Vascular injury or interruption may play a role in vertebrate limb teratogenesis. Since 5fluoro- 2'- deoxyuridine (FdU) can cause vascular injury in the murine limb and skull prior to the appearance of skeletal ma...Vascular injury or interruption may play a role in vertebrate limb teratogenesis. Since 5fluoro- 2'- deoxyuridine (FdU) can cause vascular injury in the murine limb and skull prior to the appearance of skeletal malformations in these structures, we studied the effects of this chemical on skeletal development in the chick embryo and noted any vascular injury. The yolk sacs of day three ehick embryos (Hamburger and Hamilton states 17-19) were injected with solutions of vary concentrations of FdU in saline. The embryos developed until the 10th day of incubation when they were fixed for study. Uninjected, saline injected, and sham injected control embryo were similarly fixed. Upon gross inspection, frequent diffuse and saccular hernatomas, as well as fluid-filled blisters, were noted in the limbs of embryos treated with FdU. After the embryos were fixed and cleared, and the skeletons stained, significant skeletal malformations were observed in these limbs. Bony elements of both the upper and lower limbs were affected in at least some of the embryos. The combination of FdU-induced hematomas and blisters with associated skeletal malformations in the same regions of some embryos suggests a relationship between these phenomena.展开更多
The prevalence of Class Ⅲ malocclusion varies among different countries and regions. The populations from Southeast Asian countries (Chinese and Malaysian) showed the highest prevalence rate of 15.8%, which can serio...The prevalence of Class Ⅲ malocclusion varies among different countries and regions. The populations from Southeast Asian countries (Chinese and Malaysian) showed the highest prevalence rate of 15.8%, which can seriously affect oral function, facial appearance, and mental health. As anterior crossbite tends to worsen with growth, early orthodontic treatment can harness growth potential to normalize maxillofacial development or reduce skeletal malformation severity, thereby reducing the difficulty and shortening the treatment cycle of later-stage treatment. This is beneficial for the physical and mental growth of children. Therefore,early orthodontic treatment for Class Ⅲ malocclusion is particularly important. Determining the optimal timing for early orthodontic treatment requires a comprehensive assessment of clinical manifestations, dental age, and skeletal age, and can lead to better results with less effort. Currently, standardized treatment guidelines for early orthodontic treatment of Class Ⅲ malocclusion are lacking. This review provides a comprehensive summary of the etiology, clinical manifestations, classification, and early orthodontic techniques for Class Ⅲ malocclusion, along with systematic discussions on selecting early treatment plans. The purpose of this expert consensus is to standardize clinical practices and improve the treatment outcomes of Class Ⅲ malocclusion through early orthodontic treatment.展开更多
文摘Vascular injury or interruption may play a role in vertebrate limb teratogenesis. Since 5fluoro- 2'- deoxyuridine (FdU) can cause vascular injury in the murine limb and skull prior to the appearance of skeletal malformations in these structures, we studied the effects of this chemical on skeletal development in the chick embryo and noted any vascular injury. The yolk sacs of day three ehick embryos (Hamburger and Hamilton states 17-19) were injected with solutions of vary concentrations of FdU in saline. The embryos developed until the 10th day of incubation when they were fixed for study. Uninjected, saline injected, and sham injected control embryo were similarly fixed. Upon gross inspection, frequent diffuse and saccular hernatomas, as well as fluid-filled blisters, were noted in the limbs of embryos treated with FdU. After the embryos were fixed and cleared, and the skeletons stained, significant skeletal malformations were observed in these limbs. Bony elements of both the upper and lower limbs were affected in at least some of the embryos. The combination of FdU-induced hematomas and blisters with associated skeletal malformations in the same regions of some embryos suggests a relationship between these phenomena.
文摘The prevalence of Class Ⅲ malocclusion varies among different countries and regions. The populations from Southeast Asian countries (Chinese and Malaysian) showed the highest prevalence rate of 15.8%, which can seriously affect oral function, facial appearance, and mental health. As anterior crossbite tends to worsen with growth, early orthodontic treatment can harness growth potential to normalize maxillofacial development or reduce skeletal malformation severity, thereby reducing the difficulty and shortening the treatment cycle of later-stage treatment. This is beneficial for the physical and mental growth of children. Therefore,early orthodontic treatment for Class Ⅲ malocclusion is particularly important. Determining the optimal timing for early orthodontic treatment requires a comprehensive assessment of clinical manifestations, dental age, and skeletal age, and can lead to better results with less effort. Currently, standardized treatment guidelines for early orthodontic treatment of Class Ⅲ malocclusion are lacking. This review provides a comprehensive summary of the etiology, clinical manifestations, classification, and early orthodontic techniques for Class Ⅲ malocclusion, along with systematic discussions on selecting early treatment plans. The purpose of this expert consensus is to standardize clinical practices and improve the treatment outcomes of Class Ⅲ malocclusion through early orthodontic treatment.
