Three-dimensional assessment of mandibular asymmetry in patients with unilateral cleft lip and palate at different growth stages: a cross-sectional study.

INTRODUCTION: The early diagnosis of mandibular asymmetry (MA) in patients with unilateral cleft lip and palate (UCLP) can contribute to its treatment. OBJECTIVE: The aim of this study was to evaluate the occurrence and the extent of MA in UCLP patients at different growth stages. METHODS: Cone-beam computed tomography (CBCT) of 47 UCLP patients were included, and divided into two groups (prepubertal stage and pubertal stage). The mandibular ramus height (Co-Go), mandibular body length (Go-Me), total mandibular length (Co-Me), gonial angle (CoGoMe), the volume of the mandibular condyles, and lateral chin deviation were evaluated. The cleft side (CS) and noncleft side (NCS) were compared using the paired t-test for dependent samples. Chin deviation and its possible association with specific sides were evaluated using the Mann-Whitney and Fisher's Exact tests, respectively. The significance level was set at 5%. RESULTS: Comparison of CS and NCS revealed that in prepubertal stage, Co-Me was shorter (105.5 ± 5.7 mm; p = 0.036) in the CS, and that in pubertal stage, Co-Go was lower (46 ± 6 mm; p= 0.004) and Go-Me was greater (78.5 ± 5.8 mm; p = 0.026) in the CS. In both growth stages, a significant association (p< 0.05) was observed between the side to which the chin has deviated and the CS. CONCLUSIONS: Although patients with UCLP in the prepubertal and pubertal stages presented significant measurements revealing MA, only Co-Go in the pubertal stage showed a clinically relevant difference. This specific result indicates that MA must be monitored during patients' growth.

Investigation of the association between COX-2 polymorphisms and external apical root resorption in orthodontically treated patients.

OBJECTIVE: To evaluate the association between single nucleotide polymorphisms (SNPs) in cyclooxygenase-2 (COX-2) and external apical root resorption (EARR) after orthodontic treatment. MATERIALS AND METHODS: This study analyzed the orthodontic records of patients from Regensburg University Hospital and two collaborating private practices. EARR was analyzed in the maxillary central incisors and first mandibular molars using pre- and post-treatment cephalometric and panoramic radiographs, respectively. Genomic DNA was obtained from salivary oral cells. Two SNPs in COX-2, rs5275 (3 prime untranslated region variant) and rs689466 (upstream transcript variant, downstream transcript variant), were genotyped using real-time Polymerase chain reaction (PCR). The linear regression models were fitted to assess the effects of the evaluated SNPs at a significance level of 5%. RESULTS: A total of 143 biologically unrelated patients (mean age: 13.5 ± 4.5 years) were included in the study. The F-test showed that only the regression for EARR in the mandibular molars in the dominant model for rs5275 G allele had a good fit (F = 3.50, P = 0.034). The model showed that individuals carrying at least one G allele for rs5275 had a 17% increase in EARR in the molars compared to common AA homozygotes (exp(B) = 1.17; 95% CI: 1.04, 1.32; P = 0.010). Although an effect of the G allele (rs5275) was detected, this effect did not explain much of the variability in EARR (adjusted R2 = 0.04). CONCLUSION: The results suggested that patients carrying the polymorphic form of the rs5275 were more likely to have EARR in the mandibular molars; therefore, COX-2 could have an effect on EARR. CLINICAL RELEVANCE: The knowledge of the genetic background concerning EARR after orthodontic treatment would aid in clinical practice to screen for associated genetic factors and potentially aid its prevention and management, considering that patients' genetic profiles would soon be available.

Impact of Postnatal Head Circumference Growth in Normocephalic Infants Prenatally exposed to Zika Virus in Puerto Rico.

