RESUMO
PURPOSE: The aim of this study is to provide new molecular approaches to the children with obstructive sleep apnea syndrome by evaluating the possible involvement of the PHOX2B gene, notoriously associated to congenital central hypoventilation syndrome (CCHS), in Class III malocclusion. METHODS: Fifty subjects with Class III malocclusion, aged from 8 to 14 years, and with history of sleep apneic episodes, and 20 age-matched controls were submitted to genomic DNA examination from oral cells to specifically analyze the PHOX2B genotype. RESULTS: Point "silent" mutations affecting different nucleotides of the PHOX2B gene were observed in 32 % of patients with Class III malocclusion and never in controls (0 %). CONCLUSION: The genetic data obtained in this study in children with Class III malocclusion and sleep-related breathing disorders provide new information useful to the genetic characterization of this pathology. The PHOX2B gene silent mutations can lead to structural and functional modification of their product providing to a group of children with Class III malocclusion similar features to those of CCHS (sleep apnea episodes and craniofacial malformations).
Assuntos
Predisposição Genética para Doença/genética , Proteínas de Homeodomínio/genética , Má Oclusão Classe II de Angle/genética , Apneia Obstrutiva do Sono/genética , Fatores de Transcrição/genética , Adolescente , Criança , Análise Mutacional de DNA , Feminino , Humanos , Masculino , Má Oclusão Classe II de Angle/diagnóstico , Fatores de Risco , Apneia do Sono Tipo Central/diagnóstico , Apneia do Sono Tipo Central/genética , Apneia Obstrutiva do Sono/diagnósticoRESUMO
Dental pulp stem cells (DPSC), a cell type of mesenchymal origin showing high proliferation and plasticity, are an emerging source of adult stem cells offering interesting features in view of potential applications in regenerative medicine. These features prompted us to develop a new method to cryopreserve DPSC inside a whole tooth, thus avoiding the need to purify the cells before cryopreservation and reducing the initial costs and workload of tooth banking. In this study we cryopreserved 4 human deciduous whole teeth after digging micro-channels into the tooth with an Nd:YAG laser beam (laser piercing) to allow the cryopreservative to reach the dental pulp and preserve the cells at -80°C. Then, we isolated, expanded and characterized in vitro the stem cells after tooth thawing and mechanical fracture. In parallel, we characterized cells extracted from 2 teeth cryopreserved without laser piercing and from 4 non cryopreserved, non laser pierced, freshly fractured teeth. Our data demonstrate that DPSC isolated from laser pierced cryopreserved teeth show mesenchymal stem cells morphology, immunophenotype, viability and proliferation rate similar to those of cells isolated from fresh, non cryopreserved teeth, whereas significant loss of cell viability and proliferation rate was shown by cells isolated from teeth cryopreserved without laser piercing. These data support the use of this method for prospective whole tooth banking.
Assuntos
Criopreservação/métodos , Polpa Dentária/citologia , Células-Tronco/citologia , Dente Decíduo/citologia , Diferenciação Celular/fisiologia , Processos de Crescimento Celular/fisiologia , HumanosRESUMO
Cleidocranial dysostosis is a rare congenital skeletal disorder, associated with clavicular hypoplasia or aplasia, delayed closure of cranial fontanels, brachycephalic skull, delayed exfoliation of primary dentition, eruption of permanent teeth, and multiple supernumerary and morphologic abnormalities of the maxilla and mandible. The disorder is caused by mutation in the CBFA1 gene, on the short arm of chromosome 6p21. The prevalence of cleidocranial dysostosis is estimated one per million, without sex or ethnic group predilection. The purpose of this paper is to describe the orthodontic treatment in a patient with cleidocranial dysostosis. Therapy may include removal of supernumerary teeth, surgical exposure of impacted teeth, and orthodontic treatment.