Psychosocial burden of halitosis: association between volatile sulfur compounds and quality of life in adults

Halitosis, commonly known as bad breath, is a highly prevalent condition often associated with volatile sulfur compounds (VSCs) produced by oral anaerobic bacteria. While intraoral halitosis is the most frequent type, its psychosocial impact remains underexplored in terms of its correlation with objective diagnostic markers. This study investigated the association between VSC concentrations and halitosis-related quality of life using the Halitosis Associated Life-Quality Test (HALT). In this cross-sectional study, 40 adults self-reporting halitosis were assessed using OralChroma™, a portable gas chromatograph that quantifies hydrogen sulfide, methyl mercaptan, and dimethyl sulfide. Breath samples were collected at baseline and after an L-cysteine oral rinse challenge. Participants completed the HALT questionnaire to assess emotional, social, and functional impacts. Statistical analyses included descriptive metrics, Pearson's correlation, and multiple linear regression. Model assumptions were tested for validity. At baseline, 25% of participants had VSC levels above diagnostic thresholds; after L-cysteine administration, this proportion increased to 87.5%, indicating the presence of latent halitosis. Methyl mercaptan concentration before the challenge showed a significant correlation with HALT scores (<i>r</i>= 0.353;<i>p</i>= 0.025) and was the only significant predictor in the final regression model (<i>β</i>= 1.03;<i>p</i>= 0.025;<i>R</i>²= 0.125). Elevated HALT scores were also observed in participants without clinically confirmed halitosis, suggesting that self-perception and emotional distress play a central role in patient experience. These findings highlight the relevance of combining objective VSC measurements with validated, condition-specific quality-of-life instruments to better understand and manage halitosis. Methyl mercaptan may serve as a biochemical marker of halitosis severity and also as a potential mediator of its psychosocial consequences.