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.

Avaliação da correlação entre dor e reações teciduais indesejadas da movimentação dentária induzida por diferentes tipos de força: estudo histomorfométrico, imunoistoquímico e comportamental / Evaluation of the correlation between pain and unwanted tissue reactions of induced tooth movement by different types of force: a histomorphometric, immunohistochemical and behavioral study

Este trabalho teve por objetivo avaliar a correlação entre dor e reações teciduais indesejadas da movimentação dentária induzida (MDI). Verificou-se a correlação entre hialinização no ligamento periodontal (LP) de ratos submetidos à MDI por força contínua (FC) e força contínua interrompida (FCI) e dor, avaliada por meio da presença de mediadores químicos associados à nocicepção ­ ciclooxigenase-2 (COX2) e interleucina-1 beta (IL-1ß) ­ no LP e pelo comportamento dos animais. Foram utilizados 42 ratos machos (Wistar, Rattus norvegicus), com aproximadamente 90 dias e 300g de massa corporal, divididos em 7 grupos de 6 animais: 1 grupo controle e 6 grupos submetidos à MDI por FC e FCI por 1, 3 e 5 dias. Após 7 dias de ambientação, os animais foram submetidos à indução de anquilose do incisivo superior direito e após 14 dias à instalação de dispositivo para MDI. A força aplicada foi de 50cN. Os grupos submetidos à FCI tiveram o dispositivo desativado e reativado durante os períodos experimentais. Foram realizados vídeos para obtenção dos dados comportamentais ao final dos períodos experimentais. A análise histomorfométrica foi utilizada para avaliação da hialinização. A presença de COX-2 e IL-1ß foi avaliada por meio de análise imunoistoquímica. Os seguintes comportamentos foram avaliados: Andando, Escalando, Postura Imóvel, Descansando/Dormindo e Directed Face Grooming. Houve correlação positiva moderada entre hialinização e presença de COX-2 (rs = 0,404, p<0,05) e IL-1ß (rs = 0,429, p<0,05). Também houve correlação negativa moderada entre hialinização e comportamentos exploratórios (Andando, r = -0,586, p<0,01; Escalando, r = -0,573, p<0,01) e correlação positiva moderada entre hialinização e o comportamento Descansando/Dormindo (r = 0,467, p<0,01). Os resultados sugerem que existe correlação entre dor e reações teciduais indesejadas da MDI(AU)

This study aimed to evaluate the correlation between pain and unwanted tissue reactions in response to induced tooth movement (ITM). For this purpose, the correlation between hyalinization in periodontal ligament (PL) of rats submitted to ITM by continuous force (CF) and interrupted continuous force (ICF) and pain was evaluated. Pain was assessed by the presence of chemical mediators associated with nociception ­ cyclooxygenase-2 (COX-2) and interleukin-1 beta (IL-1ß) ­ in the PL and animals' behavior. Forty-two rats (Wistar, Rattus norvegicus) with approximately 90 days and 300g of body weight were used. The animals were divided into 7 groups of 6 animals each: control group and 6 groups submitted to ITM by CF and ICF for 1, 3 and 5 days. After 7 days of habituation the animals underwent ankylosis induction of right upper incisor and after 14 days to installation of the device for ITM. A force of 50cN was applied. The groups submitted to ICF had the device deactivated and reactivated during the experimental periods. Videos were taken to obtain the behavioral data at the end of experimental periods. Histomorphometric analysis was used to evaluate the hyalinization. The presence of COX-2 and IL-1ß was assessed by immunohistochemical analysis. The following behaviors were assessed: Walking, Climbing, Immobile Posture, Resting/Sleeping and Directed Face Grooming. There was a moderate positive correlation between hyalinization and COX-2 (rs = 0.404, p<0.05) and IL-1ß (rs = 0.429, p<0.05). There was also moderate negative correlation between hyalinization and exploratory behavior (Walking, r = -0.586, p <0.01; Climbing, r = -0.573, p <0.01) and moderate positive correlation between hyalinization and the behavior Resting/Sleeping (r = 0.467, p<0.01). The results suggest that there is a correlation between pain and unwanted tissue reactions of ITM(AU)

Assessment of skeletal and dental ages of children and adolescents with type 1 Diabetes Mellitus

The present study aimed to assess the skeletal and dental ages of type 1 diabetes mellitus (T1DM) patients. Therefore, panoramic and hand-wrist radiographs of 82 patients, aged between 5 and 15 years, were collected and divided into case and control groups. The case group consisted of 41 panoramic and 41 hand-wrist radiographs of T1DM patients, whereas the control group consisted of 41 panoramic and 41 hand-wrist radiographs of patients without T1DM. Skeletal age was assessed according to the method of Greulich and Pyle (1999), whereas dental age was assessed according to the method of Nolla (1960). Chi-square tests revealed no statistically significant differences between skeletal and dental ages between the case and control groups (p > 0.05). However, in the case group, the skeletal age of females was greater than that of age-matched males (p = 0.005). Considering that skeletal and dental growth of the case and control groups were closely related, clinical interventions involving orthodontics and dentomaxillofacial orthopedics should be equally performed both for healthy and specific patient groups, such as those with T1DM.

Dental development of children and adolescents with cleft lip and palate

Aim: To evaluate the dental development of Brazilian children and adolescents with cleft lip and palate. Methods: The sample consisted of 107 panoramic radiographs of children and adolescents with cleft lip and/or palate (cleft group) and 107 panoramic radiographs of children and adolescents without cleft lip and/or palate (control group), with chronological ages ranging from 6 to 15 years, matched in gender and chronological age within 60 days. Radiographs were digitized and masked and dental age was assessed using the method described by Demirjian et al. (1973). Three trained examiners conducted the assessments. Each examiner evaluated the radiographs three times. Data were statistically analyzed using non-parametric tests and univariate linear regression (p<0.05). Results: The dental age was overestimated in relation to the chronological age in both groups (p<0.0001). Compared to the control group, there was a delay in the dental age in the cleft group of 0.17 years (2.1 months). However, no statistically significant difference in the dental age between the cleft and the control group was found even when considering the different cleft types (p=0.152). Conclusions: There was no statistically significant difference in the dental age between the cleft and the control groups. The evaluation of dental development in individuals with cleft lip and palate should be approached in the same way as in individuals without clefts, with a focus on the individualization of diagnosis and treatment planning.