American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics · 2020
Treatment and posttreatment effects of a novel magnetic palatal expansion appliance with reactivation system in dogs.
СтатьяНазвание и аннотация: Перевод пока не подготовлен
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Tong Fei, Miao Zhanqi, Zhou Xingchen, Xiao Chang, Wu Jianyong
Аннотация
INTRODUCTION: This study aimed to compare the effects of a novel magnetic palatal expansion appliance (MPEA) during the expansion and maintenance period with that of a screw expansion appliance.
METHODS: Based on previous research, the MPEA had a reactivation system that was modified for a broader working range and more stable expansion. Thirty-six male beagle dogs were assigned to a magnetic expansion (ME; n = 12), screwed expansion (SE; n = 12) or control (n = 12) group. Half of the dogs from each group were evaluated only during 5 weeks of activation, whereas the rest were evaluated for 5 weeks of activation and 8 additional weeks of retention. Nonmagnetic metal marking implants were implanted on both sides of the midpalatal suture of all dogs. Three-dimensional assessment of treatment and posttreatment dental and skeletal effects were conducted using cone-beam computed tomography. The width of the midpalatal suture, mineralization and deposition rate of bone, and fluorescence integral optical density were calculated during the expansion and retention periods using tetracycline fluorescence labeling.
RESULTS: There were increases in the value of all cone-beam computed tomography parameters in the SE and ME groups during the expansion period, and the increase was significantly greater than that of the control group (P <0.01). However, there was no significant difference in the values of any parameters during the retention period. The width of the midline sutures, mineralization and deposition rate of bone, and integral optical density in the 2 experimental groups were significantly higher than those of the control group (P <0.01), and there was no significant difference between the SE and ME groups. After the retention period, the values of all tetracycline fluorescence evaluation parameters of the experimental groups decreased significantly.
CONCLUSIONS: The novel MPEA with a reactivation system was able to expand the midpalatal suture effectively. Dental and skeletal expansion effects are similar to those of the screw expansion appliance. Wearing the appliance as a retainer can effectively maintain the expansion effect. The new bone formation rate was accelerated during the expansion process and decreased to normal levels during the retention period.
METHODS: Based on previous research, the MPEA had a reactivation system that was modified for a broader working range and more stable expansion. Thirty-six male beagle dogs were assigned to a magnetic expansion (ME; n = 12), screwed expansion (SE; n = 12) or control (n = 12) group. Half of the dogs from each group were evaluated only during 5 weeks of activation, whereas the rest were evaluated for 5 weeks of activation and 8 additional weeks of retention. Nonmagnetic metal marking implants were implanted on both sides of the midpalatal suture of all dogs. Three-dimensional assessment of treatment and posttreatment dental and skeletal effects were conducted using cone-beam computed tomography. The width of the midpalatal suture, mineralization and deposition rate of bone, and fluorescence integral optical density were calculated during the expansion and retention periods using tetracycline fluorescence labeling.
RESULTS: There were increases in the value of all cone-beam computed tomography parameters in the SE and ME groups during the expansion period, and the increase was significantly greater than that of the control group (P <0.01). However, there was no significant difference in the values of any parameters during the retention period. The width of the midline sutures, mineralization and deposition rate of bone, and integral optical density in the 2 experimental groups were significantly higher than those of the control group (P <0.01), and there was no significant difference between the SE and ME groups. After the retention period, the values of all tetracycline fluorescence evaluation parameters of the experimental groups decreased significantly.
CONCLUSIONS: The novel MPEA with a reactivation system was able to expand the midpalatal suture effectively. Dental and skeletal expansion effects are similar to those of the screw expansion appliance. Wearing the appliance as a retainer can effectively maintain the expansion effect. The new bone formation rate was accelerated during the expansion process and decreased to normal levels during the retention period.