Tongue coating: related factors


  • Conflict of interest and source of funding statement

    The authors declare that they have no conflict of interest. The study was self-funded by the authors and their institution.


Marc Quirynen

Department of Periodontology

Catholic University Leuven

Kapucijnenvoer 33

3000 Leuven





A clear relationship between tongue coating and oral malodour has been observed in many clinical trials. Why or when this coating is formed remains an open question. The aim of this study was to analyse possible factors related to the presence of tongue coating in a population complaining from oral malodour.

Materials and Methods

Patients were recruited from a halitosis clinic (UZ Leuven). Medical history, dietary and oral hygiene habits were retrieved via a questionnaire. Data were recorded on organoleptic score and level of sulphur compounds in breath, anatomical features of the tongue dorsum, amount of tongue coating (according to three indices: Miyazaki, Winkel and modified Winkel), tongue coating wet weight and salivary flow. The correlation between the presence of tongue coating and a series of parameters was analysed.


The level of oral hygiene was the strongest determinant factor for the presence of tongue coating. Smoking, presence of a denture, periodontal status and dietary habits also correlated although less obvious.


The presence of tongue coating appears to be related to several factors of which oral hygiene is the strongest.