CBCT Evaluation of Morphological Changes to Alveolar Bone Due to Orthodontic Tooth Movement

• Main Author: Hoff, Jeremy M
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01.01.2014
• Subjects: Dentistry
• ISBN: 9781321651263; 1321651260

Introduction: The mandibular process is the anatomic factor that limits the orthodontic movement of the mandibular incisors, and awareness of this structural limitation may reduce the risk of potential damage to tooth roots and alveolar bone. A decision regarding the correct placement of the lower incisors will be largely determined by the amount of adaptation possible within the alveolar bone. Purpose: The purpose of this study was to use Cone Beam Computed Tomography (CBCT) to evaluate the adaptation of alveolar bone around the mandibular anterior teeth before and after orthodontic tooth movement. Methods: This study compared changes in area (mm2) and buccal/lingual linear variation of the anterior mandibular process on CBCT images acquired before (T1) and after (T2) orthodontic treatment. Initial (T1) and final (T2) digital imaging and communications in medicine (DICOM) CBCT images of thirteen non-growing patients were imported into InVivo software for measurement. The T1 and T2 volumes were then superimposed and twenty-five sagittal slices were obtained through the region of the anterior mandible. The changes in area (mm2) and buccal/linigual variations were then averaged and compared using a Related Samples Wilcoxon Signed Rank Test, a One-Sample Wilcoxon Signed Rank Test, and an Independent-Samples Kruskal-Wallis Test ( = 0.05). Results: Statistically significant differences in area changes for the entire sample between T1 and T2 were found. These differences included statistically significant differences in buccal/lingual adaptation in all areas except the inferior buccal surface at B3 and B4 with the sit of the most change being at the levels of B1 and L1. When the data was divided by tooth region there was a clear pattern showing that the greatest amount of change occurred at the central incisors and that the least amount of change occurred in the canine region. When the data was divided by facial type there was a statistically significant difference between the dolichofacial group and the mesofacial and brachyfacial groups. However, due to the small sample size of the dolichofacial group no clinically significant conclusions could be made. Conclusion: Statistically significant adaptation of the alveolar process occurs in response to tooth movement, both in area (mm2) and buccal/lingual linear dimension. Clinically relevant conclusions can not be made due in part to the small number of dolichofacial patients as well as the small amount of change seen in most of the parameters.