

Objective: The aim of this study was to determine long-term skeletal and dental changes in tooth-anchored versus Dresden bone-anchored rapid maxillary expansion using CBCT images in adolescents., Materials and Methods: In all, 29 adolescent patients (11-17 years of age) needing skeletal expansion were randomly allocated to two different groups treated by either a Dresden bone-anchored expander or a conventional hyrax expander. Patients included did not have previous orthodontic treatment, were non-syndromic and had all teeth present in mouth. CBCT images were taken before expansion and two or more years after expansion. An independent T-test was used to determine the statistical significance between treatment groups and paired T-test was used to compare the results before and after expansion in each group., Results: Neither treatment group showed overall long-term different skeletal and dental changes in the transverse, anterior-posterior and vertical planes (P<0.05). Both treatment groups showed mild asymmetric skeletal expansion, but these were clinically insignificant., Conclusions: Both expanders had similar skeletal and dental results. The greatest changes were in the transverse plane. Changes in vertical and anterior-posterior were negligible., (Copyright © 2020 CEO. Published by Elsevier Masson SAS. All rights reserved.)

Objective: The main aim of this randomized clinical trial was to determine 3 dimensional skeletal and dental changes six months after the use of bone-anchored versus tooth-anchored rapid maxillary expanders in adolescents. The secondary aim was to determine the symmetrical or asymmetrical expansion pattern between both appliances., Materials and Methods: Fifty adolescents with skeletally constricted maxilla (mean age 13-14 years) were randomly assigned into: Dresden B-RME, Hyrax T-RME, or untreated control groups. CBCT scans were taken at initial and expander removal (6 months). Three-dimensional references and treatment landmarks were identified. Orthogonal distances were calculated from those landmarks. The main outcome was to compare skeletal and dental changes in each group and the secondary outcome was to verify if these changes were symmetric or not. Data was analysed using descriptive statistics and repeated measure MANCOVA and MANOVA., Results: Both treatment groups showed significant skeletal and dental expansion compared to controls. T-RME group had greater mean inter-molar crown expansion (5.66mm) than the B-RME group (4.17mm). Both T-RME and B-RME groups showed significant skeletal maxillary expansion compared to controls (mean 1.27mm and 1.31mm respectively, both p<0.01), although no significant difference was found between both appliances. B-RME group showed a lower ratio of dental to skeletal expansion than T-RME group. T-RME showed a symmetrical expansion pattern, whereas the B-RME showed an asymmetrical pattern relative to mid-sagittal plane. The extent of molar crown expansion was 1.84mm greater on the TAD-side compared to the Implant-side. T-RME group showed significant anterior movement of the maxillary first premolar and molar (1.5mm, p<0.05), and vertical dental extrusion (1.8mm). No significant dental vertical or anterior-posterior changes were noted in the B-RME group., Conclusions: T-RME and B-RME produced similar amounts of skeletal expansion. B-RME group produced a lower component of dental expansion. Due to the Dresden B-RME configuration, asymmetrical expansion was noted., (Copyright © 2020 CEO. Published by Elsevier Masson SAS. All rights reserved.)

