The impact of dietary and tooth-brushing habits to dental caries of special school children with disability

Research in Developmental Disabilities 31 (2010) 1160–1169

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Research in Developmental Disabilities

The impact of dietary and tooth-brushing habits to dental caries of special school children with disability Hsiu-Yueh Liu a, Chun-Chih Chen a, Wen-Chia Hu a, Ru-Ching Tang a, Cheng-Chin Chen b, Chi-Cheng Tsai c,d, Shun-Te Huang e,f,* a

School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan Department of Dental Technology, Shu Zen College of Medicine and Management, Kaohsiung, Taiwan College of Oral Medicine, Chung Shan Medical University, Taichung, Taiwan d Department of Periodontics, Chung Shan Medical University Hospital, Taichung, Taiwan e Department of Oral Hygiene, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan f Division of Dentistry for Children and Disabled, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan b c

A R T I C L E I N F O

A B S T R A C T

Article history: Received 26 July 2010 Received in revised form 13 August 2010 Accepted 17 August 2010

The daily oral activities may severely influence oral health of children with disabilities. In this survey, we analyzed the impact of dietary and tooth-brushing habits to dental caries in special school children with disabilities. This cross-sectional survey investigated 535 special school children with disabilities aged 6–12 years, 60.93% males, 39.07% females from 10 special schools in Taiwan. Oral examinations were carried out by dentists with a Kappa score of their inter-examiner agreement exceeding 0.8. Data on demographics, diet, and tooth-brushing habits of children with disabilities were collected using a standardized questionnaire completed by parents/caregivers. More than three quarters of the participants were combined with severe or profound disability. Children with profound severity in disability had a higher percentage (67.37%) in teeth-brushing by parents/ caregivers compared to those children with mild/moderate severity in disability which had a higher percentage (81.60%) in teeth-brushing by themselves. Children whose teeth were brushed by parents/caregivers had a better dental health, and lower caries prevalence. The main risk factors related to decayed teeth of children with disabilities are frequency of sweets intake, ability to brush teeth and with plaque or not. The dental health education, prevention program and periodical oral check-up to children with disabilities and their parents/caregivers should be reinforced. Brushing skill should be taught to children according to their type, severity and individual characteristics of disability. ß 2010 Elsevier Ltd. All rights reserved.

Keywords: Children with disabilities Dietary habits Tooth-brushing habits Dental caries

1. Introduction There are nearly 1.07 million(4.63%) people with disabilities in Taiwan (Disabled population by age and grade, 2009). The dental health of individuals with disabilities is worse than that of normal people of the same age since their medical, physical, social, or psychological disabilities limit their access to oral health care, diagnostic, preventive, interceptive and treatment services (Huang et al., 2010; Liu et al., 2009; Minihan & Dean, 1990; Waldman, Perlman, & Swerdloff, 1998; Wilson, 1992; Ziring et al., 1988). Those disadvantages lead their oral health to be poor, more untreated decayed teeth, and severe periodontal status

* Corresponding author at: Department of Oral Hygiene, College of Dental Medicine, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, San Ming District, Kaohsiung City 80708, Taiwan. Tel.: +886 7 3121101x2272; fax: +886 7 3233752. E-mail addresses: [email protected], [email protected] (S.-T. Huang). 0891-4222/$ – see front matter ß 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.ridd.2010.08.005

