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Developmental Enamel Defects and Their with Dental Caries in Preschoolers in Saudi Arabia
pyrig ORIGINALoARTICLE N ot C for Pu bli cat ion Association te Jeddah, sse nc e
Najat Farsia
Purpose: The aim of the present study was to examine the prevalence, severity and association of developmental enamel defects (DED) and dental caries in a sample of 4- and 5-year-old children living in Jeddah, Saudi Arabia. Methods: A total of 510 children were examined in nursery schools using a penlight, a mouth mirror and a CPI probe. Dental defects were described using the modified DED index, the caries were described using the decayed, missing and filled teeth (DMFT) index. Results: The prevalence of DED of any type was 45.4%, with that of demarcated opacities being the highest, followed by hypoplasia. The most frequently affected teeth were maxillary anterior teeth, while the least affected teeth were mandibular incisors. The mean DMFT was 3.9. A positive association between DED and caries was observed. Conclusions: The prevalence of enamel defects and caries was high, as the enamel defects were strongly associated with caries; therefore, this association must be considered when focusing on the prevalence of caries in the Saudi community. Key words: caries, developmental enamel defects, hypoplasia, opacities, primary dentition Oral Health Prev Dent 2010; 8: 85–92.
ooth enamel is the only hard tissue in the body that is not remodelled. As a result, all of the changes in the structure caused by insults during its development are permanently registered. Developmental enamel defects (DED) have an important clinical significance as they affect tooth sensitivity, tooth wear, aesthetics and dentofacial anomalies. Enamel defects may also provide valuable clues about a child’s early environment and may be predictive of similar disturbances in the permanent dentition (Seow, 1991).
T
a
Department of Preventive Dental Sciences, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia.
Correspondence: Dr Najat Farsi, Department of Preventive Dental Sciences, Faculty of Dentistry, King Abdulaziz University, PO Box 80209, Jeddah 21089, Saudi Arabia. Tel: +966 2 640 3443 ext 22136. Fax: +966 2 640 4048. Email:
[email protected]
Vol 8, No 1, 2010
Submitted for publication: 28.06.08; accepted for publication: 31.10.08.
The prevalence rates of DED in primary dentition range from 23% to 52% (Table 1) depending on the population studied, teeth examined and diagnostic criteria used. The association between dental caries and DED has been investigated in several studies (Kanchanakamol et al, 1996; Montero et al, 2003; Mackay and Thomson, 2005; Oliveira et al, 2006). The abnormal structure and morphology of the affected teeth may cause the initiation and progression of caries. Several studies have corroborated this relationship and reported the increased susceptibility of teeth with enamel defects to dental caries, suggesting that enamel hypoplasia might be a significant caries risk factor (Clarkson, 1989; Montero et al, 2003; Lunardelli and Peres, 2005). Several indices have been introduced to measure the enamel defects. The earlier indices were specific fluorosis indices that rested on the assumption that 85
England USA China Thailand Central Saudi Arabia USA USA New Zealand Brazil Brazil Western Saudi Arabia
enamel defects resulting from an excessive fluoride intake could be differentiated clinically from nonfluoride defects. The difficulty in this differentiation and classification led to the development of the second group of indices, the descriptive indices. Since these indices were based on the clinical appearance, no aetiology could be ascribed to the defect (Clarkson, 1989). The Federation Dentaire Internationale (FDI) introduced a descriptive index, the developmental enamel defect index (DED Index) (Commission on Oral Health, Research & Epidemiology, 1982). In its original form, it was time consuming, and the presentation of results and the interpretation of data were complicated, so a modified version was subsequently introduced (Clarkson and O’Mullane, 1989). The modified DED index, which is more practical in the field and more amenable to data collection and analysis, has been a useful tool in several studies and facilitated a comparison of their results. To investigate the studies on DED among the Saudi children, a literature review was carried out on the Medline database, covering the period from 1966 to 2007 and using a combination of the following MeSH terms: enamel, defect, developmental, primary, prevalence and Saudi Arabia. The review revealed that only one study has been conducted on this topic. The study, conducted in 1998 by Rugg-Gunn et al (1998) assessed the developmental defects in the enamel of primary dentition in Riyadh, Saudi Arabia. They reported the prevalence of DED among 390 boys of ages 2, 4 and 6 years using the DDE index. The prevalence of enamel hypoplasia and enamel opacities was 15% and 12%, respectively (Rugg-Gunn et al, 1998). 86
Age (years)
DED (% %)
303 300 1344 344 390 boys 698 517 436 431 228 510
3 3–6 3–5 1–4 2–6 4–5 3–5 9–10 3–5 3 4–5
33 33 24 23 – – 49 52 24 25 45
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Murray and Shaw (1979) Nation et al (1987) Li et al (1995) Kanchanakamol et al (1996) Rugg-Gunn et al (1998) Slayton et al (2001) Montero et al (2003) Mackay and Thomson (2005) Lunardelli and Peres (2005) Oliveira et al (2006) Present study
Sample size
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Country
n
Author (year)
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Table 1 Prevalence of DED of primary dentition in different populations
pyrig No Co t fo rP ub lica Enameltio Enamel te opacity n hypoplasia ss e n c e (% (% %) %) 4 21 22 23 15 6 – 6 11 – 20
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Farsi
33 12 2 9 12 27 – 39 18 – 31
The present study aimed to investigate the prevalence of DED and their association with dental caries in primary teeth of preschool children in Jeddah, Saudi Arabia.
