ORIGINAL Chu ARTICLE et al
Oral Health Status of Elderly Chinese with Dementia in Hong Kong Chun Hung Chua/Alice Ngb/Alex M. H. Chauc/Edward C. M. Lod Purpose: To compare toothbrushing habits, unstimulated salivary flow rates and oral health status of elderly Hong Kong Chinese with and without dementia. Materials and Methods: A sample size calculation was performed and a sample of 82 elderly Chinese with dementia were invited who were aged 60 or above, fit for periodontal assessment with probing and attended day-care centres. Age- and gender-matched generally healthy people without dementia were recruited as controls. Toothbrushing practices were recorded using a questionnaire. Additionally, unstimulated salivary flow rate was measured. Caries experience and periodontal status were assessed through clinical examination by the DMFT index and Community Periodontal Index (CPI), respectively. Results: Fifty-nine people with dementia and 59 age- and gender-matched generally healthy controls were recruited. Their mean age was 80 (SD = 7). Compared with the individuals in the control group, fewer people with dementia performed toothbrushing twice daily (31% vs 5%; P < 0.001). Furthermore, their unstimulated salivary flow rate was lower than that of the control group (0.30 ml/min vs 0.41 ml/min; P = 0.043). Their caries experience in mean DMFT (±SD) was similar to the control group (22.3 ± 8.2 vs 21.5 ± 8.2, P = 0.59). There was also no significant difference in the prevalence of periodontal pockets (CPI ≥3) between the two groups (78% vs 74%, P = 0.64). Conclusion: Compared to those without dementia, fewer elderly Chinese with dementia practiced toothbrushing twice daily. Although their resting salivary secretion was reduced, their caries experience and prevalence of advanced periodontal disease were not significantly different from those without dementia. Key words: caries, Chinese, dementia, elderly, oral health status, oral hygiene, periodontal, plaque, salivary flow rate Oral Health Prev Dent 2015;13:51-57 doi: 10.3290/j.ohpd.a32343
D
ementia is a disease characterised by the loss of intellectual capability of sufficient severity that normal social and/or occupational functioning is interrupted (American Psychiatric Association, 1994). The classical presentation of dementia is the development of multiple cognitive deficits, such as memory impairment, deterioration of language function, disturbances in executive functioning and failure to recognise or identify objects despite in-
a
Clinical Associate Professor, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
b
General Dental Practitioner, Hong Kong, China.
c
Dentist, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
d
Professor and Clinical Chair, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
Correspondence: Dr. C. H. Chu, 1B30, Prince Philip Dental Hospital, 34 Hospital Road, Hong Kong SAR, China. Tel: +852-2859-0287, Fax: +852-2858-2532. Email:
[email protected]
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Submitted for publication: 10.11.12; accepted for publication: 26.05.13
tact sensory function. In addition, there are psychiatric and behavioural changes, e.g. personality changes, depression and agitation, which accompany dementia (Chiu et al, 2002). The prevalence of dementia in elderly Hong Kong Chinese ≥ 70 years of age is 6% (Chiu et al, 1998). This is comparable to Europe (6% to 9%) (Berr et al, 2005) and Canada (8%) (Canadian Study of Health and Ageing Working Group, 1994). Dementia can be classified into different subtypes according to the underlying brain pathologies. Alzheimer’s disease (AD), vascular dementia (VD), dementia with Lewy bodies (DLB) and frontotemporal dementia (FTD) are the most common subtypes. According to the World Alzheimer Report by Alzheimer’s Disease International (2009), AD is the most common subtype of dementia among the elderly and accounts for 50%–75% of all dementia cases. Common early characteristic symptoms are impaired memory, apathy and depression. The on-
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set is often gradual. VD is the second most common subtype, evident in 20%–30% of all dementia cases. It is similar to AD, but memory is less affected. Additionally, patients experience more mood fluctuations. The onset is often stepwise, and physical frailty can be apparent. FTD is characterised by personality and mood changes, disinhibition and language difficulties. It accounts for 5%– 10% of dementia patients. Less than 5% of dementia patients have DLB. They often suffer from marked fluctuation in cognitive ability, visual hallucinations and Parkinsonism with tremor and rigidity. One of the most commonly used diagnostic criteria for dementia was developed by the American Psychiatric Association (1994). They include impairment of memory and at least one of the following domains: language, praxis, gnosis and executive functioning. The cognitive deficits must be sufficiently severe to cause impairment of social or occupational life compared to the previous level of functioning, and the decline does not occur only during delirium and cannot be explained by any other medical, neurological or psychiatric conditions. Comprehensive diagnosis includes history taking, physical examination and cognitive assessment, supplemented by appropriate blood and neuroimaging