Evaluation of Stress Trajectories in Craniofacial Bones in Class I Skeletal Pattern: A Finite Element Analysis Using CT Scan

Background: Occlusal forces are transmitted through the craniofacial skeleton, but the extent to which these stresses propagate to the cranial base remains unclear. Finite element analysis offers a precise tool to study stress distribution in complex craniofacial structures. Aim of the study: To evaluate stress trajectories generated by occlusal loading and determine their extension to the cranial base using CT-derived finite element models. Setting and design: An in-silico finite element study was conducted at the Department of Orthodontics and Dentofacial Orthopedics, Government Dental College & Research Institute, Bengaluru, India. Methods and materials: CT scans of healthy adults with Class I skeletal and dental patterns were converted into three-dimensional (3D) finite element models. Occlusal loads of 1000 N, 500 N, and 350 N were applied to both jaws and to the mandible alone. Stress distribution was assessed across craniofacial structures. Statistical analysis: Descriptive analysis of stress magnitudes and distribution patterns; no inferential statistics were applied. Results: High occlusal loads (1000 N, 500 N) generated stresses in the mandible exceeding cortical bone yield limits (>100 MPa), while cranial base stresses remained negligible (~0.5 MPa). Physiological loading (350 N) produced mandibular stresses within cortical bone tolerance (~76 MPa). Masseter stresses were higher in combined maxilla-mandible loading compared to mandibular-only loading. Conclusions: Occlusal forces are primarily dissipated within the mandible and maxilla, with minimal extension to the cranial base. Finite element analysis confirms the biomechanical safety of orthodontic loading with respect to cranial structures.