MATERIALS AND METHODS Sampling procedure The present study was carried out in the municipality of Jeddah, the main city located on the west coast of Saudi Arabia. The study was approved by the Ethical Committee of the Department of Preventive Dental Sciences at King Abdulaziz University in Jeddah. A sample of children was drawn from 4- and 5-year-olds attending nursery schools in Jeddah. The sample size was determined using published tables that provided the sample size for given combinations of precision, confidence levels (CLs) and variability (Israel, 2007). The needed sample size for ±5% precision level was 385 for a CL of 95% and a P value of 0.05. The total number of children attending the preschools in Jeddah was 12,159, with 1954 children in public schools and 10,205 children in private schools. The preschools were stratified according to the funding source (private or public) and geographic location (east, centre, north or south). Eight preschools were selected: one private and one public school from each of the geographical areas of the city. All of the children who were 4 and 5 years old and who were present at the schools on the day of examinations with a signed consent form were considered eligible to take part in the study. Excluded from the study Oral Health & Preventive Dentistry
Vol 8, No 1, 2010
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Colour photographs showing typical examples of the different types of enamel defects are presented in the WHO manual (WHO, 1997). These photographs were used as a guide in scoring the teeth for DED. Buccal surfaces, that is from the incisal edges or cuspal points to the gingiva from the mesial to the distal embrasure, were inspected visually for defects and, if there was any doubt, areas such as hypoplastic pits were checked with the periodontal probe to confirm the diagnosis. Any gross plaque or food deposits were removed and the teeth were examined in a wet condition. If there was any doubt about the presence of an abnormality, the tooth surface was scored as ‘normal’. Similarly, a tooth surface with a single abnormality < 1 mm in diameter was scored as ‘normal’. Any abnormality that could not be readily
ot
0. normal 1. demarcated opacity 2. diffuse opacity 3. hypoplasia 4. other defects 5. demarcated and diffuse opacities 6. diffuse opacity and hypoplasia 7. demarcated opacity and hypoplasia 8. all three conditions.
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Children were examined by two calibrated examiners for the presence of DED and dental caries. Before commencing the main study, 20 children were examined in duplicate, and the intra- and interexaminer agreement was high (j > 0.8). The clinical examinations were conducted in the nursery school under penlight. The teeth were evaluated for the presence of enamel defects and dental caries using a mouth mirror and a CPI probe. The buccal surfaces of all primary teeth were assessed for the presence or absence of DED using the World Health Organization (WHO) criteria mentioned in the Oral Health Survey Basic Methods manual of the WHO. The WHO uses the modified DED Index (WHO, 1997). Codes of enamel surfaces were classified into one of the following categories:
n
Clinical examination
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were children who had refused to take up the dental examination. A total of 510 children were examined, of whom 175 were from public schools and 335 were from private schools.
pyrig No Co Farsi t fo r P was classified into one of the three basic types u scored as ‘other defects’. A tooth was regardedblas ica present once any part of it had penetrated the tion te erupted mucosa, and any abnormality present on the ss e n c e portion was recorded. If more than two-thirds of a tooth surface was heavily restored, badly decayed or fractured, it was not examined. The child was recorded as DED present if he/she had at least one tooth with any type of enamel defect. The child having at least one tooth with demarcated or diffuse opacity was reported as a case of opacity. The presence of hypoplasia in at least one tooth was recorded as a case of hypoplasia. With regard to dental caries, an examination was conducted using the decayed, missing and filled teeth (DMFT) index according to WHO diagnostic criteria (WHO, 1997). For the purpose of training and calibration, a pilot study was carried out on 20 children who were not involved in the main study. These children were examined using colour photographs showing examples of enamel defects. Examinations in duplicate were conducted using the kappa statistic to check the diagnostic reliability of the examiners. All data management and analysis were performed using the SPSS statistical program (version 10). The prevalence of enamel defects was calculated with a respective confidence interval (CI) of 95% and with respect to the distribution of the defect by arch, teeth and type of defect. Statistical significance for differences between proportions was assessed using the chi-square test. The association between DED and dental caries was assessed using chi-square and t tests. P values < 0.05 were considered to be statistically significant.
