EVALUATION OF DENTAL HEALTH AMONG ADOLESCENTS WITH MENTAL DISORDERS EVALUACIJA ZDRAVLJA ZUBA KOD ADOLESCENATA SA MENTALNIM POREMEĆAJIMA Authors

Background/Aim. According to the World Health Organization (WHO), there is an increasing prevalence of mental disorders among children and adolescents worldwide. Previous studies have shown that people with mental disorders, regardless age, have an increased prevalence of dental caries due to several reasons. The aim of this study was to determine prevalence of dental caries in adolescents with mental disorders and to consider possible risk factors that might contribute to their current dental health status. Methods. The study was conducted as an observational cross-sectional study. The study group comprised 70 randomly selected hospitalized adolescents with mental disorders. The control group comprised 70 randomly chosen mentally healthy adolescents. They were matched to the study group by gender and age. All the participants were subjected to targeted dental examination according to criteria recommended by the WHO. Collection of data related to mental disorders of the study group was obtained from the patient?s medical records. All collected data were organized and analyzed by descriptive statistical parameters and regression models. Results. Majority of the study group patients were diagnosed with schizophrenia, schizotypal and delusional disorders (F20-F29), as well as behavioral and emotional disorders usually occurring in childhood and adolescence (F90-F98). Almost 90% of them were treated with antipsychotics of the second generation, as monotherapy or in combination with first-generation antipsychotics. Adolescents with mental disorders had significantly more carious and extracted teeth and three times less filled teeth than mentally healthy adolescents in the control group. The mean value of the decay-missing-filled teeth (DMF) index in the study group patients was also significantly higher than the mean value of DMF index in the control group subjects. Conclusion. It seems that mental disorder among adolescents mainly affects oral health indirectly, decreasing motivation of patients in maintaining oral hygiene.


Introduction
According to the latest reports of the World Health Organization (WHO), mental disorders are the 3 rd leading cause of disability of European citizens 1 , and previous study suggests an increasing prevalence of mental disorders among children and adolescents worldwide 2 .Adolescence is a period between childhood and adulthood, from 14 to 18 years of age, and according to some studies, up to 25 years of age 3 .In this specific part of life, many problems and psychological disorders reach their peak 4 .The most common mental disorders in this period are depressive and anxiety disorders, obsessive-compulsive disorders and posttraumatic stress disorders 4 .Many of these patients are treated solely by psychotherapeutic methods, but some of them also need to receive pharmacological agents that are not approved for persons less than 18 years of age.Moreover, some severe mental disorders, like schizophrenia, depression, anxiety, attention deficit hyperactivity disorder and bipolar disorder, frequently require pharmacological treatment in adolescents 5 .Dental caries is a major public health problem globally and it is the most widespread noncommunicable disease 6 .Previous studies have shown that people with several mental disorders have an increased prevalence of dental caries [7][8][9][10] .This can be explained by several reasons: mental disorders lead to lack of motivation, lack of oral hygiene, fear to visit a dentist, difficulty to access health services and adverse effects of antipsychotic medication, mainly xerostomia, could be also present 10 .In Serbia no research has been conducted to oral and dental health of this vulnerable group of psychiatric patients.Therefore, the aim of this study was to determine prevalence of dental caries, to register condition of teeth still present, and to consider possible risk factors that have possibly contributed to the current dental health status of adolescents with mental disorders.

