Evaluation of the agreement of horizontal and vertical linear measurements obtained from digital models, printed models and direct measurements.

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.

Fluctuating arch symmetry: a comparison of two methods of assessment - applicability and efficiency.

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.

Sex determination through maxillary dental arch and skeletal base measurements using machine learning.

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.

Changes in the arch width and buccal corridor after fixed orthodontic treatment with Damon self-ligating system: premolar extraction vs. non-extraction.

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.

Maxillary arch dimensions in bilateral cleft lip and palate in the age 0-5 months.

INTRODUCTION: The complete bilateral cleft lip and palate (BCLP) divides the maxillary arch into three segments, separated from each other, resulting in abnormal growth of the alveolar arch. This study evaluated the maxillary arch dimensions in BCLP and compared them with neonates without craniofacial anomalies. METHODS: This retrospective study was conducted in a tertiary cleft centre. Sixty-six neonates aged 0-5 months were divided into two groups: cleft group-children with BCLP (23 boys and 18 girls) and control group-children without craniofacial deformities (15 boys and 10 girls). The dental models were processed by a 3D scanner. Landmarks were marked to achieve inter-canine distance, inter-tuberosity distance and arch length measurements. t-Tests were used for intergroup comparisons (p < .05). RESULTS: The maxillary cleft arch was demonstrated to be wider and longer in the posterior region compared to the control group. The inter-canine distance did not present differences between the cleft and controls. The inter-canine distance of the control group was the only measurement influenced by the variable sex. CONCLUSIONS: The cleft significantly interfered with the arch posterior width and arch sagittal length, making them larger. There was no statistical difference in the measurements between sex in the cleft group.

Accuracy of arch expansion with two thermoplastic materials in Invisalign® patients: EX30® and SmartTrack®.

OBJECTIVE: The purpose of this retrospective study was to compare accuracy of arch expansion using two different thermoplastic materials in Invisalign aligners: EX30® (Polyethylene Terephthalate Glycol, or PETG) and SmartTrack® (polyurethane). METHODS: The study sample comprised 65 adult patients consecutively treated with Invisalign from two private practices: group 1 - treated with EX30® (358 teeth) and group 2 - treated with SmartTrack® (888 teeth). Six hundred and twenty-three measurements were assessed in three digital models throughout treatment: model 1 - initial, model 2 - predicted tooth position, and model 3 - achieved position. Sixteen reference points per arch were marked and, after best alignment, 2 points per tooth were copied from one digital model to another. Linear values of both arches were measured for canines, premolars, and first molars: on lingual gingival margins and cusp tips of every tooth. Comparisons were performed by Wilcoxon and Mann-Whitney test. RESULTS: Both termoplastic materials presented significant differences between predicted and achieved values for all measurements, except for the lower molar cusp tip in the SmartTrack® group. There is no statistical difference in the accuracy of transverse expansion between these two materials. Overall accuracy for EX30® aligners in maxilla and mandible were found to be 37 and 38%, respectively; and Smarttrack® presented an overall accuracy of 56.62% in the maxilla and 68.72% in the mandible. CONCLUSIONS: It is not possible to affirm one material expands better than the other. Further controlled clinical studies should be conducted comparing SmartTrack® and EX30® under similar conditions.

Accuracy of Invisalign® aligners in adult patients: a retrospective study of angular tooth movements.

OBJECTIVE: This retrospective study aimed to assess the predictability of Invisalign® aligners regarding rotational, mesio-distal and buccal-lingual tip movements. METHODS: Two materials were included in the analysis - EX30, used until 2013; and SmartTrack, in current use. The study comprised 56 adult patients treated with Invisalign Comprehensive. Data sample were assessed on three sets of digital models; model 1 - initial, model 2 - predicted, and model 3 - achieved. Sixty reference points were marked in each dental arch, and two reference planes assisted the superimposition. The degree of rotation, mesio-distal and buccal-lingual tip was obtained via trigonometric calculations, through a previously published validated method. The accuracy of outcomes was compared according to the types of tooth movement and teeth groups,and the influence of predetermined variables on movement accuracy was also investigated. RESULTS: Rotation and mesio-distal tip did not present any significant difference when comparing EX30 and SmartTrack groups. Only buccal-lingual tip presented a significant difference, incisor and canine groups treated with EX30 aligners presented an increase in accuracy (p= 0.007 and p = 0.007, respectively). For each additional degree planned for rotation movements, there was an increase of 0.35° in the discrepancy, and an increase of 0.40° and 0.41° for mesio-distal and buccal-lingual tip, respectively. EX30 and SmartTrack discrepancies were compared by multilevel linear regression. CONCLUSION: EX30 aligners reached higher accuracy for buccal-lingual tip in anterior teeth. However, for rotation and mesio-distal tip, SmartTrack and EX30 are similarly accurate. The total amount of planned movement has a significant impact on accuracy rates, with a decrease in accuracy for every additional degree.

