Dimethylsulphidemia: the significance of dimethyl sulphide in extra-oral, blood borne halitosis.

Halitosis is a symptom and not a diagnosis. Rather, the topic represents a spectrum of disorders, including intra-oral, otorhinolaryngological, metabolic, systemic, pulmonary, psychological and neurological conditions. Halitosis may be the third most common trigger for patients to seek dental care and can cause significant impact on patient quality of life. About 10% of all genuine halitosis cases are attributed to extra-oral processes. Some authorities have reported that the nasal cavity and the oropharynx are the most common sites of origin of extra-oral halitosis. However, recent evidence appears to suggest that blood borne halitosis may be the most common subtype of extra-oral halitosis. Tangerman and Winkel report that dimethyl sulphide was the main volatile implicated in extra-oral blood borne halitosis. They proposed a hitherto unknown metabolic condition by way of explanation for this finding, resulting in systemic presence of dimethyl sulphide in blood and alveolar breath. This paper reviews the knowledge base regarding the behaviour of dimethyl sulphide in physiological systems and those disorders in which blood borne halitosis secondary to dimethylsulphidemia is thought to have an aetiopathological role.

Intra- and extra-oral halitosis: finding of a new form of extra-oral blood-borne halitosis caused by dimethyl sulphide.

AIM: The aim of this study was to unravel the origen and cause of intra-oral and extra-oral halitosis. MATERIAL AND METHODS: We studied 58 patients complaining of halitosis, using gas chromatography of volatile sulphur compounds (VSCs) in mouth and nose breath, organoleptic scoring of mouth and nose breath, Halimeter readings of mouth air and tongue-coating inspection. Subjects had no precence or history of periodontitis. RESULT: Of 58 patients, 47 patients had halitosis of oral origin, six had halitosis of extra-oral origin and five had no halitosis (halitophobia). A strong correlation was found between the degree of intra-oral halitosis as measured by organoleptic scoring of mouth breath and the concentration of the VSCs hydrogen sulphide (H(2)S) and methyl mercaptan (CH(3)SH) in mouth breath. Taking into account the much larger odour index of CH(3)SH, it was concluded that CH(3)SH is the main contributor to intra-oral halitosis. In all six cases of extra-oral halitosis, halitosis was caused by the presence of elevated levels of dimethyl sulphide (CH(3)SCH(3)) in mouth and nose breath. CONCLUSION: Our study provides evidence that the VSC, CH(3)SH and to a lesser extent H(2)S are the main contributors to intra-oral halitosis and that CH(3)SCH(3) is the main contributor to extra-oral or blood-borne halitosis, due to a hitherto unknown metabolic disorder.

Trimethylaminuria (fish-odour syndrome) and oral malodour.

A small but important percentage of oral malodour cases have an extra-oral aetiology and certain of these fall into the category of 'blood-borne halitosis'. Odoriferous substances generated within the body and transported to the lungs via the circulatory system may, if sufficiently volatile, leave with the exhaled air and impart a foetid odour to the breath. The aliphatic tertiary amine, trimethylamine, is such a volatile compound that is generated to excess in patients with a metabolic disorder known as trimethylaminuria (fish-odour syndrome). This article highlights this condition and draws attention to its potential role in the causation of recalcitrant oral malodour.