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(Feldman et al., 1997; Forsberg, Quick-Nilsson, Gustavson, & Jagell, 1985; Haavio, 1995; Ivancic Jokic, Majstorovic, Bakarcic, Katalinic, & Szirovicza, 2007; Karjalainen et al., 2002; Liu et al., 2009; Martens et al., 2000; O’Leary, Kinirons, Stewart, Graham, & Hartnett, 2007; Pieper, Dirks, & Kessler, 1986; Shaw, Maclaurin, & Foster, 1986; Waldman, Perlman, & Swerdloff, 2000). The caries prevalence, DT (number of decayed teeth of the permanent dentition) and DMFT index (the sum of decayed, missing, and filled teeth of the permanent dentition) of 12-year-old children with disabilities in Taiwan showed 69.43%, 1.95 and 3.14, compared to 37.30%, 1.15 and 2.58 of normal 12-year-old children (Chen & Huang, 2007; Huang, 2005). The dental hygiene status (dental plaque, gingivitis and calculus index) appeared disparity between children with disability and normal children (Chen & Huang, 2007; Huang, 2005). The percentage (11.45%) of heavy plaque of children with disability was higher than normal children (3.57%). The former had lesser healthy gingival tissue and without calculus (32.14% and 66%) than normal children (43.73% and 82.95%) (Chen & Huang, 2007; Huang, 2005). The poor oral health status, more unmet decayed teeth and worse dental hygiene are related to poor oral hygiene behavior and sweets in the diet of children with disabilities (Huang, 1998; Liu et al., 2009). Studies in Sweden and Japan (Gizani et al., 1997; Kinirons, 1983; Yoshino et al., 2001) have reported that the oral health of children with disabilities can be improved to a similar or even better status than that of normal children at the same age in spite of their disadvantages. The main reasons for this improvement can be accredited to the practice of tooth-brushing by themselves or by their caregivers in daily life or diet control by institutes and schools (Kinirons, 1983). Therefore, the purpose of this study was to explore the dental health status, and analyze the impaction of dietary and tooth-brushing habits to dental caries of special school children with disability in order to establish an oral health prevention program as early as possible for children in special education schools in the future. 2. Materials and methods 2.1. Study design and population This was a cross-sectional study conducted during the period from October to December, 2006. Six hundred and sixty-five eligible children aged 6–12-year olds from 10 out of 18 special primary schools were classified into mild to profound disabilities according to the definition of Physically and Mentally Disabled Citizens Protection Act (2004). After the process of assessment, the severity is regulated by the central competent authority in charge of health in Taiwan. The children with disabilities adapted their disability identification in our study included sensory disability, intellectual disability, multiple disabilities, limb disability, autism and other disabilities evaluated and certified by the central competent authority in charge of health. The procedures, contents of survey and questionnaire were explained to the parents or caregivers of all children with disabilities, and written consents were obtained from those parents or guardians who agreed their children to participate. One hundred and thirty samples were excluded from the study because of parents or caregivers not completing the questionnaire. The final sample size was 535 (a response rate of 80.45%). 2.2. Oral examination Oral examination, according to the criteria of the principles and methods endorsed by World Health Organization (WHO) (1997), was carried out by six well-trained dentists who were evaluated prior to the survey and achieved acceptable reliability and inter-examiner agreement with a Kappa score exceeding 0.8. A disposable dental mirror, a standard dental explorer and a flashlight were used for the oral examination in the classroom, lobby, auditorium, or other open space of the schools with the help of nursing staff. Dental radiographs were not used in this study. Usually, the caries experience was determined on the basis of a total 20 teeth in the primary dentition or 24 teeth in the permanent dentition up to 12 years old. The following indices are applied to describe the status and severity of dental caries by prevalence, frequency and intensity. DMFT and deft index are used as dental caries indices to describe numerically the amount (the prevalence) of dental caries in mixed dentition of individual. This provides the total cumulative caries experience (WHO, 1987). These caries indices are presented as following: deft + DMFT: mean number of decayed, missing or filled teeth of mixed dentition; dt + DT: mean number of decayed teeth of mixed dentition; et + MT: mean number of missing teeth of mixed dentition; ft + FT: mean number of filled teeth of mixed dentition; caries prevalence is the expression of the number of exiting cases of dental caries in a population at a specific point in time and calculated using the formula: total number of population with one or more than one decayed teeth/total number of population in this study  100%; filling rate is restorative index that calculated using the formula: (total number of decayed teeth/total numbers of decayed teeth and filled teeth)  100% (Gluck, Knox, Glass, & Wolfman, 1972). 2.3. Questionnaire The standardized self-administered survey questionnaire used in the previous study (Huang, 2005) was modified by a panel of experts and reviewed by school teachers and students’ parents for assessment of its face validity, was completed by a parent or caregiver. This questionnaire was constructed by the following four parts: demographic characteristics of the