examinations (Small, 2006). Several screening tests are advocated for diagnosing and assessing dementia with reasonable reliability. The Mini-Mental State Examination is also widely used. It covers the subject’s orientation to time and place, recall ability, short-term memory and arithmetic ability (Folstein et al, 1975). Apolipoprotein E genotype was shown to be a major susceptibility factor for AD, and this association was also found among the Chinese in Hong Kong (Mak et al, 1996) and Taiwan (Hong et al, 1996). Oral health can also be significantly affected by dementia. With the progression of severity in dementia, the ability for patients to perform self-care, including oral hygiene practice, deteriorates gradually. Salivary dysfunction may also be present due to the pharmaceutical treatment of the disease, caused for instance by the side effects of cholinesterase inhibitors. In particular with patients with AD, the submandibular salivary output can be impaired (Ship et al, 1990). All of these were possible factors contributing to the significantly higher number of coronal and root surface caries among dementia patients (Warren et al, 1997; Ellefsen et al, 2008). Salivary dysfunction may also increase the risk of burning mouth syndrome and opportun-
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istic infection, such as oral candidiasis. People with dementia showed decreased use of dentures, increased prevalence of denture-related mucosal lesions, increased plaque accumulation and increased number of decayed retained roots (Chalmers et al, 2003). Higher risks of oral disease were related to the severity of dementia, but not to specific dementia subtypes. Oral health is an integral part of general health. This pilot study aimed to compare toothbrushing habits, unstimulated salivary flow rate and oral health status of elderly Hong Kong Chinese with and without dementia. Four null hypotheses were tested. First, there is no difference in toothbrushing habits between elderly Hong Kong Chinese with vs without dementia. Second, there is no difference in unstimulated salivary flow rate between elderly Hong Kong Chinese with vs without dementia. Third, there is no difference in caries experience between elderly Hong Kong Chinese with vs without dementia. Finally, there is no difference in prevalence of advanced periodontal disease between elderly Hong Kong Chinese with vs without dementia.
MATERIALS AND METHODS The target population selected for this project consisted of elderly people who a) were ≥ 60 years of age, b) had been diagnosed with dementia and c) were fit for periodontal assessment with probing. Those who need antibiotic prophylaxis for dental treatment were excluded. Recruitment of participants was carried out in the day-care centres of the Hong Kong Alzheimer’s Disease Association and St. James’ Settlement Kin Chi Dementia Care Support Service Center in March, 2010. After the sample size estimation, a quota sample of 82 elderly people was invited to the study through the daycare centres via Email and letters of invitation. The study protocol was submitted to the Hong Kong Alzheimer’s Disease Association and the St. James’ Settlement Kin Chi Dementia Care Support Service Center, and ethical approval was sought from/granted by the Institutional Review Board (IRB UW 12-126). The invitation letter described and explained the purposes and procedures of the study. Written consent was obtained before the study. The study comprised a questionnaire survey, sialometric assessment and oral examination. The questionnaire documented the participants’ toothbrushing habits, use of dental aids, difficulties in oral hygiene practice and personal data (Chu and
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Lo, 2010). The sialometric assessment meaured the unstimulated salivary flow rate (Chu et al, 2011). A stimulated salivary flow rate test was not carried out because of the risk of swallowing the salivary stimulator (rubber tubing). Participants were instructed not to eat, drink or smoke for an hour before the sialometric assessment. During the salivary flow rate test, they were asked to expectorate resting saliva into a 50-ml disposable container for 5 min. Clinical examination was conducted by two calibrated, trained examiners using dental mirrors with LED lights and WHO probes (Chu et al, 2008). Cotton rolls were used for moisture control and visualisation of tooth surfaces. The oral examination was performed according to the guidelines of the World Health Organization (1997). The examination assessed oral mucosal status, caries experience using the DMFT index and periodontal status using the community periodontal index (CPI). No radiographs were taken. The DMFT index was used to measure the caries experience of the permanent teeth, where D stands for decayed tooth, M denotes missing tooth due to decay and F represents filled tooth. The CPI, assessing periodontal status with a CPI probe, was taken in 6 sextants. Healthy gums with no bleeding on probing were scored ‘0’. A score of 1 indicates no bleeding after probing, 2 means calculus is present, 3 means a periodontal pocket 4 to 5 mm deep and a score of 4 for periodontal pocket(s) ≥ 6 mm in depth. Six index teeth (16/17, 11, 26/27, 46/47, 31 and 36/37), defined according to the FDI tooth numbering system, were