|Year : 2020 | Volume
| Issue : 4 | Page : 174-180
The Impact of Sex Differences and Oral Health Behaviors on Oral Health-related Quality of Life among Patients with Schizophrenia in Taiwan: A Cross-sectional Study
Li- Ling Huang M.D 1, Kuan- Ying Hsieh M.D 2, Shu- Wen Chen M.D 3, Shu- Fen Yu M.D 4, Shu- Mei Chang M.D 5, Shu- Yun Chen M.D 5, Frank Huang-Chih Chou M.D. Ph.D 6
1 Department of Nursing, Kaohsiung Municipal Kai-Syuan Psychiatric Hospital; Department of Nursing, Fooyin University, Kaohsiung, Taiwan
2 Department of Child and Adolescent Psychiatry, Kaohsiung Municipal Kai-Syuan Psychiatric Hospital; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical Universit, Kaohsiung, Taiwan
3 Kaohsiung Taliao Psychiatric Nursing Home, Kaohsiung, Taiwan
4 Shang Hao Dentist Clinic, Kaohsiung, Taiwan
5 Department of Nursing, Kaohsiung Municipal Kai-Syuan Psychiatric Hospital, Kaohsiung, Taiwan
6 Department of Superintendent, Kaohsiung Municipal Kai-Syuan Psychiatric Hospital, Kaohsiung, Taiwan
|Date of Submission||28-Jun-2020|
|Date of Decision||24-Sep-2020|
|Date of Acceptance||25-Sep-2020|
|Date of Web Publication||17-Dec-2020|
Frank Huang-Chih Chou
No. 130, Kaisyuan Second Road, Kaohsiung 80276
Source of Support: None, Conflict of Interest: None
Objective: Oral health denotes general well-being, meaning that the person can perform functions such as eating, talking, and keeping smile. Those functions can impact on oral health-related quality of life (OHRQoL) with differences between sexes. In this study, we intended to examine sex differences and oral health behaviors in OHRQoL among institutionalized patients with schizophrenia. Methods: We recruited 150 institutionalized patients (99 men and 51 women) with schizophrenia in a nursing home. We measured OHRQoL with the 36-item Short-form Health Survey (SF-36) questionnaire, and oral health by oral cleaning habits, oral health problems, and oral health care. Results: The mean values of the SF-36 physical component summary (PCS) score and mental component summary (MCS) score were 62.4 and 49.9, respectively, which were lower in women than those in men. Cooperativeness was a protective factor, but toothache and bleeding gums were risk factors in PCS. The standard cleaning method and cooperativeness were protective factors, but toothache, bleeding gums, and swollen gums were risk factors in MCS. Conclusion: Our study finding showed that women tended to report poorer physical and OHRQoL than men even after controlling oral health behaviors and problems. Toothache and bleeding gums were risk factors for poor OHRQoL. The findings provide useful information for health-care resource planning in patients with schizophrenia.
Keywords: 36-item Short-Form Health Survey, oral health, the SF-36 mental component summary, the SF-36 physical component summary
|How to cite this article:|
Huang LL, Hsieh KY, Chen SW, Yu SF, Chang SM, Chen SY, Chou FH. The Impact of Sex Differences and Oral Health Behaviors on Oral Health-related Quality of Life among Patients with Schizophrenia in Taiwan: A Cross-sectional Study. Taiwan J Psychiatry 2020;34:174-80
|How to cite this URL:|
Huang LL, Hsieh KY, Chen SW, Yu SF, Chang SM, Chen SY, Chou FH. The Impact of Sex Differences and Oral Health Behaviors on Oral Health-related Quality of Life among Patients with Schizophrenia in Taiwan: A Cross-sectional Study. Taiwan J Psychiatry [serial online] 2020 [cited 2023 Jan 31];34:174-80. Available from: http://www.e-tjp.org/text.asp?2020/34/4/174/303681
| Introduction|| |
Health-related quality of life (QoL) is defined as individuals' perception of their position in life in the context of value systems and the culture in which they are related to their personal goals, expectations, and standards . Furthermore, health-related QoL conceptually is being focused on subjective perceptions about one's ability to do important activities that are influenced by one's health status .
