# Ergonomic Sports Mouthguards: A Narrative Literature Review and Future Perspectives
###### Abstract  
Sports activities can increase participants' risk of orofacial trauma. Therefore, it is crucial to have a comprehensive understanding of various types of sports mouthguards. This study aims to present a narrative literature review on ergonomic mouthguards, including their indications for use, classifications, materials, manufacturing methods, and the current status of additive manufacturing in their production. Research of the existing literature was performed in the Google Scholar, MEDLINE/PubMed, Web of Science, and ScienceDirect databases to identify the currently available publications on the topic of sports mouthguards from January 1951 to August 2023. The terms used were \"sports mouthguard\", \"mouthguards and orofacial traumas\", and \"mouthguards and additive manufacturing\". A total of 920 articles were found, and 39 articles were selected and included in this review. While consensus exists regarding the significance of using sports mouthguards with optimal attributes, there is a need for standardization in the methodology for manufacturing custom-made mouthguards. These can be fashioned with conventional ethylene vinyl acetate (EVA) copolymer reinforcements. Such standardization would ensure uniform stress distribution and guarantee ample protection for oral tissues, allowing for universal reproducibility among dental practitioners. Additive manufacturing stands as an innovative method for fabricating mouthguards, displaying promising benefits. However, the materials and methodologies employed in this workflow still require refinement and characterization for a safe clinical integration. sports dentistry; orofacial trauma; sports mouthguard; reinforced mouthguards; 3D printing 2023 11353 11.11353 11. The average percentages of athletes in various sports who have experienced any type of orofacial injuries are as follows: wrestling (83.3%), boxing (73.7%), basketball (70.6%), karate (60.0%), jiu-jitsu (41.2%), handball (37.1%), soccer (23.3%), judo (22.3%), and field hockey (11.5%) [8]. The causes can range from direct to indirect traumas. Direct traumas occur when an athlete's facial structures come into contact with another athlete or even equipment during training and competitions [1]. On the other hand, indirect traumas happen when an individual's maxilla and mandible come into intense contact due to falls or impacts, for instance [19]. In cases of significant impacts, the face is the most vulnerable structure in the human body and often the least protected [16]. An athlete has a 10% chance of experiencing an orofacial trauma in each training or competition session, and a 33% to 56% chance over their entire career [20]. However, it is important to note that the prevalence of such injuries varies depending on the type of sport practiced, the athlete's age and gender, and the level of contact in the competition [20; 21]. Generally, the frontal region of the maxilla is subjected to horizontal impacts, resulting in a prevalence of 90% of dental injuries occurring in the upper central incisors. These impacts also affect the surrounding structures, causing not only functional and painful issues for the athlete but also aesthetic and psychological concerns [12; 14; 22; 23]. The use of an appropriately designed mouthguard by athletes in sports activities should be encouraged [9; 10]. Given the importance of preventing orofacial injuries in sports practice, the American Dental Association recommends the use of mouthguards in various sports, including acrobatic activities, basketball, cycling, boxing, horseback riding, extreme sports, track events, hockey, soccer, gymnastics, handball, ice hockey, skateboarding, lacrosse, martial arts, racquet sports, rugby, skiing, skydiving, softball, squash, surfing, volleyball, water polo, shot putting, weightlifting, and wrestling [11]. Mouthguards are classified into three groups according to their fabrication: stock, boil and bite, and custom-made [1; 6; 7]. Additionally, they can be fabricated from various materials that can influence their effectiveness [5].