Introduction: This study aimed to examine the role of dentofacial morphology in discriminating semi-isolated indigenous groups. These populations present a similar pattern of dietary habits. Studies in human genetics have reported a large intertribal genetic distance and low intratribal variation., Methods: This study was conducted following the Strengthening the Reporting of Observational Studies in Epidemiology guidelines. Face dimensions were measured through facial photogrammetry, and dental arches and tooth size were evaluated using plaster models. A total of 98 subjects in the permanent dentition and belonging to 4 indigenous groups were analyzed: Arara-Iriri (n = 20), Arara-Laranjal (n = 33), Assurini (n = 25), and Xicrin-Kayapó (n = 20). The random and systematic errors were verified using the Dahlberg formula and the intraclass correlation coefficient (ICC), respectively. In order to evaluate the discrimination of the variables to identify the indigenous groups, a discriminant analysis was performed (P <0.05)., Results: A small causal error (Dahlberg, 0.13-1.81) and excellent replicability (ICC, 0.75-0.99) for face dimensions as well as for models (Dahlberg, 0.10-0.68; ICC, 0.94-0.99) were observed. The discriminant analysis allowed the identification of 4 populations by facial and dental arch dimensions and tooth size. Dentofacial biometry revealed an accuracy of 98% for females and 100% for males, which confirms a high intragroup homogeneity and considerable intergroup heterogeneity for dentofacial features., Conclusions: Biometric measurements of the human face added with tooth size and dental arch dimensions are very useful to identify remote indigenous populations with high accuracy. Supported by previous studies in human genetics, these findings reinforce the role of genetic variation in the determination of dentofacial features., (Copyright © 2019 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Background: Condylar Hyperplasia (CH) is a self-limiting mandibular condyle disorder that shows asymmetry progress in conjunction with associated occlusal changes as long as condylar growth is still active and leads to facial asymmetry. This study aimed to analysis the difference of dental arch characteristics  based on genders in orthodontic patients with suspected CH in a North Sumatra subpopulation. Methods: This is a retrospective study of suspected CH patient's clinical records who sought for the initial orthodontic treatment between January 2015 to March 2019. Patient with facial asymmetry (based on photography, posterior crossbite and midline deviation), the positive temporomandibular joint disorder in functional analysis, and no history of facial trauma were included in the study. Dental arch asymmetry was based on the measurement of dental midline deviation, canine tip in the dental arch, the distance of the upper canines from the palatal suture, and inter canine distance. The evaluation of dental arch was achieved by comparing arch width and length. Results: There was a significant difference (p<0.05) of upper canine distance from the palatal suture in female patients when evaluating upper dental arch asymmetry. There was a moderate correlation (r=0.379) in midline deviation between upper and lower dental arch. The dimension and dental arch form were mid and flat, and there was moderate correlation (r=0.448) between the upper and lower dental arch form in these suspected CH patients. Conclusion: Indeed skeletal asymmetry, the evaluation of the dental arch characteristic symmetry and arch form showed asymmetric occlusal characteristics in orthodontics patient with suspected  CH in the North Sumatera subpopulation. In treating these patients, we recommend the plaster cast evaluation as essential and routine procedure in order to understand the complexity of occlusal change due to active growth of condylar and limitation in radiography evaluation., Competing Interests: No competing interests were disclosed., (Copyright: © 2020 Sofyanti E et al.)

Background: Condylar Hyperplasia (CH) is a self-limiting mandibular condyle disorder that shows asymmetry progress conjunction with associated occlusal changes as long as condylar growth is still active and leads to facial asymmetry. This study aimed to evaluate dental arches by analyzing dental arch asymmetry and form in orthodontic patients with CH in a North Sumatra subpopulation. Methods: This is a retrospective study of suspected CH patient's clinical records who sought for the initial orthodontic treatment between January 2015 to March 2019. Patient with facial asymmetry (based on photography, posterior cross bite and midline deviation), positive temporomandibular joint disorder in functional analysis, and no history of facial trauma were included in the study. Dental arch asymmetry was based on the measurement of dental midline deviation, canine tip in the dental arch, distance of the upper canines from the palatal suture, and inter canine distance. The evaluation of dental arch was achieved by comparing arch width and length. Results: There was a significant difference (p<0.05) of upper canine distance from the palatal suture in female patients when evaluating upper dental arch asymmetry. There was a moderate correlation (r=0.379) in midline deviation between upper and lower dental arch. The dimension and dental arch form was mid and flat, and there was moderate correlation (r=0.448) between the upper and lower dental arch form in these CH patients. Conclusion: The evaluation of dental arch symmetry and arch form showed asymmetric occlusal characteristics in orthodontics patient with CH in North Sumatera subpopulation. In treating these patients, we recommend the plaster cast evaluation as essential and routine procedure in order to understand the complexity of occlusal change due to active growth of condylar and limitation in radiography evaluation., Competing Interests: No competing interests were disclosed., (Copyright: © 2020 Sofyanti E et al.)

