Oral health status and treatment needs among psychiatric inpatients in Rennes, France: a cross-sectional study

Severe mental disorders have a chronic course associated with a high risk for co-morbid somatic illnesses and premature mortality, but despite this increased risk, general health care needs in this population are often neglected [1‐3].

In this context, oral health is important because it is critical for overall systemic health. Indeed, bad oral health (periodontitis) is a risk factor for poor glycemic control [4] and cardiovascular disease [5] and there is fair evidence of the association of pneumonia with bad oral health [6]. Moreover, pain and discomfort caused by oral diseases can result in eating difficulties leading to poor levels of nutrition. Bad oral health can affect daily quality of life, well-being and self-esteem.

People with severe mental illness commonly exhibit many factors which may contribute to poor oral health: xerostomia caused by psychiatric medication, lack of motivation for self-care and oral hygiene, tobacco consumption. Dental cost, fear and difficulty in accessing healthcare facilities are the most commonly cited barriers to dental care [7, 8].

Indeed, numerous international original studies [3, 7‐14] and one meta-analysis [15] reported that oral health status of mentally ill patients was poor compared to normal population: in literature, DMFT (number of Decayed, Missing due to decay and Filled Teeth) ranged from 14.9 [9] to 26.7 [8] except in Davengere, India where the very low DMFT (0.9 with mean patients’ age 36.7) [3] was allotted by the authors to the water fluoride concentration (1.5-2 ppm). Multivariate analyses, when carried out, showed that many factors might affect the oral health of these specific patients: DMFS (number of Decayed, Missing or Filled Surfaces) or DMFT was correlated with socio-demographic factors (age [3, 12‐14, 16‐18], male gender [12]), psychiatric factors (duration of the mental illness [3, 19], psychiatric diagnosis [19], diagnostic of schizophrenia compared to mental retardation [16]), physical factor (high Body Mass Index [20]), care factors (type of ward: open, closed, chronic of special ward [18]; infrequent dental visit [17]) and behavioral factors (irregularity of hygiene habits [3], frequent snacking [17]).

Currently decayed teeth were associated with neglected tooth brushing [8] and perceived xerostomia [19].

The number of missing teeth was associated with age [18], elementary level of education [13], low income [13] and length of stay in institution [13].

The care index (ratio of the number of Filled teeth to the DMFT) was associated with education of only elementary school [13], low income [13] and length of stay in institution [13].

In France, the mandatory health insurance partly covers conservative and surgical dental care (70%), prosthetics and orthodontics treatment (30 to 50%). The complementary health insurance companies or additional insurances coverage depends on the subscribed contract. Since 2000, people who do not work enough (200 h work within the last three months) to get access the mandatory health insurance can benefit from the CMU (universal health insurance). For all low level income people, the CMU is free. They also get access to CMUc (complementary CMU if their annual income is below 7 771€) which includes a basket of free dental prosthetic care. In France in 2007, 4 398 063 people were affiliated to the CMUc, that is 6.8% of the population (3.6% for the Ille-et-Vilaine department). People with severe psychiatric illness usually have very low incomes and can be fully covered by the CMUc. Furthermore, from a financial point of view, somatic treatments (including dental care) are free of charge for patients hospitalized in psychiatric hospitals or in the psychiatric ward of general hospitals. From a practical point of view, some psychiatric hospitals have a somatic care ward which includes dental care or dental consultations. But in France, there is no across-the-board formal connection between psychiatric and somatic treatment and the somatic care of patients undergoing psychiatric treatment remains heterogeneous [21].

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. Furthermore, few studies [3, 11, 14, 22] were carried out in mental health institutions having a dental department.

The goal of this study was to determine the oral health status and treatment needs of institutionalized patients in a large psychiatric hospital, where a dental service was part of the mental health hospital and to study the possible relationships between DMFT and various variables. The results were compared to the average population and to psychiatric in-patients in other countries reported in literature.

The population consisted of 659 patients (February, 7th 2006): 391 men (59.3%; 95% Confidence Interval = [55.5%-63.1%]) and 268 women (40.7% [36.9%-44.5%]). The mean age was 47.3 years.

Of the total sample (185 patients), 24 patients were excluded: 14 subjects refused to participate and 10 were unable to cooperate due to their psychiatric disease. Among the 161 examined patients, 95 (59.0%) were men and 66 (41.0%) were women. There were significantly more men than women in the sample. The sample’s sex ratio was reflective of the population’s sex ratio. The ages ranged from 18 to 90 years (mean age 46.9 ± 17.5) (Table 1).

The two most common psychiatric disorders were schizophrenia (F20-F29 in ICD-10; 36.6%) and mood disorders (F30-F39; 21.1%) (Table 2). The mean duration of cumulated hospitalizations at the CHGR was 4.8 years (0–40 years ± 7.9 years). Most patients (80.7%) were prescribed psychotropic medication. The mean number of prescribed drugs was 6.7 ± 3.1.

