Tribst João Paulo Mendes, de Oliveira Dal Piva Amanda Maria, Borges Alexandre Luiz Souto, Bottino Marco Antonio
Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos, SP, Brazil.
Dent Traumatol. 2018 Dec;34(6):429-437. doi: 10.1111/edt.12432. Epub 2018 Sep 21.
BACKGROUND/AIMS: Mouthguards (MGs) are devices that can reduce the risks of facial trauma. However, the large variety of MG types and thicknesses raises the question of which type is the most effective and beneficial for the athletes. The aim of this study was to evaluate stress distribution in the skull, teeth, and jaws as a consequence of a direct impact.
Using modeling software, a human skull was modeled and a human jaw was created with all teeth inserted into the respective alveolus. The models were divided according to the MG type (custom-made or stock) and thickness (1, 2, and 4 mm). Two models without MG were evaluated with and without teeth contact. The geometries were exported to analysis software and the materials were considered ideal. Fixation occurred at the base of the foramen magnum. The load (500 N) was applied on the canine tooth with a ball. Maximum principal (MPa) and Von-Mises results were obtained.
Without any protection, the generated tensile stress was of greater magnitude causing more damage in the absence of teeth contact. The presence of a MG significantly reduced the generated stress in all structures, and the customized/individualized type was more efficient than stock MGs.
In extreme situations when it is impossible to use a MG, keeping the teeth in maximum intercuspal position is less harmful. Despite this, the use of any MG is beneficial and assists in dampening the generated stress. The thicker the device, the greater the capacity for decreasing the damage in all structures. The use of individual protectors for each patient is even more beneficial for preventing trauma during at-risk activities of impact.
背景/目的：口腔护具（MGs）是能够降低面部创伤风险的装置。然而，MGs的种类繁多且厚度各异，这就引发了哪种类型对运动员最为有效和有益的问题。本研究的目的是评估直接撞击导致的颅骨、牙齿和颌骨中的应力分布。
使用建模软件，构建了一个人类颅骨模型，并创建了一个人类颌骨模型，所有牙齿均植入各自的牙槽窝。根据MG类型（定制或成品）和厚度（1、2和4毫米）对模型进行划分。对两个未使用MG的模型在有和没有牙齿接触的情况下进行评估。将几何模型导出到分析软件中，并将材料视为理想材料。在枕骨大孔底部进行固定。用一个球对犬齿施加500牛的载荷。获得了最大主应力（MPa）和冯·米塞斯应力结果。
在没有任何保护的情况下，产生的拉应力更大，在没有牙齿接触时造成的损伤更大。MG的存在显著降低了所有结构中产生的应力，定制/个性化类型比成品MG更有效。
在无法使用MG的极端情况下，将牙齿保持在最大牙尖交错位危害较小。尽管如此，使用任何MG都是有益的，有助于减轻产生的应力。装置越厚，减少所有结构损伤的能力就越大。为每个患者使用个性化护具在有撞击风险的活动中预防创伤更为有益。
