A validated finite element study of blunt trauma to the human maxilla

Six embalmed cadaver heads were obtained, prepared and subsequently impacted to the medial maxilla with a 142-gram baseball traveling at 14 m/s. Measurements of strain were obtained through the use of strain gauge rosettes located at the medial palate and both canine fossae. Three dimensional finite element models of a dentate human maxilla were constructed for the purpose of investigating the mechanical response to a simulated blunt impact. Convergence testing revealed that a refined mesh with over 70,000 degrees of freedom was necessary to obtain sufficient accuracy within the analysis. The simulated load case involved a transient, dynamic impact to the medial maxilla with boundary conditions imposed at the buccal segments of the model analogous to the experimental case. Results were validated by a direct comparison to the displacements and principal strains gathered from experimental and epidemiological data. For the examined load case, displacements were highly localized at the anterior portion of the maxillary incisors. The comparison of experimental and calculated principal strains as a result of the simulated impacts revealed a 1.67 to 11.37% difference in magnitude.