マウスガードの使用が外傷性衝撃時の上顎中切歯の生体力学的応答に及ぼす影響．3次元有限要素法による解析

Mouthguard Use Effect on the Biomechanical Response of an Ankylosed Maxillary Central Incisor during a Traumatic Impact: A 3-Dimensional Finite Element Analysis.

• Alexandre Luiz Souto Borges
• Amanda Maria de Oliveira Dal Piva
• Laís Regiane da Silva Concílio
• Tarcisio José de Arruda Paes-Junior
• João Paulo Mendes Tribst

抄録

(1) 背景。コンタクトスポーツでは外傷はよくあることであるが、外傷性衝撃時に上顎中切歯のアンクラウス化に伴うマウスガード（MG）着用の影響についてはデータがない。(2)方法この状況における骨と歯の応力分布を評価するために、皮質骨、海綿骨、軟部組織、歯根象牙質、エナメル質、歯根膜を含む上顎中切歯のモデルを作成し、拮抗歯をモデル化した。一方のモデルは、厚さ4mmのMGを受けた。両モデルとも有限要素に細分化した。摩擦のない接触を使用し、剛体がモデルに1m-sで衝突する非線形動的衝撃解析を行った。それぞれのモデルについて、4つの異なる状況を合計したアンクルーズド歯根膜のシミュレーションを行った。その結果をフォン・ミーゼス応力マップで示しました。(3)結果(3)結果：歯と骨への応力集中は，MGなしのモデルでは19.5MPa，アンクラウズド歯のモデルでは37.3MPaと高く，機械的応答は歯根膜が健全でMGが位置している患者では1.8MPa，7.8MPaと最も良好な結果が得られた．(4) 結論。MGの使用は、骨、象牙質、エナメル質、歯根膜に発生する応力を和らげる作用があるため、健康な歯とアンクラウズド歯には有益である。しかし、アンクルーズ歯の患者さんは、MGを使用しても、健康な歯に比べて歯根破折を起こしやすくなります。

(1) Background: Trauma is a very common experience in contact sports; however, there is an absence of data regarding the effect of athletes wearing mouthguards (MG) associated with ankylosed maxillary central incisor during a traumatic impact. (2) Methods: To evaluate the stress distribution in the bone and teeth in this situation, models of maxillary central incisor were created containing cortical bone, trabecular bone, soft tissue, root dentin, enamel, periodontal ligament, and antagonist teeth were modeled. One model received a MG with 4-mm thickness. Both models were subdivided into finite elements. The frictionless contacts were used and a nonlinear dynamic impact analysis was performed in which a rigid object hit the model at 1 m·s. For each model, an ankylosed periodontal ligament was simulated totaling 4 different situations. The results were presented in von-Mises stress maps. (3) Results: A higher stress concentration in teeth and bone was observed for the model without a MG and with ankylosed tooth (19.5 and 37.3 MPa, respectively); the most promising mechanical response was calculated for patients with healthy periodontal ligament and MG in position (1.8 and 7.8 MPa, respectively). (4) Conclusions: The MG's use is beneficial for healthy and ankylosed teeth, since it acts by dampening the generated stresses in bone, dentin, enamel and periodontal ligament. However, patients with ankylosed tooth are more prone to root fracture even when the MG is in position compared to a healthy tooth.