Vertical facial types and chin morphology effects on the facial profile attractiveness / 中国组织工程研究

BACKGROUND:Individuals with different vertical facial types have different chin morphologies. For the individuals with different vertical facial types, what is the most beautiful chin morphology? OBJECTIVE:To evaluate the effects of vertical facial types and chin morphology on facial profile attractiveness. METHODS:Three beautiful females were selected, including one with high mandibular angle, one with average angle and one with low angle. Their facial profile photographs were taken. A series of new pictures were generated by the smal scale (2 mm per unit) modification of soft tissue chin in the sagittal direction and vertical direction. Raters consisting of 17 orthodontists and 35 laypersons were selected for aesthetic ratings, in order to evaluate the facial profile attractiveness of the individuals with different vertical facial types. RESULTS AND CONCLUSION:There was no esthetic difference of vertical change in female with high angle;while slightly protrude chin was perceived to be more beautiful than retruded chin. For the female with average angle, lower chin was more attractive than higher chin;slightly protruded chin was beautiful than excessive protruded chin and retruded chin. For the individual with low angle, higher chin was preferred by raters;slightly protruded chin was more beautiful than excessive protruded chin and retruded chin.The results indicate that the effects of vertical facial types and chin morphology to facial profile attractiveness are different. In clinical orthodontic, vertical facial types should be taking into consideration to change the chin morphology of the patents, in order to obtain better profile attractiveness.

The predictability of dentoskeletal factors for soft-tissue chin strain during lip closure / 대한치과교정학회지

OBJECTIVE: To investigate the dentoskeletal factors which may predict soft-tissue chin strain during lip closure. METHODS: The pretreatment frontal and lateral facial photographs and lateral cephalograms of 209 women (aged 18-30 years) with Angle's Class I or II malocclusion were examined. The subjects were categorized by three examiners into the no-strain and strain groups according to the soft-tissue chin tension or deformation during lip closure. Relationships of the cephalometric measurements with the group classification were analyzed by logistic regression analysis, and a classification and regression tree (CART) model was used to define the predictive variables for the group classification. RESULTS: The lower the value of the overbite depth indicator (ODI) and the higher the values of upper incisor to Nasion-Pogonion (U1-NPog, mm), overjet, and upper incisor to upper lip (U1-upper lip, mm), the more likely was the subject to be classified into the strain group. The CART showed that U1-NPog was the most prominent predictor of soft-tissue chin strain (cut-off value of 14.2 mm), followed by overjet. CONCLUSIONS: To minimize strain of the soft-tissue chin, orthodontic treatment should be oriented toward increasing the ODI value while decreasing the U1-NPog, overjet, and U1 upper lip values.

Changes in soft tissue chin resulting from premolar extraction and incisor retraction in adult female patients / 대한치과교정학회지

The purpose of this study was to evaluate changes in soft tissue chin thickness and to investigate correlations between hard and soft tissues measurements after orthodontic treatment conducted by premolars extraction and incisor retraction. The sample consisted of 35 female adults with Angle classification class I or class II division 1 malocclusion. Using lateral cephalometric radiographs taken before and after treatment, hard and soft tissue structures were measured and reproducible six landmark on soft chin tissue were used to locate the various points of soft tissue contour of the chin. The results were as follows : 1. There were signigicant correlations between pretreatment B-B', Pm-Pm' and pretreatment vertical skeletal measurements such as angle of MP & HP, angle of MP & PP, ALFH and between a-a', b-b', Me-Me' and measurements of symphyseal morphology such as SL, SW, PL. 2. There were significant decreases at B-B', Pm-Pm' and significant increases at a-a', b-b' between pre-and posttreatment measurements. 3. There were significant correlations among soft tissues changes and hard tissue changes except for changes at B-B' and the range of correlation coefficient was about 0.3-0.4. 4. There were significant differences at deltaUI-VP, angle of LI &