Association between Purpose in Life/(<i>Ikigai</i>), Prefrontal Cortex Function, and the Prevention of Halitosis Caused by Mental Stress, Pseudo-Halitosis, and Halitophobia

Abstract

Halitosis is a condition characterized by unpleasant oral odor or oral malodor problems that can lead to social and psychological impediments; it can be either genuine halitosis or pseudo-halitosis. One of the extra-oral conditions of genuine halitosis is mental stress, which causes a reduction in both saliva secretion and the presence of salivary lysing agents known as lysozymes, leading to oral malodor. Even in the absence of objective oral malodor, persons with pseudo-halitosis complain of halitosis symptoms, while those with halitophobia have a fear of halitosis. Genuine halitosis caused by stress, pseudo-halitosis, and halitophobia may all be due to anxiety resulting from an excessive need of approval from others. Purpose in life (PIL)/(ikigai), which is related to prefrontal cortex function, has been shown to be an effective way to manage stressful events, and is negatively correlated with an excessive need of approval from others. PIL/(ikigai), similar to prefrontal cortex function, develops through positive experiences from infancy to adolescence, such as spending time in beautiful natural surroundings, having success at meeting valued goals, and gaining empathetic acceptance and affection from others. Understanding the traits and developmental conditions associated with PIL/(ikigai) and prefrontal cortex function could improve the ability of individuals to manage stressful events, thereby promoting the prevention of halitosis, pseudo-halitosis, and halitophobia. The present proposal could contribute to future empirical research.