Methods
The study was conducted as an observational cross-sectional study.It was adjusted to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement for improving the quality of observational studies 11 .Also, it has received approval of the Ethics Committee of the Clinic for Mental Disorders "Dr.Laza Lazarević" Belgrade and Community Health Center "Vračar" in Belgrade.The research was conducted in accordance to Declaration of Helsinki 12 .The participation of all participants was voluntary.Each participant and their legal representative (for persons under 18 years old) was informed, through a special brochure, of the type of the research, data collection procedure, and other aspects of the study; written consent was obtained from all participants or their legal representatives to use personal data for research purposes.Two groups of participants were formed: the study group comprised 70 randomly selected adolescents with mental disorders, hospitalized at the Clinic for Mental Disorders "Dr.Laza Lazarević" in Belgrade ("bias-coin" randomization).The inclusion criteria for entering the study were that the patient was hospitalized, younger than 25 years and diagnosed with mental disorders (according to the 10 th Revision of the International Classification of Diseases 13 ) at least two years prior to the study.The exclusion criteria were hospitalized patients older than 25 years diagnosed with mental disorder in the period shorter than two years from the time of the survey, the simultaneous presence of severe somatic illnesses or severe disability, and inability to communicate or a refusal to cooperate.The control group comprised 70 randomly chosen mentally healthy adolescents ("bias-coin" randomization) who were being treated at the Community Health Center "Vračar" in Belgrade.They were matched to the study group by gender and age.The exclusion criteria were the diagnosis of any mental or somatic illness and the use of drugs that can cause oral changes or xerostomia (antibiotics, antifungals, blood pressure medication, corticosteroids, diabetes medication, etc.) 14 .All the participants were subjected to targeted dental examination according to criteria recommended by the WHO 15 .Dental check-ups were carried out by the dentist (VĐ) at the Clinic for Mental Disorders "Dr.Laza Lazarević" in Belgrade, and the Community Health Center "Vračar" in Belgrade.Examinations were performed in the daylight, using flat dental mirrors and sharp probes.Dental check-ups were carried out with the aim of measuring parameters of oral and dental health and assessing the decayed, missing, filled (DMF) index, which is used for oral health assesment 16 .Clearly visible lesions with cavities on tooth surfaces were registered as caries; teeth having only changes in transparency, but with intact surface and without cavitation were registered as being healthy.Collection of data related to mental disorder of the study group was obtained from the patient's medical records.All collected data were organized and evaluated using dedicated software (SPSS 23.0 Inc., Chicago, IL, USA) and were analysed by descriptive statistical parameters and regression models.The descriptive statistical parameters were represented by the measures of central tendency (mean value and median), measures of variability (standard deviation and variation interval) and were expressed in percentages.The methods for testing the differences in numerical data (age, DMF index) were represented by the t-test of independent groups.If there were no grounds for application of parametric statistical methods, Mann-Whitney test was applied.For testing data of different categories (gender, parents education level, etc.), Pearson's χ2-test was used.The relationship between DMF index and the independent variables used in this study was evaluated using a linear regression model -univariate (individually for each of the independent variables) and multivariate (if any of independent variables was statistically significant in univariate regression analysis).Level of significance was set at p≤0.05

Results
Socio-demographic characteristics of all participants are shown in table 1.The groups were comparable in terms of age and gender (Table 1).Statistically significant difference between these groups was observed only in terms of place of residence; all patients from the control group lived in urban area, while only 52% of the study group lived in this type of area.Only 29.3% of the study group patients had both of parents with high school education, which was quite opposite to the control group patients.Majority of the study group patients were diagnosed with schizophrenia, schizotypal and delusional disorders (F20-F29), as well as behavioral and emotional disorders, with onset usually occurring in childhood and adolescence (F90-F98) -figure 1. Concerning schizophrenia, schizotypal and delusional disorders (Figure 2), majority of patients were diagnosed with acute and transient mental disorders.Among the study group patients with behavioral and emotional disorders, with onset usually occuring in childhood and adolescence (Figure 3), most of them were diagnosed with mixed behavioral disorders and emotions.All patients from the study group were treated with an average of 3.27 ± 0.83 (2 to 5) psychiatric drugs (Table 2).Almost 90% of them were treated with antipsychotics of the second generation, as monotherapy or in combination with first-generation antipsychotics (Table 2).Also, almost half of the study group patients were treated with antidepressant drugs, while 70.7% were treated with anxiolytics.In addition to the above mentioned groups of psychiatric drugs, 40% of the patients received hypnotics, 65.3% mood stabilizers, while only 6.7% of study group patients received anticholinergics (Table 2).Adolescents with mental disorders had significantly more carious and extracted teeth, and three times less filled teeth than mentally healthy adolescents in control group (Table 3).The mean value of the DMF index in the study group patients (6.45 ± 3.48) was also significantly higher than the mean value of DMF index in the control group subjects (2.75 ± 2.12).The difference in all four observed source variables between the groups was statistically significantly different and significantly less favorable for the study group (Table 3).In terms of socio-demographic characteristic, there was no statistically significant difference in the value of the DMF index among participants in both groups (Table 4).Also, in relation to the characteristics of the mental disorder, no statistical significance was found in mean values of the KEP index within the study group patients (Table 5).
By defining the mean value of the DMF index of adolescents with mental disorders as a outcome, none of the independent variables were statistically significant in the univariate regression analysis, so the multivariate regression model was not formed (Table 6).