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subject, demographic characteristics of the parents, dietary and living habits (including intake of sweets), and toothbrushing habits of children with disabilities, and consisted of closed-ended items with dichotomous, ordinal and multiple level response choices to comprehend the above relevant variables. Sweet foods, including chocolate, candy, cake, bakery, ice cream, carbonated beverages, juice, milk with sugar, wheatbased food/products, were indicated as high-carbohydrate foods. Nuts, raisins and chewing gum were excluded from the list of sweet foods. Educational levels of parents were classified into both high, one high and one low, and both low. Both high educational levels were the parents had educational background up to university level. One high and one low educational level was either father or mother had university education level and another one with senior high school education level or parents had senior high school education level. Both parents had junior high school or one had lower than junior high school education level belongs to both low education levels. According to Hollingshead’s Two-Factor Index of Social Position (1957), occupation levels were classified into five levels: unskilled, partly skilled, skilled, intermediate, and professional. Cross-tabulation analyzed of occupation combined the analysis with both skilled, one skilled and one unskilled, and both unskilled. Both skilled occupation levels were the parents who had occupation up to skilled levels. One skilled and one unskilled occupation level was that one of father or mother who had skilled, intermediate or professional occupation level and another one with unskilled or partly skilled occupation level. Both unskilled occupation levels were the parents occupation levels belong to unskilled or partly skilled level. 2.4. Statistical analysis All data, including information from the oral examination and questionnaire, were input in a computer database using Microsoft Access software (Microsoft, Redmond, WA, USA), and statistical computations were analyzed with SAS version 8.2 statistical software (SAS Institute, Cary, NC, USA) and JMP version 5.0 (SAS Institute). Categorical variables were compared using Pearson’s x2 test and are presented as proportions, and differences between numerical variables were analyzed using analysis of variance (ANOVA) and t-test and are presented as the mean and standard deviation (SD). Differences at the 5% probability level were considered statistically significant. 2.5. Ethical approval The ethical approval was obtained from the Human Experiment and Ethics Committees of Kaohsiung Medical University (Protocol number: KMUH-IRB-950125). 3. Results The mean age of individuals was 9.42 years old (ranged from 6 to 12 years). Their disabilities of mild/moderate, severe and profound were 23.74%, 56.82% and 19.44%, respectively. The numbers of boys and girls were 60.93% and 39.07%, respectively. The oral health related indices of female was higher than male, but not showed any statistically significant difference by gender. The average of dt + DT, deft + DMFT indices and caries prevalence of children in mixed dentition were 2.46  3.35, 3.85  4.04 and 58.69%, respectively. Caries prevalence decreased significantly when the parents had higher education levels, and the parents had higher skilled occupation levels (Table 1). The children with mild or moderate disabilities had statistically significantly worse dental health related indices than those children with severe and profound disabilities. The dt + DT, deft + DMFT index and caries prevalence significantly decreased from 3.33  3.90 to 2.00  3.07 (p = 0.0090); from 4.69  4.26 to 3.82  4.64 (p = 0.0247); from 68.50% to 50.96% (p = 0.0170), respectively, when the grade of disability got worse (Table 1). The comparison of parents’ education level showed that the children of parents with both high education level would have lesser dt + DT, et + MT, deft + DMFT indices and caries prevalence than children of the parents with lower education level. The deft + DMFT index and caries prevalence showed statistical significance (p = 0.0474 and p = 0.0002, respectively) among three education levels (Table 1). The parents’ occupation levels also showed that the children of parents with both high skilled levels had lower dt + DT, et + MT and deft + DMFT indices, and significantly lower caries prevalence (p = 0.0061) than the children of the parents with both unskilled levels (Table 1). In our study, more than one-third (36.28%) of children actively asked for sweets, 37.85% of the sample received sweets from parents, caregivers or school teachers as a reward for behavior control. Those children showed statistically significantly higher dt + DT (3.02  3.77, p = 0.0009) and deft + DMFT (4.29  3.40, p = 0.0187) indices and caries prevalence (64.74%, p = 0.0155) compared to those children who did not receive sweets as a reward for behavior control (Table 2). More than 70% of children took sweets at least once a week. The dt + DT and deft + DMFT indices and caries prevalence increased statistically significantly when children had higher frequency of sweets intake (all p < 0.0500). Children who never/sometimes took sweets had the lowest dt + DT and deft + DMFT indices, caries prevalence, and the best dental status (Table 2). More than one-third (35.16%) of the children’s tooth-brushings were done by their parents or caregivers. Children who brushed their teeth by themselves had statistically significantly higher dt + DT (2.77  3.50) index, deft + DMFT index (4.18  4.07) and caries prevalence (63.25%) than those children who brushed teeth by parents or caregivers (p = 0.0027, p = 0.0077, and p = 0.0041) (Table 2). Children who brushed their teeth less than three times a day comprised 76.36% of the sample, and who tend to have worse oral conditions than children who brushed their teeth more than three times a day (Table 2).

Table 1 Oral health of mixed dentition by demographics of 6–12-year-old children with disabilities. n

Total 535 Gender Male 326 Female 209 Severity of disability Mild/moderate 127 Severe 304 Profound 104 Parents’ education level Both low 147 One low, 121 one high Both high 231 Parents’ occupation Both unskilled 221 One unskilled, 145 one skilled Both skilled 86

(%)

dt + DT

p-Value

et + MT

p-Value

ft + FT

p-Value

deft + DMFT index

p-Value

Caries prevalence (%)

p-Value

Filling rate (%)

p-Value

Mean

(SD)

Mean

(SD)

Mean

(SD)

Mean

(SD)

2.46

(3.35)

0.25

(0.89)

1.13

(2.14)

3.85

(4.04)

(60.93) (39.07)

2.34 2.64

(3.32) (3.41)

0.3120

0.21 0.33

(0.69) (1.13)

