An investigation into the occurrence and effects of sports induced maxillofacial injuries : mouthguards as protective modalities

In England and Wales, up to 1.4 million people attend emergency departments, each year, with head injuries. A number of these derive from sporting activities, which have an inherent risk of facial injury from traumatic impacts against fellow competitors, projectiles, posts or the ground. Monitoring the incidence and aetiology of sports injuries can enhance the understanding of head injuries, and the development of more effective protective modalities. This thesis starts with a questionnaire survey, which systematically describes the interplay between the types of sport, the sex of the players, the anatomical site, and the regularity of incidence of fractures. Alongside, the contribution of protective devices in common usage and the technology behind the materials used. A question often arises how thick should a mouthguard be for an individual. Through a series of manufacturing assessments, this thesis investigates the finished mouthguard thickness from a large sample group of experienced participants in relation to manufacturing thickness. Subsequently, this thesis proposes a new mouthguard manufacturing technique, whereby it was found that increasing the anterior angulation of the dental model by varying degrees ( 15°, 30° & 45°) produces a redistribution of thinning patterns of the 4 mm EVA mouthguard material and increases thickness. By rotating the anterior section of the dental model by 45°, there was a 75% increase in anterior thickness, from a mean of 1.6mm (SD: 0.34), with the model on a flat plane, to 2.8mm (SD: 0.16), with the model held at a 45° angle. Finally, this thesis explores how bone density either by ageing or individuality may affect the impact performance of the mouthguard from the values obtained from both studies. Thus, highlighting the question does the mouthguard need to be more bespoke for the individual in terms of bone density as well as what sport they play.