This study was performed to cephalometrically assess the soft tissue chin changes from orthodontic treatment and after 5 years post-treatment. Variability in the soft tissue chin structure between the different facial types and between the sexes was also evaluated.

Sixty patients, treated by Dr. Ricketts, were selected from the Rocky Mountain Data system files. Pretreatment, post-treatment and 5 year post-treatment cephalograms were taken on each patient and the soft tissue chin thickness was measured at six points around the symphysis. Means and standard deviations were calculated for each point on the symphysis by sex and facial type.

The post-treatment data indicated an overall mean increase in the soft tissue chin thickness in the total sample with a range of 0.4 - 0.8 mm over the six measured points around the symphysis. Five years post-treatment data showed an increase in the soft tissue chin thickness with a range of 1.0 - 1.2 mm around the symphysis. The male sample demonstrated a greater increase in the soft tissue chin thickness than the female sample. The total female sample did not show a significant increase in the soft tissue chin thickness; however, the dolichofacial female group showed a thickness increase with a range of 0.9 - 1.3 mm after treatment and a range of 1.0 - 1.3 mm 5 years after treatment.

The male dolichofacial group showed the greatest amount of increase in the soft tissue chin thickness with a range of 0.8 - 1.4 mm after treatment and 1.6 - 2.5 mm 5 years post-treatment.

The soft tissue chin thickness was found to vary at all points around the symphysis except for the two points at, and closest to, menton. The mesofacial female sample showed a more even thickness around the chin after treatment.

Females, after 15 years of age, showed no increase in the soft tissue chin thickness. Patients younger than 9 years of age showed a smaller "B" point thickness than the rest of the group.

It was concluded that the soft tissue chin thickness does not increase uniformly around the symphysis and that the thickness varies between the facial types. This study demonstrates the importance of evaluating the soft tissue chin thickness before treatment and of considering the changes that occur after treatment.

LLU Discipline





Graduate School

First Advisor

Lee E. Olsen

Second Advisor

James R. Wise

Third Advisor

Norman S. Carter

Fourth Advisor

Gary G. Morikone

Fifth Advisor

Grenith J. Zimmerman

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Chin -- growth & development; Cephalometry; Orthodontics



Page Count

2 vi; 63

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