Background: Condylar Hyperplasia (CH) is a self-limiting mandibular condyle disorder that shows asymmetry progress conjunction with associated occlusal changes as long as condylar growth is still active and leads to facial asymmetry. This study aimed to evaluate dental arches by analyzing dental arch asymmetry and form in orthodontic patients with CH in a North Sumatra subpopulation. Methods: This is a retrospective study of suspected CH patient's clinical records who sought for the initial orthodontic treatment between January 2015 to March 2019. Patient with facial asymmetry (based on photography, posterior cross bite and midline deviation), positive temporomandibular joint disorder in functional analysis, and no history of facial trauma were included in the study. Dental arch asymmetry was based on the measurement of dental midline deviation, canine tip in the dental arch, distance of the upper canines from the palatal suture, and inter canine distance. The evaluation of dental arch was achieved by comparing arch width and length. Results: There was a significant difference (p<0.05) of upper canine distance from the palatal suture in female patients when evaluating upper dental arch asymmetry. There was a moderate correlation (r=0.379) in midline deviation between upper and lower dental arch. The dimension and dental arch form was mid and flat, and there was moderate correlation (r=0.448) between the upper and lower dental arch form in these CH patients. Conclusion: The evaluation of dental arch symmetry and arch form showed asymmetric occlusal characteristics in orthodontics patient with CH in North Sumatera subpopulation. In treating these patients, we recommend the plaster cast evaluation as essential and routine procedure in order to understand the complexity of occlusal change due to active growth of condylar and limitation in radiography evaluation., Competing Interests: No competing interests were disclosed., (Copyright: © 2020 Sofyanti E et al.)

Backgrounds: Intraoral scanner (IOS) accuracy is commonly evaluated using full-arch surface comparison, which fails to take into consideration the starting position of the scanning (scan origin). Previously a novel method was developed, which takes into account the scan origin and calculates the deviation of predefined identical points between references and test models. This method may reveal the error caused by stitching individual images during intraoral scan. This study aimed to validate the novel method by comparing the trueness of seven IOSs (Element 1, Element 2, Emerald, Omnicam, Planscan, Trios 3, CS 3600) to a physical impression digitized by laboratory scanner which lacks linear stitching problems., Methods: Digital test models of a dentate human cadaver maxilla were made by IOSs and by laboratory scanner after polyvinylsiloxane impression. All scans started on the occlusal surface of the tooth #15 (universal notation, scan origin) and finished at tooth #2. The reference model and test models were superimposed at the scan origin in GOM Inspect software. Deviations were measured between identical points on three different axes, and the complex 3D deviation was calculated. The effect of scanners, tooth, and axis was statistically analyzed by the generalized linear mixed model., Results: The deviation gradually increased as the distance from scan origin increased for the IOSs but not for the physical impression. The highest deviation occurred mostly at the apico-coronal axis for the IOSs. The mean deviation of the physical impression (53 ± 2 μm) was not significantly different from the Trios 3 (156 ± 8 μm) and CS 3600 (365 ± 29 μm), but it was significantly lower than the values of Element 1 (531 ± 26 μm), Element 2 (246 ± 11 μm), Emerald (317 ± 13 μm), Omnicam (174 ± 11 μm), Planscan (903 ± 49 μm)., Conclusions: The physical impression was superior compared to the IOSs on dentate full-arch of human cadaver. The novel method could reveal the stitching error of IOSs, which may partly be caused by the difficulties in depth measurement.