RESULTS A total of 510 eligible children (204 males and 306 females) with ages of 4 and 5 years were examined. The prevalence of enamel defects observed was 45.4%. The data in Table 2 show the frequency distribution of enamel defects according to demographics and school-type status. The prevalence of enamel defects was 47.1% for males and 44.4% for females, but this difference was not statistically significant. A significant difference (P = 0.025) was detected when DED was analysed with respect to the age of the examined children. The older the child, the lower the prevalence of DED. Children in public schools seemed to be more commonly affected by DED than those in private schools, but this difference was not 87
12.7
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% DED
10 8 6
7.1
7.3
53
52
8.4
6.1
6.7
6.9
63
64
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12.0
12
n
14
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Maxillary Teeth
by N ht
pyrig No Co t fo rP ub lica tio n te ss e n c e
Farsi
7.3
4.7
4 2 0 55
54
51
61
62
65
Mandibular Teeth 14
% DED
12 10 8 6
8.4
7.8
6.7
5.9 4.1
4
3.9
2
1.2
1.8
1.2
72
71
81
0.8
0 75
74
73
82
83
significant. Opacities, either demarcated or diffuse, were present in 31% and hypoplasia in 20.2% of the sample. Hypoplasia was observed more frequently in the younger age group. The data in Figure 1 show the frequency distribution of primary teeth that were affected by DED. The most frequently affected teeth were the maxillary incisors followed by the maxillary and mandibular canines. The least frequently affected teeth were mandibular incisors. A total of 10,086 teeth were examined. The data in Table 3 show the distribution of each type of enamel defect among the examined teeth. Demarcated opacities were the defects most frequently found in the examined teeth (2.4%), followed by enamel hypoplasia in 2.3% and diffuse opacities in 1%, which were more frequent than combined defects. The teeth most frequently affected by demarcated opacities were mandibular canines. Diffuse opacity and enamel hypoplasia were recorded mostly in maxillary central incisors. The mean DMFT score of the children was 3.99 and ranged from 3.73 in 4-year-olds to 4.13 in 5-year-old children. A significant association between enamel defects and caries was observed in the 88
84
85
Fig 1 Frequency distribution of primary teeth affected by DED.
present study (Table 4). Children with enamel defects had a higher caries prevalence and mean DMFT score than those without defects. The differences were highly significant in both sexes and age groups.
DISCUSSION Epidemiological studies on the prevalence of DED in primary dentition exhibit a wide variability in the prevalence rates. A comparison of the findings in the present study with those in similar studies must be done carefully due to the difference in population, environmental influences and methods of reporting, such as the index and criteria used in the examination. Studies can differ on several aspects: for example, whether only hypoplasia was considered as a defect of the enamel or whether enamel opacities were also considered; whether only the anterior teeth, only the canines or the whole dentition were examined; the type of illumination employed for the examination; and whether, prior to the examination, brushing, prophylaxis and drying of the teeth were carried out or not. Oral Health & Preventive Dentistry
44.8 46.9
150 82
232
Total (510)
0.361
0.025
0.312
Total
Maxillary Central Lateral Canine First molar Second molar Mandibular Central Lateral Canine First molar Second molar
9471
1005 1010 933 952 933
1020 1020 1018 990 997
10,086
874 934 949 943 938
n
Normal
1000 1014 1019 1002 1006
n
Total
93.9
98.5 99 91.7 96.2 93.6
87.4 92.1 93.1 94.1 93.2
%
246
2 6 59 15 29
28 16 36 22 33
n
2.4
0.2 0.6 5.8 1.5 2.9
2.8 1.6 3.5 2.2 3.3
%
Demarcated opacity
99
3 1 1 4 5
42 18 7 7 11
n
1
0.3 0.1 0.1 0.4 0.5
4.2 1.8 0.7 0.7 1.1
%
Opacities
Diffuse opacity
158
105 53
60 98
69 89
n
Table 3 Percentage of enamel defects for each tooth type among the sample
P value using chi-square test.
