This study was performed to analyze the psychologic change of Tae-kwon-do Athletes who were wearing the mouth guard and one of contact sports during their matches of Tae-kwon-do 10 selected Tae-kwon-do athletes who had no injuries which they had college Tae-kwon-do sparring matches in the Cheon-an area have participated in the study. The oral impressions if the selected athletes were taken to produce for individual custom mouth guards. After the mouth guards were produced, each of them sat in a chair and attached G.S.R. surface electrodes in the palms of the ends of the second and third fingers of their left hands without moving their left hands, And then they were asked to watch footages of Tae-kwon-do games to stimulate them as if the had have a mock match, and Labscribe2 which are one of polygraphy was used to record their G.S.R. values. To determine whether the mouth guards affected the changes of their psychological status during the sparring matches of not, the experimental group wore the mouth guards while they watched the footages, and the control group didn’t wear any mouth guards. The G.S.R. values of the two groups were measured while the watched the footages. To see if there were and significant polygraphy differences between the experimental group and the control group in G.S.R. values, a statistical package SPSS was used to make a comparative analysis. And there were significant change in between the experimental and control group that wore the mouth guards, and it was concluded the wearing mouth guards exerts an influence on change in the psychological state of Tae-kwon-do athletes while they watch a footage of mock match.

It is necessary to make preventive method for the trauma and disturbance complications of orofacial area because athletic trauma are physical and mental defects. Since 1913, an italian boxer discussed mouth guard with dentist and used it. It was reported that mouth guard from field prevented trauma, increased the muscle force and activated electromyogram although the history of mouth guard wearing was short. The mouth guard has prevented the trauma and also increased the muscle force. The purpose was to study muscle force and activity of EMG with mouth guard wearing. It concluded that mouth could prevent trauma and increase the muscle force

From ancient soldier to mordern athletes, it has been discussed that some oral appliance have enhanced performance and decreased stress or improve strength. Since mouth guard was used by Italien Boxer on 1930’s for prevent of orofacial injury, some investigators have researched the co-relationship between jaw position and strength. This experiment was performed to study the relationship between mouth guard and E.M.G. 20 Taekwondo students were participated in this study. They were wearing Mouth guard and checked Brachialis physical activity by E.M.G. The muscle activity of mouth guard wearing group was higher than that of non-wearing group.

Physical movement is reduced because of convinient life style by advancing of science. People need physical movement and athletes also need more physical training for their health and better records because of reduced movement in modern life style. Some athletes competing in contact sports wear dental mouth guards to reduce the risk of orofacial trauma and to increase the strength of muscle. It has been speculated that the use of mouth guards improves athletic ability such as muscular strength and equilibrium. The purpose of this study was to test the influence of C.M(custom made) mouth guard according to strength of taekwondo athletes. 5 trained subjects participating in taekwondo students in D University were included in this study. Deltoid muscular activity were tested by means of electromyograph (E.M.G) with or without wearing mouth guard. Subjects have pressed with 5 Kg barbell. The data were transferred to computer system as raw and integral data. The data were analysed by computer system, showing wearing mouth guard had higher action potential than non-wearing mouth guard. This meant that wereing mouth guard could enhance the muscle force in deltoid. It suggested that taekwondo athletes could use C.M mouth guard without any negative effect on their muscle strength.

Some sports players use dental mouth guards to reduce the risk of orofacial trauma. Althoug mouth guard have been shown to protect against orofacial injury, many players do not use them during training and playing because of discomfort and breathing problems. This study was performed to measure the alteration of respirotory volume during wear the mouth guard. I checked 5 D university male students ventlation with and without mouth guard in steady state. Air flow and volume were decreased during wearing Mouth guards compare to not wering. It suggested that mouth guard would have change the ventilation patterns.

Most Authors reported that mouth guard is a part of equipment for body-contact sports players. Mouth guards protect orofacial injuries but have some problems in breathing and speaking. Some authors reported that mouth guards have also improve the muscle strength and sport ability. This experiment was performed to study the change of masseter muscle EMG after wearing of mouth guard. 10 D university male base ball players were participated in this study. After impression taking, mouth guards were constructed and weared. Masseter muscle EMG and nasal ventilation after ten day's adaptation were checked. They were requested clenching with or without mouth guard. EMG and nasal ventilation were checked by iworx 104 instrument simultaneousley. The result showed that masseteric EMG were improved and nasal ventilation were stable after wearing mouth guard. It concluded that mouth guard had improved muscle activity and stabilized the nasal ventilation depend on experimental method.