Influence of the metal post material, tooth location in the dental arch, and metal artifact reduction tool on vertical root fracture diagnosis in cone beam CT.

This study aimed to evaluate the influence of the metal post composition, tooth location in the dental arch, and metal artifact reduction (MAR) on vertical root fracture (VRF) diagnosis in cone beam computed tomography (CBCT). Twenty-two unirradicular premolars (12 sound and 10 fractured) and two alveolar sockets of a mandible (anterior and posterior regions) composed the sample. CBCT scans of each tooth with a metal post placed into the root canal-silver-palladium (Ag-Pd), cobalt-chromium (Co-Cr), or nickel-chromium (Ni-Cr)-were individually acquired for each mandibular region, and two conditions of MAR, using a OP300 device (Instrumentarium, Finland). Images were assessed by five evaluators independently for VRF detection. Diagnostic values were calculated and compared among all groups using multi-way ANOVA with Tukey post hoc test to investigate the effect of post material, anatomical region, and MAR on VRF diagnosis (α = 0.05). Values of area under the receiver operating curve and specificity were not influenced by the studied factors (p > 0.05). Sensitivity was influenced by the MAR in both mandibular regions (p < 0.05). In the anterior region, sensitivity values increased when the MAR was enabled, regardless of the metal post material (p < 0.05). Similar behavior was noticed in the posterior region for Ni-Cr (p < 0.05) but not for Ag-Pd and Co-Cr posts (p > 0.05). The MAR improved the sensitivity in VRF diagnosis for all tested metal posts in the mandibular anterior region and for the Ni-Cr post in the mandibular posterior region. Therefore, for images obtained in the OP300 CBCT device, activation of the MAR is suggested in these cases.

Comparison of maxillary transversal changes between auxiliary beta-titanium expansion arch and miniscrew-assisted rapid palatal expansion.

OBJECTIVE(S): This study compared buccal bone thickness, dental inclinations and maxillary transverse width dimensions changes between auxiliary beta-titanium expansion arch (AEA) and miniscrew-assisted rapid palatal expansion (MARPE). MATERIALS AND METHODS: The sample consisted of 29 patients, aged between 18 and 40 years, with transverse maxillary deficiency and treated without extractions, divided into two groups: group AEA: comprised 13 individuals (initial mean age: 29.23 ± 9.13 years) treated using auxiliary beta-titanium expansion arch; group MARPE: comprised 16 patients (initial mean age: 24.92 ± 7.60 years) treated with miniscrew-assisted rapid palatal expansion. Buccal bone thickness, dental inclinations and transverse width dimensions (dental, nasal base and jugular) were measured in cone-bean computed tomographies at pre- and post-treatment stages. The variables were compared using the independent t-test. RESULTS: The buccal bone thickness was similar for both groups at the post-treatment stage. The second premolars were significantly more buccal inclined in the AEA group and the right maxillary first molars in the MARPE group. The intercanine and intermolar distances were statistically significantly greater in the MARPE group. Changes in dental arch transverse dimensions were significantly greater for the MARPE group. CONCLUSION: Both treatment protocols corrected the maxillary transverse discrepancy; however, MARPE provided greater correction.

