In dry mouth clinic, there are many patients who complained of subjective feelings of dry mouth despite their normal salivation. This dry mouth frequently comorbid with glossodynia or oral dysaesthesia. So far, these complaints have been thought to be ‘psychogenic’. Namely, psychosocial factors and/or individual factors have long been considered as main cause. Even if oral surgeons referred patients to psychiatry clinic, a majority of them wished to avoid consultation, or, would sometimes complain that the dry mouth got worse after medication. Therefore, it is very important and difficult problems for clinical oral surgeons to see how look at these patients and to learn how cope with them.<br>From my own years of experience in psychosomatic studies, I think ‘distorted cognition ’ is central to these pathogenesis. These distorted cognition cause dissociations between subjective and objective findings. Moreover, I have propose a hypothesis that neurochemical dysfunction of some sort of neurotransmitter systems and distortions of information-processing in cerebral association area related to thought and memory underlie the distorted cognition.<br>Patients with subjective dry mouth never tell a lie about their symptoms, but they have just ‘ neural network error’ in their brain. We should take up to problems of oral discomfort at the root of their complaint.<br>If we suspect their complaints as the cause of psychogenic, it might be often unsuccessful in treatment. First of all, to listen carefully to complaints from them is very important, and then we have to do differential diagnosis. If patients are diagnosed the symptom form with distorted cognition, medication using SSRI or SNRI is necessary for reconstruction of impaired neuronal network. Of course oral surgeons have to receive advanced education and training to use psychotropic drugs. At the same time, it is needed for sensitive response to patients and family members.<br>The distorted cognition with these patients are associated with dysfunction of neurotransmitter systems and information-processing in peripheral to higher central nervous system. Strange complaints and persistent therapeutic demand are representatives of the distorted cognition. If we regard queer complaints as neural network errors, we can see the psychogenic complaints as distorted cognition.<br>At present, this hypothesis cannot be shown objectively, but it might be possible that some new approaches such as brain imaging make mechanisms of the distorted cognition more clear. It is very important to collect evidence-based diagnosis, therapies and pathophysiological mechanism for dry mouth as an oral psychosomatic disorder.