External Root Resorption Associated with Maxillary Expansion Therapies as Evaluated via Cone Beam Computed Tomography: A Retrospective Randomized Clinical Trial

  • Author / Creator
    Forst, Darren D
  • Objective: To investigate and develop an appropriate measurement protocol possessing adequate precision in both intra- and inter-rater reliability for in vivo maxillary first molar volume measurements using cone beam computed tomography (CBCT) images. To assess in vivo through the use of CBCT imaging whether the type of maxillary expansion appliance [BAME versus tooth-anchored maxillary expander (TAME)] impacts the amount of external root resorption in maxillary first molars as compared to a no treatment control group. Methods: 62 adolescents requiring maxillary expansion were randomly allocated to groups: TAME, BAME, and control. CBCT images were acquired at baseline and approximately 12-months. Segmentation procedures were investigated and developed to quantify maxillary first molar ERR. Dental volumes were measured on the CBCT images at both time points to assess maxillary first molar dental volume changes. Results: Excellent intra- and inter-rater agreement for segmentation. Automated thresholding with manual refinements on a 2D slice-by-slice basis, yielded the highest intra- and inter-rater reliability statistics. There lacked statistically significant evidence (p>0.05) of differences in external root resorption (both percentage and absolute volume) between TAME, BAME, and control groups. Conclusion: Whole tooth CBCT segmentation employing grayscale thresholding with 2D slice-by-slice manual refinements possesses excellent intra- and inter-rater reliability. There is no statistically significant evidence supporting increased ERR with TAME or BAME versus control.

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  • Graduation date
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  • Degree
    Master of Science
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    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
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  • Institution
    University of Alberta
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  • Department
  • Supervisor / co-supervisor and their department(s)
  • Examining committee members and their departments
    • Carey, Jason (Mechanical Engineering)
    • Martinez, Ysidora (Dentistry)
    • Secanell, Marc (Mechanical Engineering)
    • Flores-Mir, Carlos (Dentistry)