RESUMO
Mandibular prognathism (MP) is a recognizable phenotype associated with dentoskeletal class III malocclusion. MP is a complex genetic trait, although familial recurrence also suggests the contribution of single inherited variations. To date, the genetic causes of MP have been investigated using linkage analysis or association studies in pooled families. Here for the first time, next-generation sequencing was used to study a single family with a large number of MP-affected members and to identify MP-related candidate genes. A 6-generation kindred with MP segregating as an autosomal dominant character was recruited. To identify family members affected by MP, a standard cephalometric procedure was used. In 5 MP subjects separated by the largest number of meioses, whole-exome sequencing was performed. Five promising missense gene variants (BMP3, ANXA2, FLNB, HOXA2, and ARHGAP21) associated with MP were selected and genotyped in most other family members. In this family, MP seemed to consist of 2 distinct genetic branches. Interestingly, the Gly1121Ser variant in the ARHGAP21 gene was found to be shared by all MP individuals in the larger branch of the family with nearly complete penetrance. This variant is rare in the Caucasian population (frequency 0.00034) and is predicted as damaging by all bioinformatic algorithms. ARHGAP21 protein strengthens cell-cell adhesions and may be regulated by bone morphogenetic factors, thus influencing mandibular growth. Further studies in both animal models and human patients are required to clarify the significance of this association.
Assuntos
Proteínas Ativadoras de GTPase/genética , Variação Genética/genética , Prognatismo/genética , Adolescente , Adulto , Idoso , Anexina A2/genética , Proteína Morfogenética Óssea 3/genética , Criança , Exoma/genética , Feminino , Filaminas/genética , Genes Dominantes/genética , Estudos de Associação Genética , Ligação Genética/genética , Genótipo , Glicina/genética , Proteínas de Homeodomínio/genética , Humanos , Masculino , Má Oclusão Classe III de Angle/genética , Meiose/genética , Pessoa de Meia-Idade , Mutação de Sentido Incorreto/genética , Linhagem , Penetrância , Análise de Sequência de DNA , Serina/genética , Adulto JovemRESUMO
Orthodontics is a branch of dentistry that aims at the resolution of dental malocclusions. The specialist carries out the treatment using intraoral or extraoral orthodontic appliances that require forces of a given load level to obtain a tooth movement in a certain direction in dental arches. Orthodontic tooth movement is dependent on efficient remodeling of periodontal ligament and alveolar bone, correlated with several biological and mechanical responses of the tissues surrounding the teeth. A periodontal ligament placed under pressure will result in bone resorption whereas a periodontal ligament under tension results in bone formation. In the primary stage of the application of orthodontic forces, an acute inflammation occurs in periodontium. Several proinflammatory cytokines are produced by immune-competent cells migrating by means of dilated capillaries. In this paper we summarize, also through the utilization of animal models, the role of some of these molecules, namely, interleukin-1ß and vascular endothelial growth factor, that are some proliferation markers of osteoclasts and osteoblasts, and the macrophage colony stimulating factor.
Assuntos
Citocinas/biossíntese , Modelos Animais de Doenças , Má Oclusão/terapia , Técnicas de Movimentação Dentária , Fator A de Crescimento do Endotélio Vascular/biossíntese , Animais , Má Oclusão/metabolismo , Má Oclusão/patologia , Osteoblastos/metabolismo , Osteoblastos/patologia , Osteoclastos/metabolismo , Osteoclastos/patologia , RatosRESUMO
AIM: Unilateral posterior crossbite (UPCB) is characterised by an inverse relationship of the upper and lower buccal dental cusps and may involve one or several teeth. The aim of this study was to compare the electromyographic outcomes of patients with UPCB and those of healthy controls. MATERIALS AND METHODS: Fifteen patients (mean age 11.5 years) with UPCB and fifteen healthy controls (mean age 12 years) were examined at the Department of Orthodontics, Second University of Naples. Surface electromyography was performed on patients and controls. RESULTS AND CONCLUSION: Patients with UPCB had less muscle activation than healthy subjects (p<0.0001) and an asymmetric muscle activation with 89.23% muscle balancing for temporals and 83.21% for masseters. The control group showed a 99.32% of muscle balancing for temporals and 97.77% for masseters. These findings suggest that asymmetric muscle activation may influence maxillary and mandibular growth in adolescents with UPCB.
Assuntos
Eletromiografia/métodos , Má Oclusão/fisiopatologia , Músculo Masseter/fisiopatologia , Músculo Temporal/fisiopatologia , Adolescente , Conversão Análogo-Digital , Criança , Feminino , Humanos , Masculino , Contração Muscular/fisiologia , Debilidade Muscular/fisiopatologia , TorqueRESUMO
This cephalometric study was designed to evaluate the dentoskeletal anteroposterior and vertical changes produced by Cetlin therapy (lower lip bumper, ACCO, cervical headgear) to correct Class II Division 1 malocclusion in the late mixed dentition. All measurements were made on 2 lateral headfilms, at pretreatment and at 1 year after beginning treatment. The selected sample (n = 110; 67 boys and 43 girls; mean age, 10 to 11 years) and the control group (n = 100; 48 boys, 52 girls; mean age, 10 to 11 years) matched for number, age, and malocclusion. The average observation interval was 13 months. The final measurements between intervals were averaged and tested for significance by analysis of variance. A one-factor (group) repeated measure model and a two-factor (group and facial type) repeated measure model were fitted to each variable separately and significance values were set at P