examined. If the index tooth in a particular sextant was missing, the highest score among all of the teeth that remained in the sextant was taken. The score was identified by the examination of the specified index teeth or all teeth. Calibration exercises were carried out on 5 elderly patients ≥ 60 years of age in the Prince Philip Dental Hospital (PPDH) prior to the survey in order to reduce inter-examiner discrepancies. Duplicate examinations were carried out on 10% of participants during the clinical examination. The Kappa statistic was used to evaluate the inter-examiner reproducibility for caries and periodontal assessment. The dementia participants who had given their consent were examined in their respective centres. The patients’ medical histories were checked to ensure that they had no significant systemic diseases, such as valvular heart disease, prior to the oral examination. The diagnosis and the stage of dementia were recorded. They were informed about
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their oral health conditions and a written report was given to each participant after the assessment. From the registered list of Chinese people who had attended PPDH and were not receiving dental treatment, a control group of age- and gender-matched elderly people with dementia or a significant systemic disease was recruited. They were invited for examination at PPDH. Prior to the main study, the examiners conducted a pilot study on 10 other elderly people in PPDH to calibrate inter- and intra-examiner agreement between examiners for the oral examination. The caries experience (DMFT) of non-institutionalised elderly was 17.6 (Department of Health, 2002). We aimed to detect at least a 10% difference in DMFT between the 2 samples and estimated that the common standard deviation (sigma) would be 3.4. Setting the power at 0.8 and the Pvalue (α) at 0.05, the necessary sample size was 54. Assuming that the response rate was 70%, recruitment of 82 patients with dementia was required. Matching the gender and age, the same number of generally healthy elderly without dementia were recruited to act as the control group. The data collected were analysed using SPSS 17-0 (SPSS; Chicago, IL, USA). A parametric t-test and the chi-square test were used to study various independent variables. The cut-off point for statistical significance was set at 0.05.
RESULTS Eighty-two elderly people with dementia were invited, and 59 (47 females, 12 males) joined this study. Their mean age (±SD) was 79.8 ± 7.4. The response rate was 72%. They all suffered from a mild level of late-onset Alzheimer’s disease. A sexand age-matched group of 59 healthy elderly people without dementia were recruited and examined as the control group. Therefore, the total number of elderly participants was 118. The Kappa values for caries and periodontal assessment of the duplicate examination are 0.95 and 0.75, respectively. There were 63% (n = 37) people from the dementia group and 5% (n = 3) people from the control group who had difficulties with oral hygiene practice. The three main problems encountered by the dementia participants were forgetfulness (forgetting to brush or forgetting that he/she had already brushed) (73%, n = 27), unwilling to brush (35%, n = 13), inability to brush (lack of dexterity and the lack of an assistant to help perform brush-
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Table 1 DMFT, DT, MT, and FT in Chinese elderly with and without dementia Dementia (N = 59)
Control (N = 59)
Tooth status
Index
Mean ± SD
Mean ± SD
P
Caries experience
DMFT
22.3 ± 8.2
21.5 ± 8.2
0.59
Decayed teeth
DT
1.2 ± 1.9
0.8 ± 1.4
0.28
Missing teeth
MT
18.9 ± 9.4
18.3 ± 8.9
0.75
Filled teeth
FT
2.5 ± 3.3
2.4 ± 2.5
0.88
SD: standard deviation.
Table 2 CPI in Chinese elderly with and without dementia Periodontal status
Highest CPI
Dementia (N = 47)
Control (N = 50)
Healthy
0
0 (0%)
1 (2%)
Reversible gingivitis
1
5 (11%)
7 (14%)
Calculus present
2
5 (11%)
5 (10%)
Shallow pockets present
3
24 (51%)
26 (52%)
Deep pockets present
4
13 (27%)
11 (22%)
CPI: community periodontal index.
ing) (22%, n = 8). More people in the dementia group received assistance in brushing than did people in the control group (31% vs 5%; P < 0.001). Fewer people in the dementia group brushed at least twice daily than in the control group (67% vs 83%; P = 0.045). Eighty-one percent (n = 48) of people from the dementia group and 98% (n = 58) from the control group completed the sialometric assessment. There were 14% (n = 8) participants in the dementia group and 15% (n = 9) in the control group who were under medication associated with xerostomia. The mean unstimulated salivary flow rates (ml/min) of the dementia and control groups were 0.30 ± 0.17 and 0.41 ± 0.28, respectively (P = 0.043). Most dementia participants (95%, n = 56) had a healthy oral mucosal status. In 3% (n = 2) each of people with and without dementia (control), candidiasis on the palate and/or labial commissures was evident. Additionally, one individual (2%) with dementia presented with lichen planus on the buccal mucosa. The caries experience (mean DMFT ± SD) was 22.3 ± 8.2 for the dementia group and 21.5 ± 8.2 for the control group (P = 0.585). Their mean number of decayed teeth (DT), missing teeth (MT) and filled teeth were similar, as illustrated in Table 1.