0.1792

1.05 1.27

(2.16) (2.10)

0.2485

3.60 4.23

(3.98) (4.12)

0.0757

56.44 62.20

0.1856

30.53 34.89

0.2904

(23.74) (56.82) (19.44)

3.33 2.25 2.00

(3.90) (3.14) (3.07)

0.0090

0.16 0.27 0.34

(0.48) (0.88) (1.23)

0.1461

1.20 0.99 1.48

(2.08) (1.84) (2.87)

0.1994

4.69 3.50 3.82

(4.26) (3.67) (4.64)

0.0247

68.50 57.24 50.96

0.0170

29.46 32.32 37.10

0.4774

(29.46) (24.25)

2.71 2.55

(3.25) (3.38)

0.1143

0.27 0.31

(0.82) (1.01)

0.3130

1.29 1.12

(2.15) (1.89)

0.6085

4.28 3.98

(3.96) (3.94)

0.0474

70.07 59.50

0.0002

31.22 35.94

0.6968

(46.29)

2.04

(3.19)

0.18

(0.62)

1.07

(2.26)

3.29

(3.94)

(48.89) (32.08)

2.60 2.23

(3.14) (2.98)

0.25 0.32

(0.85) (1.21)

1.15 1.07

(1.95) (2.10)

4.00 3.61

(3.88) (3.82)

(19.03)

1.83

(2.90)

0.17

(0.54)

1.33

(2.72)

3.33

(3.96)

0.1225

0.5285

0.6835

58.69

32.37

48.92 0.3397

65.61 59.31 45.35

33.79 0.0061

30.40 30.23 40.42

0.2956

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Variable

1163

1164

Table 2 Oral health of mixed dentition by dietary and tooth-brushing habits of 6–12-year-old children with disabilities. n

(%)

Ask for sweets No 332 (63.72) Yes 189 (36.28) Frequency of sweets intake Never/sometimes 124 (24.65) At least once a week 366 (72.76) At least once a day 13 (2.59) Sweets as a reward in behavior control No 312 (62.15) Yes 190 (37.85) Ability to brush teeth Brushed by themselves 332 (64.84) Brushed by parents/ 180 (35.16) caregivers Frequency of toothbrushing each day Sometimes 20 (3.91) <3 times 391 (76.36) 3 times, after meals 101 (19.73) Plaque No 392 (73.68) With plaque 140 (26.32)

dt + DT

p-Value

Mean

(SD)

2.03 3.21

(2.82) (4.03)

1.43 2.80 4.00

et + MT

p-Value

Mean

(SD)

0.0005

0.27 0.24

(0.86) (0.95)

(2.12) (3.57) (5.00)

<.0001

0.15 0.28 0.08

1.96 3.02

(2.76) (3.77)

0.0009

2.77 1.89

(3.50) (2.94)

2.85 2.57 1.97 2.16 3.21

ft + T

p-Value

Mean

(SD)

0.7139

1.05 1.26

(2.17) (2.08)

(0.52) (0.95) (0.28)

0.0557

0.98 1.18 0.85

0.29 0.23

(0.95) (0.83)

0.4812

0.0027

0.28 0.22

(1.00) (0.68)

(3.50) (3.38) (3.13)

0.2361

1.15 0.23 0.21

(3.17) (3.63)

0.0027

0.24 0.31

deft + DMFT index

p-Value

Caries prevalence (%)

p-Value

Filling rate (%)

p-Value

Mean

(SD)

0.2603

3.35 4.71

(3.75) (4.39)

0.0004

54.22 66.14

0.0071

31.85 32.56

0.8651

(2.34) (2.10) (1.91)

0.6031

2.56 4.27 4.92

(3.33) (4.16) (5.72)

0.0003

45.97 62.30 69.23

0.0109

31.77 32.18 21.21

0.6619

1.15 1.04

(2.25) (1.90)

0.5680

3.40 4.29

(3.68) (3.40)

0.0187

53.85 64.74

0.0155

34.83 28.89

0.1589

0.4889

1.13 1.08

(1.99) (2.20)

0.7866

4.18 3.19

(4.07) (3.85)

0.0077

63.25 50.00

0.0041

31.50 34.26

0.5421

(2.78) (0.69) (0.83)

<.0001

0.80 1.09 1.26

(1.67) (2.05) (2.18)

0.6054

4.80 3.89 3.44

(5.32) (3.96) (3.95)

0.3299

65.00 59.59 53.47

0.4524

19.50 30.66 41.53

0.0579

(0.83) (1.04)

0.4248

1.10 1.21

(2.08) (2.28)

0.5942

3.49 4.73

(3.88) (4.31)

