Assessment of the Magnitude and Asymmetry of Micro-implant-assisted Rapid Maxillary Expansion
نام عام مواد
[Thesis]
نام نخستين پديدآور
Elkenawy, Islam Mohamed Hassan
نام ساير پديدآوران
Moon, Won
وضعیت نشر و پخش و غیره
نام ناشر، پخش کننده و غيره
University of California, Los Angeles
تاریخ نشرو بخش و غیره
2020
يادداشت کلی
متن يادداشت
51 p.
یادداشتهای مربوط به پایان نامه ها
جزئيات پايان نامه و نوع درجه آن
M.S.
کسي که مدرک را اعطا کرده
University of California, Los Angeles
امتياز متن
2020
یادداشتهای مربوط به خلاصه یا چکیده
متن يادداشت
Micro-implant assisted rapid palatal expander such as the Maxillary Skeletal Expander (MSE) have been utilized to achieve skeletal expansion as an alternative to surgically assisted expansion with some success. Previous studies show significant effects on the mid-face, including a degree of asymmetry. The aim of this study is to quantify the magnitude, parallelism, and asymmetry of expansion in non-growing patients and to explore possible factors that can predict the pattern of asymmetry of expansion. We examined orthodontic non-growing patients (n=31) with an average age of 20.4 years old, with Cone Beam Computed Tomography (CBCT) images taken before and right after expansion using MSE. Those images were superimposed, and expansion was analyzed utilizing the Mid-Sagittal Plane (MSP) as a reference plane. Average magnitude of total expansion was 5 mm at the Anterior Nasal Spine (ANS), and 4.77 mm at the Posterior Nasal Spine (PNS) which showed statistical significance using a paired t-test with p<0.01. Expansion was parallel in the antero-posterior dimension where expansion at the PNS was 95% of that at the ANS. The sample was evaluated for asymmetry and divided into two groups; symmetric (n=15) and asymmetric (n=16), with 16 out of 31 patients exhibiting statistically significant asymmetry. The asymmetric group showed statistical significance asymmetry at p<0.05 when comparing expansion at both sides. In order to validate any possible predicting factors, correlation of the asymmetry of expansion and multiple measurements of predicting factors was performed to both compare the direction of asymmetry, as well as the total magnitude of asymmetry. MSE achieved highly parallel expansion in the sagittal plane in non-growing patients with an average magnitude of 5 mm at the ANS. However, transverse asymmetry of expansion was noted in 51% of the patients where one side expanded more than the other by at least 1.1 mm. Lack of correlation was noted between the magnitude of asymmetry and both the initial asymmetry of the mid-face, as well as the difference in density values bilaterally. However, the direction of asymmetry of expansion at ANS was moderately associated with the initial asymmetry of the frontozygomatic suture.
اصطلاحهای موضوعی کنترل نشده
اصطلاح موضوعی
Dentistry
نام شخص به منزله سر شناسه - (مسئولیت معنوی درجه اول )