The OralChroma TM CHM-2: a comparison with the OralChroma TM CHM-1

Already decades ago, the diagnosis of halitosis was facilitated with the arrival of chair-side instruments to score the breath odor. These devices are used for a more objective assessment of halitosis compared with organoleptic scoring, but these too have their disadvantages. To overcome some of the drawbacks of the original model of the OralChroma (CHM-1), few years ago a second generation of this machine (CHM-2) was introduced. This study compared both devices in a clinical setting. All records of the patients visiting a specialized halitosis consultation over a period of 5 years (2012-2017) were examined. The correlations of the OralChroma CHM-1 and CHM-2 with the organoleptic and Halimeter® measurements were analyzed. Additionally the sensitivity, specificity, and negative and positive predicted values were calculated. A total of 581 data points were included (CHM-1: 292, CHM-2: 289). The correlations between both models with the organoleptic measurements were not statistically significant different. The CHM-2 seemed superior to the CHM-1 in the quantification of dimethyl sulfide with a detection rate of 95% and 61%, respectively. Additionally, the CHM-2 was significantly more sensitive for dimethyl sulfide than the CHM-1. However the latter showed in turn a better sensitivity for hydrogen sulfide and methyl mercaptan. The CHM-2 showed a better sensitivity for dimethyl sulfide than its predecessor. However, its sensitivity for hydrogen sulfide and methyl mercaptan was worse. Dimethyl sulfide is the main volatile implicated in extra-oral blood-borne halitosis, this makes the OralChroma CHM-2 the instrument of choice when this is suspected.