Objective: The objective of this study was to compare the effects on upper dental arch size and shape after maxillary expansion with Hyrax, Quad-helix, and a differential opening expander in bilateral cleft lip and palate (BCLP) patients., Materials and Methods: Seventy-five BCLP patients were divided into three groups: Hyrax (H), Quad-helix (QH), and Expander with differential opening (EDO). Digital models were obtained before (T1) and after 6 months (T2) of maxillary expansion. Twelve landmarks were placed by one investigator on T1 and T2 dental models of each group, and x,y coordinates for each landmark were collected. For dental arch size analysis, centroid size of each dental arch at T1 and T2 was calculated from raw coordinates and was used as the measure of size. Procrustes Analysis was performed for dental arch shape analysis. Analysis of variance was used to compare the groups for size and shape differences ( P < .05)., Results: There were no significant dental arch size differences among the expanders at T1 or T2. Differences in arch shape were found between all groups at T2. Intragroup arch shape showed a significant variation for the QH and EDO groups. while it remained stable in the H group., Conclusions: Both the QH and the EDO create dental arch shape changes with greater intercanine than intermolar increase. The H does not change the dental arch shape.

Background: Sex determination is the first step in personal identification in the forensic field. This study aimed to evaluate sexual dimorphism by using palatal rugae pattern and odontometrics, construct an Egyptian equation for sex determination using the discriminant function analysis. Participants and methods: The study sample included 200 participants of both sexes. Maxillary arch impressions were taken with alginate impression material using stainless steel impression tray. Identification and measurements were done to study the palatal rugae pattern, dental arch dimensions, and maxillary canine. Results: There was a highly statistically significant difference between males and females with higher male values regarding the total palatal rugae number, wavy rugae number, primary rugae number, arch length, width, maxillary canine right width, maxillary canine left width, intercanine distance, and maxillary canine right index while there was a highly statistically significant difference with higher female value regarding the straight rugae numbers. Four Egyptian equations were constructed using discriminant function analysis to determine the sex of an unidentified person. Conclusions: Palatal rugae pattern, dental arch dimensions, and maxillary canine index can be considered as useful tools for sex determination in the forensic field.

Background and Trial Design: The Scandcleft intercentre study evaluates the outcomes of four surgical protocols for treatment of children with unilateral cleft lip and palate (UCLP). Originally 10 cleft centres in Denmark, Finland, Norway, Sweden, and the UK participated in a set of three randomized trials of primary surgery. Three groups of centres (Trials 1, 2, and 3) tested their traditional local surgical protocols (Arms B, C, and D) against a common protocol (Arm A)., Objectives: To evaluate dental arch relationships at age 8 years after four different protocols of primary surgery for UCLP. These results are secondary outcomes of the overall trial., Methods: Study models of 411 children (270 boys, 141 girls) with non-syndromic UCLP at a mean age of 8.1 (range 7.0-10.0) years were available. Dental arch relationships were analysed using the GOSLON Yardstick by a blinded panel of 11 orthodontists. To assess reliability, Kappa statistics were calculated. The trials were tested statistically with t-tests., Results: Comparisons within each trial showed no statistically significant differences in the mean 8-year index scores or their distributions between the common protocol and the local team protocol. The mean index scores were Trial 1: Arm A 3.03, Arm B 2.82, Trial 2: Arm A 2.78, Arm C 2.64, and Trial 3: Arm A 3.06, Arm D 3.08. Comparisons between the trials detected a significantly (P < 0.005) better mean index score Trial 2 Arm C than in Trial 3 Arm D. The intra- and inter-rater reliabilities were acceptable., Conclusion: The results of these three trials do not provide evidence that one surgical protocol is better than the others., Trial Registration: ISRCTN29932826., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objectives: The present study validated data that had been reported to the Swedish Quality Registry for Cleft Lip and Palate (CLP) under new requirements from 2016, when use of the 5-year-old (5YO) and the Modified Huddart and Bodenham (MHB) indices for rating occlusion in children born with unilateral CLP (UCLP) was introduced., Materials and Methods: The sample included blinded study casts (n = 97) and photos (n = 4) of 5-year-old children who had been born with UCLP in 2009-2011 and were enrolled at one of six cleft centres in Sweden. Fourteen orthodontists from the centres assessed the patients (n = 101) using the 5YO and the MHB indices. Median 5YO and MHB scores of the 14 assessments were compared with original registry data (n = 61). Each centre devised code keys to protect the identities of their patients in the registry., Results: Interrater agreement among the 14 orthodontists was good for the 5YO index (quadratic-weighted kappa: 0.72-0.92) and the MHB index (intraclass correlation coefficient: 0.991-0.994). Comparisons of median 5YOs for each identifiable child with their registry data (n = 61) found total agreement for 70.5 per cent. Comparisons between median MHBs and registry data showed very good or good agreement in 93.4 per cent of the cases., Limitations: Two teams lost their code keys, which reduced the sample to 61 patients., Conclusions: The dentoalveolar outcome data in the CLP registry was trustworthy. There was good agreement among the Swedish cleft teams assessing the 5YO and MHB indices in children born with UCLP at age 5 years., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Orthodontic Society.)