OBJECTIVE: We aimed to describe the head circumference (HC) growth trends for non-microcephalic infants exposed to the Zika virus (ZIKV) in utero. METHODS: This was a medical record review of non-microcephalic neonates exposed to ZIKV whose mothers received prenatal care at the fetal evaluation unit (2015-2017). The mean HC values of babies from prenatal age to 1 year old were compared with the standardized values on HC growth charts. RESULTS: Sixty-three mother-infant pairs were included, and 56 infants (boys, 30%; girls, 70%) were evaluated. The mothers tested positive for ZIKV; their babies had a mean gestational age of 38 weeks (32-42) and a mean birth weight of 3,150 grams (1,190-4,220). The mean HC growth of the fetuses (19-34 weeks gestational age) placed them in the 25th percentile, increasing to the 50th percentile (according to the World Health Organization [WHO]). Compared with other growth charts (INTERGROWTH- 21st [International Fetal and Newborn Growth Consortium for the 21st Century] and Puerto Rico reference values), the mean HC grew in the 50th percentile at 18 to 30 weeks of gestational age, indicating normal growth in children from Zika-positive women. According to the WHO chart, the postnatal HCs of both the girls and boys reached the 75th and 50th percentiles, respectively. CONCLUSION: Postnatal HC growth was normal. Results from this study suggest that infants exposed to ZIKV in utero can be normocephalic at birth. Therefore, the neurodevelopmental outcomes of such infants should be followed throughout childhood and adolescence, regardless of their HCs at birth.

Maxillary protraction anchored on miniplates versus miniscrews: three-dimensional dentoskeletal comparison.

OBJECTIVE: This retrospective study aimed to compare the three-dimensional (3D) outcomes of the novel miniscrew-anchored maxillary protraction (MAMP) therapy and the bone-anchored maxillary protraction (BAMP) therapy. METHODS: The sample comprised growing patients with skeletal Class III malocclusion treated with two skeletal anchored maxillary protraction protocols. The MAMP group comprised 22 patients (9 female, 13 male; 10.9 ±â€…0.9 years of age at baseline) treated with Class III elastics anchored on a hybrid hyrax expander in the maxilla and two mandibular miniscrews distally to the permanent canines. The BAMP group comprised 24 patients (14 female, 10 male; 11.6 ±â€…1.1 years of age at baseline) treated with Class III elastic anchored in two titanium miniplates in the infra-zygomatic crest and two miniplates in the mesial of the mandibular permanent canines. Three-dimensional displacements were measured in the pre- and post-treatment cone-beam computed tomography scans superimposed on the cranial base using the Slicer Automated Dental Tools module of 3D Slicer software (www.slicer.org). Mean differences (MD) between groups and 95% confidence interval (CI) were obtained for all variables. Intergroup comparison was performed using the Analysis of Covariance (P < .05). RESULTS: Both groups showed improvements after treatment. The MAMP group showed a smaller anterior (MD: -1.09 mm; 95% CI, -2.07 to -0.56) and 3D (MD: -1.27 mm; 95% CI, -2.16 to -0.74) displacements of the maxilla after treatment when compared with BAMP. Both groups showed negligible and similar anteroposterior changes in the mandible (MD: 0.33 mm; 95% CI, -2.15 to 1.34). A greater increase in the nasal cavity width (MD of 2.36; 95% CI, 1.97-3.05) was observed in the MAMP group when compared with BAMP. LIMITATIONS: The absence of an untreated control group to assess the possible growth impact in these findings is a limitation of this study. CONCLUSION: Both BAMP and MAMP therapies showed adequate 3D outcomes after treatment. However, BAMP therapy produced a greater maxillary advancement with treatment, while MAMP therapy showed greater transversal increases in the nasal cavity.

Heights of maxillary sinus and piriform aperture are valuable in sex prediction: a cone beam computed tomography study.

PURPOSE: This study utilized cone-beam computed tomography images to assess the potential of maxillary sinus (MS) and piriform aperture (PA) measurements in sex prediction and to identify possible correlations between these structures and the MS ostium. METHODS: A total of 204 images were selected and divided into two groups: 102 for constructing and testing the formula, and 102 for validation. In each subgroup, the images were equally divided for 11 measurements by two examiners in the MS (height, width, length, and total width), PA (height and width), and maxillary ostium diameter. RESULTS: Significant correlations were found in males and in the total analysis for all measurements of the right MS, while the length of the left MS showed a positive correlation with PA height. In the total analysis, the height of the left MS and the total width along the MS also positively correlated with PA height. When tested, the constructed formula resulted in an accuracy of 82.4%. CONCLUSION: Tomographic images proved to be excellent tools for sex prediction, as the measurements described in this study could be reproduced and analyzed in different populations, considering that craniometric characteristics may vary across populations.

