Howard Lee

Abstract

Current methods of temporary anchorage device (TAD) planning and placement are performed by radiographic analysis in a two-dimensional plane that lends itself to inaccuracy secondary to variations in the angle from which the radiograph is taken, as well as the magnification of the radiographic image, resulting in an increased likelihood of placement errors. The purpose of this study was to compare a three-dimensional (3D) TAD planning and placement technique to a traditional two-dimensional (2D) technique. In the 2D group, periapical radiographs and pre-fabricated wire guides were used for planning and placement of TADs on five plastic models. For the 3D group, surgical drill guides were fabricated using cone beam computed tomography (CBCT) data, and were used for TAD placement on five models identical to the 2D group. Four TADs were placed in each maxillary model, between the cuspids and bicuspids and between the 1st bicuspids and between the 2nd bicuspids and 1st molar bilaterally.

TAD placement was evaluated on the criteria of 1) Horizontal position- the amount of deviation from the midpoint between two adjacent roots. 2) Vertical position the level where adjacent roots to the TAD were at least 2.5 mm apart and 3) Angulation the angle formed by the long axis of the TAD and the long axis of the tooth anterior to the TAD.

The results were evaluated using two-sample t-tests at the significance level of α= .05. No significant difference was noted in the horizontal position between the 2D and 3D groups. There was a significant difference noted in the vertical position between the 2D and 3D groups, although both the 2D and the 3D methods were successful at placing TADs at a level where the roots were at least 2.5 mm apart. There was a significant difference in the ability of the 3D group to achieve a TAD placement angle closer to the desired 35° angle to maximize TAD stability. A statistically significant difference existed between the ideal measurements and the measurements of both the 2D and 3D groups for all three of the evaluation criteria. The incidence of TADs contacting the adjacent roots was similar in both groups.

In conclusion, the three dimensional placement technique used in this study shows potential in improving the precise planning and placement of TADs. However, more research needs to be conducted to assure the proper fit and the stability of computer-aided design/computer-aided manufacturing (CAD/CAM) surgical drill guides.

LLU Discipline

Orthodontics and Dentofacial Orthopedics

Department

Orthodontics and Dentofacial Orthopedics

School

Graduate Studies

First Advisor

Mark Batesole

Second Advisor

Joseph Caruso

Third Advisor

Jay Kim

Fourth Advisor

Kitichai Rungcharassaeng

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

2008

Date (Title Page)

3-2008

Language

English

Library of Congress/MESH Subject Headings

Dental Instruments; Orthodontic Appliances; Orthodontic Anchorege Procedures -- methods; Radiography -- diagnosis; Imaging, Three-Dimensional; Cone-Beam Computed Tomography

Type

Thesis

Page Count

xi; 33

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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