Upper First Premolar Positioning Evaluation for the Stability of the Dental Occlusion: Anatomical Considerations

The present study aimed to find the proper distorotation of the upper first premolar to achieve the therapeutic ideal advocated for the stability of the human occlusion. Normal teeth were analyzed and occlusal photocopies of upper arch were made to perform the 2 measurements. The first parameter was the angle formed by the perpendicular to the wire through the buccal cusp and a line connecting the buccal and the lingual cusps of the upper first premolar. The second one was the angle from the buccal line and the sagittal plane of the model. The amount of distorotation was calculated and a method to bond the bracket was suggested.