Organoleptic and halitometric assessments do not correlate well in intra-oral halitosis: a systematic review and meta-analysis

•None of the halitosis measuring devices is superior significantly to the others, and our data with very low certainty does not suggest changing subjective measurement to objective measurement.•The halitosis measuring devices’ sensitivity and specificity are not outstanding.•Our findings suggest the need to exclude patients with extra-oral halitosis if the diagnosis would make with sulfide monitors.