Development of a portable bad-breath monitor and application to field study of halitosis

Approximately 90% of oral malodour is believed to originate from foul-smelling gases such as volatile sulphur compounds (H₂S, CH₃SH, CH₃SCH₃), produced by oral bacteria. To detect the volatile sulphur compounds (VSC) objectively and easily is necessary for better diagnosis of halitosis especially for private clinics or field study. We have developed a bad-breath monitor, Breathtron™, equipped with a semiconductor gas sensor and a special filter for removing obstructive gases. 16 gases were used to reveal sensing characteristic of this sensor. The sensitivity of the sensor was high enough to detect 0.01 ppm VSC. The mouth air of 42 volunteers was analyzed. Adequate correlation was found between Breathtron™ vs. gas chromatography (r = 0.817). The correlation between Breathtron™ and olfactory panel was also confirmed (r = 0.644). Furthermore, we examined 869 adults (386 males and 483 females) in a Japanese rural town under informed consent. Halitosis was seen in about 40% of the examinees. The amount of tongue coating and the number of present teeth were found to be related to halitosis. Breathtron™ can be used widely at private clinics or even in field study of halitosis for its portable size, simple operation, and short measuring time.