Oral health, rarely life-threatening, is nevertheless a major public health problem with high prevalence, and it affects an individual's QoL. Oral health has been defined as the state of the mouth and the associated structures. An individual with good oral health can avoid diseases in the future, can masticate food sufficiently, maintain a socially acceptable appearance, and continue in their desired social rôle ,. Based on a conceptual model to explain the pathways, oral health and QoL are linked inseparably . Clinical practice of dentistry, dental research, and dental education are identified as obvious factors influencing oral health-related QoL (OHRQoL) . Studies have associated periodontal disease with low OHRQoL ,,,10]. The relationship between oral and general health (GH) is complicated, especially in patients with schizophrenia. Oral health status is important from the physical and the psychological viewpoints because it influences appearance, speech, sense of taste, ability to chew to eat and to socialize, self-image, as well as social well-being ,,. Oral diseases affect a patient's QoL through social and psychological impacts, such as low self-esteem and self-confidence ,,. An individual's dental condition can be better expressed through its impact on their QoL than using clinical indices . Therefore, clinicians should monitor oral health and strategize dental health-care programs, institutional priorities, and policies for enhancing OHRQoL.
Oral health is related to mental illness, social and medical support, as well as the health care system . Institutionalized older patients have been reported to have poor oral health . Patients with schizophrenia are at a greater risk of developing missing teeth, tooth decay, and periodontal diseases . Poor lifestyle and unhealthy behaviors (e.g., diet with high sugar, use of drugs, tobacco and alcohol usage, as well as inadequate oral hygiene), along with social-demographic factors (such as low education, low income, or poor support), explain the poor oral health in this population ,. Interventions such as oral health assessments using standard checklists designed for non-dental personnel, assistance with oral hygiene, management of iatrogenic dry mouth, and early dental referral have been suggested . OHRQoL is a subjective measure that can be confounded by the patients' cognitive function. In previous studies, patients with schizophrenia show a wide variation between subjective perception and objective evaluation of dental status . Clinicians usually observe pain, which may be hindered in patients with schizophrenia . Patients with schizophrenia are at risk of poor oral health, but the relation of oral health behaviors and OHRQoL is not clear. Therefore, to determining oral health factors that are the most closely related to QoL in patients with schizophrenia is essential.
Over the years, several studies have found a sex difference in QoL . Women tend to report lower health-related QoL scores than men, although woman may, in fact, be healthier ,. Therefore, we must consider sex difference when determining the association between oral health and QoL.
To the best of our knowledge, no specific questionnaire exists for evaluating OHRQoL in patients with schizophrenia. Previous studies have been based on expert opinions or on questionnaire that have not been validated among ethnic Chinese groups ,. Furthermore, most studies have depended on examination by a dentist or on face-to-face interviews, neither of which are nor cost-effective, especially in the nursing home setting . Important limitations exist in recognizing poor oral health and the treatment requirements of institutional patients ,. Because of the special status of this group with poor oral conditions and more complicated treatments, additional information is required on factors influencing health-related OHRQoL of institutionalized patients with schizophrenia.
In this study, we hypothesized that the OHRQoL would be related between oral health and sex in institutionalized patients with schizophrenia. To achieve this objective, we recruited patients with schizophrenia from a southern Taiwan nursing home, and evaluated the impact of oral health behaviors, oral problems, and general issues such as age, sex, and social status on OHRQoL. Carrying out a cross-sectional study and using multiple regression models, we intended to document the oral health behaviors, and to explore the potential inter-relationships among oral health, sex and OHRQoL.
| Methods|| |
Participants were recruited between January 2015 and February 2015 from the Kaohsiung Municipal Kai-Syuan Psychiatric Hospital affiliated Da-Liao Lily Psychiatric Nursing Home in Taiwan. The inclusion criteria were patients with schizophrenia with ages between 18 and 65 years. Written informed consents were obtained from all participants before the assessment. Individuals received a face-to-face interview. We excluded those showing any cognitive deficits (e.g., intellectual disability, neurocognitive disorder, intoxication, dementia due to withdrawal from substance use, or withdrawal from substance use) that could have prevented them from understanding the study purpose or completing the copies of questionnaire.