0.0032

55.61 66.43

0.0230

34.10 28.14

0.1694

H.-Y. Liu et al. / Research in Developmental Disabilities 31 (2010) 1160–1169

Variable

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Table 3 Severity of disability related to dietary and tooth-brushing habits. Variable

Gender Male Female Ask for sweets No Yes Frequency of sweets intake Never/sometimes At least once a week At least once a day Sweets as a reward in behavior control No Yes Ability to brush teeth Brushed by themselves Brushed by parents/caregivers Frequency of tooth-brushing each day Sometimes <3 times 3 times, after meals Plaque No With plaque

Mild/moderate

Severe

Profound

p-Value

n

(%)

n

(%)

n

(%)

88 39

(69.29) (30.71)

184 120

(60.53) (39.47)

54 50

(51.92) (48.08)

0.0261

65 60

(52.00) (48.00)

191 106

(64.31) (35.69)

76 23

(76.77) (23.23)

0.0006

72 30 23

(57.60) (24.00) (18.40)

123 76 93

(42.12) (26.03) (31.85)

5 26 64

(5.26) (27.37) (67.37)

<.0001

70 48

(59.32) (40.68)

186 101

(64.81) (35.19)

56 41

(57.73) (42.27)

0.3555

102 23

(81.60) (18.40)

199 93

(68.15) (31.85)

31 64

(32.63) (67.37)

<.0001

3 101 21

(2.40) (80.80) (16.80)

12 220 60

(4.11) (75.34) (20.55)

5 70 20

(5.26) (73.69) (21.05)

0.6656

88 38

(69.84) (30.16)

225 78

(74.26) (25.74)

79 24

(76.70) (23.30)

0.4738

A significantly higher proportion (48.00%; p = 0.0006) of children with mild/moderate disabilities asked for sweets compared to children with severe (35.69%) and profound disabilities (23.23%). And the dental health related index of the former was statistically significantly higher than the latter two groups. Regarding to the frequency of tooth-brushing each day, most children with mild disabilities brushed their teeth more than three times with 16.80% less than those with severe (20.55%) and profound disabilities (21.05%). Approximately 81.60% of children with mild or moderate disabilities brushed their teeth by themselves, but 68.15% of children with severe disability and only 32.63% of children with profound disability

Table 4 Type of oral care related to socio-demography, dietary and tooth-brushing habits. Variable

Gender Male Female Parents’ education level Both low One low, one high Both high Parents’ occupation Both unskilled One unskilled, one skilled Both skilled Ask for sweets No Yes Frequency of sweets intake Never/sometimes At least once a week At least once a day Sweets as a reward in behavior control No Yes Frequency of tooth-brushing each day Sometimes <3 times 3 times, after meals Plaque No With plaque

Brushed by themselves

Brushed by parents/caregivers

n

(%)

n

p-Value

202 130

(60.84) (39.16)

110 70

(61.11) (38.89)

0.9527

107 86 115

(34.74) (27.92) (37.34)

33 30 108

(19.30) (17.54) (63.16)

<.0001

141 85 48

(51.46) (31.02) (17.52)

72 55 34

(44.72) (34.16) (21.12)

0.3775

184 142

(56.44) (43.56)

138 40

(77.53) (22.47)

<.0001

71 234 7

(22.76) (75.00) (2.24)

46 123 6

(26.29) (70.29) (3.42)

0.4698

199 116

(63.17) (36.83)

104 66

(61.18) (38.82)

0.6646

10 246 76

(3.01) (74.10) (22.89)

10 145 25

(5.55) (80.56) (13.89)

0.0251

243 89

(73.19) (26.81)

135 42

(76.27) (23.73)

0.4493

(%)

1166

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Table 5 Regression analysis on risk factors associated with decayed teeth of mixed dentition. Variable

Intercept Age Gender Severity of mental retardation

Parents’ education level

Frequency of sweets intake

Ability to brush teeth Frequency of tooth-brushing each day

Plaque

Term

(year) Male Female Mild/moderate Moderate Profound Both low One low, one high Both high Never/sometimes At least once a week At least once a day Brushed by themselves Brushed by parents/caregivers Sometimes 3 times, after meals <3 times No With plaque

Estimate

6.6636 0.4550 Reference 0.2059 Reference 0.6276 0.3229 Reference 0.3625 0.5528 Reference 1.1224 2.7999 Reference 1.1810 Reference 0.1366 0.6273 Reference 1.0245