Estándares de perímetro cefálico argentinos y de la Organización Mundial de la Salud: estudio comparativo / Argentine and World Health Organization head circumference standards: A comparison study

Introducción. Diversos estudios han evidenciado diferencias poblacionales en el tamaño cefálico que cuestionan la validez universal del estándar de la Organización Mundial de la Salud (OMS) para evaluar el crecimiento cefálico. Objetivos. Comparar las referencias argentinas de perímetro cefálico (PC) de 0 a 5 años con los estándares de la OMS. Población y métodos. Se compararon los percentiles 3 y 97 de PC de las referencias argentinas con los correspondientes del estándar de la OMS y se calcularon los porcentajes de niños clasificados como microcefálicos (PC < percentil 3 de la OMS) y macrocefálicos (PC > percentil 97 de la OMS) a edades específicas entre el nacimiento y los 5 años de edad. Resultados. La comparación de las referencias argentinas con los estándares de la OMS, muestra que ­en ambos sexos­ en el percentil 3, desde el primer mes y hasta los 6 meses, las referencias argentinas se encuentran por debajo de los estándares de la OMS, son similares entre los 9 y 18 meses, y luego se ubican por encima hasta los 60 meses. En relación con el percentil 97, las referencias argentinas se ubican por encima de los estándares de la OMS desde el nacimiento hasta los 60 meses en ambos sexos. Conclusiones. El tamaño cefálico de los niños y niñas argentinos difiere del de los estándares de la OMS. La adopción de los estándares de la OMS en nuestra población incrementa el porcentaje de diagnóstico de macrocefalia a todas las edades.

Introduction. Several studies have shown population differences in head circumference (HC) that question the universal validity of the World Health Organization (WHO) standard to assess head growth. Objectives. To compare the Argentine reference charts for HC from 0 to 5 years of age with the WHO standards. Population and methods. The 3rd and 97th percentiles for HC based on the Argentine reference charts were compared with the corresponding WHO standard and the percentage of children classified as having microcephaly (HC < 3rd percentile of the WHO) and macrocephaly (HC > 97th percentile of the WHO) at specific ages between 0 and 5 years were estimated. Results. The comparison of the Argentine reference charts with the WHO standards shows that, in both males and females, at the 3rd percentile, the Argentine reference charts are below the WHO standards from 1 to 6 months of age, similar from 9 to 18 months of age, and then above until 60 months old. In relation to the 97th percentile, the Argentine reference charts are above the WHO standards from birth to 60 months in both boys and girls. Conclusions. The head size of Argentine children is different from that established by the WHO standards. The adoption of the WHO standards for our population increases the percentage of macrocephaly diagnosis at all ages.

Artificial intelligence model for predicting sexual dimorphism through the hyoid bone in adult patients.

The objective of this study was to develop a predictive model using supervised machine learning to determine sex based on the dimensions of the hyoid bone. Lateral cephalometric radiographs of 495 patients were analyzed, collecting the horizontal and vertical dimensions of the hyoid bone, as well as the distance from the hyoid to the mandible. The following algorithms were trained: Logistic Regression, Gradient Boosting Classifier, K-Nearest Neighbors (KNN), Support Vector Machine (SVM), Multilayer Perceptron Classifier (MLP), Decision Tree, AdaBoost Classifier, and Random Forest Classifier. A 5-fold cross-validation approach was used to validate each model. Model evaluation metrics included areas under the curve (AUC), accuracy, recall, precision, F1 score, and ROC curves. The horizontal dimension of the hyoid bone demonstrated the highest predictive power across all evaluated models. The AUC values of the different trained models ranged from 0.81 to 0.86 on test data and from 0.78 to 0.84 in cross-validation, with the random forest classifier achieving the highest accuracy rates. The supervised machine learning model showed good predictive accuracy, indicating the model's potential for sex determination in forensic and anthropological contexts. These findings suggest that the application of artificial intelligence methods can enhance the accuracy of sex estimation, contributing to significant advancements in the field.

Sex prediction through machine learning utilizing mandibular condyles, coronoid processes, and sigmoid notches features.