The study was approved by the institutional review board of Kaohsiung Municipal Kai-Syuan Psychiatric Hospital (IRB protocol number = KSPH-2014-36 and date of approval = December 31, 2014), with the stipulation of obtaining informed consent from all study participants.
Thirty-six item Short-form Health Survey
The self-administered 36-item SF-36 is to assess HRQoL in the preceding month. The questionnaire items are assessed on 3-6-point Likert-like scales. SF-36 is an internationally known instrument to assess the construct of HRQoL. It was translated into Chinese for the Taiwanese population in 1996, and it has shown good psychometric properties . SF-36 measures several domains of HRQoL, including physical functioning, rôle limitations due to physical health problems, bodily pain (BP), GH perceptions, vitality, social functioning (SF), rôle limitations due to emotional problems (RE), and mental health (MH). Moreover, the instrument allows users to compute two summary scores for HRQoL-physical component summary (PCS) and mental component summary (MCS). A score was calculated for each domain and was transformed to obtain a value ranging from 0 to 100 . A relatively high total score indicates better OHRQoL than a relatively low total score. The internal reliability (Cronbach's α) of SF-36 in the present study was 0.75.
Oral health questionnaire
We designed a copy of oral health questionnaire because we were unaware of established copy of questionnaire to examine the oral health of psychiatric patients. The questionnaire was self-administered, covering oral cleaning habits, oral health problems, and oral healthcare. The content of the questionnaire was reviewed and modified by a senior psychiatrist and a dentist for expert validity. The participants were asked seven questions about oral cleaning habits. Those questions included self-cleaning, method, frequency, toothbrush exchange, and learning. In addition, participants were asked four questions about self-perception of oral health problems and conditions. Those included gingival bleeding, toothache, swollen gums, and halitosis. Another set of questions was to assess the use of oral health care measures. Participants were asked to indicate dental visit experiences over the last three years, type of dental treatment, co-cooperativeness, and intervals between visits. Treatments included tooth extraction, filling, periodical inspection, endodontic therapy, scaling, and gum treatment. Responses were coded as “yes” and “no.”
Research assistants explained the procedures and methods of completing research questionnaire to the participants individually. The participants were allowed to ask questions if they had problems while completing the copy of the questionnaire, and the research assistants helped revolve their problems.
We did descriptive analysis of sociodemographic variables and SF-36 scores with t-test and Chi-square test. To preliminarily examine the associations between participants' oral health and OHRQoL, we conducted correlation analyses.
We used linear regression models to compare the PCS or MCS of oral health parameters. We did sequential multiple linear regression analyses to examine whether the differences in PCS or MCS between men and women could be explained by the distribution of oral health parameters. Model 1 included sex and other demographic characteristics (age, education, marital status, onset, course, hospitalization, and smoking status). We then constructed model 2 with sex, demographic characteristics, and oral health parameters as the independent variables.
Statistical analyses were computed using Statistical Package for Social Science version 20.0 software (SPSS Inc., Chicago, Illinois, USA). The differences between the groups were considered significant if p < 0.05.
| Results|| |
Totally, we enrolled 150 individuals with schizophrenia and obtained valid responses pertaining to personal history and to the SF-36 and the copy of oral health questionnaire. As shown in [Table 1], no significant difference existed between men and women in age (both slightly above 55 years old), education (around 8–9 years), marital status (mostly not married), onset (slightly above 25 years old), course (around 32 years), hospitalization (around 7 times), and smoking status (around one quarter).
