Analysis On The Correlation The Posed Smile Of The Teenagers

Objective:The purpose of this study was to show whether there are some differences between the orthodontists'esthetic judgments on posed smile and those of the laypersons', thus broaden the understanding of how facial soft and hard tissues related to the esthetics of the teenagers' smiles.Method:Images of the posed smile were captured from CanonEOS50D digital video clips of 60 teenagers who have normal occlusions (30 girls,30 boys).The images of the smile were judged by panels of orthodontists and laypersons, using the visual analog scale(VAS). Quantitative measurements of the soft and hard tissues were made by using the smile images, cephalometric radiographs, and study models. Statistical analysis(SPSS13.0) was carried out on data which were gained from the smile images, cephalometric radiographs, and study models.Result:The analysis of one-way ANOVA(F=7.415, p=0.007<0.05) showed significant difference between the judgments of the orthodontists and those of the laypersons; Pearson correlation analysis showed that the esthetic judgments of orthodontists negatively correlated with the gingival display(r=-0.275, p<0.05); they positively correlated with the maximum maxillary incisor exposure (r=0.209, p<0.05); they negatively correlated with the interlabial gap(r=-0.40, p<0.05); they negatively correlated with the SNA(r=-0.314, p<0.05); they negatively correlated with the SNB(-0.260, p<0.05); and they positively correlated with the U1-L1 (r=0.284, p<0.05). The esthetic smile judgments of laypersons positively correlated with the maximum maxillary exposure(r-0.345, p< 0.05); they positively correlated with the mandibular plane angle (r=0.291, p<0.05); they positively correlated with the basal plane angle (r=0.291, p<0.05);and they positively correlated with the lip and chin groove angle (r=0.303 p<0.05)Conclusion:The study showed that there are significant differences between the orthodontists'esthetic judgments on posed smile and those of the laypersons'. More communication between them was needed when planning orthodontic treatment. The most significant component of both orthodontists and laypersons was the maximum maxillary incisor exposure, it was suggested that the orthodontists should pay special attention to the position of the maxillary incisor.