Characteristics of the mandible structures have been relevant in anthropological and forensic studies for sex prediction. This study aims to evaluate the coronoid process, condyle, and sigmoid notch patterns in sex prediction through supervised machine learning algorithms. Cephalometric radiographs from 410 dental records of patients were screened to investigate the morphology of the coronoid process, condyle, and sigmoid notch and the Co-Gn distance. The following machine learning algorithms were used to build the predictive models: Decision Tree, Gradient Boosting Classifier, K-Nearest Neighbors (KNN), Logistic Regression, Multilayer Perceptron Classifier, Random Forest Classifier, and Support Vector Machine (SVM). A 5-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 ROC curves were constructed. All tested variables demonstrated statistical significance (p < 0.10) and were included in the construction of the predictive model. The Co-Gn variable stood out as the most important among the evaluated independent variables, showing greater relevance in three of the four algorithms used in assessing feature importance. In the analysis of the models' performance, the AUC ranged from 0.82 [95% CI = 0.72-0.93] to 0.66 [95% CI = 0.53-0.76] for the test data, and from 0.83 [95% CI = 0.80-0.87] to 0.71 [95% CI = 0.61-0.75] for cross-validation. The precision of the models ranged from 0.83 [95% CI = 0.75-0.91] to 0.68 [95% CI = 0.58-0.78] in the test phase, and from 0.78 [95% CI = 0.74-0.82] to 0.69 [95% CI = 0.65-0.75] in cross-validation. The SVM, KNN, and Gradient Boosting Classifier algorithms stood out with the highest AUC and precision values in both cross-validation and testing. The use of condyle, coronoid process, and sigmoid notch characteristics, in combination with supervised machine learning predictive models, shows potential for contributing to sex prediction based on morphometric bone characteristics, particularly regarding the distance between the condyle and gnathion. However, given the study's limitations, these findings should be interpreted with caution.

Head circumference and intelligence, schooling, employment, and income: a systematic review.

BACKGROUND: No consensus exists about the role of head circumference in identifying children at risk of suboptimal development. The objective of this study was to evaluate the association between head circumference and intelligence, schooling, employment, and income. The review 1) summarizes the overall evidence and 2) restricts the evidence to a subset of articles that met minimum quality criteria. METHODS: PubMed, Web of Science, PsycINFO, LILACS, CINAHL, WHO Institutional Repository for Information Sharing and UNICEF Innocenti were searched to identify published studies. Cohort, case-control or cross-sectional studies which evaluated the associations of interest in the general population, premature babies, babies with low birth weight or small for gestational age were included; head circumference must have been measured before the age of 20 years. Two reviewers independently performed study selection, data extraction and quality assessments. RESULTS: Of 2521 records identified, 115 were included and 21 met the minimum quality criteria. Ninety studies investigated if early measures of head circumference predict later outcomes and 25 studies measured head circumference and the outcome at the same timepoint; 78 studies adjusted the head circumference for age and sex. We identified large heterogeneity and inconsistency in the effect measures and data reported across studies. Despite the relatively large number of included articles, more than 80% presented serious limitations such as lack of adjustment for confounding and severe selection bias. Considering the subset of articles which met the minimum quality criteria, 12 of 16 articles showed positive association between head circumference and intelligence in the general population. However, in premature babies, 2 of 3 articles showed no clear effect. Head circumference was positively associated with academic performance in all investigated samples (5 of 5 articles). No article which evaluated educational attainment and employment met the minimum quality criteria, but the association between head circumference and these outcomes seems to be positive. CONCLUSIONS: Larger head circumferences are positively associated with higher levels of intelligence and academic performance in the general population, but there is evidence of non-linearity in those associations. Identifying a group of children in higher risk for worse outcomes by a simple and inexpensive tool could provide an opportunity to mitigate these negative effects. Further research is needed for a deeper understanding of the whole distribution of head circumference and its effect in premature babies. Authors should consider the non-linearity of the association in the data analysis. TRIAL REGISTRATION: Association between head circumference and intelligence, educational attainment, employment, and income: A systematic review, CRD42021289998 .

Facial morphology analysis of Caucasian Brazilian adult women using stereophotogrammetry.

