Assessing the association between vitamin D receptor and dental age variability.

OBJECTIVES: To explore the association between genetic polymorphisms in vitamin D receptor (VDR), vitamin D serum levels, and variability in dental age. MATERIAL AND METHODS: This cross-sectional study was based on an oral examination, panoramic radiograph analysis, and genotype analysis from biological samples. Dental age was evaluated using two different methods: Demirjian et al. (Hum Biol 45:211-227, 1973) and Hofmann et al. (J Orofac Orthop.78:97-111, 2017). The genetic polymorphisms BglI (rs739837) and FokI (rs2228570) in VDR were genotyped through real-time PCR. The vitamin D level was also measured in the serum. Delta (dental age-chronological age) was compared among genotypes in VDR in the co-dominant model. Multiple linear regression analysis was also performed. An established alpha of 5% was used. RESULTS: Genotype distributions of BglI and FokI were not associated with dental maturity (p > 0.05). In the logistic regression analyses, genotypes in BglI and FokI and vitamin D levels were not associated with variability in dental age (p > 0.05). CONCLUSIONS: The genetic polymorphisms BglI and FokI in VDR and the vitamin D levels were not associated with variability in dental age. CLINICAL RELEVANCE: To unravel the factors involved in dental maturity can improve dental treatment planning in pediatric and orthodontic practice.

Correlation between Insulin-Like Growth Factor I and Skeletal Maturity Indicators.

Objective: The purpose of this study was to evaluate the correlation between the growth maturity indicators in orthodontic patients. Design: This cross-sectional study was performed on 37 orthodontic patients (17 males and 20 females). An anamnesis, clinical and image examination, and blood sample collection were performed. The inclusion criteria were non-syndromic Class II patients of both gender, age ranging between 10 to 16 years. The lateral cephalometric radiographs were evaluated using 6-stage cervical vertebrae maturation (CVM) technique. The hand-wrist radiographs were staged using the 11-stage skeletal maturation indicator (SMI) technique. Blood was collected in the same week of the images to quantify IGF-1 levels in serum. Data were tested for normality by Shapiro-Wilk test. The Pearson test was used to determine the correlation strength between the variables (alpha of 5%). Results: A strong correlation was observed only between SMI stages and CVM stages in the total sample (r=0.864; p<0.0001) and according to the gender (r=0.793; p<0.0001 for females; and r=0.753; p<0.0001 for males). IGF-1 was only moderately correlated with SMI stages and CVM stages. Conclusion: Hand-wrist and cervical vertebral stages were strongly correlated among them, however, IGF-1 was only moderately correlated with both skeletal maturity indicators.

Dentoalveolar Evaluation of Lower Incisors by CBCT after Treatment with Herbst Appliance.

This study aimed to evaluate the effects of the Herbst appliance on the proclination and protrusion of the lower incisors, and to verify if the device causes alveolar bone loss in the anterior region of the mandible. This is a retrospective study. The sample consisted of 35 individuals. The treatment group consisted of 22 individuals (8 girls and 14 boys; initial mean age of 8.2 years) who used the Cantilever Herbst appliance for a period of 12 months. The control group consisted of 13 individuals (3 girls and 10 boys; initial mean age of 8.9 years) who received no treatment and were followed up for a period of approximately 18 months. Cone-beam computed tomography scans were performed at the beginning and at the end of the observational period. The medullary bone thickness (MT), buccal cortical bone thickness (BCT), lingual cortical bone thickness (LCT), and lower incisors proclination and protrusion were evaluated. Data were submitted to statistical analysis (ANCOVA and Student's t-test) with a significance level of 5%. There was no significant difference in MT, BCT, LCT and incisor proclination between groups. Incisor proclination increased in the treated group with no statistical significance. The treatment group showed a significant increase in the protrusion of the incisors (p = 0.02). The Herbst appliance promoted a small proclination and protrusion of the lower incisors, without relevant clinical implications. The Herbst appliance did not cause bone loss in the anterior region of the mandible during Class II treatment.

Dentoalveolar evaluation of lower incisors by cbct after treatment with herbst appliance

Abstract This study aimed to evaluate the effects of the Herbst appliance on the proclination and protrusion of the lower incisors, and to verify if the device causes alveolar bone loss in the anterior region of the mandible. This is a retrospective study. The sample consisted of 35 individuals. The treatment group consisted of 22 individuals (8 girls and 14 boys; initial mean age of 8.2 years) who used the Cantilever Herbst appliance for a period of 12 months. The control group consisted of 13 individuals (3 girls and 10 boys; initial mean age of 8.9 years) who received no treatment and were followed up for a period of approximately 18 months. Cone-beam computed tomography scans were performed at the beginning and at the end of the observational period. The medullary bone thickness (MT), buccal cortical bone thickness (BCT), lingual cortical bone thickness (LCT), and lower incisors proclination and protrusion were evaluated. Data were submitted to statistical analysis (ANCOVA and Student's t-test) with a significance level of 5%. There was no significant difference in MT, BCT, LCT and incisor proclination between groups. Incisor proclination increased in the treated group with no statistical significance. The treatment group showed a significant increase in the protrusion of the incisors (p = 0.02). The Herbst appliance promoted a small proclination and protrusion of the lower incisors, without relevant clinical implications. The Herbst appliance did not cause bone loss in the anterior region of the mandible during Class II treatment.

