Computed Tomography-Based 3-Dimensional Finite Element Analyses of Various Types of Plates Placed for a Virtually Reduced Unilateral Condylar Fracture of the Mandible of a Patient.

PURPOSE

This study was performed to evaluate stresses in various types of plates placed for a virtually reduced unilateral condylar fracture of the mandible using computed tomography-based 3-dimensional finite element (FE) models of a patient to select the optimal plate system.

MATERIALS AND METHODS

A computed tomography-based FE model of the mandible of a patient with a unilateral condylar fracture was constructed. The fracture was virtually reduced and fixed with 1 straight titanium plate; 2 straight titanium plates; 2 straight poly-L-lactic acid plates; and 4-hole (box), 5-hole (strut), and 7-hole (lambda) condylar plates. Stresses developing in these plates were analyzed by applying 478.1 N of bite force at the first molar of the contralateral side of the mandible.

RESULTS

The magnitudes of tensile stress were within the tensile strength in all types of plates. However, the magnitudes of compressive stress in 1 straight titanium plate and 2 straight poly-L-lactic acid plates were beyond the compressive strength. The tensile and compressive stresses of the 5-hole (strut) plate were the smallest among the 3 types of condylar plates.

CONCLUSIONS

Fixation by 2 straight titanium plates or any type of condylar plate was biomechanically indicated for the condylar fracture of this patient. Among these plates, the 5-hole (strut) plate was considered optimal. FE analysis is useful in selecting the optimal fixation method in the individual patient.