Effect of labio-lingual inclination on mandibular anterior teeth displacement and stress distribution with fixed lingual retainers: A finite element study.

Labio-lingual displacement and stress distribution of mandibular anterior teeth may be altered by changes in incisor inclination, and the role of a lower lingual fixed retainer in modifying these effects remains unclear. Therefore, it is of interest to determine the effect of the presence of a lower lingual fixed retainer and variation in labio-lingual inclination on displacement patterns and cervico-apical stress distribution of surrounding tissues. Eight 3D finite element models of the anterior mandible were constructed, and incisor inclination was modified to 80°C, 90°C, 100°C, and 110°C relative to the mandibular plane in retainer and non- retainer groups. A vertical load of 187 N was applied to evaluate labio-lingual displacement, periodontal ligament (PDL) stress distribution, and strain energy. The findings showed that displacement patterns, cervico-apical stress distribution, and strain energy were comparable in both groups. It can be concluded that mandibular anterior inclination influences biomechanical response, while the presence of a lingual fixed retainer does not significantly alter stress distribution or displacement patterns.