Resumo O objetivo deste estudo foi avaliar os efeitos do aparelho de Herbst na proclinação e protrusão dos incisivos inferiores, bem como verificar se o aparelho causa perda óssea alveolar na região anterior da mandíbula. Trata-se de um estudo retrospectivo. Foi utilizada uma amostra de 35 indivíduos. O grupo tratado foi formado por 22 indivíduos (8 meninas e 14 meninos; idade média inicial de 8,2 anos) que utilizaram o aparelho de Herbst com Cantilever por um período de 12 meses. O grupo controle foi composto por 13 indivíduos (3 meninas e 10 meninos; idade média inicial de 8,9 anos) que não receberam tratamento e foram acompanhados por um período de aproximadamente 18 meses. Exames de tomografia computadorizada de feixe cônico foram realizados no início e no final do período observacional. Foram avaliadas a espessura óssea medular (EM), espessura óssea cortical vestibular (ECV), espessura óssea cortical lingual (ECL), proclinação e protrusão dos incisivos inferiores. Os dados foram submetidos a análise estatística (ANCOVA e teste t de Student) com nível de significância de 5%. Não houve alteração estatisticamente significativa na EM, ECV, ECL e proclinação dos incisivos entre os grupos. Houve um aumento na proclinação dos incisivos no grupo tratado, sem significância estatística. O grupo tratado apresentou aumento significativo na protrusão dos incisivos (p=0,02). O aparelho de Herbst promoveu uma pequena proclinação e protrusão dos incisivos inferiores, sem implicações clínicas relevantes. O aparelho de Herbst não causou perda óssea na região anterior da mandíbula durante o tratamento da Classe II.

Twenty-year clinical experience with fixed functional appliances.

INTRODUCTION: Considering the large number of fixed functional appliances, choosing the best device for your patient is not an easy task. OBJECTIVE: To describe the development of fixed functional appliances as well as our 20-year experience working with them. METHODS: Fixed functional appliances are grouped into flexible, rigid and hybrid. They are different appliances, whose action is described here. Four clinical cases will be reported with a view to illustrating the different appliances. CONCLUSIONS: Rigid fixed functional appliances provide better skeletal results than flexible and hybrid ones. Flexible and hybrid appliances have similar effects to those produced by Class II elastics. They ultimately correct Class II with dentoalveolar changes. From a biomechanical standpoint, fixed functional appliances are more recommended to treat Class II in dolichofacial patients, in comparison to Class II elastics.

Twenty-year clinical experience with fixed functional appliances

ABSTRACT Introduction: Considering the large number of fixed functional appliances, choosing the best device for your patient is not an easy task. Objective: To describe the development of fixed functional appliances as well as our 20-year experience working with them. Methods: Fixed functional appliances are grouped into flexible, rigid and hybrid. They are different appliances, whose action is described here. Four clinical cases will be reported with a view to illustrating the different appliances. Conclusions: Rigid fixed functional appliances provide better skeletal results than flexible and hybrid ones. Flexible and hybrid appliances have similar effects to those produced by Class II elastics. They ultimately correct Class II with dentoalveolar changes. From a biomechanical standpoint, fixed functional appliances are more recommended to treat Class II in dolichofacial patients, in comparison to Class II elastics.

RESUMO Introdução: considerando-se o grande número de aparelhos propulsores mandibulares, não é uma tarefa fácil escolher o melhor deles para o seu paciente. Objetivo: descrever o desenvolvimento desses aparelhos e a experiência clínica de vinte anos dos autores na sua utilização. Métodos: os aparelhos funcionais fixos aqui apresentados foram classificados em flexíveis, rígidos e híbridos, e o modo de ação de cada um deles foi descrito e ilustrado por meio de quatro casos clínicos. Conclusões: os aparelhos propulsores rígidos fornecem mais resultados esqueléticos do que os flexíveis e os híbridos. Esses últimos têm efeito semelhante ao uso de elásticos com direção de Classe II e, basicamente, corrigem a má oclusão de Classe II com alterações dentoalveolares. Do ponto de vista biomecânico, os propulsores fixos estão mais indicados para tratar a Classe II em pacientes dolicofaciais do que os elásticos de Classe II.