Evaluation the scanning accuracy of Blue-Light laboratory scanners in complete edentulous Maxilla with multiple implants with titanium scan bodies / Evaluación de la precisión de escaneado de los escáneres de laboratorio de luz azul en maxilares desdentados completos con implantes múltiples con cuerpos de escaneado de titanio

Abstract To evaluate the accuracy of complete arch scanning with multiple implant titanium scan bodies using laboratory scanners. A master model of an edentulous maxillary arch with 6 implants was fabricated. Titanium scan bodies were inserted into the model. Three laboratory scanners were used: D2000 (3Shape), Vinyl High Resolution (Smart Optics), and inEos X5 (Dentsply Sirona). The master model was consecutively scanned ten times using dental laboratory scanners (LS) without detaching and repositioning the scan bodies. Linear and angular accuracy between adjacent implants was measured using inspection software (Control X, Geomagic). The accuracy of the complete arch scans was calculated. Implant regions were defined as; parallel (R1: #24-26 and #16-14), angled (R2: #22-24 and #14-12), angled to occlusal plane (R3: #12-22), and cross-arch (R4: #16-26). The effect of LS and implant region on accuracy was compared using two-Way ANOVA (α=0.05). Significant greater linear distortion was noted in R4 (61.2±17.9µm) compared to R1 (23.4±15.5µm) and R2 (26±17.7µm) (p<0.01). Greater linear distortions were noted in R4 with D2000 (0.07±0.016 degrees) and Vinyl High Resolution (0.067±0.02 degrees) than inEos X5 (0.032±0.021 degrees) (p>0.05). Greater mean linear precisions were noted in R1 (9±8µm) and R3 (9.3±8.3µm) than R4 (12.6±10.3µm) (p<0.05). The highest linear precision was noted in D2000 (7.2±7.6µm) (p<0.05). The angular precision of D2000 (0.02±0.015 degrees) was the highest (p<0.01). The angular precisión of R4 (0.036±0.018 degrees) was the lowest (p<0.01). This study revealed that the trueness was affected by the implant region and the precision was affected by both LS and implant region.

Resumen Evaluar la precisión del escaneado de la arcada completa con cuerpos de escaneado de titanio de múltiples implantes utilizando escáneres de laboratorio. Se fabricó un modelo maestro de una arcada maxilar edéntula con 6 implantes. Se insertaron cuerpos de escaneo de titanio en el modelo. Se utilizaron tres escáneres de laboratorio: D2000 (3Shape), Vinyl High Resolution (Smart Optics) e inEos X5 (Dentsply Sirona). El modelo maestro se escaneó consecutivamente diez veces usando escáneres de laboratorio dental (LS) sin separar y reposicionar los cuerpos de escaneo. La precisión lineal y angular entre implantes adyacentes se midió utilizando un software de inspección (Control X, Geomagic). Se calculó la precisión de los escaneos completos del arco. Las regiones del implante se definieron como; paralelo (R1: #24-26 y #16-14), angulado (R2: #22-24 y #14-12), angulado al plano oclusal (R3: #12-22) y cruzado (R4: #16-26). El efecto de LS y la región del implante en la precisión se comparó mediante ANOVA de dos vías (α=0,05). Se observó una distorsión lineal significativamente mayor en R4 (61,2±17,9µm) en comparación con R1 (23,4±15,5µm) y R2 (26 ±17,7µm) (p<0,01). Se observaron mayores distorsiones lineales en R4 con D2000 (0,07±0,016 grados) y vinilo de alta resolución (0,067±0,02 grados) que en inEos X5 (0,032±0,021 grados) (p>0,05). Se observaron precisiones lineales medias mayores en R1 (9±8µm) y R3 (9,3±8,3µm) que en R4 (12,6±10,3µm) (p<0,05). La mayor precisión lineal se observó en D2000 (7,2±7,6 µm) (p<0,05). La precisión angular de D2000 (0,02±0,015 grados) fue la más alta (p<0,01). La precisión angular de R4 (0,036±0,018 grados) fue la más baja (p<0,01). Este estudio reveló que la veracidad se vio afectada por la región del implante y la precisión se vio afectada tanto por LS como por la región del implante.

