Evaluation Of Lips Position Of Soft Tissue Profile Of Adolescents In Lanzhou

Objective:To study lip protrusion of soft tissue profile of Han adolescent in Lanzhou region and assess whether there are some esthetic differences between laypersons and orthodontists on the most-favored lips position of soft tissue profile of adolescent.Methods:Average male and female profiles were constructed with Photoshop8.0and analysis system software (Winceph8.0, Rise, Sendai, Japan) from the profiles of80Han adolescents male and female with individual normal occlusions in Lanzhou region by measuring the lateral cephalograms, then the other profiles were developed by protruded or retruded in1mm incements lip position in each, and the13images were arranged with the average profile in the center for each sex. Fifty laypersons and fifty orthodontists were asked to select the3most-favored profiles for each sex from a series of facial silhouettes with varying anteroposterior lip positions and rank them in order of preference and select the least-favored profile for each sex.Results:The lip protrusion values of Han male soft tissue profile relative to Sn-Pg’line in Lanzhou area was7.50±1.72mm for the upper lip and5.86±1.83mm for the lower lip. The lip protrusion values of Han female soft tissue profile relative to Sn-Pg’ was6.23±1.73mm for the upper lip and4.94±2.03mm for the lower lip. The most-favored lip protrusion relative to Sn-Pg’line rated by the laypersons for Han male was3.5-5.5mm for the upper lip and1.9～3.9mm for the lower lip. Rated by the orthodontists was5.5～7.5mm for the upper lip and3.9～5.9mm for the lower lip; The most-favored lip protrusion relative to Sn-Pg’line rated by the laypersons for Han female was2.2～4.2mm for the upper lip and0.9～2.9mm for the lower lip; Rated by the orthodontists was4.2-6.2mm for the upper lip and2.9～4.9mm for the lower lip. Both the laypersons and the orthodontists preferred a profile with slightly retruded lip position. But the laypersons favored a more retruded lip position for Han female and male. The least-favored profile was the most protrusive.Conclusions:Both the laypersons and the orthodontists preferred a profile with slightly retruded lip position,but there are some differences between the laypersons’preference and the orthodontists’, the laypersons preferred a profile with more retruded lip position.