[Table 2] compares the oral health characteristics between men and women. Around 90% of the participants reported self-cleaning with toothbrush and toothpaste. Learning of oral cleaning was prevalent in both sexes. The cleaning frequency was about 1.5 times per day. More than 95% of the participants visited a dentist in the last three years, and the reasons mainly included toothache (60%), followed by swollen gums (4.7%), and bleeding gums (2.7%). In the type of dental treatment, the participants visited a dentist mostly for periodical inspection (68.0%), followed by scaling (50.7%), and filling (30.7%). Men significantly reported better co-operativeness (84.8% vs. 66.7%, p = 0.01) but significantly lower prevalence of swollen gums (2.0% vs. 9.8%, p < 0.05) than women.
|Table 2: Comparisons of oral health characteristics between men and women|
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[Table 3] compares the SF-36 scores between men and women. Men showed significantly higher values of PCS and MCS than women (64.6 vs. 58.0, p < 0.001; 51.1 vs. 47.5, p < 0.05, respectively). Considering the different domains of SF-36, men were scored significantly higher than women in physical function (88.7 vs. 67.3, p < 0.001), BP (87.4 vs. 76.9, p < 0.01), SF (82.4 vs. 73.0, p < 0.05), emotional rôle (82.5 vs. 69.3, p < 0.05), and MH (54.7 vs. 49.1, p < 0.05).
|Table 3: Comparisons of 36 item Short-form Health Survey scores between men and women|
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[Table 4] and [Table 5] summarize the results obtained using our multiple regression models. In Model 1, where we included sex and demographic data as independent variables, we found that men reported significantly higher PCS and MCS scores than women (β = 0.269, p < 0.01; β = 0.170, p < 0.05), respectively. Married persons reported significantly higher PCS and MCS than single people (β = 0.204, p < 0.05; β = 0.232, p < 0.05, respectively). Patients' sex and demographic characteristics explained 12.4% of the variance in PCS and explained 7.9% of the variance in MCS. In the final regression model, 52.6% of the variance in PCS and 45.7% of the variance in MCS were explained. In oral health parameters, co-operativeness was a protective factor, whereas toothache and bleeding gums were risk factors in PCS. The use of the standard cleaning method and co-operativeness were protective factors, and toothache, bleeding gums, and swollen gums were risk factors in MCS. Sex remained a significant factor regardless of whether other parameters were adjusted for, suggesting that the differences could not be fully explained using demographic characteristics or oral health parameters.
|Table 4: Relationships between related factors and scores of physical component summary: multiple regression models|
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|Table 5: Relationships between related factors and scores of mental component summary: multiple regression models|
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| Discussion|| |
In this study, we examined oral health parameters and their impacts on the OHRQoL of patients with schizophrenia in a nursing home in Taiwan. Male sex and co-operativeness were protective factors, whereas toothache and bleeding gums were risk factors in physical and MH. The standard cleaning method was a protective factor for MH but not for physical health. As shown in [Table 3], men reported significantly higher PCS (p < 0.001) and MCS (p < 0.05) than women. Moreover, the results of our regression analysis showed that the differences existed in PCS [Table 4] and MCS [Table 5] between men and women cannot be fully explained using oral health and that sex plays a rôle.
The mean age of our study group [Table 1] was about 56 years. Poor oral health is a reported risk factor among older adults. A previous study reported that 68% of the institutionalized older adults have no natural teeth, and 22% have neither natural nor artificial teeth . Dental loss could be the cause and consequence of poor oral health. Poor oral health behaviors, such as not brushing teeth and non-standard cleaning methods, can cause dental loss. Poor oral conditions, such as bleeding gums when brushing, toothache, and swollen gums, prevented patients from brushing teeth, leading to poorer oral health. Therefore, the inclusion of age in the regression model is important when considering the effects of other factors on OHRQoL.