This cross-sectional observational study aimed to evaluate and compare facial metrics in women aged 20-65 years using a three-dimensional (3D) stereophotogrammetry system and to establish standardized values for facial metric variations in different age subgroups. This study included 84 Caucasian women divided into two groups based on their age: group 1 (G1) included women aged 20-40 years and group 2 (G2) included women aged 41-65 years. Twenty-one morphometric points on the face were identified, and the facial images were captured using a 3D stereophotogrammetry system, Twenty-three linear measures and 12 angular measures were evaluated, revealing statistically significant differences in 11 linear and 5 angular measures between the groups. In the G2 group, nasal and mouth width, lip philtrum height, Tragus-Nasion and Tragus-Pronasale lengths were increased, along with increased nasofrontal angle, decreased palpebral fissure inclination, and lip vermilion angles. However, palpebral fissure width and height, binocular width, and lip vermilion height were reduced. The aging process in women causes substantial changes in facial features, particularly in the middle and lower thirds of the face. Conversely, no major changes were observed in the upper third of the face. Our study findings provide potential insights for clinicians in developing facial rejuvenation procedures as well as for forensic purposes and surgical planning. The standardized facial metrics values in different age subgroups can guide clinicians in determining appropriate treatment plans for patients seeking facial rejuvenation.

Facial soft tissue changes in adolescent patients treated with three different functional appliances: a randomized clinical trial.

INTRODUCTION: Patients with Class II, division 1 malocclusion generally seek treatment to improve facial esthetics. Therefore, the orthodontist needs to know the changes in the soft profile produced by functional appliances. OBJECTIVE: This study evaluated the soft tissue profile changes in patients treated during the peak of the pubertal growth spurt. METHODS: Thirty selected patients were randomized into three treatment groups: Twin Block (TB), Herbst with dental anchorage (HDA), and Herbst with skeletal anchorage (HSA). All patients had computed tomographic images: pretreatment (T1) and after 12 months of active treatment (T2). Twenty-four soft tissue cephalometric measures were analyzed. The normality of all data was assessed by the Shapiro-Wilk test. Intragroup comparisons were analyzed using the t-paired test; the inter-group comparisons were determined through ANOVA and the post-hoc Tukey test. RESULTS: At T1, no significant differences were observed between groups. At T2, in the intragroup comparison, facial soft tissue changes were statistically significant in the three groups for the lower lip, sulcus inferioris, facial soft tissue convexity in HDA group and TB group, and H angle in HDA group and HSA group, and soft tissue pogonium in TB group. In the inter-group comparison, no statistically significant differences were observed. CONCLUSION: It can be concluded that there were significant changes in soft tissue measurements that benefited Class II, division 1 patient's facial profile treated with the functional appliances Twin Block, Herbst, and Herbst with skeletal anchorage. Nevertheless, no significant differences were detected among the effects obtained by the three treatment protocols.

Tomographic diagnosis of alveolar bone coverage impact in orthodontic planning: cross-sectional study.

INTRODUCTION: Alveolar bone coverage can be diagnosed through cone beam computed tomography (CBCT) and this information can prevent orthodontic tooth movement beyond the biological limit. OBJECTIVE: This study evaluated the impact of the bone coverage (BC) diagnosis by CBCT in the orthodontists' planning. METHODS: One hundred fifty-nine Brazilian orthodontists suggested treatment plans for six patients at two different times, using two sequential questionnaires. The first questionnaire consisted of extra and intra-oral photographs, one panoramic radiograph; one lateral cephalometric radiograph with Steiner and Tweed analysis, and the patient chief complaint. The second questionnaire included the same presentations of cases with tomographic images and the radiologist's report. The McNemar test assessed the difference between the first and the second treatment plans. RESULTS: In all six cases, most participants changed the treatment plan after evaluating the CBCT images and the radiologist's report (93.7% in case 5, 78.6% in case 4, 74.2% in case 3, 69.8% in case 6, 66% in case 2 and 61% in case 1; p≤0.01). CONCLUSION: The evaluation of bone coverage through CBCT images has a substantial impact on the orthodontic diagnosis and planning of the Brazilian orthodontists.

Descriptive analysis of the cases published in the Align® Global Gallery.

