Effects of a chattering teeth training oral appliance for working memory improvement in healthy volunteers: a cross-over randomized trial

BACKGROUND: Memory is an important part of the mental activity. Chattering teeth training practiced in Korean Medicine (known as gochi in Korean), which is a practice of making a sound by touching the upper and the lower teeth, has been accepted as a modality for the dental health. The purpose of this study is to confirm the effect of a specially designed intraoral appliance, the No-Sick Exerciser, on working memory improvement in healthy participants. METHODS: Thirty healthy participants aged between 16 and 30 years will be recruited and randomized into sequence A and B of 15 each, as in a cross-over design (sequence A: chattering teeth training oral appliance)-chewing the gum; sequence B: chewing the gum—chattering teeth training oral appliance with a washout period of one week. The primary outcome will be assessed by the digit span test and secondary outcomes by the symbol digit modality test and the word list recall, which will be conducted before and after each intervention, four times on each participant. DISCUSSION: This protocol proposes the rationale and method for the use of an intraoral appliance for working memory improvement. If the oral appliance demonstrates better feasibility for working memory improvement compared with chewing gum, a large scale study will be needed to investigate the effectiveness of the device on populations who require memory improvement.