The prevalence of dental problems was greater than 60% in our study [Table 2]. This finding has been due to several causes. First, patients with schizophrenia frequently do not recognize their disease and health status owing to poor cognitive function . Second, the side effects of psychiatric medications, (such as hyposalivation , hypersalivation with clozapine , and extrapyramidal side effects such as dystonia- and dyskinesia-related posture change), which prevent effective brushing of teeth  were reported to be related to poor oral health. Periodontal disease was associated with the metabolic side effects of second-generation antipsychotic drug ,. Moreover, patients with schizophrenia show negative symptoms, causing neglected self-care and maintenance of good oral hygiene . Therefore, they neglect their oral health problems or are unaware of dental treatment needs . Interventions such as oral health assessments using standard checklists designed for non-dental personnel, assistance with oral hygiene, management of iatrogenic dry mouth, and early dental referral have been suggested .
We examined the oral cleaning habits, oral health problems, and oral healthcare among the study participants. It is important for us to learn which factor has the strongest influence on patients' OHRQoL to implement better resource planning and prioritization. For example, toothache and bleeding gums are the oral health problems associated with poor physical health, whereas toothache, bleeding gums, and swollen gums were associated with poor MH. Toothache, bleeding, and swollen gums are relatively vague terms because they can be caused by dental caries or periodontal diseases, and they have been reported to negatively impact on OHRQoL .
Moreover, we investigated patients' attitudes toward dental visits. Co-operativeness was considered as the patients' behavior during dental treatment. Patients with schizophrenia may not act against a dental visit, but could resist heavily the treatment process. Cognitive impairment and excess negative symptoms can strongly influence their awareness and expression of pain . Therefore, psychoeducation about co-operativeness during dental treatment is important in improving physical and MH.
Sex, an unmodifiable factor, was shown to have a clinically meaningful impact on physical and MH [Table 2]. Women are more vulnerable to poor QoL than men, both physically and mentally. In a recent nationally representative study on health-related QoL conducted in the United States, women have been reported lower scores than men across different age groups with various instruments . In our multivariable analysis, we found a difference in physical and MH between men and women, regardless of which other factors were adjusted for in the model [Table 4] and [Table 5]. Previous studies suggested that women have lower pain tolerance, are more willing to consult physicians, and give higher pain ratings than men ,,. Another suggestion is that the distributions of chronic conditions in women and men are different ,.
The readers are warned against over-interpret the study results because our study has six study limitations:
- The participants were recruited at on-site visits. Those who were not interested in participating in the study may not have been included.
- The data were drawn from copies of self-reported questionnaire, which might have resulted in shared method variance. We did not obtain collateral information from medical staff or family to double check for participants' levels or severities of dental problems and oral health behaviors.
- Other risks and protective factors related to OHRQoL might exist. They include comorbid physical diseases and psychiatric disorders, but we did not examine them in this study. We did not evaluate the medication used and report of side effect. History and severity of schizophrenia and related cognitive function impairment were also not evaluated in our study. The multiple regression analysis suggested that sex, co-operativeness, toothache, and bleeding gums explain 52.6% of the variability in PCS, whereas sex, standard cleaning method, and cooperativeness were protective factors in MCS, and toothache, bleeding gums, swollen gums explain 45.7% of the variability in MCS. For example, factors such as participants' psychiatric diagnosis, substance use disorder (esp., betel nut use disorder), physical illness, dentures, social expectations, personality and functional status warrant further investigation ,.
- Our self-reported questionnaire to collect the status of oral health was not validated or compared with dentists' examination.
- Our study is a cross-sectional analysis. We could not differentiate properly between whether a person had low OHRQoL because of his/her poor oral health and whether a person with low OHRQoL was more likely to develop poor oral health.
- The oral health questionnaire was only reviewed and modified by a senior psychiatrist and a dentist for expert validity. However, it was not validated through comparing with other oral health questionnaire. Future studies with a longitudinal design would be valuable to further evaluate this issue when elucidating the causal relationship of oral health and OHRQoL.