Relación entre la compresión maxilar y potencial impactación del canino superior: Scoping review / Relationship between the maxillary transverse dimension and impacted canines: Scoping review

El canino maxilar permanente corresponde al segundo diente más frecuentemente impactado en el arco dental. La etiología de esta patología aún no está totalmente definida, sin embargo, investigadores plantean la deficiencia del ancho del hueso maxilar como una posible causa. Objetivo: Investigar la evidencia que asocia menores dimensiones transversales del maxilar a la ocurrencia de la impactación de caninos superiores y esclarecer la posible relación. Materiales y métodos: Se realizó una revisión sistemática exploratoria a partir de una búsqueda amplia de la literatura en bases de datos PubMed, Cochrane, EBSCO y Multibuscador UNAB. Los artículos fueron recopilados, identificados y filtrados según el diagrama de flujo de declaración PRISMA. Resultados: La búsqueda identificó 755 estudios, de los cuales 14 fueron incluidos. Los estudios varían en diseño, edad de estudio y métodos de diagnóstico. La mitad de los estudios reporta una asociación positiva entre compresión maxilar e impactación canina superior, mientras que la otra mitad una asociación negativa. Conclusiones: No hay evidencia suficiente para poder asociar compresión maxilar con impactación de caninos superiores. Estudios con métodos de diagnóstico rigurosos son necesarios para una mejor comprensión. No obstante, se enfatiza la importancia de un diagnóstico precoz, para garantizar mejores resultados y pronóstico más favorable.

The permanent maxillary canine is the second most frequently impacted tooth in the dental arch. The etiology of this disease is not completely defined, yet some researchers propose the deficiency of the width from the maxilla as a possible cause. Objective: To investigate available evidence correlating smaller transverse maxilla dimensions with the occurrence of potential impaction of upper canines and clarify the possible relation. Materials and methods: A systematic exploratory review was carried out based on comprehensive search of the literature in databases such as PubMed, Cochrane, EBSCO and UNAB multi search engine. The articles were compiled, identified and filtered systematically according to the PRISMA flow diagram. Results: Our search identified 755 studies, 14 of which were included. These studies vary in design, patients age, and methods for detection. Half of the studies show a positive correlation between maxillary compression and potential upper canine impaction, whereas the other half show a negative correlation. Conclusions: There is not enough evidence to link maxillary compression to upper canine impaction. Studies with rigorous diagnostic methods for detection are necessary for a better understanding of this relation. Nonetheless, the importance of early diagnosis must be emphasized to guarantee better results and a more favorable prognosis.

Influence of scanbody design and intraoral scanner on the trueness of complete arch implant digital impressions: An in vitro study.

This study aimed to compare the accuracy of full-arch digital implant impressions using seven different scanbodies and four intraoral scanners. A 3D-printed maxillary model with six implants and their respective multi-unit abutments was used for this study. Seven scanbodies (SB1, SB2, SB3, SB4, SB5, SB6, and SB7) and four intraoral scanners (Primescan®, Omnican®, Trios 3®, and Trios 4®) were assessed. Each combination group was scanned ten times and a dental lab scanner (D2000, 3Shape) was used as a reference. All scans were exported as STL files, imported into Convince software (3Shape) for alignment, and later into Blender software, where their 3D positions were analyzed using a Python script. The 3D deviation, angular deviation, and linear distance between implants #3 and #14 were also measured. Accuracy was measured in terms of "trueness" (scanbody 3D deviation between intraoral scan and desktop scan). Kruskal-Wallis followed by the Bonferroni correction was used to analyze the data (⍺ = .05). The study found statistically significant differences in digital impression accuracy among the scanners and scanbodies (p<0.001). When comparing different intraoral scanners, the Primescan system showed the smallest 3D deviation (median 110.59 µm) and differed statistically from the others, while Trios 4 (median 122.35 µm) and Trios 3 (median 130.62 µm) did not differ from each other (p = .284). No differences were found in the linear distance between implants #3 and #14 between Trios 4, Primescan, and Trios 3 systems. When comparing different scanbodies, the lowest median values for 3D deviation were obtained by SB2 (72.27µm) and SB7 (93.31µm), and they did not differ from each other (p = .116). The implant scanbody and intraoral scanner influenced the accuracy of digital impressions on completely edentulous arches.

A new way of analyzing tooth movement using universal coordinate system geometry single point superposition in a 3D model.