SE

95%CI

p-Value

Lower

Upper

1.11 0.07

4.48 0.59

8.85 0.32

0.0000 0.0000

0.29

0.37

0.78

0.4791

0.35 0.47

1.32 1.25

0.06 0.60

0.0756 0.4930

0.39 0.35

1.13 1.24

0.40 0.13

0.3522 0.1137

0.33 0.88

0.48 1.06

1.77 4.54

0.0007 0.0017

0.33

1.82

0.54

0.0003

0.75 0.80

1.33 2.20

1.61 0.94

0.8552 0.4333

0.33

0.37

1.67

0.0021

R-square = 0.1474.

could perform this task by themselves (Table 3). The severity of disability was associated with the percentage and frequency of tooth-brushing dependent on parents or caregivers (p < 0.0001) (Table 3). The dental health related indices were lower in the children whose tooth-brushing was carried by parents or caregivers (Table 2). We further analyzed the relation between tooth-brushing habits and daily care ability (Table 4). The children had sweets as a reward in behavior control brushed their teeth dependently upon their parents/caregivers (22.47%) was significantly lower than those who brushed their teeth by themselves (43.56%; p < 0.0001) (Table 4). There was a trend of higher percentage (26.81%) of children, who brushed their teeth by themselves, had plaque accumulation than those who brushed their teeth assisted by parents/caregivers (23.73%) (Table 4). Finally, the regression analysis revealed that sweets intake more than once a day or a week, brushing teeth by individual and with plaque are risk factors to have a higher number of decayed teeth of children with disabilities in special schools (Table 5). 4. Discussion There were 76.26% of children with severe or profound disabilities in our study; more than 60% of them were intellectual disability or multiple disabilities. So, they had disparity in getting social and dental care resources, and had the disadvantages of to realize the importance of oral hygiene, poor manual dexterity to handle brushing instruments or tools to brush their teeth, and to manipulate regular tooth-brushing properly and in proper way. The barriers of physical, visual, or hearing made them face more difficult to comprehend complex tasks. Meantime, how to eat diet and sweeten properly is another important matter and easily ignored. Hence their oral health status was poor. Several surveys have claimed that the oral health of children with disabilities is poorer than that of normal children in terms of either dental caries, gingival or periodontal diseases (Donnell, Sheiham, & Wai, 2002; Forsberg et al., 1985; Kao & Chou, 1991; Karjalainen et al., 2002; Martens et al., 2000; Pieper et al., 1986; Shaw et al., 1986; Tesini, 1981). A same tendency was reported in our previous studies conducted in Taiwan. The decayed teeth number and caries prevalence of children with disabilities aged 9.42 years were higher than those of normal children (Chen & Huang, 2007; Huang, 2005). The filled teeth number of children with disabilities was also lower than normal children (Chen & Huang, 2007; Huang, 2005). The children with intellectual disability and Down syndrome had a higher plaque index and gingival index than normal children had in Taiwan (Kao & Chou, 1991). It was reported that children with disabilities had a very high number of decayed teeth and a low number of filled teeth, which was severely impacted by the grade of disabilities; the oral health such as prevalence of untreated decay teeth of children with disabilities indicated nearly twice as high compared with general children at the same age (Newacheck, McManus, Fox, Hung, & Halfon, 2000). The present study showed the same tendency that the average decayed teeth number was nearly three times more than the filled teeth number in the mixed dentition of children with mild/moderate disabilities, and more than two times in children with severe disabilities, close to 1.35 times in children with profound disability (Table 2). Children with mild/moderate disabilities had much higher dt + DT and deft + DMFT indices than that of children with severe and profound disabilities (p = 0.0090 and p = 0.0247, respectively) (Table 1) could be related to: (1) children with mild/ moderate disabilities asked for sweets actively also showed significantly higher frequency of sweets intake than children

