A novel approach for early evaluation of orthodontic process by a numerical thermomechanical analysis

Abstract

The main objective of this paper is to propose a novel method that provides an opportunity to evaluate an orthodontic process at early phase of the treatment. This was accomplished by finding out a correlation between the applied orthodontic force and thermal variations in the tooth structure. To this end, geometry of the human tooth surrounded by the connective soft tissue called the periodontal ligament and the bone was constructed by employing dental CT scan images of a specific case. The periodontal ligament was modeled by finite strain viscoelastic model through a nonlinear stress-strain relation (hyperelasticity) and nonlinear stress-time relation (viscoelasticity). The tooth structure was loaded by a lateral force with 15 different quantities applied to 20 different locations, along the midedge of the tooth crown. The resultant compressive stress in the periodontal ligament was considered as the cause of elevated cell activity that was modeled by a transient heat flux in the thermal analysis. The heat flux value was estimated by conducting an experiment on a pair of rats. The numerical results showed that by applying an orthodontic force to the tooth structure, a significant temperature rise was observed. By measuring the temperature rise, the orthodontic process can be evaluated. KEYWORDS finite element method, mechanical stress, orthodontic loading, thermal analysis, viscohyperelastic behavior

Three‐dimensional finite element stress analysis of teeth adjacent to a traumatized incisor

“…Deformation and stresses are mediated between teeth and bone by the PDL . Injury to the PDL is thought to play an important role in the mechanisms of tooth trauma and tooth mobility .…”

“…The impact to a single tooth might not represent the most common scenario, but even with major injuries where more teeth are involved, stresses may have been propagated to adjacent Deformation and stresses are mediated between teeth and bone by the PDL. 24 Injury to the PDL is thought to play an important role in the mechanisms of tooth trauma and tooth mobility. 25 Displacement, which was also demonstrated on teeth adjacent to the impacted incisor, can interrupt vascular blood supply and cause pulp necrosis which is one of the predisposing factors for inflammatory root resorption.…”

Three-dimensional finite element analysis of the effect of alveolar cleft bone graft on the maxillofacial biomechanical stabilities of unilateral complete cleft lip and palate

“…In order to conform to the clinical reality as much as possible, the experiment was performed by dividing maxillofacial bones with reference to the original bone sutures, 0.2 mm widths [ 48 – 50 ] were adopted on the bone sutures when the gaps between maxillofacial bones were measured in Siemens NX meanwhile according to the age of the patient elected. The inherent properties of bones [ 51 – 54 ] and periodontal membranes [ 55 – 59 ] are anisotropic, bones [ 60 ] and periodontal membranes [ 46 ] are biphasic materials consisting of solid and liquid phases, meanwhile, bones [ 61 – 63 ], bone sutures [ 64 , 65 ] and periodontal membranes [ 66 ] have viscoelastic properties. Since bone does not exhibit a large number of time-dependent material behaviors generally, the viscoelastic effect of the bone liquid phase can be neglected [ 67 – 69 ].…”