INTRODUCTION: Superposing 3D models is an imminent need. However, current methods rely on marking multiple points on the maxilla and mandible, which could increase point marking and overlapping errors. OBJECTIVE: This study aimed at developing a method for superimposing 3D models of the maxillary and mandibular arches with Autodesk Inventor® engineering software, using a single universal coordinate system (UCS) point superposition. METHODS: A total of 104 STL (stereolithography) models of the maxillary and mandibular arches exported from My iTero® platform were retrospectively selected, in which T0 and T1 were the initial and refinement periods, respectively (n=26 per group). The X, Y, and Z coordinates associated with a single point in each arch were inserted into the models with SlicerCMF® software for model orientation. The arch models with UCS registration were transferred to Autodesk Inventor® for superimposition and to measure tooth movements performed during Invisalign® treatment. Arch expansion, intrusion and rotation were analyzed by two examiners. The statistics were performed using intraclass correlation coefficients (ICC), Dahlberg's formula, and t-test (p<0.05). RESULTS: A reliable method of superimposing 3D digital models using a single UCS point in the maxilla and mandible was developed. ICC showed excellent intra- and inter-examiner correlation (ICC>0.90). A systematic error was not found concerning linear and angular measurements (<1mm and <1.5°, respectively). Digital dental movements could be analyzed, including arch expansion, dental intrusion, and tooth rotation. CONCLUSIONS: The developed method was proven reliable and reproducible for superimposing 3D models of the maxillary and mandibular arches by using UCS system.

Growth Outcomes Audit for Unilateral Cleft Lip and Palate (UCLP) After 2-stage Palate Repair.

PURPOSE: To assess the impact of 1 and 2-stage palatoplasty protocol on the dental arch relationships in unilateral cleft lip and palate (UCLP) in a single center. METHODS: Our study consisted of 349 individuals divided into 2 groups according to the palatoplasty protocol. Two-stage group comprised 169 subjects with UCLP (mean age: 6.9 y, 110 male and 59 female) who underwent lip, nasal ala, and anterior palate repair with vomer flap from 3 to 6 months (first surgery stage). Soft palate repair occurred from 12 to 18 months (second surgery stage). The one-stage group comprised 180 subjects with UCLP (mean age: 7.2 y, 108 male and 72 female) who underwent 1-stage palatoplasty. Dental models were evaluated by 3 experienced orthodontists applying Goslon Yardstick and the 5-year-old index (FYOI). The influence of the palatoplasty technique and surgeon factor on the interarch relationship was evaluated. The weighted Kappa was used to assess intraexaminer and interexaminer agreements for comparisons of dental arch relationships. Intergroup comparisons were conducted using the χ 2 test ( P <0.05). RESULTS: The intraexaminer reliability was very good (0.81 to 0.98) and interexaminer reliability varied from satisfactory to very good (0.56 to 0.83). The mean occlusal index of the 2-stage and 1-stage groups was 2.77 and 3.03, respectively. The variability of the mean index between surgeons varied from 2.38 to 3.2 in the 2-stage group and 2.91 to 3.2 in the 1-stage group. There were significant differences in the frequency of Goslon 5 index ( P =0.002) between groups, with the 2-stage group presenting less cases (1.18%) than the group 1-stage (11.11%). CONCLUSION: The interarch relationship was similar for both palate repair protocols. Two-stage palatoplasty showed a decreased prevalence of Goslon index 5.

What Are the Effects on Palate of Early Lip Surgery in Children With Cleft Lip and Palate? Cross-Sectional Evaluation From 5-Year-Old.

This study aimed to evaluate the postsurgical effects from 5 years on the palate after surgical repair of the lip at 3 or 9 months of age in children with cleft lip and palate. Eighty-four digitized dental impressions were divided into the following groups: group 1 (G1): lip surgery at 3 months of life; group 2 (G2): lip surgery at 9 months of life; group 3 (G3): without orofacial cleft. Five angular (C'IC, ICM, IC'M', CMM', and C'M'M) and 3 linear parameters (C-C', c-c', and M-M') were evaluated. Statistical analysis was applied with α=5%. Intraclass Correlation Coefficient was significantly smaller in G1 than in G3 ( P =0.005), while IC'M' was significantly smaller in G3 than in G1 ( P <0.001). C'M'M was significantly smaller in G1 than in G2 and G3 ( P <0.001). The distances C-C' and c-c' were significantly smaller in G1 than in G2 and G3 ( P <0.001). There was a statistically significant difference in both G1 and G2 ( P <0.001, in all) in the analysis of palatal symmetry. Linear regression analysis showed that the, 11.2% of outcomes determined by c-c' distance can be explained by the age of lip repair ( P =0.013). In conclusion, lip surgery at 3 months of life showed a tendency toward more restriction in 5-year postsurgery palate development. The age of cheiloplasty is one of the factors that can influence palatal development; however, other factors may be associated and should be studied.