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No association was found between the DMFT score and regular toothbrushing. Seventeen percent (n = 10) of people with dementia were edentulous, as were 14% (n = 8) in the control group; all of these were excluded from the periodontal status examination. No one (0%) suffering from dementia and only one (2%) participant without dementia had a healthy periodontal status (Table 2). The prevalence of advanced periodontal disease (CPI ≥ 3) of people in the dementia and control groups was 78% and 74%, respectively (P = 0.64)
DISCUSSION According to the results of the study, the first and second null hypotheses are rejected. Compared with those without dementia, there were fewer elderly Chinese with dementia who practiced toothbrushing twice daily, and their resting salivary secretion rate was reduced. However, the third and fourth null hypotheses were accepted, because there was no significant difference in caries experience or prevalence of advanced periodontal disease between elderly Hong Kong Chinese with dementia and those without dementia.
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In Hong Kong, the prevalence of dementia in elderly Chinese ≥ 70 years was 6.1% (Chiu et al, 1998). They reside at home or in institutions for the elderly. There is no registered list of people with dementia in Hong Kong. Thus, we could only contact principal non-governmental organisations to recruit people with dementia for our study. We chose day-care centres for elderly people with dementia; the members were all diagnosed with dementia by medical doctors. This is because we expected to recruit more elderly dementia patients in these centres. There were more female participants in our survey because there are more elderly women in the centres. In this study, the elderly participants suffered from late-onset (aged 60 or above) Alzheimer’s disease. Due to the lack of cooperation of elderly people with Alzheimer’s disease at the severe stage, we were only able to recruit and carry out the survey and examination on those with mild Alzheimer’s disease. Also, some of the elderly people in the day-care centres were having regular dental checkups and perceived no need to join our study. Hospitalised and institutionalised subjects for whom it was difficult to provide consent were not included in this study. Therefore, the participants were by no means a fully representative of the population of people with dementia in Hong Kong. The number of dementia participants is not large but is regarded as reasonable for a pilot study. The response rate was considered satisfactory. So far, there has been no study reporting the oral health conditions of people with dementia in the Chinese population, and this study promotes a rational understanding of the oral health status of people with dementia. The information gathered is useful for the planning of a full-scale survey with a larger population. Another limitation of this study is that the participants of the control group were generated by the computer system from the registry at PPDH. This allowed us to find an age- and sex-matched control group. Although the hospital is open to the public and we selected people who were not receiving treatment, the people who attended the hospital would likely have perceived the need for dental care and might not be representative of the general population in Hong Kong. A study by Chu et al (2008) also demonstrated the need for bitewing radiographs in caries detection of adolescents. With the supplementation of bitewing radiographs, there was a 105% increase in the number of caries detected in a group of Chinese young adults (Chu et al, 2008). However, the
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use of x-rays in an epidemiological survey is controversial. It is advocated that the radiographs not be used purely for epidemiological purposes, unless the films are also clinically justified and available to clinicians who are caring for the individuals concerned (Kidd et al, 1993). This study did not take any radiographs, as we did not provide subsequent dental care. The level of cooperation of the participants in both the clinical examination and the questionnaire survey was satisfactory. Sufficient training and calibration exercises were carried out before the examination, which allowed for better communication between the examiners and led to satisfactory inter-examiner agreement. For those people with dementia who were unable to follow the instructions of the examination, great patience and assistance from the staff of the centres were required. A few participants refused to cooperate and even showed aggressive behaviour in the sialometric assessment. Therefore, we could not perform the assessment on all of them. According to the results of those participants who completed the sialometric assessment, the elderly with dementia had a lower unstimulated salivary flow rate. This was in accordance with the findings by Ship et al (1990). They also found that people with AD had significantly lower unstimulated submandibular salivary flow compared to those without the disease. In addition, elderly dementia patients had organic reasons for the reduction of unstimulated saliva flow, such as neurological changes due to underlying brain pathology. Another reason might be because the dementia patients could not understand the instructions of the test and did not expectorate all of the saliva for assessment. Regular brushing of teeth twice a day (morning and night) is a common oral hygiene practice. There were significantly more elderly people from the dementia group who did not perform this regular toothbrushing compared to the control group. The reasons that they brushed less could be their cognitive decline and the difficulty in performing the oral hygiene practice. In this survey, caretakers reported several problems when performing oral hygiene practice on elderly people with dementia. The elderly might not understand the need, and therefore refuse to brush. They might refuse to open their mouths and even show aggressive behaviour towards the caretakers and family members with whom they were familiar. The lack of knowledge in correct oral hygiene practice could also be a factor. Lack of dexterity, lack of assis-