Objectives: To investigate the efficiency and movement pattern of upper arch expansion using Invisalign aligners. The correlation between the amount of designed expansion and the efficiency of bodily expansion was evaluated, as were the initial molar torque and efficiency of bodily expansion., Materials and Methods: Twenty Chinese adult patients who underwent arch expansion with Invisalign aligners were included in this study. Records of pretreatment (T0 stage) and immediately after completing the expansion phase (T1 stage) were collected, including digital models and cone-beam computed tomography. Dolphin 3D, Geomagic Studio 12.0, and Meazure software were employed to measure data and calculate differences between the expected and actual outcomes., Results: There were significant differences between the expected and actual expansion amounts ( P < .05). The average expansion efficiencies of the upper canine crown, first premolar crown, second premolar crown, and first molar crown were 79.75 ± 15.23%, 76.1 ± 18.32%, 73.27 ± 19.91%, and 68.31 ± 24.41%, respectively. The average efficiency of bodily expansion movement for the maxillary first molar was 36.35 ± 29.32%. Negative correlations were found between preset expansion amounts and the efficiency of bodily expansion movement ( P < .05), and between initial maxillary first molar torque and efficiency of bodily expansion movement ( P < .05)., Conclusions: Aligners could increase the arch width, but expansion was achieved by tipping movement. The evaluation of initial position and preset of sufficient root-buccal torque of posterior teeth were necessary due to the lower efficiency of bodily buccal expansion by the Invisalign system.

This study aimed to investigate changes in types of dental arch form during adolescence and explore adolescent changes in size and form of dental arch. Hong Kong Chinese were recruited and digital dental arch models were obtained at ages 12, 15, and 18 years. Geometric morphometrics was used to investigate adolescent changes of dental arch form. There were 225 participants from whom digital models at all three age periods were available. Three types of dental arch form were identified through clustering. Significant changes (p < 0.001) in types of dental arch form were noted during age 12-18 years. During age 12-18 years, significant changes in centroid size and form of dental arch were observed (p < 0.001). No significant changes were observed during 15-18 years. Adolescent changes of dental arch form occur primarily during age 12-15 years, whereas dental arch form was relatively stable during age 15-18 years.

Introduction: This study aimed to evaluate the ability of dental clinicians to predict posttreatment dental arch forms in patients with malocclusion with the aid of 3D imaging and digital software in comparison with a conventional method., Methods: Pretreatment and posttreatment dental plaster casts of 100 patients (200 maxillary models and 200 mandibular models) were selected. Three orthodontists selected the best-fitted archwires among 5 commercially available preformed nickel-titanium archwires using 2 methods. In the conventional method, they fit the archwires to pretreatment casts, and in the digital method, they fit the scanned wire to a 3D digital model, using Ortho-Aid, a locally developed 3D software, using clinical bracket points as reference for wire fitness. The predicted posttreatment archwire in each method was compared with the best-fit archwire on the actual posttreatment model of each patient in both methods, and the level of agreement was calculated. The interobserver agreement between the 3 orthodontists in each method was evaluated using intraclass correlation coefficient and the Dahlberg formula., Results: Orthodontists predicted the final treatment outcome in 50% of cases using the conventional method and 58% using the digital method. However, the range of method error was significantly higher in the conventional method (0.425-3.853 mm for the conventional vs 0.451-0.584 mm for the digital)., Conclusions: Although the clinicians' ability to predict the final dental arch form after orthodontic treatment and the agreement between clinicians increased by the use of digital equipment, orthodontists can predict the final arch form in about 60% of patients., (Copyright © 2019 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