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with severe or profound disabilities, and (2) the risk factors, such as tooth-brushing with or without help by parents/ caregivers, for the decayed teeth in the mixed dentition of children with disabilities (Tables 2, 3, and 5). Besides, children with mild/moderate disabilities showed significantly higher percentage of brushing their teeth by themselves (or lesser by their parents/caregivers), and less percentage in never brushing their teeth as compared to children with severe or profound disabilities. However, the former had higher frequency in brushing teeth than latter (Table 3). Since most of children with disabilities, especially children with severe or profound disabilities have their disabilities in cognition, memory, communication, and manual dexterity cannot care their activities of daily life completely. The same situation happens in the tooth-brushing behavior of those children with disabilities. Since they cannot take the diet, sweetened foods actively, brush their teeth properly; these daily activities concerning dental care must be supplied, feed or cared by their parents/caregivers mostly. All of their disabilities will lead children with disabilities having poor dental health and oral hygiene. Definitely, the socio-economic status such as lower status of education level and economic status of their parents will impact the disparity of the dental health status of children with disabilities prominently (Batista, Moreira, Rauen, Corso, & Fiates, 2009; Kumar, Sharma, Duraiswamy, & Kulkarni, 2009; Pannuti et al., 2003; Sogi & Bhaskar, 2002). In our study, the dental health status (dt + DT, et + MT, deft + DMFT indices) and caries prevalence of children were significantly related to their parents’ education and occupation level respectively (Table 1). These results were in consistent with our previous study (Chen & Huang, 2007; Huang, 2005). Since the sweets were given by parents to their children with disabilities mostly, if parents were not aware of the harmful effects of sweets and brush children’s teeth properly and carefully, children with disabilities will have poor dental health definitely. Children who had high snack intakes and brushed irregularly had significantly higher caries experience than those with low snack intakes and regular tooth-brushing (Stecksen-Blicks & Holm, 1995; Vallejos-Sanchez et al., 2008). There was an inverse relationship between caries prevalence and the parents’ educational level. The percentage of children who never or irregularly brushed their teeth was highest in the caries active group (Eronat & Koparal, 1997). In our study, children actively asked for sweetened foods had frequency of sweets intake more than once a week. Their parents or caregivers offer them sweets as a reward in behavior control had statistically significantly higher dt + DT and deft + DMFT indices and caries prevalence (Table 2). Children who consumed sugary liquids at main meals had a mean caries experience of 5.14; for those who did not it was 3.65. The consumption of sugary liquids during main meals showed a significant association with a higher presence of caries, while consumption of sweet milk and dairy products, fruit and foods without sugar at main meals was significantly associated with lower caries experience. A higher consumption of foods containing starch and sugar in between meals was significantly associated with a greater presence of caries (Llena & Forner, 2008). Llena and Forner (2008) also reported that sweet snacks, industrial bread and soft drink consumption showed a positive association with caries while cheese and nuts showed a negative association. Logistic regression suggested that consuming sugary liquids and foods rich in semihydrolyzed starch increased the chances of suffering caries by 1.05 and 1.13, respectively. In our study, two-third of children, not regard to the severity of disability, took sweets usually. Most of children with mild or moderate disabilities tended to ask sweets more actively, and less than half of the children with profound disabilities actively asked sweets. As the severity of disability increased, the percentage of children asking for sweets decreased. In the contrary, parents or caregivers offered sweets as a reward to children for behavior control increased especially those with profound disabilities (Tables 2 and 3). As previous study, our study also extremity apparently that children with mild or moderate disabilities, had less disadvantages and better manual dexterity (Martens et al., 2000). They can obtain sweets actively by themselves and more often. Since most of the foods, nutrients and sweets are offered by their parents and caregivers, if parents or caregivers did not control the frequency and type of taking sweets, their children’ teeth will be exposed in the high risk environment of caries (Tables 2 and 4). Liu et al. (2009) noticed that children with intellectual disability who brushed their own teeth completely by themselves had a statistically significantly higher number of DMFT index (2.96  3.45) and caries prevalence (74.55%) of the permanent dentition than those children whose teeth were brushed partially or totally by their parents/caregivers (1.90  2.82 and 1.83  2.96, 52.38% and 53.66%, respectively). Our study showed the same tendency that children with profound severity in disability had a higher percentage in teeth-brushing completely by parents/caregivers, and they had a better dental health, fewer caries prevalence, lower plaque index and healthy gingival. In contrast, children with mild/moderate severity in disability had a higher percentage in tooth-brushing by themselves and with poor dental health (Table 3). In this study, the tooth-brushing behavior of children cared by parents/caregivers showed better dental health, lesser dt + DT and deft + DMFT indices and caries prevalence than those children who cared by themselves (Table 2). This was in agreement with Liu et al. (2009) who reported that children with disabilities who brushed their teeth themselves had higher dt + DT and deft + DMFT indices, and caries prevalence, compared to those children brushed their teeth by parents/ caregivers. This could be associated with that teeth-brushing cared by parents/caregivers had higher percentage of low plaque index and healthy gingival tissue than children whose teeth-brushing were cared by themselves (Table 4). In this study, only 3.91% children did not brush teeth daily, 96.09% of children brush teeth more than once a time daily. These children did not brush teeth daily had very poor dental health status than those brushed their teeth daily. It is quite different from Gizani’s report in which a considerable percentage (22.1%) of mentally retarded children did not brush daily, while 91% did not receive assistance in tooth-brushing from their parents or caretakers. Gizani et al. (1997) concluded that poor oral hygiene existed in 31.8% of handicapped children. Lower frequency of brushing behavior had some impacts to