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tance, and forgetfulness were the major problems encountered by elderly people with dementia who brushed by themselves. Studies demonstrated that elderly people with dementia had poorer oral hygiene (Warren et al, 1997; Chalmers et al, 2003). Supervised toothbrushing in the elderly should be promoted. Given any lack of dexterity or areas that are not cleaned well, the caregiver could provide assistance immediately. In the later stages of dementia, the elderly frequently need assistance in oral hygiene maintenance (Frankel, 2004). In uncooperative cases, other methods, such as using mouth cleaning swabs, could be an alternative, although swabs cannot not remove as much plaque and debris as toothbrushes (Chalmers and Pearson, 2005). Other studies reported that there were significantly more dental caries and filled surfaces in elderly people with than without dementia (Chalmers et al, 2003; Ellefsen et al, 2008). However, we did not find more decayed teeth and higher caries experience among elderly people with dementia. This could be due to the sampling method and the fact that we did not include institutionalised and hospitalised elderly. Further studies can be performed to investigate whether institutionalised and hospitalised elderly are more at risk of acquiring dental caries. We found that elderly people with dementia, on average, had more than one decayed tooth. Dental caries should not be left untreated because the complexity of restoration increases and the restorability of the decayed tooth decreases over time. In addition, elderly people with advanced stages of dementia cannot cooperate in more complex treatments or difficult extraction. Delayed dental care imposes more suffering on the patient, is a greater challenge for dentists and involves higher costs. Hence, regular dental check-ups and preventive care are both very important. The aim of dental care is to maintain existing dentition with minimal changes in the occlusion (Ettinger et al, 2000). Apart from treatment, dentists should pay attention to behavioural management in people with dementia, as cognitive impairment progresses with time. Treatment must be planned taking the severity of the condition into consideration and involving caretakers and guardians (Ghezzi and Ship, 2000). In general, removable dentures are more appropriate than complex prosthetics, such as implants, regarding ease of oral hygiene maintenance (Chu and Chow, 2006). As the cognitive impairment progresses, shorter, less stressful appointments and
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the use of the least traumatic interventions should be arranged (Ettinger et al, 2000). More intensive preventive care, such as fluoride application, is essential (Chu et al, 2010). Oral sedatives or anxiolytics, such as short-acting benzodiazepines before treatment, could be considered to manage behavioural problems (Kocaelli et al, 2002). Although the majority of the elderly brushed twice a day, the periodontal condition was still unsatisfactory. It was noteworthy that the majority (78%) of the elderly people in the dementia group had periodontal pockets, which often required advanced periodontal treatment. There could be problems in brushing techniques or the presence of plaque-retentive factors, which could hinder efficient plaque removal; hence, we gave individual oral hygiene reinforcement to participants and their guardians or caretakers to facilitate adequate plaque control and thus limit the progression of periodontal diseases. Further tooth loss due to periodontal diseases would lead to several problems, including a decrease in masticatory function and ill-fitting dentures. Moreover, elderly people with dementia are likely to have problems cooperating with dental procedures and be unable to accept new designs or fitting of new dentures (Kocaelli et al, 2002). Like many developed cities in the world, Hong Kong is facing an aging population phenomenon. The proportion of people aged 65 and above in Hong Kong in 2008 was 13%, and it is estimated to be 24% by the year 2025 (Census and Statistics Department, 2013). As the risk of dementia is related to aging, we can expect that there will be more people suffering from dementia in the future. However, the number of dentists will not have increased in the coming decade. It is thus probable that dentists in Hong Kong will face a greater challenge in maintaining the oral health of the elderly with dementia.
CONCLUSIONS In this study, there were fewer elderly Chinese with dementia than without who practiced toothbrushing twice daily. Although their resting salivary secretion was reduced, their caries experience and prevalence of advanced periodontal disease were found to be similar to those without dementia.
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ACKNOWLEDGEMENTS The authors wish to thank the Hong Kong Alzheimer’s Disease Association, St. James’ Settlement Kin Chi Dementia Care Support Service, and the Prince Philip Dental Hospital for their approval to conduct this study. This study was developed from a community health project, and the authors would like to thank Drs. YC Chan, WP Cheung, TK Ho, CK Lau, KM Mak, HSA Tam, and CHT Woo for their contributions to the study.
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