Mouthguard Design and Facial Skeletal Profile Effect on Respiratory Function in Athletes

Mouthguards provide protection from concussion, dento-alveolar injury, and fracture of the facial skeleton. It is also known that some facial skeletal forms do predispose patients to dental trauma. Facial profile type has a significant effect on breathing and airway patency. Many elite athletes refrain from wearing mouthguards during contact sports because of a belief that they make breathing difficult. Our hypothesis is that a custom mouthguard will have no effect on respiration in athletes either at rest or whilst exercising. The hypothesis will be tested by measuring respiratory functional parameters in athletes in simulated exercise modes with different types and designs of mouthguards in place. This will be done as an unblinded randomised case control cross over study. 31 male subjects were recruited in this study. Skeletal measurements were obtained of the participant by measurements on standard lateral cephalometric radiography. Two mouth guards of different design were fabricated for each subject. Each participant was tested three times either wearing no mouthguard, mouth guard A or mouth guard B. The respiratory data collected include ventilation (Ve), Oxygen consumption (VO2), and heart rate (HR) at mild, moderate and maximum intensity of exercise. Each participant was tested a further two times. A repeated measure ANOVA found no statistical difference between the three groups of data at minimal, moderate and maximal levels of exercise (p>0.05). Secondary endpoints such as skeletal profile and airway dimension were also explored. The conclusion of this trial is that there is no statistical difference between ventilation, work of breathing or heart rate of an elite athlete and the use or type of custom mouthguard worn and the level of exercise. Scientific Background Mouthguards provide protection from concussion, dento-alveolar injury, and fracture of the facial skeleton.* Dento-alveolar and facial trauma is a common and frequent preventable presentation to emergency department in Western Australia in contact sport playing population. Many elite athletes do not wear mouthguards.* Common reasons for this are that mouthguards have been reported to affect respiration and subjectively increase “air hunger.”* Other reasons include gagging and interference with speech and on-field communication.* There have been a number of studies performed that have assessed the effect of mouthguards on FEV1 / PEF, airway resistance and VO2 Max during exercise.* Results from these studies have been equivocal and may be due to the use of small cohorts, as well as different types of mouthguards.* Mouthguards can be fabricated both as a custom mould for each individual or as a stock format which is heated up and moulded to the jaw. Custom made mouthguards are considered to be the ‘gold standard’ when compared to stock mouthguards as they have better shock absorbing capability and are rated higher in terms of fit and comfort.* However there is consensus in mouthguard design in even the custom made group with variation in thickness, occlusal extension and palatal surface area coverage. Our study has targeted elite athletes as there is an argument that if protective equipment is considered to restrict performance an athlete may not wear it. Elite athletes are role model’s to children and other athletes who mimic their on field behaviour, and if the current perceived deficiencies are addressed in mouthguard design then potentially more athletes would wear them. Recent studies have shown no difference in the protective capability of a mouthguard with palatal coverage and one without.* This study will compare mouthguards with the usual palatal surface area coverage against one without palatal surface coverage. In this study all athletes will have measurements taken of their facial skeletal profile and jaw structure. Jaw structure has been shown to affect the airway patency in individuals who suffer from obstructive sleep apnoea.* Oral and maxillofacial surgeons can alter the oropharyngeal airway with jaw advancement procedures which have been shown to have a beneficial effect on airway patency this patient population.* Similarly, athletes with narrow airways may be predisposed to difficulty breathing with and without a mouthguard in place.* Perhaps elite athletes performance can be aided by jaw advancement procedures, or the effect of a mouthguard be minimised with an advancement procedure enabling the athlete to wear their protective equipment. (* Denotes annotation for reference – I am currently undergoing training in endnote) Aims and Objectives The aim of this trial is to reduce the incidence of facial trauma (i.e. dento alveolar / facial skeletal and concussion) preventable by the use of mouthguards. The researchers will explore the design of mouthguards, and promote one that will increase mouthguard utilisation in the elite athlete population. If mouthguards are shown not to affect ventilatory parameters to lobby health insurance bodies to improve mouthguard subsidies and reduce rebates for dento-alveolar trauma sustained whilst engaging in contact sport without wearing protective equipment. The researchers would also like to approach sports administrators to make the use of mouthguards compulsory in elite professional sports. Study Design and Hypothesis Our null hypothesis is that there is no difference in respiratory parameters between a custom mouthguard and no mouthguard worn by athletes during various levels of intensity of exercise. This study is an equivalence study. The hypothesis will be tested using an unblinded randomised case control cross over study.