The aim was to analyze the changes in mandibular dental arch shape during adolescence and assess its relation to late mandibular incisor crowding. Longitudinal study included 68 orthodontically untreated subjects (49% female) and analyzed their data for the ages of 12, 15, 18 and 21 years. Measurements included anterior arch depth, intercanine, interpremolar/anterior and intermolar/posterior width, Little's Irregularity and Bolton's index and the ratio between anterior arch depth and width. Males had significantly greater posterior widths than females at any age ( p < 0.05). The anterior arch depth continuously decreased ( p < 0.05), while width increased after the age of 18 years. Mandibular incisor crowding increased during all investigated periods ( p < 0.05). The increase of intercanine width at 12-21 years of age reduced the risk for mandibular incisor crowding in the same period by 74% (OR: 0.265: 95% CI 0.076-0.931; p = 0.045). The shape of mandibular dental arch continues to change during adolescence becoming more squared while mandibular incisor crowding increases. The increase in mandibular intercanine width reduces the risk of crowding.

Objective: The purpose of this study was to investigate a relationship between gingival tissue biotypes and arch form with Schneiderian membrane thickness, using limited cone beam computed tomography., Materials and Methods: A total of 90 subjects were selected. For each subject three parameters were assessed - gingival biotype - clinically by Probe transparency method as thin or thick and coded as 0 and 1, respectively, gingival thickness and Schneiderian membrane thickness in mm, arch form as square, oval, or tapered (radiographically by cone beam computed tomography images). Central incisors and first molars were assessed for gingival biotype and gingival thickness and Schneiderian membrane thickness was determined at 16. Numerical data were estimated for normal distribution. Analysis of Variance test was followed by Tukey honestly significant difference test and Pearson's correlation coefficient test for analysis., Results: Thin gingival biotype was found associated with the central incisors and thick gingival biotype with molars. Limited cone beam computed tomography scans evaluation revealed highest prevalence of square arch form followed by oval, and tapered. The average thickness of the Schneiderian membrane was 1.18 ± 0.43 mm on left side and 1.09 ± 0.41 mm on right side with a range of 0.50 - 2.00 mm. Mean Schneiderian membrane thickness was more in case of thick gingival biotype and with square arc form both on right and left sides., Conclusions: The Schneiderian membrane thickness was positively and highly associated with gingival biotype. The gingival biotype and arch form had significant effect on Schneiderian membrane thickness and can provide valuable clinical information on Schneiderian membrane thickness preoperatively for implant placement and sinus lift procedures., Competing Interests: None

Objective: To compare the influence of 3 different time protocols of cleft lip and palate operations on the growth of the dentoalveolar arch in patients with unilateral cleft lip and palate (UCLP)., Materials and Methods: We evaluated 64 plaster casts of 8-year-old boys with UCLP operated on according to 3 different time protocols: lip repair at the age of 6 months and palate repair at 4 years, lip repair at 3 months and palate repair at 9 months, and neonatal lip repair and palate repair at 9 months. The control group contained 13 plaster casts of 8-year-old boys. The dentoalveolar arch width was measured between deciduous canines and between the second deciduous molars; the length was measured between incisive papilla and the line connecting both tuber maxillae., Results: All measured distances were statistically significantly smaller in boys with UCLP than in the control group. Intercanine width was not statistically significantly different between the patients operated on according to the different time protocols. In comparison to the lip repair at 6 months and palate repair at 4 years, the intermolar width was statistically significantly smaller in the group with neonatal lip repair; the alveolar arch length was statistically significantly shorter in both groups with lip repair performed neonatally or at 3 months., Conclusions: The length of the dentoalveolar arch is shorter after surgical repair of cleft lip neonatally or at the age of 3 months. Cleft palate repair at 9 months can contribute to a reduction in the width of the dentoalveolar arch.