A three dimensional finite element analysis of apical stress distribution during intrusion of maxillary central incisor with different inclinations in labial and lingual appliance systems

Abstract

The objective of this study was to evaluate apical stress distribution during intrusion of the maxillary central incisor with different inclinations in the labial and lingual appliance systems using a three-dimensional finite element model.The three-dimensional finite element models of the maxillary central incisor were produced with 25 ° (normoclined), 30 ° (proclined), and 20 °(retroclined) inclinations. Each incisor model was subjected to an intrusive force of 15cN. The stress level at the apex was calculated in terms of maximum principal stresses.The stress distribution at the apex and cervix was lower in the labial compared to the lingual appliance system for the maxillary central incisor models with an inclination of 25° (normoclined) and 30° (proclined). Whereas the maxillary central incisor model with 20° (retroclined) inclination in the lingual appliance system showed the maximum stress in the cervical region.During intrusion, no significant differences in stress patterns were seen at the root apex in normoclined and proclined maxillary central incisor models in either of the appliance systems, except for the retroclined central incisor model which showed maximum stresses in the cervical region.