Dens invaginatus as a biomechanical risk modifier in dental trauma: finite element analysis

Abstract

Introduction/Aims Traumatic dental injuries are common in childhood and may adversely affect functional and psychosocial well-being. Dens invaginatus, a developmental anomaly caused by the infolding of the enamel organ during odontogenesis, alters tooth morphology and may influence biomechanical behavior under traumatic loading. This study aimed to evaluate stress distribution and deformation patterns in permanent maxillary lateral incisors with different types of dens invaginatus using three-dimensional dynamic finite element analysis and to compare them with a morphologically normal tooth.Material and Methods Finite element models representing four dens invaginatus configurations of maxillary lateral incisors (#22) were analyzed under dynamic impact loading generated by a rigid steel sphere (radius 10 mm; velocity 10 m/s). Horizontal and vertical impact scenarios were simulated. In addition, a static occlusal force of 100 N was applied to the palatal surface to reproduce functional contact. Stress distribution and deformation patterns were compared with those of a morphologically normal incisor model.Results Dens invaginatus models showed substantially higher biomechanical responses than the normal tooth under both loading directions. Tooth stresses increased by approximately 110-130%, deformation values nearly doubled, and microstrain levels rose progressively with anomaly severity. The lowest responses were observed in the Type I model, whereas the Type IIIb configuration consistently demonstrated the highest stress, deformation, and strain values. Principal stresses in surrounding structures were also elevated, increasing by roughly 40-70%.Conclusions Dens invaginatus markedly modifies the biomechanical response of lateral incisors subjected to traumatic forces. Both internal morphology and impact direction influence stress distribution, with vertical loading generating greater stresses. Increased biomechanical susceptibility was evident even in the mildest form (Type I), while the most severe configuration (Type IIIb) exhibited the highest stress and deformation responses, indicating that dens invaginatus should be regarded as a clinically relevant biomechanical risk factor in dental trauma assessment.