In order to determine the effects ofa new approach to preventive oral health treatment for forensic psychiatric patients, 3 studies were carried out using a Dutch version of the Oral Health Impact Profile-14 (OHIP-14-NL), among Dutch forensic psychiatric patients. In the first study, it was determined that the psychometric characteristics of the OHIP-14-NL were good and that attention to oral healthcare contributed positively to quality of life. The second study, which made use of an improved version of the OHIP-14-NL indicated that patients with a high level of anxiety for dental treatment and poor oral health reported a lesser quality of life. The third study showed that an effectively carried out programme of personal oral care can play an important role in the reduction of halitosis and in the improvement of quality of life. Moreover, it appeared that the retrospective version of the OHIP-14-NL was a useful method for determining the correlation between quality of life and oral health and for evaluating change therein within a relatively short period of time.