Master of Science (M.S.) in Dentistry
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College of Dental Medicine
Publication Date / Copyright Date
Nova Southeastern University
Barak Jones. 2017. Investigating lip protrusion aesthetics by comparing the facial profile view with an oblique view. Master's thesis. Nova Southeastern University. Retrieved from NSUWorks, College of Dental Medicine. (92)
Introduction: Orthodontists strive to enhance facial esthetics. Notable orthodontists including Holdaway, Ricketts, Merrifield and more each made contributions to help diagnose facial disharmonies and improve treatment outcomes. Numerous studies have evaluated the face from two perspectives, frontal and profile. Orthodontic treatment can significantly transform a facial profile. Orthodontic literature has time and again compared photos, line drawings and silhouettes in order to define a harmonious profile. Some have concluded that a more protrusive lip profile than what had been outlined traditionally is now preferred. However, while this debate continues, in this dynamic world the profile perspective is not the most commonly encountered. Instead, the oblique view of the face most often dominates billboards, magazines, social media and human interactions. Objective: This study aimed to evaluate facial esthetics from an oblique perspective and thereby discover the differences that lateral profile esthetics have with oblique view esthetics and to refine the idea of an ideal lip position by involving the oblique perspective. Methods: This cross-sectional study included two human subjects, one male and one female. For the study, we photographed their faces with lips in repose from two angles: lateral profile and the oblique three-quarter profile. We then morphed the images in Adobe Photoshop to create five variations of lip protrusion per each original image. The degree of lip protrusion was equivalently manipulated so the oblique profile image sets matched the lateral profile image sets. After randomizing the images within each set, we then included them in a digital survey and administered it to 425 individuals. Judges ranked images in each set from most to least preferred. Following data collection, statistical analysis was run to evaluate findings. Results: From the oblique images of the female, judges preferred the lower lip 2 mm posterior to the E-plane. From the male oblique images, judges preferred (with no significant difference between the two) the lower lip at 4 mm and 6 mm posterior to the E-plane. From the lateral profile images, judges preferred the lower lip 4 mm posterior to the E-plane for the female and 6 mm posterior to the E-plane for the male. Conclusion: The preferred degree of lip protrusion judged from the oblique perspective differed from the preferred lip protrusion seen in the profile. From the oblique perspective a more protrusive lip position tended to be preferred. However, protrusion of the lower lip beyond the E-plane was considered undesirable from all perspectives. The gender, race and age of the judges had no impact on the preference of lip protrusion.
Esthetics, Lip, Oblique, Orthodontics, Perspective, Profile
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