Evaluation of athletic mouthguard through vibration test on maxillary teeth of human dry skull

The athletic mouthguard has been used for the prevention of orofacial injuries in contact sports. In this research, the effectiveness of a mouthguard was evaluated for its protection of the maxillary teeth of a human dry skull through experimental modal analysis. The upper central incisor was excited by an electrodynamic shaker. The frequency response functions of the upper teeth were then recorded on an FFT analyzer in order to identify modal shapes of the maxillary arch with and without a mouthguard. In addition, transient response simulations were carried out and decay rates of transient response waves were compared. As a result, when the mouthguard was in place, the resonance peaks of the frequency response functions were dampened, and the nodes of the modal shapes for the anterior teeth were indefinite in the frequency domain over 1 kHz. In the transient response simulation, the decay rates of transient response waves when the mouthguard was used were significantly higher than those when the mouthguard was not used (p<0.01). The results suggest that the mouthguard relieves the stress concentrated on the anterior teeth in a frontal collision by absorbing and dispersing some of the shock energy, thus quickly stopping the vibration of the maxillary teeth. These findings support the clinical fact that mouthguards prevent orofacial injuries in sporting activities.