Abstract

Objective: This study compared surface area and volume measurements made from 3D scans of physical teeth and segmented teeth taken from Cone-Beam Computed Tomography (CBCT) scans of a cadaver. Methods: A cadaver specimen was imaged by CBCT and all the teeth were subsequently extracted and cleaned of any tissue. Of all the extracted teeth, sixteen single-rooted teeth were included in this study. The extracted teeth were scanned with a 3M True Definition 3rd Generation intraoral scanner (3M, ESPE) to generate a stereolithography (STL) file to serve as the control for this study and their surface area and volume measurements as well as geometries were compared to segmentations of those teeth performed in one of two software programs, either ITK-SNAP (http://itksnap.org) or Osirix MD (Pixmeo SARL, Bernex, Geneva, Switzerland). Surface area and volume measurements as well as geometric comparisons were all performed in Geomagic (Version 2018.1.2. Raindrop, USA). Wilcoxon signed-rank tests were performed to test for statistical differences at a significance level of  = 0.05. Results: The average difference in surface area and volume between the ITK-SNAP reconstructed segmentations (IST) and the True Definition optically scanned teeth (TDT)

was 4.88  7.79 mm2 (p = 0.029) and -7.66  17.31 mm3 (p = 0.109), respectively. The average difference in surface area and volume between the Osirix MD reconstructed segmentations (OST) and the TDT was 51.38  18.28 mm2 (p < 0.001) and -38.83  18.55 mm3 (p < 0.001), respectively. The average 3D geometric discrepancy was - 0.015mm for the IST and -0.097 for the OST. No statistical difference was observed between anterior and posterior teeth or between mandibular teeth or maxillary teeth (p > 0.05 for both IST and OST). Conclusion: Variations in bone density did not affect the accuracy of segmentations. Both the IST and OST were geometrically similar to the TDT, but only the IST can be considered reasonably accurate. Both software programs tended to overestimate surface area and underestimate volume; however, Osirix MD did so to a greater extent.

LLU Discipline

Orthodontics and Dentofacial Orthopedics

Department

Orthodontics and Dentofacial Orthopedics

School

School of Dentistry

First Advisor

Kitichai Rungcharassaeng

Second Advisor

Joseph Caruso

Third Advisor

Gina Roque-Torres

Degree Name

Master of Science in Orthodontics and Dentofacial Orthopedics (MSODO)

Degree Level

M.S.

Year Degree Awarded

2019

Date (Title Page)

9-2019

Language

English

Library of Congress/MESH Subject Headings

Dental Anatomy; Spiral Cone-Beam Computed Tomography; Bone Density; Stereolithography

Type

Thesis

Page Count

xi, 44 p.

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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