Discussion
In both groups, approximately the same number of subjects was gender-related, which indicates homogeneity of the sample and allows adequate interpretation of the results of the study group.Gender and age are individual characteristics who determined general and oral health 17 .Study on the global burden of diseases, injuries and risk factors from 2015 indicate that the incidence of dental caries of permanent teeth is the greatest in the age group of 15 to 19 years and its gradually decrease in older age groups 18 .
However, in addition to individual characteristics, environmental factors also influence health, as well as the interaction of individual characteristics with environmental factors and vice versa 17 .Thus, poor economic conditions are recognized as factors that have negative effects on health; education is also a factor that plays a significant role in developing skills and knowledge needed for positive lifestyle changes 17.As the sample of this study consisted of adolescents that are in the educational period of life, it is important to analyze the parent or guardian education level as well, because they can contribute to development of positive lifestyles if they themselves understand their importance.This study has shown that in most adolescents with mental disorders both parents had a high school education (29.3%).Also 26.7% of study group patients did not have father or mother figure in their family.Cianeti et al have shown that dental caries presence was higher in children where the mothers' and fathers' educational level was lower 19 .Also, Crocombe et al showed that children, whose parents had higher education level have approximately half the relative risk of caries, compared to children whose parents had low levels of education 20 .
Also, nearly 50% of adolescents with mental disorders lived in periurban and rural areas, in opposite to participants of the control group, where 100% of patients were living in urban area.Many previous studies have shown a significantly higher prevalence of dental caries with rural residence location [21][22][23] .The latest national research on the health of the citizens of the Republic of Serbia, precisely points to the importance of access to health services, which depends on many factors, and also on the distance of the health service 17 .Moreover, the results of this national survey have shown that the rural population often experience barriers to obtain the dental health care (19.3%) 17 .
In the present study, the most common diagnostic category of mental disorders in the study group were schizophrenia, schizotypal and delusional disorders (42.7%), which is similar to previous studies about oral health of psychiatric patients [24][25][26] .Velasco-Ortega et al have shown in their research about actual dental status and treatment needs of older adults with and without chronic mental disorders in Spain that 56% of study group patients suffered from schizophrenia 24 .Also, research about prevalence of bucco-dental pathologies in patients with psychiatric disorders in Venezuela showed that even 60% of patients had schizophrenia as most common mental disorder 25 .On the other hand, Bertaud-Gounot et al have shown that 36.6% of psychiatric inpatients in Rennes, France, had schizophrenia 26 .Djordjevic et al. in their research have come to conclusion that oral diseases, especially dental caries and periodontal disease, are much more prevalent in patients with schizophrenia than in healthy population, possibly due to the nature of this psychiatric disorder, length of hospital treatment and oral-side effects of psychotropic medications used for schizophrenia 27 .Schizophrenia is a chronic mental disorder characterized with disturbances in thoughts, behavioral changes, and impaired cognitive functions.All this affect a person's ability to carry out daily activities and maintain oral hygiene 28 .
The patients of the study group in the present study were treated with the average number of 3.27 ± 0.73 psychotropic drugs (2 to 5), and the most used medications were antipsychotics of the second generation (89.3%), anxiolytics (70.7%) and mood stabilizers (65.3%).Okamoto et al showed that patients with schizophrenia, who used antipsychotics, and especially anxiolytics, show higher level of hypo-salivation 29 .Hyposalivation consequently leads to a buildup of dental plaque on marginal gingiva, which is a major etiologic factor for the occurrence of caries 30 .
The mean value of DMF index of the study group patients in our study was 6.45 ± 3.48, which is two times higher than in the control group participants (0.64 ± 0.86).Also, results of our study point that the study group patients had seven times higher mean value of carious teeth, four times higher mean value of extracted teeth, and even four times lower mean value of filled teeth than the control group participants.This indicates that adolescents with mental disorders and their parents have a lack of motivation for rehabilitation of carious teeth and weak habits in maintaining oral hygiene, which is confirmed by previous studies 31,32 .

Conclusion
Results of this study suggest that mental disorders mainly affects oral health indirectly, decreasing motivation of patients in maintaining oral hygiene.

Table 1 . Socio-demographic characteristics of all participants
n-

number of patients; %-percent of patients; p-significance; X-mean value; SD-standard deviation; Med-median; min-minimum; max-maximum; a χ 2 -test; b t-test of independent groups Table 2. Medical data of the study group patients
n-

Table 4 . The mean value of DMF index among patients of both groups by socio-demographic characteristics
X-mean value; SD-standard deviation; p-significance; a Mann-Whitney test; b Kruskal-Wallis test

Table 5 . The mean value of DMF index among the study group patients by medical data
X-