Validation of pairs of antagonist teeth for the evaluation of shortened dental arch in epidemiological studies.

The aim of this study was to evaluate the accuracy of pairs of antagonist teeth (epidemiological criterion) for defining pairs of teeth in occlusal contact (clinical criterion) and to estimate the agreement between the prevalence of "shortened dental arch" (SDA) and "functional dentition" (FD) when occlusal units (OUs) or posterior occluding pairs (POPs) are defined by the epidemiological or clinical criterion. Data were collected in an epidemiological oral health survey conducted in a municipality in Minas Gerais, Brazil. OUs and POPs were defined by the epidemiological criterion (dental crown status) or clinical criterion "gold standard" (carbon paper record of occlusal contacts during habitual maximum intercuspation). SDA corresponded to the presence of an intact anterior region and three to five OUs. FD was based on the concomitant presence of ≥ 1 tooth in each arch, 10 teeth in each arch, 12 anterior teeth, ≥ 3 premolar POPs, and ≥ 1 molar POP bilaterally. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the epidemiological criterion were calculated. The study included 197 adults. Sensitivity, specificity, PPV, and NPV were 88.5, 87.9, 92.5, and 81.9%, respectively, and accuracy was 88.3%. The epidemiological criterion proved to be valid and could be used in epidemiological studies to calculate the prevalence of reduced dental configurations that consider POPs. The assessment of oral functionality is an aspect that should be included in the diagnosis of the clinical condition of patients, contributing to a more effective individual and collective oral health care plan.

Spontaneous changes in mandibular incisor crowding from mixed to permanent dentition: a systematic review.

INTRODUCTION: Dental crowding is the most prevalent malocclusion in the mixed and permanent detitions and can have a major impact on dentofacial esthetics. However, adjustments to the development and growth of the dentition can potentiate self-correction of dental crowding during childhood. OBJECTIVE: To evaluate the physiological behavior of mandibular incisor crowding in the transition from mixed to permanent dentition. METHODOLOGY: Five electronic databases (PubMed, Scopus, Web of Science, LILACS and LIVIVO) and part of the gray literature (Proquest and Google Scholar) were investigated, based on the eligibility criteria associated with the acronym PECO, until June 2022. The risk of bias was assessed using the ROBINS-E tool and the certainty of evidence, the GRADE tool. RESULTS: Among the 2.663 studies identified, five were selected for qualitative analysis, of which one have a low risk of bias, and four, a moderate risk. A total of 243 patients were evaluated. Evidence with a high level of certainty was generated indicating a tendency for improvement in mandibular incisor crowding from mixed to permanent dentition, with mandibular incisor crowding decreasing from 0.17 to 4.62 mm on average. The mandibular incisor crowding reduction seems to be associated with the amount of initial crowding and spontaneous dental arch dimensional changes that occur in the mixed dentition and culminate in the increase in arch perimeter, leeway space, incisor protrusion and transverse growth of the maxillary and mandibular arch. CONCLUSION: Based on moderate scientific evidence, spontaneous longitudinal changes in dental arch in the transition from the mixed to the permanent dentition demonstrate a spontaneous improvement in mandibular incisor crowding by up to 4.62 mm. These evidence provide a scientific basis for planning only longitudinal follow-up in patients with mild to borderline moderate mandibular incisor crowding in the mixed dentition avoiding overtreatment.

Correlation between cleft width and dental arch symmetry in cleft lip and palate: a longitudinal study.