One hundred and ten patients (68.3%) were free of any soft tissue lesion. The 51 remaining patients had one or several lesions: 20 patients (12.4%) had oral ulcers, 11 patients (6.8%) were diagnosed with oral candidiasis, while 8 patients (5%) exhibited oral leucoplakia.

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 below average (0.5 mg/min) was found in 80.3% of the patients. The buffer capacity was insufficient for 76.9% of the people, medium for 21.4% and good for only 3.6%. The number of lactobacilli was high for all patients (> 10⁵ lactobacilli/ml), the number of Streptococcus Mutans was high (> 10⁵ SM/ml) for 54.5% of the people. Finally, the caries risk was high for all the patients (CARIO-ANALYSE Microbiologic Index > 8).

Among the 143 dentate patients, the mean plaque index was 1.2 ± 0.7 (the most frequent value was 1and was found in 57.3% of the examined teeth; 0: 20.7%; 2:15.1% and 2: 6.9% and 3: 1.9%), the mean calculus index was 0.5 ± 0.6 (the most frequent value was 0 in 68.0% of the examined teeth; 1:23.9%; 2:6.4% and 3:1.7%) and the mean OHI-S was 1.7 ± 1.1. OHI-S was excellent for only 1 patient, good for 44.8% of the patients, fair for 41.3% and poor for 11.2%. Eighteen patients (12.6%) patients never cleaned their teeth.

Fifty-four patients (33.5%) declared that they don’t smoke. Twenty-four (14.9%) said they were used to smoke less than 10 cigarettes a day and 34 (21.3%) smoked 10 cigarettes a day or more.

The DMFT (Table 3) was 15.8 ± 8.8. Missing teeth represented 46.2% of the total DMFT, filled teeth, 29.7% and decayed teeth 23.4%. The mean DMFT significantly increased with age (p > 0.0001), diagnosis (ANOVA: F = 2.0225; p = 0.0475) and length of hospitalization (p = 0.0154). The DMFT distribution by type of mental disorder showed that the patients with Organic mental disorders and Mental retardation had the highest mean scores (respectively 20.8 ± 9.3 and 19.3 ± 9.0) and the patients with somatoform disorders had the lowest mean score (6.7 ± 8.3).

Out of the 143 dentate patients, 23.0% were caries free, 34.8% had 1 to 3 decayed teeth and 42.2% had more than 4 decayed teeth.

Among the 161 examined patients’ teeth altogether, 13.31% of the teeth were decayed, 17.1% had been filled, 26.4% had been lost because of caries (31.5% lost because of caries or other reasons).

Bivariate analysis using Chi-square tests (Table 4) showed that DMFT over 16 was associated with age over 45 (p < 0.0001), length of hospitalization over 5 years (p = 0.0233), disability (p = 0.0021) and plaque index over 1 (p = 0.0111). The subjects were divided into two categories according to the DMFT (DMFT-16): 16 or less (n = 80) and over 16 (n = 81). The cutoff point (16.0) was the mean DMFT (15.8 ± 8.8).

Logistic regression models were used to identify factors associated with the DMFT-16. All the variables listed in Table 3 and Table 4 were introduced in the first model in order to control possible confounding effects. In SPSS, the binary logistic regression according to the “forward LR” method kept 2 variables. The logistic regressions analysis showed that age and Degree of disability were significant contributors to the fact of having a high DMFT. Age and degree of disability explained 24.5% (R2) of the DMFT-16’s variations.

Among the 143 dentate patients, 122 (93.0%) needed dental care: 41 (28.7%) needed extractions (3.1 ±3.00 teeth extractions per people), 114 (79.7%) needed restorative care (4.0 ± 3.2 dental cares per person) and 31(21.7%) needed crowns (1.7 ± 1.10 crown per patient).

Removable dentures were needed by 66 patients (41.0%) in order to replace one or several missing teeth (some patients needed several dentures): 15 (9.3%) needed one or two simple dentures, 44 (27.3%) needed one or two partial dentures, 11 (6.8%) needed one or two complete dentures, 6 (3.7%) had a denture which needed to be repaired.

Eighteen patients (11.2%) were totally edentulous and 10 (6.2%) had one edentulous arch. Among the 18 (11.2%) totally edentulous patients, 10 (55.6%) had a full set of complete dentures, 3 (16.8%) wore only an upper complete denture, 5 (27.8%) had no denture at all.

The 120 (83.9%) partially or totally edentulous patients had 7.0 ± 8.3 (from 0 to 28) missing (and not replaced) teeth. (Here, in order to evaluate the prosthetic needs, a missing tooth was considered as not replaced if there was still enough space to allow its replacement by a prosthetic tooth. Extracted teeth for orthodontic reasons were not considered as missing not replaced teeth).