INTRODUCTION: Social media enhanced access to information, making it easier to share dental treatments. OBJECTIVE: This study aimed to conduct a descriptive analysis of the clinical cases published on the Align® Global Gallery platform. MATERIAL AND METHODS: A retrospective cross-sectional study of 1,582 cases was conducted, data extracted referred to the following basic information: case number; patient's age; reported gender; Invisalign® package modality; treatment time; aligner exchange protocol; total number of aligners per arch; type of retainers, and inclusion of initial and final panoramic and cephalometric radiographs. RESULTS: The majority were young (mean age 24.6 years, SD = 11.6), female patients (69.1%) with Class I malocclusion (39.4%) and crowding (77.9%). Comprehensive treatment was common (66.5%), with an average treatment time of 18 months (SD = 8.56; 95% CI = 17.6-18.5), with the most frequently reported aligner exchange protocol being 7 days (49.5%), with an average of 50.6 aligners in the upper arch (SD = 26.9; 95% CI = 49.2-51.9), and 48.7 in the lower arch (SD = 26.1; 95% CI = 47.4-50.0). Arch expansion (66.9%) and interproximal reduction (59.7%) were common approaches, while extractions were rare (4.3%). In most cases, initial lateral cephalometric (80.4%) and panoramic (93.3%) radiographs were presented. However, the final radiograph count dropped, with lateral cephalometric at 69.2%, and panoramic at 82.2% of cases. CONCLUSION: Cases in the Align®Global Gallery mostly feature Class I patients with crowded teeth, treated with expansion and interproximal reduction. The absence of standardized information and post-treatment data restricts the applicability of these findings to broader Invisalign® treatment trends.

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.

Referencias argentinas de perímetro cefálico desde el nacimiento hasta los 19 años / Argentine reference charts for head circumference from birth to 19 years of age

Introducción. El perímetro cefálico (PC) es un indicador del crecimiento cerebral y es necesario contar con referencias de crecimiento que permitan determinar variaciones normales o patológicas. Objetivos. Presentar las primeras referencias argentinas de perímetro cefálico entre el nacimiento y los 19 años, y compararlas con las referencias de Nellhaus, utilizadas en nuestro país hasta la actualidad. Población y métodos. Para la construcción de estas referencias, se combinaron datos de la Encuesta Nacional de Nutrición y Salud 2018 y estudios transversales realizados entre 2004 y 2007 en las provincias de Buenos Aires y La Pampa, que incluyeron 8326 niños, niñas y adolescentes sanos. Las curvas de crecimiento fueron ajustadas con el método LMS. Para evaluar la magnitud de las diferencias entre estas referencias y las de Nellhaus, a diferentes edades, se graficaron los centilos 2, 50 y 98. Resultados. El PC mostró un incremento de tamaño variable con la edad, de mayor magnitud en los primeros años de vida, y un ligero incremento en la pubertad. Los valores del centilo 98 de las referencias argentinas fueron mayores que los de Nellhaus en todas las edades. Los valores del centilo 2 de la referencia nacional fueron menores que los de Nellhaus durante los primeros 2 años de vida, similares entre los 3 y 7 años, y mayores a partir de esta edad. Conclusiones. Las curvas argentinas describen adecuadamente el patrón de crecimiento del PC. Las diferencias halladas con la referencia de Nellhaus pueden atribuirse a cambios seculares.

Introduction. Head circumference (HC) is an indicator of brain growth; growth charts are necessary to determine normal or pathological variations. Objectives. To present the first Argentine HC reference charts between birth and 19 years of age and to compare them with the Nellhaus charts, which have been used in our country to date. Population and methods. These references were developed based on combined data from the National Survey on Nutrition and Health of 2018 and cross-sectional studies conducted between 2004 and 2007 in the provinces of Buenos Aires and La Pampa, which included 8326 healthy children and adolescents. Growth curves were adjusted using the LMS method. To assess the differences between these reference charts and the Nellhaus charts, at different ages, the 2nd, 50th, and 98th percentiles were plotted. Results. HC showed a variable increase in size with age, which was greater in the first years of life, and a slight increase at puberty. The values for the 98th percentile of the Argentine reference charts were higher than those of the Nellhaus charts at all ages. The values for the 2 nd percentile of the national reference were lower than those of the Nellhaus charts during the first 2 years of life, similar between 3 and 7 years of age, and higher after this age. Conclusions. The Argentine curves adequately describe the growth pattern of HC. The differences found with the Nellhaus charts may be attributed to secular changes.

