All ETDs from UAB

Advisory Committee Chair

David M Sarver

Advisory Committee Members

Amjad Javed

Nathaniel Lawson

Document Type


Date of Award


Degree Name by School

Master of Science (MS) School of Dentistry


The purpose of this study is to determine age-related changes of the lower face by age and by gender. The secondary purpose of this study is to stress the importance of the clin-ical exam for orthodontic patients in the frontal view, the way most patients perceive themselves. Also, individualized treatment planning with age-appropriate incisor display is crucial for esthetic outcomes. Materials and Methods: Specific dimensions of the lower face were measured at patients initial clinical exam before starting orthodontic treatment. All patients were from Dr. David Sarver's private practice in Vestavia Hills, AL collected from 1/1/2002-11/4/2014. The following parameters were recorded in mil-limeters: commissure height, philtrum length, maxillary incisor length to lip at rest, max-illary incisor show on smile, gingival display on smile, maxillary incisor length, maxil-lary incisor width, and lip incompetence. The data was input into OrthoTracTM software. The patients ranged in age from six years old to seventy-six years old; two thousand fe-males and 1,650 males comprised the dataset. For analysis, the patients were first sepa-rated by gender and then by age. The average and the standard deviation for each parameter were calculated. The linear regression analysis between age groups and parameters and lip incompetence compared to philtrum-commissure height difference were also calculated. Re-sults: The soft tissue of the lower face changes consistently over time. Males have more pronounced changes than females; gingival display remains constant in both sexes. There was an increasing linear association between philtrum lengths, commissure heights, and max-illary crown height for both sexes. There was a decreasing linear association for maxillary incisor to lip at rest, gingival display on smile, and lip incompetence in both sexes. As lip separation increases, the philtrum-commissure length difference also increases, especially after a difference of nine millimeters. Conclusions: A through initial clinical exam is es-sential for treatment planning. Males and females have similar soft tissue trends over time. The lips consistently lengthen with time, decreasing incisor display at rest, maxillary incisor display on smile, and lip incompetence. The application of soft tissue changes that occur over time is important for treatment planning and determining age-appropriate incisor display.

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Dentistry Commons



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