RESUMO
Extracellular matrix molecules provide to tissues their mechanical properties and constitute a reservoir of local or regional signals that regulate cellular function. Collagens, the major components of osseous and collagenous matrices, have structural similarities, but are encoded by different genes. We describe here osteogenesis imperfecta, a collagen I, the principal constituent of bone, genetic disease, and its craniofacial implications. By comparing it with genetic disorders of cartilage collagen (Kniest and Stickler syndromes) we try to clarify the respective influences of these matrix molecules upon craniofacial development.
Assuntos
Doenças do Colágeno/genética , Desenvolvimento Maxilofacial/genética , Animais , Colágeno Tipo I/genética , Anormalidades Craniofaciais/genética , Modelos Animais de Doenças , Proteínas da Matriz Extracelular/genética , Genótipo , Humanos , Osteogênese Imperfeita/classificação , Osteogênese Imperfeita/genética , FenótipoRESUMO
In orthodontics and dentofacial orthopaedics, where genetic and environmental factors interpenetrate from the early stages of development, the clinician tries to determine how mechanics could influence patient's growth pattern. Comparing monozygotic and dizygotic twins, in their similarities and their differences, gives some answers... but raises some questions too. In this article, we gather some clinical studies and case reports, on diagnosis and treatment aspects of malocclusions.
Assuntos
Desenvolvimento Maxilofacial/genética , Gêmeos/genética , Fenômenos Biomecânicos , Doenças em Gêmeos , Meio Ambiente , Humanos , Má Oclusão/classificação , Má Oclusão/genética , Fenótipo , Anormalidades Dentárias/genética , Gêmeos Dizigóticos/genética , Gêmeos Monozigóticos/genéticaRESUMO
Osteogenesis imperfecta is a genetic disease that varies in severity and is characterized by fragile bones that fracture easily. Many extra-skeletal manifestations can be noted such as blue sclerotic markings, dentinogenesis imperfecta and impaired hearing or deafness. In most cases, an anomaly of collagen is the cause. It is usually accompanied by a specific Class III type cranio-facial morphology with open bite and increased incidence of impacted permanent molars. Orthodontists called upon to treat the dental aspects of this malady, should be careful to protect their patients against bacterial infection and hemorrhages, and to be well aware of the side affects that can be caused by the biophosphanates that constitute the basis of current medical treatment of osteogenesis imperfecta.
