نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Introduction:
The purpose of this study was to evaluate chephalometric changes of soft tissue profile after four first premolar extraction of upper and lower arch in class I bimaxillary dentoalveolar protrusion (B.D.P.) cases.
Materials and Methods:
This investigation consisted of 20 female patients with B.D.P. The mean age of this group was 16±6 years with a range of 12 to 38 years. All of them treated by extraction of four first premolars with standard edgewise technique. Pre and post lateral cephalograms were traced and the cephalometric criteria were measured.
Results:
This study showed that upper and lower lip protrusion were decreased 2.7±2.9 (p<0/001), 2.8±2.8 (p<0/001) mm respectively. The angle between upper incisor to SN and lower incisor to mandibular plane decreased 10.3±5.8 and 8.3±5.2 respecticly. The angle between upper and lower incisor increased about 17.6±9.5. By using stepwise regression analysis the ratio of upper lip retraction to maxillary incisor retraction was 0.63:1 and the ratio of lower lip retraction to mandibular incisor retraction was 0.62:1.
Conclusion:
This study concluded that a strong correlation exists between retraction of anterior teeth and the position of lips.
کلیدواژهها English
