Abstract

Introduction: Comprehensive orthodontic treatment often entails extraction of teeth to accomplish treatment goals. A potential side effect of extraction therapy is arch length shortening resulting in decreased space for the tongue which may cause a low tongue posture and a possible reduction in airway space. The purpose of the study was to retrospectively determine if extractions of all first premolars during orthodontic treatment and the resulting movement of mandibular incisors are correlated with a reduction in airway volume.

Materials and Methods: The T1 and T2 CBCT’s of 80 patients were collected and reviewed. The cases were divided into treatment (extraction) and control (non-extraction) groups and further separated into Class I and Class II malocclusion. The changes in arch width, arch depth, amount of lower incisor movement, minimum cross sectional area (MCSA), and upper airway volume were measured and analyzed.

Results: Arch width at T1 in Cl 1 cases had a statistically significant difference between TG and CG (P = .011). There was significant differences in arch width between the TGs and CGs of Cl 1 and Cl 2 cases at T2. The difference in arch width was between Cl 1 TG and Cl 1 CG (P < .001) and between Cl 2 TG and Cl 2 CG (P = .002). The difference in arch depth between Cl 1 TG and Cl 1 CG (P < .001) and between Cl2 TG and Cl 2 CG (P < .001). There was no significant change in the nasopharynx, oropharynx, or MCSA. The Pearson’s Correlation Coefficient found that the nasopharynx had a positive correlation with oropharynx (P < .001;.002;.003) and MCSA (P = .005;.006;.007). The oropharynx had a positive correlation to the MCSA. (P < .001).

Conclusion: Arch depth and arch width had significant differences between CG and TG in both Cl 1 and Cl 2 subjects. No statistically significant difference was found for nasopharynx, oropharynx, and MCSA. No statistically significant differences were found in changes of airway dimensions with extraction of premolars. No statistically significant differences were found in changes of airway dimensions with increased mandibular incisor retraction.

LLU Discipline

Orthodontics and Dentofacial Orthopedics

Department

Orthodontics and Dentofacial Orthopedics

School

School of Dentistry

First Advisor

V. Leroy Leggitt

Second Advisor

Toufic Jeiroudi

Third Advisor

Gina Roque-Torres

Degree Name

Master of Science in Orthodontics and Dentofacial Orthopedics (MSODO)

Degree Level

M.S.

Year Degree Awarded

2021

Date (Title Page)

9-2021

Language

English

Library of Congress/MESH Subject Headings

Tooth Extraction; Mandibular Incisors; Airway Management; Cone-Beam Computed Tomography

Type

Thesis

Page Count

xi, 53 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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