Introduction: Apical root resorption is one of the most common adverse effects of orthodontic treatment. Forces used during orthodontic tooth movement can cause permanent loss of apical surfaces of teeth and although most reported cases of root resorption are asymptomatic, the process is irreversible and often unpredictable. Thus, it is of clinical interest to investigate which patients may be at greatest risk.

Purpose: This study utilized Cone Beam Computed Tomography (CBCT) to evaluate whether rapid maxillary expansion (RME) in Hispanic patients increased the severity of orthodontically induced apical root resorption.

Materials and Methods: Pre-treatment (T1) and post-treatment (T2) Digital Imaging and Communications in Medicine (DICOM) CBCT images of patients treated at Loma Linda University were imported into OsiriX MD software (version 12.5.2, Pimeo, Bemex Switzerland) for tooth length measurement of maxillary central incisors in sagittal and coronal views. The amounts of root resorption (RR) were calculated and compared between Hispanic and Non-Hispanic White patients treated with and without RME using analysis of covariance (ANCOVA). Spearman Rho correlation tests and Chi-squared analysis were performed to evaluate the relationship between RR and age, gender, and treatment time. All statistical analyses were performed at α = 0.05.

Results: A total of 180 patients were included in this study. Non-Hispanic White patients that underwent rapid maxillary expansion experienced greater amounts of root resorption (p > .05) compared to Hispanic and non-expansion patients. There were no statistically significant differences in overall RR comparing expansion and non-expansion groups, or between ethnicities (p > .05). Age, treatment time, and gender showed no statistically significant correlation with RR (p > .05). Conclusions: Non-Hispanic White patients that underwent rapid maxillary expansion experienced statistically, but not clinically, significant higher levels of root resorption. Age, treatment time and gender had no effect on RR.

LLU Discipline

Orthodontics and Dentofacial Orthopedics


Orthodontics and Dentofacial Orthopedics


School of Dentistry

First Advisor

V. Leroy Leggitt

Second Advisor

Gabriela Garcia

Third Advisor

Kitichai Rungcharassaeng

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Root Resorption* / diagnostic imaging; Root Resorption* / etiology



Page Count

x, 37 p.

Digital Format


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.


Loma Linda University Electronic Theses and Dissertations

Collection Website



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