In this cross-section study, we investigated the effects of the oral health of institutionalized patients with schizophrenia in Taiwan on their OHRQoL. The study showed a difference in OHRQoL between men and women. Those findings add to the current literature on sex differences in OHRQoL, providing useful information for decision makers to plan and prioritize health care resource for oral health in patients with schizophrenia in Taiwan and other countries. Further prospective studies considering physical illness are needed to confirm our findings.
| Financial Support and Sponsorship|| |
This research received no external funding.
| Conflicts of Interest|| |
The authors declare no potential conflicts of interest in publishing this report.
| References|| |
The WHOQOL Group: The World Health Organization Quality of Life assessment (WHOQOL): position paper from the World Health Organization. Soc Sci Med
1995; 41: 1403-9.
Gift HC, Atchison KA: Oral health, health, and health-related quality of life. Med Care
1995; 33: NS57-77.
Yewe-Dyer M: The definition of oral health. Br Dent J
1993; 174: 224-5.
Dolan TA: Identification of appropriate outcomes for an aging population. Spec Care Dentist
1993; 13: 35-9.
Locker D: Measuring oral health: a conceptual framework. Community Dent Health
1988; 5: 3-18.
Gift HC, Atchison KA, Dayton CM: Conceptualizing oral health and oral health-related quality of life. Soc Sci Med
1997; 44: 601-8.
Ng SK, Leung WK: Oral health-related quality of life and periodontal status. Community Dent Oral Epidemiol
2006; 34: 114-22.
Needleman I, McGrath C, Floyd P, et al.: Impact of oral health on the life quality of periodontal patients. J Clin Periodontol
2004; 31: 454-7.
Cunha-Cruz J, Hujoel PP, Kressin NR: Oral health-related quality of life of periodontal patients. J Periodontal Res
2007; 42: 169-76.
Jansson H, Wahlin Å, Johansson V, et al.: Impact of periodontal disease experience on oral health-related quality of life. J Periodontol
2014; 85: 438-45.
Ranta K, Tuominen R, Paunio I: Perceived oral health status and ability to chew among an adult Finnish population. Gerodontics
1987; 3: 136-9.
Ekelund R: Dental state and subjective chewing ability of institutionalized elderly people. Community Dent Oral Epidemiol
1989; 17: 24-7.
Wey MC, Loh S, Doss JG, et al.: The oral health of people with chronic schizophrenia: a neglected public health burden. Aust N Z J Psychiatry
2016; 50: 685-94.
Yang M, Chen P, He MX, et al.: Poor oral health in patients with schizophrenia: a systematic review and meta-analysis. Schizophr Res
2018; 201: 3-9.
Đorđević V, Jovanović M, Miličić B, et al.: Prevalence of dental caries in hospitalized patients with schizophrenia. Vojnosanit Pregl
2016; 73: 1102-8.
Al Shamrany M: Oral health-related quality of life: a broader perspective. East Mediterr Health J
2006; 12: 894-901.
Brown S, Inskip H, Barraclough B: Causes of the excess mortality of schizophrenia. Br J Psychiatry
2000; 177: 212-7.
Fitzpatrick J: Oral health care needs of dependent older people: responsibilities of nurses and care staff. J Adv Nurs
2000; 32: 1325-32.
Kisely S, Baghaie H, Lalloo R, et al.: A systematic review and meta-analysis of the association between poor oral health and severe mental illness. Psychosom Med
2015; 77: 83-92.
Frederic D, Corinne R, Matthieu R, et al.: The schizophrenia oral health profile: development and feasibility. Transl Neurosci
2018; 9: 123-31.
Tang LR, Zheng W, Zhu H, et al.: Self-reported and interviewer-rated oral health in patients with schizophrenia, bipolar disorder, and major depressive disorder. Perspect Psychiatr Care
2016; 52: 4-11.
Urban-Kowalczyk M, Pigońska J, Śmigielski J: Pain perception in schizophrenia: influence of neuropeptides, cognitive disorders, and negative symptoms. Neuropsychiatr Dis Treat
2015; 11: 2023-31.