This study aimed to evaluate the influence of cleft width on dental arch symmetry of children with unilateral cleft lip and palate. Forty-one children were subjected to impression preoperatively (T1; mean age = 0.31 ± 0.07 years) and postoperatively (T2; mean age = 6 .73 ± 1.02 years). Eighty-two digitized dental casts were analyzed by stereophotogrammetry software. The cleft palate width was measured in the anterior (P-P'), middle (M-M'), and posterior (U-U') regions. Also, the following measurements were obtained: anterior intersegment (I-C') and intrasegment (I-C); total intersegment (I-T') and intrasegment (I-T); cleft-side (C'-T') and non-cleft-side (C-T) canine tuberosity. Paired t test and Pearson correlation coefficient were applied (α = 5%). Cleft width had the following means: 10.16 (± 3.46) mm for P-P', 12.45 (± 3.00) mm for M-M', and 12.57 (± 2.71) mm for U-U'. In the longitudinal analysis, I-C' had a significant reduction, while the other measurements significantly increased (p < 0.001). Asymmetry was verified in the following analyses at T1: I-C' vs. I-C and I-T' vs. I-T (p < 0.001); at T2, only in I-C' vs. I-C (p < 0.001). At T1, P-P' vs. I-C' (r = 0.722 and p < 0.001), P-P' vs. I-T' (r = 0.593 and p < 0.001), M-M' vs. I-C' (r = 0.620 and p < 0.001), and M-M' vs. I-T' (r = 0.327 and p < 0.05) showed a positive and significant correlation. At T2, there was a correlation between M-M' and I-C' (r = 0.377 and p < 0.05). In conclusion, the anterior and middle cleft widths influenced palatal asymmetry in the first months of life, while middle width influenced residual asymmetry.

Incisor irregularity and dental arch dimensions changes in subjects with different severity of anterior crowding: a 37-year follow-up.

BACKGROUND: Occlusal stability is one of the goals of orthodontic treatment, and keeping teeth aligned in the long term is a challenge for the orthodontist. This study aimed to compare the long-term incisors irregularity and dental arches dimensions changes in subjects treated with 4 premolar extractions with different pretreatment Little's irregularity index (LII). The knowledge of long-term outcomes is evidence-based information for the prognosis of future treatments. METHODS: In total, 41 treated subjects were divided into two groups according to mandibular Little irregularity value at pretreatment (mild or severe). The maxillary and mandibular LII, transversal, and longitudinal widths were assessed at pretreatment, posttreatment, and 37-year posttreatment. Chi-square and independent t tests were used for intergroup comparison. RESULTS: The groups presented similar behavior for all stages of maxillary and mandibular arch dimensions changes. Maxillary irregularity was corrected in both groups after treatment, and the alignment was acceptable in the long term. In the mild group, the mandibular incisor irregularity returned to pretreatment values in the long term. The mandibular LII increased in the severe group but did not return to pretreatment values in the long term. CONCLUSIONS: The mild crowding group presented proportionally more relapse of mandibular incisor irregularity than the severe crowding group in the long term. Even so, the correction of mild and severe crowding with the extraction of 4 premolars showed satisfactory results in the long term, even with the presence of maturational changes and relapse.

Dental arch changes comparison between Expander with Differential Opening, Hyrax-type and Haas-type expanders: A prospective clinical study.

OBJECTIVE: Compare changes in arch form after RME achieved by Expander with Differential Opening (EDO), Hyrax-type and Haas-type expanders. MATERIALS AND METHODS: Dental models were obtained from 61 patients aged 7-11 years before expansion (T1) and 6 months after the active phase when the appliances were removed (T2). The groups were formed according to the expander used: EDO (n = 18, mean age: 9.46 ± 0.82 years), Hyrax-type (n = 22, mean age: 9.62 ± 1.57 years) and Haas-type (n = 21, mean age: 9.29 ± 1.05 years). The expander`s activation protocol consisted of 7 mm, except for EDO`s anterior screw, which was 9 mm. The measurements of upper and lower intercanine distance, inter-first permanent molar, arch perimeter and length, maxillary canine and first-permanent molar inclination, and palatal depth were performed using the OrthoAnalyzer 3D software. Intergroup comparisons of T1 and between changes (T2-T1) were performed using ANOVA followed by Tukey. RESULTS: In the upper intercanine distance EDO provided a greater increase than Haas-type. In the distance between upper fist permanent molars EDO showed higher values than Haas-type and Hyrax-type. In the lower intercanine distance and maxillary arch length, Haas-type promoted higher increase than EDO. CONCLUSIONS: The EDO promoted greater transverse changes in anterior region than Haas-type and greater transverse changes in posterior region of the maxilla than both conventional expanders. The appliance used for RME influences dental arch changes after treatment; therefore, it is recommended to individualize the choice of expander depending on the clinical necessity of each case.