Distinguishing Subjective Halitosis.

Halitosis is chronic, endogenous malodor that is etiologically classified. Subjective halitosis, which may appear in clinically neurologic (neurogenic) or psychologic (psychogenic) forms, cannot be confirmed by using tests or performing visual inspection despite insistent complaints of malodor by the patient. Neurogenic forms mainly consist of chemosensory dysfunctions (dysguisa, dysosmia) and self-halitosis (retronasal olfaction, bloodborne olfactory receptor responses, phantosmia); whereas psychogenic forms are olfactory hallucinations, halitophobia, olfactory obsession, and delusional halitosis. This article reports clinically important properties of subjective halitosis that may be difficult to manage and provides a tool to aid dental pracitioners. Practitioners can identify suspected subjective halitosis cases by asking patients simple questions to distinguish between subjective and objective forms.