The purpose of this study is to compare the smile changes after receiving orthodontic treatment among class I, class II and class III malocclusion, to identify the cephalometric factor affecting smile variables changes after treatment and to develop smile variables for lateral and oblique view photos to help in orthodontic analysis and treatment planning.
Materials and Methods
78 people in permanent dentition who had been received orthodontic treatment in Taipei medical university hospital were enrolled. According to their dental overjet(OJ), these patients were divided into class I (n=34, 0mm
In class I malocclusion, a significant difference between T1 and T2 (P<0.05) were found in maxillary incisor angle of the oblique view, and also upper lip to Ear-Eye connecting line angle in lateral smiling photo (P=0.02) and maxillary incisor angle in oblique view(P=0.02). Statistically significant differences were also found in maxillary incisor angle in T1(P=0.04) and T2-T1(P=0.04), nasolabial angle in T1(P=0.01) and T2(P=0.03), upper lip to Ear-Eye connecting line angle in T2-T1(P<0.02), and lateral smile index in T2(P=0.04) between class I and class II malocclusion in lateral smiling photo. There were no significant differences in T1, T2, and
T2-T1 in oblique smiling photo between class I and Class II malocclusion
The frontal, oblique and lateral smiling measurements showed significant changes following orthodontic treatment. Orthodontists should take oblique and lateral smiling photo as routine data collection, treatment planning and use it for assessment of treatment outcomes.