Comprehensive comparison of protective effect of customized multi-layered versus boil-and-bite mouth guard on orofacial tissues: A finite element analysis framework

This paper aims to numerically investigate the protective efficiency of multilayered and boil-and-bite mouthguards on orofacial hard and soft tissues subjected to impact loadings. To the best of our knowledge, this is the first attempt which studies the protective efficacy of mouthguards on orofacial injuries including both hard and soft tissues such as articular disks, stylomandibular and sphenomandibular ligaments, that are commonly neglected in clinical and numerical studies. To address this issue, a finite element based numerical framework has been proposed using the Abaqus finite element software. This study considers three different situations of the craniofacial structure, without any mouthguard, with the customized multilayered mouthguard and with a boil-and-bite mouthguard. The protective effectiveness of mouthguards is numerically evaluated based on pressure and displacement distributions on the orofacial hard and soft tissues under two different actual impact loadings. In all cases the results revealed that the customized multilayered mouthguard can more effectively reduce the stress concentration on orofacial hard and soft tissues which is the key factor to evaluate the protective efficiency of different types of mouthguard. As an example, a comparison between the protective efficiency of multilayered and boil-and-bite mouthguards reveals that under uppercut punch impact loading, the multilayered mouthguard performs 18.45% and 21.32% more effective respectively for upper and lower teeth and stylomandibular ligament. Furthermore, the simulation results for stylomandibular ligament and articular disk enable us to conclude that wearing a customized multilayered mouthguard cannot be replaced by a boil-and-bite mouthguard, since it causes more harm in comparison to the unprotected case.