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.

Disparate and parallel craniofacial climatic adaptations in native populations of Asia, North America, and South America.

Understanding the impact that climate had in shaping cranial variation is critical for inferring the evolutionary mechanisms that played a role in human diversification. Here, we provide a comprehensive study aiming to analyze the association between climate and cranial variation of high latitude populations living in temperate to cold environments of Asia, North America, and South America. For this, we compiled a large morphometric dataset (N = 2633), which was combined with climatic and genomic data. We tested the influence of climate on the facial skeleton, nasal protrusion, and cranial vault and through multiple statistical tests at two geographical scales: intracontinental and intercontinental. We show that populations living in cold areas share a morphological pattern characterized by an increase in nasal height, facial and orbital heights and widths, a decrease in facial protrusion, and larger, longer, and lower cranial vaults. There are also distinctive features; populations from north Asia present the tallest noses, largest faces, and cranial vaults of the whole sample. Nasal breadth dimensions show small values in Asians, large values in South Americans, and non-significant changes in arctic North America. The morphological pattern in populations living at high latitude may be the result of parallel adaptation, as supported by physiological, morphometric, ecological, and genetic explanations, while the differences in magnitude and phenotypic expression could be due to the diverse population histories, severity of climate, and cultural strategies. Overall, our study shows that climate is a relevant factor shaping modern human morphology and it should be considered when studying modern human evolution and diversification.

Variabilidad en la medición del ángulo ANB de Steiner entre estudiantes de odontología y ortodoncia. Medición del Angulo ANB de Steiner / Variability in Steiners ANB angle measurement between undergraduate dental students and postgraduate students in orthodontics

Introducción: El ángulo ANB de Steiner entrega la relación entre el maxilar y la mandíbula en sentido anteroposterior y es una de las medidas cefalométricas más aplicadas en ortodoncia. Su identificación precisa podría presentar dificultades, influyendo directamente en el posterior estudio cefalométrico, diagnóstico y plan de tratamiento. El objetivo de esta investigación fue comparar la medición del ángulo ANB de Steiner entre estudiantes de pregrado de odontología y postítulo de ortodoncia de la Facultad de Odontología de la Universidad de Chile 2020. Materiales y Métodos: Por medio del programa Adobe Photoshop CS6 (Adobe System ®), se solicitó a los estudiantes la identificación de los puntos Nasion, A y B en 5 telerradiografías laterales de cráneo. Al aplicar los criterios de inclusión y exclusión se reclutaron 15 estudiantes de cada grupo. Luego se unieron los puntos mediante trazados, se midió el ángulo ANB de Steiner y se utilizó el coeficiente de correlación intraclase (ICC) para determinar el grado de acuerdo. Resultados: Se encontró un coeficiente de correlación intraclase ICC promedio de 0.97 entre ambos grupos de estudiantes. Conclusión: No hay diferencia estadística en la determinación del ángulo ANB de Steiner entre estudiantes de pregrado de odontología y postítulo de ortodoncia.

Background: The Steiner ANB angle measures the relationship between the maxilla and mandible in the anteroposterior direction and is one of the most applied cephalometric measurements in orthodontics. Its precise identification could pose difficulties, directly influencing the subsequent cephalometric study, diagnosis and treatment plan. The aim of this research was to compare the measurement of the Steiner ANB angle between dental student and postgraduate students in orthodontics from the Faculty of Dentistry of the University of Chile 2020. Materials and Methods: Using the Adobe Photoshop CS6 program (Adobe System ®), the students were asked to identify the Nasion, A and B points in 5 lateral cephalogram of the skull. By applying the inclusion and exclusion criteria, 15 students were recruited from each group. The points were then joined by tracing, the Steiner ANB angle was measured, and the intraclass correlation coefficient (ICC) was used to determine the degree of agreement. Results: An average ICC intraclass correlation coefficient of 0.97 was found between both groups of students. Conclusion: T here is no statistical difference in the determination of the Steiner ANB angle between undergraduate students of dentistry and postgraduate students of orthodontics.

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.