Introduction: Mild to moderate deviations from normal facial types can significantly change orthodontic treatment modalities. Studies linking ambient air pollution with respiratory problems, as well as craniofacial morphology with respiratory problems are well established.1-19 In this study we aimed to determine if there was a correlation between ambient air pollution and maxillofacial growth and development. We also wanted to determine if further research should be done in this area, and if so how can the study be improved. Materials and Methods: We selected Santa Maria, CA and Upland, CA as sample areas due to their significant differences in air quality. Initial lateral cephalometric radiographs were collected from 400 patients in each area. The combined 800 subjects' addresses were geocoded and ambient air pollution exposure was calculated based on air quality statistics from the California Air Resources Board, Environmental Protection Agency and NAVTEQ. Vertical measurements of facial depth (FD), total face height (TFH), lower face height (LFH), facial axis (FA), and mandibular plane (MP) were made on the initial T1 lateral cephalometric radiographs. Statistical Analysis: Spearman's rho was used to determine if an association existed between the pollution metrics and craniofacial outcome variables. Results: At a statistically significant level, no association exists between the pollution metrics (TRI, RD, TP, O3, PM2.5NAA, PM2.5N24HA) and the craniofacial measurements (FD, MP, FA, LFH, TFH). The air quality between Upland and Santa Maria did differ significantly for O3, PM2.5NAA, and PM2.5N24HA. Conclusions: Increased exposure to ambient air pollution did not seem to have an effect on the craniofacial morphology of our sample groups. We were unable to account for the many confounding variables, which may have hampered our ability to see any correlation. Future studies should attempt to incorporate dichotomous sampling areas and account for as many confounding variables as possible.

LLU Discipline

Orthodontics and Dentofacial Orthopedics


Orthodontics and Dentofacial Orthopedics


School of Dentistry

First Advisor

Caruso, Joseph

Second Advisor

Leggitt, V. Leroy

Third Advisor

Soret, Samuel

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded

January 2012

Date (Title Page)




Library of Congress/MESH Subject Headings

Santa Maria, Calif.; Upland, Calif.; Face; Air Pollutants - Adverse effects; Environmental Exposure - advense effects

Subject - Local

Facial depth; Facial axis; face height; Ambient air pollution; Craniofacial growth; Craniofacial morphology; Facial types; Cephalometric radiographs



Page Count

54 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 & Dissertations

Collection Website



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