Effect Of Nose-prominence On Antero-Posterior Lip Position Of The Most Favored Chinese Facial Profiles In Different Skeletal Malocclusion

The lip position plays an important role in the esthetics of the profile. Orthodontists often determine the design according to the preference of the patients with the A-P position of lip. In different times, scholars from different countries have studied and explored the lip position, so we have a better understanding of the lip profile. However, in the previous studies mostly have a normal nose and chin. Clinical patient’s situation is often complex, so how to get a harmonious and beautiful appearance of the patient under the condition of the patient is a difficult task for every orthodontist.The perfect profile depends not only on the lip, the chin and nose also has a significant impact. For orthodontists, we can hardly change the position of the chin and nose, but try to understand the effect of chin and nose on profile lip position is very necessary. In recent years, scholars study the effect of chin on lip position, but the effect of nose is lack of research. Nose prominence is a key factors influence the profile. Try to understand the effect of different nose projection on lip position will assist us to make more personalized treatment goal. ObjectiveTo assess the effect of nose prominence on the most favored Chinese A-P lip position in different skeletal malocclusion, and compare the esthetic preference between orthodontists and laypeople. MethodA profile photograph with natural facial expression of a Chinese female with classⅠocclusion, classⅠkeletal pattern was digitized. The image was digitally manipulated to shape classⅠ, classⅡand class Ⅲskeletal facial profile by photoshops CS6.Then each of them was further digitally manipulated to generate five images with different nose prominence, so we can have fifteen pictures in all. Finally, the lips of each of the fifteen pictures changes was protruded or retruded to make a series picture. Chinese orthodontists and laypeople were asked to choose the top 3 most favored profiles from the series of various pictures. Results1. With classⅠof normal nose prominence: Orthodontists and laypeople prefer retruded lip position than the standard lip position.2. With classⅠ, orthodontists prefer standard lip position than laypeople.3. With classⅠ, no matter how nose prominence change, orthodontists and laypeople’s favorite lip is constant. Nose projection has no effect on lip position with classⅠ.4. With class II of normal nose prominence: Orthodontists and laypeople are prefer retruded lip position than the average lip position.5. With class II, no matter how nose prominence change, orthodontists and laypeople’s favorite lip is constant. Nose projection has no effect on lip position with class II.6. With class III of normal nose prominence: Orthodontists and laypeople prefer the average lip position.7. With class III,with the decrease of nose prominence, orthodontists and laypeople’s favorite lip is constant. With the increase of nose prominence, laypeople preffer prutruded lip position. Nose projection may has effect on lip position with class III.Conclusion1. Nose prominence has no effect on A-p lip position of the most favored Chinese facial profile with classⅠ.2. Nose prominence has no effect on A-p lip position of the most favored Chinese facial profile with classⅡ.3. Nose prominence has effect on A-p lip position of the most favored Chinese facial profile with class III.4. There is almost no difference between orthodontists and laypeople about the appreciation of lip position.