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dental health. Children with disabilities who brush their teeth occasionally or once per day had a higher percentage of bleeding gingival tissue which could leads to rapid development of periodontal diseases with tooth loss at young age (Kahabuka & Ndalahwa, 2006). As it is difficult to achieve proper brushing in intellectual disability children, brushing more than once per day with the assistance from parents or caretakers may serve a purpose towards attaining good oral hygiene of these children (Kahabuka & Ndalahwa, 2006). It is quite difficult to teach children with disabilities how to brush their properly and cleanly. In previous studies, higher frequency of gingivitis caused by the improper brushing way was reported to be happened in mentally retarded children than the general population (Pope & Curzon, 1991). Waldman showed that gingivitis was found in 37% among children with mental retardation in Kenya while dental plaque was found in all sites (Waldman, Swerdloff, & Perlman, 1999). In brushing teeth behavior, children with disabilities who brushed their teeth less than three times a day had higher dt + DT and dmft + DMFT indices, caries prevalence, and less ft + FT and filling rate as compared to those children with disabilities brushed their teeth more than three times a day (Table 3). In the present study, almost 40% of children who brushed their teeth by themselves had statistically significantly higher dt + DT and deft + DMFT indices and caries prevalence than those children brushed their teeth by their parents/caregivers (Table 2). The high caries prevalence may be explained by that those children with disability brushed their teeth themselves were without proper instruction, lacking supervision during tooth-brushing or check-up after tooth-brushing. Most children with intellectual disabilities are able to brush their teeth themselves and majority of those who cannot obtain the assistance in brushing (Kahabuka & Ndalahwa, 2006). In our study, more than 60% of children with disabilities brushed their teeth completely reliant on their parents or caregivers had better dental health condition compared to those who brush teeth by themselves. Those children with disability brushed their teeth themselves may have stronger willingness or more authority to brush their own teeth, but in fact, they still have some problems related to their manual dexterity, IQ, communication and cognition. Also they did not have enough education about how to brush teeth sufficiently and properly, therefore could lead to higher caries prevalence and decayed teeth number. The higher the manual dexterity, the less brushing help is provided. Manual dexterity is adversely related to oral health as a whole. Self-sufficiency is certainly not a guarantee for better oral hygiene or lower caries experience. It was shown that the percentage of caries-free children was the lowest for mildly mental retarded children (Chiwata & Takeda, 2007; Martens et al., 2000). In our study, children who brushed their teeth more than twice a day comprised two-thirds of the sample. The normal children in Taiwan at a comparative age brushed their teeth at same frequency were more than three quarters (Chen & Huang, 2007). A similar percentage of the same teeth-brushing frequency of children with disabilities or normal children means that most children, either with disabilities or normal, brush their teeth quite often and regularly. But a higher percentage of the children with profound disabilities brushed their teeth at sometimes or completely dependent on their parents or caregivers greatly reflected the severity of disability lead to their disadvantages in oral health. Although the frequency of tooth-brushing by children with disabilities is so often, parents and caregivers do not seem to help their children brush their teeth after taking sweets. In fact, the knowledge, attitudes, and daily practices of surrounding persons such as parents, caregivers, and members of family at home will highly influence the outcome of oral care for children with disabilities. Another study emphasized that the behavior of family and institutions towards people with physical and psychological handicaps is very important in order to make a project of primary prevention successful (Santoro, Maiorana, Galletta, Novi, & Pavanello, 1991). Shaw et al. (1986) also mentioned that severely intellectually handicapped children can be instructed in oral hygiene and can carry out tooth-brushing procedures for themselves if they were encouraged and motivated by parents and school staff. The results of our present study and the findings of other investigators (Martens et al., 2000; Nunn, 1987; Shaw et al., 1986) indicated a correlation between the level of oral hygiene and the severity of the disability. Manual dexterity is an important factor in reaching optimal oral hygiene that reflected by the child’s motor skills. From our results, the dexterity tests correlated significantly with plaque scores (Felder, James, Brown, Lemon, & Reveal, 1994). However, the higher the manual dexterity, the less brushing help is provided. Indirectly, the manual dexterity became a related-factor of tooth decayed. 5. Conclusions Our results revealed that children with disabilities had poor oral health characterized by very high decayed teeth and low filled teeth. Based on regression analysis, the risk factors related to decayed teeth of children with disabilities were frequency of sweets intake, ability to brush teeth and with plaque or not. The dental health education concerning toothbrushing skill, dietary behavior and prevention program to the parents of children with disabilities should be reinforced, and brushing skill should be taught to children with disabilities according to their type, severity and individual’s characteristics of disability. Acknowledgements The authors gratefully acknowledge the dentists from Tomlin children’s dental clinic and Dada clinics, nurses of special schools, children and their parents for their cordial help, participation and cooperation. This project was funded by the Bureau of Health Promotion, Department of Health, Taiwan.

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