In summary, the main results of this study were the DMFT (15.8) of psychiatric inpatients and especially the mean number of missing (7.3) and decayed teeth (3.7). Eleven point two percent was totally edentulous. The dental unmet treatment needs were important: 93% of the patients needed dental care and 83.9% needed teeth replacement. Saliva flow was extensively below normal and oral hygiene was poor (Plaque index = 1.2 meaning between one third and two third of the teeth surfaces covered by soft debris). Bad dental health was associated with age and the degree of disability.

Regarding the validity of our results, 24 (13%) people were excluded because they either refused to participate (n = 14) or were unable to cooperate (n = 10). Thus, the response rate was 87%. This was a good response rate compared to similar studies where the average response rate was 82% [7, 9‐12, 16, 18, 27] (from 58% [10] to 97% [13]). But this might introduce a selection bias. Indeed, regarding people unable to cooperate (n = 10), it is difficult to brush their teeth regularly. Thus, oral health of the sample might have been worse if they had been included. Regarding people who refused to participate, we can make no assumption.

Some information was asked to the patient (tooth brushing and smoking habits). Their reliability and validity is questionable. For each of these questions, the nurse was also questioned. When we had any doubts about the patient’s answer, we did not record it.

Compared to literature (with mean age = 47.3 ± 5 years), the mean DMFT (15.8) was one of the lowest for non-fluoride water areas. It was lower than that found in middle-income countries: Serbia (DMFT = 24.4 with mean patients’ age = 46) [12] and Turkey (DMFT = 19,25 with mean age = 52,3) [16], and high-income countries like Israel (DMFT = 23.8 with mean age = 53) [11]. It was slightly higher than that found in Taiwan (13.9 with mean age = 51) [13].

Missing teeth (46.2%) accounted for the largest portion of the number of teeth ever affected by tooth decay (DMFT) as ever in literature. The number of filled teeth may be a reflection of the available treatments for the patients. In our study, proportion of filled teeth accounted for 29.7% of the DMFT. It was the highest in literature. In our population, dental treatment was available and free. On the opposite, in a lot of studies, no routine treatment was available. Only emergency cares in the form of extractions were provided.

The number of decayed teeth (3.7) was still high. Preventive actions are still needed in order to reduce the incidence of tooth decay.

Regarding edentulousness, the proportion of totally edentulous in-patients (11.2% with mean age = 47) was lower than that found in similar studies (mean ages ranges 42–52), where rates of edentulousness ranged from 18% to 26% [11, 12, 16] except in one study in Hong Kong: 7% (mean age = 45) [9].

Compared to low income French population (DMFT = 14.8 in the 35–44 year-olds and 24.5 in the 65–74 year-olds) [28, 29], the DMFT (14.5 in the 35–44 year-olds and 22.6 in the 65–74 year-olds) was about the same (Table 5). But the number of decayed teeth was almost four times higher (5.0 in the 35–44 and 4.2 in the 65–74) and the number of missing teeth (because of tooth decay) was lower (3.0 in the 35–44 and 15.4 in the 65–74). The number of filled teeth (6.4 in the 35–44 and 3.0 in the 65–74) was almost 1.5 times lower.

Thus, the psychiatric patients had considerably more important treatment needs than the general population (four times more untreated decayed teeth). Even if the psychiatric hospital had a dental service, there was still a lack of dental care compared to the French population. The dental office didn’t manage to cope with the extensive treatment needs.

Actually, the gap between psychiatric in-patients and French population (not only low-income) might probably be higher. Available data regarding oral health of French population are old (1997 and 1999). As in many industrialized countries, oral health of French population might have improved over time.

This article aimed at showing to psychiatrists the oral health and needs of psychiatric patients. Tooth decay and tooth loss in psychiatric patients are avoidable. But the dental team, when existing, really needs psychiatrist’s support to change things. Psychiatrists and their care-giving staff must be aware and get involved in dental issues. Considering the findings of this study, the following suggestions are made:

This study highlighted that the DMFT and the number of missing teeth were lower than those found in most other countries; the number of filled teeth was higher. Dental care was accessible and free.

But the need of care of psychiatric patients still exceeded that of the general population. We know now that tooth decay is an avoidable disease. Thus, preventive measures have to be implemented to lower the incidence of tooth decay and alleviate the burden of untreated decays. Screening must be systematized and access to care must be encouraged.

Psychiatrists, physicians, nurses, caregivers, hospital administrators, must be aware of poor dental health of mentally ill people and coordinate their efforts to facilitate prevention and access to dental care.

This study was partly funded by the CHU of Rennes and the Faculty of Dentistry of Rennes.