A Method for Detecting the Deterioration in the Shock Absorption Capability of Mouthguards

Abstract

Objective methods for mechanical assessment of mouthguards used for a prolonged period of time are currently unavailable. The aim of this experimental study was to establish a quantitative method for assessing the preventive effect of mouthguards. 10 participants volunteered for this study. Impact loads were simulated by dropping a 250-g steel rod from a height of 100 mm onto upper front teeth of 10 custom ethylene vinyl acetate mouthguards fixed to a steel receiving rod. The mean output from load cells equilaterally placed between plates at the base of the apparatus was measured as the impact pressure (N). Its attenuation ratio (%) was calculated as the ratio of the difference in impact pressures without and with a mouthguard to impact pressure without a mouthguard. Impact pressure with mouthguard was approximately 60% of that without mouthguard in all cases. Intraclass correlations showed excellent intra-rater and inter-rater reliability for attenuation ratio (0.98 and 0.94, respectively). Bland-Altman plots indicated lack of systematic bias. The results suggest that attenuation ratio of impact pressure calculated by the proposed method is a valid criterion for assessing the preventive effect of mouthguards. The method may enable early detection of mouthguard deterioration and their timely replacement.

Key words

ethylene vinyl acetate - intraclass correlations - minimal detectable change - Bland-Altman plot - deterioration - impact injury