Yu T, Enkh-Amgalan N, Zorigt G, et al.: Gender differences and burden of chronic conditions: impact on quality of life among the elderly in Taiwan. Aging Clin Exp Res
2019; 31: 1625-33.
Orfila F, Ferrer M, Lamarca R, et al.: Gender differences in health-related quality of life among the elderly: the role of objective functional capacity and chronic conditions. Soc Sci Med
2006; 63: 2367-80.
Case A, Paxson C: Sex differences in morbidity and mortality. Demography
2005; 42: 189-214.
Jaeken K, Cadenas de Llano-Perula M, Lemiere J, et al.: Reported changes in oral health-related quality of life in children and adolescents before, during, and after orthodontic treatment: a longitudinal study. Eur J Orthod
2019; 41: 125-32.
Stark H, Holste T: Survey of the dental prosthodontic care provided for residents of Würzburg old people's homes. Dtsch Zahnarztl Z
1990; 45: 604-7.
Sheiham A, Steele JG, Marcenes W, et al.: Prevalence of impacts of dental and oral disorders and their effects on eating among older people; a national survey in Great Britain. Community Dent Oral Epidemiol
2001; 29: 195-203.
Tseng HM, Lu JF, Gandek B: Cultural issues in using the SF-36 Health Survey in Asia: results from Taiwan. Health Qual Life Outcomes
2003; 1: 72.
Ware JE Jr., Kosinski M, Gandek B, et al.: The factor structure of the SF-36 health survey in 10 countries: results from the IQOLA project. International quality of life assessment. J Clin Epidemiol
1998; 51: 1159-65.
Takeda T, Nakataki M, Ohta M, et al.: Negative and positive self-thoughts predict subjective quality of life in people with schizophrenia. Neuropsychiatr Dis Treat
2019; 15: 293-301.
Bardow A, Nyvad B, Nauntofte B: Relationships between medication intake, complaints of dry mouth, salivary flow rate and composition, and the rate of tooth demineralization in situ
. Arch Oral Biol
2001; 46: 413-23.
Matos Santana TE, Capurso NA, Ranganathan M, et al.: Sublingual atropine in the treatment of clozapine-induced sialorrhea. Schizophr Res
2017; 182: 144-5.
Nielsen J, Munk-Jørgensen P, Skadhede S, et al.: Determinants of poor dental care in patients with schizophrenia: a historical, prospective database study. J Clin Psychiatry
2011; 72: 140-3.
Vancampfort D, Stubbs B, Mitchell AJ, et al.: Risk of metabolic syndrome and its components in people with schizophrenia and related psychotic disorders, bipolar disorder and major depressive disorder: a systematic review and meta-analysis. World Psychiatry
2015; 14: 339-47.
Kaye EK, Chen N, Cabral HJ, et al.: Metabolic syndrome and periodontal disease progression in men. J Dent Res
2016; 95: 822-8.
Pelletier JF, Lesage A, Boisvert C, et al.: Feasibility and acceptability of patient partnership to improve access to primary care for the physical health of patients with severe mental illnesses: an interactive guide. Int J Equity Health
2015; 14: 78.
Arnaiz A, Zumárraga M, Díez-Altuna I, et al.: Oral health and the symptoms of schizophrenia. Psychiatry Res
2011; 188: 24-8.
Maia CV, Mendes FM, Normando D: The impact of oral health on quality of life of urban and riverine populations of the Amazon: a multilevel analysis. PLoS One
2018; 13: E0208096.
Hanmer J, Kaplan RM: Update to the report of nationally representative values for the noninstitutionalized US adult population for five health-related quality-of-life scores. Value Health
2016; 19: 1059-62.
Greenspan JD, Craft RM, LeResche L, et al.: Studying sex and gender differences in pain and analgesia: a consensus report. Pain
2007; 132 Suppl 1: S26-45.
Bowling A, Banister D, Sutton S, et al.: A multidimensional model of the quality of life in older age. Aging Ment Health
2002; 6: 355-71.
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]