Depression is a disease which can cause diagnostic difficulties and put on „masks’ of physical symptoms which may divert the attention from the mental source of the problem. Thus, the dental treatment of psychiatric patients is often ineffective. The disorders of the masticatory apparatus as well as pains in the facial muscles and teeth mask the primarily sources such as anxiety, depression, or psychogenic pains. Consequently, patients are subjects to long term specialist laboratory and hospital treatment. They undergo many redundant tests, including surgical treatment.Dental treatment in these patients may last many years, and proves unsuccessful. The patients claim that the chronic pain often leading to the addiction to analgesics was the reason of their bad mental condition. In the case of masked depressions the salient factor is the accurate and prompt diagnosis enabling to provide the patients with adequate anti-depressants. With the course of the medical treatment a gradual relief of the dental symptoms has been observed.The aim of the study was to present the problem of the masked depression on the basis of case studies of patients complaining of facial bone displacement, malformation of muscles, teeth displacement, and toothaches with no clinical evidence, and who nevertheless were subjects to ineffective dental treatment. The research underlines the importance of detailed medical interview accompanied by an adequate and prompt diagnosis as the basis for sufficient specialist psychiatric treatment.