• References

• 1 Auroy P, Duchatelard P, Zmantar NE, Hennequin M. Hardness and shock absorption of silicone rubber for mouth guards. J Prosthet Dent 1996; 75: 463-471
• 2 Biagi R, Cardarelli F, Butti AC, Salvato A. Sports-related dental injuries: knowledge of first aid and mouthguard use in a sample of Italian children and youngsters. Eur J Paediatr Dent 2010; 11: 66-70
• 3 Blignaut JB, Carstens IL, Lombard CJ. Injuries sustained in rugby by wearers and non-wearers of mouthguards. Br J Sports Med 1987; 21: 5-7
• 4 Cetinbaş T, Sönmez H. Mouthguard utilization rates during sport activities in Ankara, Turkey. Dent Traumatol 2006; 22: 127-132
• 5 Cohenca N, Roges RA, Roges R. The incidence and severity of dental trauma in intercollegiate athletes. J Am Dent Assoc 2007; 138: 1121-1126
• 6 Coto NP, Brito e Dias R, Costa RA, Antoniazzi TF, de Carvalho EP. Mechanical behavior of ethylene vinyl acetate copolymer (EVA) used for fabrication of mouthguards and interocclusal splints. Braz Dent J 2007; 18: 324-328
• 7 Duddy FA, Weissman J, Lee RA, Paranjpe A, Johnson JD, Cohenca N. Influence of different types of mouthguards on strength and performance of collegiate athletes: a controlled-randomized trial. Dent Traumatol 2012; 28: 263-267
• 8 Gould TE, Piland SG, Shin J, Hoyle CE, Nazarenko S. Characterization of mouthguard materials: physical and mechanical properties of commercialized products. Dent Mater 2009; 25: 771-780
• 9 Greasley A, Karet B. Towards the development of a standard test procedure for mouthguard assessment. Br J Sports Med 1997; 31: 31-35
• 10 Haley SM, Fragala-Pinkham MA. Interpreting change scores of tests and measures used in physical therapy. Phys Ther 2006; 86: 735-743
• 11 Harriss DJ, Atkinson G. Ethical standards in sport and exercise science research: 2014 update . Int J Sports Med 2013; 34: 1025-1028
• 12 Knapik JJ, Marshall SW, Lee RB, Darakjy SS, Jones SB, Mitchener TA, delaCruz GG, Jones BH. Mouthguards in sport activities: history, physical properties and injury prevention effectiveness. Sports Med 2007; 37: 117-144
• 13 Kumamoto D, Maeda Y. Are mouthguards necessary for basketball?. J Calif Dent Assoc 2005; 33: 463-470
• 14 Labella CR, Smith BW, Sigurdsson A. Effect of mouthguards on dental injuries and concussions in college basketball. Med Sci Sports Exerc 2002; 34: 41-44
• 15 Lieger O, von Arx T. Orofacial/cerebral injuries and the use of mouthguards by professional athletes in Switzerland. Dent Traumatol 2006; 22: 1-6
• 16 Maeda Y, Yonehata Y, Satoh H. Mouthguard retention: is design or accuracy of fit more critical?. Quintessence Int 2009; 40: 13-18
• 17 Maeda Y, Kumamoto D, Yagi K, Ikebe K. Effectiveness and fabrication of mouthguards. Dent Traumatol 2009; 25: 556-564
• 18 Maeda Y, Machi H, Tsugawa T. Influences of palatal side design and finishing on the wearability and retention of mouthguards. Br J Sports Med 2006; 40: 1006-1008
• 19 Maeda Y, Yasui T, Tanaka Y, Ando T, Ishigami K, Ueno T, Matsumoto M, Matsuda N. Is Mouthguard Effective for preventing Traumatic Injuries during Sports Events?: A Strategic Protocol Formulated by the Japanese academy of Sports Dentistry (JASD) to Accumulate Scientific Evidence. Int J Sports Dent 2013; 6: 7-11
• 20 Maestrello CL, Mourino AP, Farrington FH. Dentists’ attitudes towards mouthguard protection. Pediatr Dent 1999; 21: 340-346
• 21 McNutt T, Shannon SW, Wright JT, Feinstein RA. Oral trauma in adolescent athletes: a study of mouth protectors. Pediatr Dent 1989; 11: 209-213
• 22 O’Malley M, Evans DS, Hewson A, Owens J. Mouthguard use and dental injury in sport: a questionnaire study of national school children in the west of Ireland. J Ir Dent Assoc 2012; 58: 205-211
• 23 Onyeaso CO. Secondary school athletes: a study of mouthguards. J Natl Med Assoc 2004; 96: 240-245
• 24 Ozawa T, Takeda T, Ishigami K, Narimatsu K, Hasegawa K, Nakajima K, Noh K. Shock absorption ability of mouthguard against forceful, traumatic mandibular closure. Dent Traumatol 2014; 30: 204-210
• 25 Padilla R, Dorney B, Balikov S. Prevention of oral injuries. J Calif Dent Assoc 1996; 24: 30-36
• 26 Park JB, Shaull KL, Overton B, Donly KJ. Improving mouth guards. J Prosthet Dent 1994; 72: 373-380
• 27 Rossi GD, Lisman P, Leyte-Vidal MA. A preliminary report of structural changes to mouthguards during 1 season of high school football. J Athl Train 2007; 42: 47-50
• 28 Sasayama C, Taniuchi H, Takamata T, Kagiya S, Kasahara T, Nagasawa S, Osuga N, Shomura M, Iwasaki T, Tomida M. A Study on New Materials for Sports Mouthguards. ―Application of Silicone-based Materials Mixed with Crystallized Quartz Fillers―. J Sports Dent 2014; (in Japanese); 17: 31-38
• 29 Takahashi M, Koide K, Mizuhashi F. Study on the Thickness of Mouthguard Sheet after a Vacuum-Forming Process – The Influence of Mouthguard Sheet Material. Ann Jpn Prosthodont Soc 2011; (in Japanese); 3: 346-352
• 30 Takamata T, Hashii K, Yamaki T, Numano H, Kato Y, Okada Y, Anzai M, Shomura M. Shock Absorption Characteristics of Commercial Custom-made Sports Mouthguard Materials. Int J Sports Dent 2009; 2: 62-71
• 31 Takeda T, Ishigami K, Shintaro K, Nakajima K, Shimada A, Regner CW. The influence of impact object characteristics on impact force and force absorption by mouthguard material. Dent Traumatol 2004; 20: 12-20
• 32 Takeda T, Ishigami K, Handa J, Naitoh K, Kurokawa K, Shibusawa M, Nakajima K, Kawamura S. Does hard insertion and space improve shock absorption ability of mouthguard?. Dent Traumatol 2006; 22: 77-82
• 33 Tanaka Y, Maeda Y, Yang TC, Ando T, Tauchi Y, Miyanaga H. Prevention of Orofacial Injury via the Use of Mouthguards among Young Male Rugby Players. Int J Sports Med 2015; 36: 254-261
• 34 Yeşil Duymuş Z, Gungor H. Use of mouthguard rates among university athletes during sport activities in Erzurum, Turkey. Dent Traumatol 2009; 25: 318-322