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    Inside Dentistry

    March 2013, Volume 9, Issue 3
    Published by AEGIS Communications


    Mouthguards Are Not One Size Fits All

    Not all mouthguards provide the same level of protection—research into dental science, materials, and technology has yielded innovative solutions in reducing orofacial injuries

    By Brett Dorney, BDS, FRACDS, FASD, FICD

    Many sports have the potential for orofacial injuries due to falls, collisions, or contact with hard surfaces. Contact sports, such as football, rugby (Figure 1), hockey, basketball, and soccer, carry a greater risk of high-impact collisions, and players are especially prone to dental injuries. These collisions involve acute transmission of energy to the teeth and supporting structures with fractures, dislocations, separations, and crushing injuries occurring. Recent research has shown the improved ability of custom-built mouthguards to prevent injuries.1 A correctly designed and manufactured custom-built mouthguard will reduce the consequences of such traumas, but it must remain in place at impact to allow absorption and distribution of the impact forces.2

    Background

    The first mouthguards—rubber that was trimmed and hollowed out—were worn by boxing contestants over 100 years ago. This type of mouthguard is represented today by the unfitted “stock” mouthguard—a simply curved rim of ethylene vinyl acetate. The period of most rapid development in mouthguard technology was in the United States between 1950 and 1965, when extensive field studies and material testing—principally in American football—were undertaken.3 It was learned that a mouthguard should be worn on the maxillary teeth, as the anterior maxillary teeth were the most likely to be injured.4

    Dental injuries are normally not life threatening and may not prevent the injured athlete from further participation in sport. However, such injuries (Figure 2) are complex and expensive to treat, can be disfiguring, and may become a life-long problem. The American Dental Association and the Australian Dental Association5 both recommend the use of a mouthguard, with a strong message to wear only a professionally fitted mouthguard.

    The Academy for Sports Dentistry, founded in San Antonio, Texas, in 1983, recommends that anyone participating in a sport that presents risk of injury to the teeth, jaws, or oral soft tissues, or that shows a potential risk of concussion, could benefit from a properly fitted and properly worn mouthguard.

    The boil-and-bite mouthguard is fitted and formed in the mouth by heat, finger, tongue, and biting pressure.6 Even though they are the most common type of mouthguard used, they have limited protective capacity, can be poorly fitting, have poor durability, and interfere with speech and breathing. They are not recommended, as they may be displaced on impact, with the possibility of lodging in the oropharynx, causing a life-threatening situation.7

    The correct solution is to prepare and fit customized mouthguards that are made on models based on impressions of the player’s mouth. There is an increased cost in providing this professional care, but the benefits provided outweigh the risk of a severe dental injury and its associated expense (Figure 3).

    The improvement in ethyl vinyl acetate mouthguard blanks, with the introduction of pressure lamination for mouthguard construction in 1974, has allowed the production of accurately fitting mouthguards.8 Efficient and complete lamination cannot be achieved with vacuum machines.

    The results of pressure lamination are:

    • Precise adaptation
    • Negligible deformation
    • Capacity to thicken as required using additional blanks
    • Ability to place inserts or modify the shore hardness of the mouthguard blanks to achieve better adaptation.8

    The thickness of the mouthguard’s labial and occlusal surfaces is responsible for the mouthguard’s ability to absorb and spread impact energy.1 While laboratory testing of mouthguards has shown improvement in energy absorption at up to 4 mm in thickness, this is generally too thick to wear comfortably. This result challenges researchers to consider new designs and better materials to improve impact absorption in mouthguards thinner than 4 mm. The most recent mouthguard research is published in a new textbook written by a research team at Tokyo Dental School.1 The team’s research in the areas of dental science, materials, and technology has produced innovative solutions in reducing dental injuries in sport.

    The influence of a balanced occlusion was investigated, and it was concluded that the support of the mandibular dentition by the mouthguard is indispensable in reducing impact force and tooth distortion.1 A controversial area researched is whether mouthguards can prevent mandibular bone fractures and concussion. The laboratory study used an artificial skull model and tested a 3-mm pressure-laminated mouthguard post-lamination. The conclusions of this study were as follows1

    • Within the limits of this study, mouthguards can reduce distortion to the mandible and acceleration of the head from a direct blow to the mandible.
    • Mouthguards might prevent mandibular bone fractures and concussion.

    Possibly the most exciting development is the creation of a mouthguard with a hard insert and buffer space over the anterior maxillary teeth.1 The test results showed a significantly greater buffer capacity from this new design of mouthguard. It is proposed the mouthguard distorts into the space over the anterior teeth, with impact energy being absorbed.9

    Conclusion

    It is dangerous to assume that all mouthguards provide the same level of protection.10 Mouthguards should fit accurately, be of sufficient thickness, have even occlusal contact, and not interfere with breathing or speech. Mass-produced mouthguards cannot fulfil these requirements.1

    Note

    Training on how to design and construct modern pressure-laminated mouthguards is available by attending the Team Dental Course, which is operated annually by the Academy for Sports Dentistry. This course will be conducted as part of the Academy for Sports Dentistry 31st Annual Symposium, August 1–3, 2013, in Philadelphia.

    References

    1. Taketa T, Ishigami K, Nakajima K, Kurokawa K. Mouth­guards: The Effects and the Solutions for Underlying Prob­lems. Hauppauge, NY: Nova Science Publishers, Inc., 2010.

    2. Harcourt K. Sporting injuries–are they preventable? Aust Dent J. 1989;34(5):485-486.

    3. Heintz WD. Bureau of Dental Health Education. Mouth protectors: a progress report. J Am Dent Assoc. 1968;77(3):632-636.

    4. Chapman PJ. Mouthguards and the role of sporting team dentists. Aust Dent J. 1989;34(1):36-43.

    5. Australian Dental Association. Oral Health Committee. Mouthguard statement. Australian Dental Association News Bulletin. July 1996.

    6. Park JB, Shaull KL, Overton B, Donly KJ. Improving mouthguards. J Prosthet Dent. 1994;72:373-380.

    7. Jagger R. Mouthguards. Br Dent J. 1996;180(2):50.

    8. Hunter K. Modern mouthguards. Dental Outlook. 1989;15:3-5.

    9. Westerman B, Stringfellow PM, Eccleston JA. Beneficial effects of air inclusions on the performance of ethlyen vinyl acetate (EVA) mouthguard material. Br J Sports Med. 2002;36(1):51-53.

    10. Dorney B. Mouthguard protection in sports injury. Case report. Aust Dent J. 1994;39(6):372.

    About the Author

    Brett Dorney, BDS, FRACDS, FASD, FICD
    Clinical Lecturer
    Faculty of Dentistry
    Sydney University
    Sydney, Australia


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    Image Gallery

    Figure 1 A 16-year-old male after a rugby accident.

    Figure 1

    Figure 2 Cricket accident involving a 17 year-old female.

    Figure 2

    Figure 3 Injury sustained while wearing a boil and bite mouthguard.

    Figure 3