BackgroundSevere mental disorders have a chronic course associated with a high risk for co-morbid somatic illnesses and premature mortality and oral health is critical for overall systemic health. But general health care needs in this population are often neglected. Some studies have aimed at determining the oral health status of psychiatric in-patients but to date, no emphasis has been placed on oral health of psychiatric patients in France. The goal of this study was to assess the oral health and treatment needs of institutionalized patients in a large psychiatric hospital, where a dental service was available and free, to compare it with the average population, with psychiatric in-patients in other countries and to provide recommendations for psychiatrists and care-giving staff.MethodsThe dental status (DMFT), the oral hygiene (OHIS: Simplified Oral Hygiene Index), the saliva flow rate were recorded on a randomized patient sample. Demographic and medical data were retrieved from the institutional clinical files.ResultsAmong the 161 examined patients, 95 (59.0%) were men and 66 (41.0%) were women. The mean age was 46.9 ± 17.5 years. The majority was diagnosed schizophrenia (36.6%) or mood disorders (21.1%). The mean OHIS was 1.7 ± 1.1. Among the 147 patients who agreed to carry out the salivary examination, the average saliva flow rate was 0.3 g ± 0.3 g/min. Saliva flow under the average rest saliva flow (0.52 mg/min) was found for 80.3% of the patient. The mean DMFT was 15.8 ± 8.8 (D = 3.7 ± 4.4, M = 7.3 ± 9.4, F = 4.7 ± 4.9) and significantly increased with age (p < 0.001) and degree of disability (p = 0.003) (stepwise linear regression). Eighteen patients (11.2%) were edentulous.ConclusionsThe DMFT was similar to low income French population but psychiatric patients had almost 4 times more decayed teeth, slightly less missing teeth and 1.5 times less filled teeth. Oral health appeared to be better than in most other countries. But compared to general population, the still unmet dental and prosthetic needs indicated the major need of enhanced access to dental care and specific preventive programs.