51.7 42.2
92 140
45.4
47.1 44.4
96 136
%
Gender Male (204) Female (306) Age (years) 4 (178) 5 (332) School type Private (335) Public (175)
n
P value
31
10 3 21 18 26
43 39 21 28 21
n
0.15
0.444
0.191
2.3
1 0.3 2.1 1.8 2.6
4.3 3.8 2.1 2.8 2.1
%
Enamel hypoplasia
230
31.3 30.3
33.7 29.5
33.8 29.1
%
P value
3
0 0 0 0 0
3 0 0 0 0
n
0
0 0 0 0 0
0.3 0 0 0 0
%
Demarcated and diffuse opacity
103
64 39
46 57
49 54
n
20.2
19.1 22.3
25.8 17.2
24 17.6
%
21
0 0 2 0 4
7 3 2 2 1
n
0.2
0 0 0 0 0
0.7 0 0 0 0
%
Demarcated opacity and hypoplasia
Hypoplasia
16
0 0 2 1 0
3 4 4 0 2
n
0.231
0.014
0.056
P value
0.2
0 0 0 0 0
0 0 0 0 0
%
Diffuse opacity and hypoplasia
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DED
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Table 2 Frequency distribution of DED according to demographics and school-type status
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Vol 8, No 1, 2010
pyrig No Co Farsi t fo rP ub lica tio n te ss e n c e
89
Caries present
P value*
by N ht
Enamel defects
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Table 4 Comparison of caries in children with and without enamel defects
pyrig No Co t fo rP ub lica DMFT (mean) P value**tio n te ss e n c e n
Gender Male Female Age (years) 4 5 Total
fo r
%
n Present (96) Absent (108) Present (136) Absent (170)
75 61 99 95
78.1 56.5 72.8 55.9
0.001
Present (92) Absent (86) Present (140) Absent (192)
65 44 109 112
70.7 51.2 77.9 58.3
0.008
Present (232) Absent (278)
174 58
75.4 20.9
0.002
0.000 0.000
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5.55 3.74 4.51 2.85
0.007
4.82 2.57 5.02 3.47
0.001
4.94 3.19
0.000
0.001 0.000
*Chi-square test; **t test.
In the present study, the prevalence of children with DED on at least one tooth was 45%, which falls within the upper end of the range seen in other studies (Table 1). In previous studies, the populations with the lowest prevalence were from China (Li et al, 1995), Thailand (Kanchanakamol et al, 1996) and Brazil (Lunardelli and Peres, 2005; Oliveira et al, 2006). A higher prevalence of DED that could reach 98% was reported among children from New Zealand (Mackay and Thomson, 2005), as well as in aboriginal children (Pascoe and Seow, 1994) and children with chronic malnutrition (Li et al, 1996) or chronic diseases (Avsar and Kalayci, 2008; Kusiak et al, 2008). The lack of differences in the prevalence of DED between genders is in agreement with most similar studies (Needleman et al, 1991; Slayton et al, 2001), but is in contrast to the results of Li et al (1995) who reported the prevalence of DED to be higher among males. Reduction in the prevalence of DED in the older age group could be due to the occurrence of decay in the affected teeth. The changes in tooth appearance resulting from caries destruction may make pre-existing enamel defects difficult to diagnose. In addition, the older the children, the greater the possibility that defective teeth are treated by stainless steel crowns or extraction. A study carried out by Lunardelli and Peres (2006) also reported the same relationship of DED to age. Similar to most other studies (Slayton et al, 2001; Mackay and Thomson, 2005; Lunardelli and Peres, 2005), opacities were more prevalent than hypoplasia. It was reported that the women who gave 90
birth before the age of 20 years are more likely to have children with enamel opacities, but not with enamel hypoplasia (Slayton et al, 2001). In Saudi Arabia, there is a common practice for women to get married and give birth before the age of 20 years. This could explain the higher prevalence of enamel opacities in the present sample. The tooth defects that were more prevalent in the maxilla than in the mandible and tended to present bilaterally support the hypothesis of the influence of time-dependent systemic factors on the aetiology of these defects (Li et al, 1995). The teeth most frequently affected by defects were the maxillary incisors, while the mandibular incisors were the least frequently affected. This finding agrees with those of other studies (Li et al, 1995; Aine et al, 2000; Lunardelli and Peres, 2005). In a certain anatomic location, such as anterior teeth, it has been suggested that enamel defects could be caused by minor physical trauma to the face such as mouthing of objects by infants (Skinner and Hung, 1989) or from intubation of premature infants (Fadavi et al, 1992). Goodman and Armelagos (1985) suggested that morphological factors, such as enamel prism length and direction, might, in addition to chronological development, affect the distribution of enamel defects. In agreement with the suggestions of Goodman and Armelagos (1985), the thickness of enamel might explain the results of the present study as developmental defects were most commonly observed on the maxillary anterior teeth. The primary Oral Health & Preventive Dentistry
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Vol 8, No 1, 2010
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• DED were prevalent in primary dentition, with most defects located on maxillary anterior teeth.
n
CONCLUSIONS
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maxillary anterior teeth have thicker enamel than their mandibular counterparts. Mandibular primary anterior teeth have the thinnest enamel and are usually worn significantly, precluding the observation of enamel defects in many instances. Among the 10,086 examined teeth, only 6.1% had enamel defects of any type. The frequency of enamel defects observed for each tooth type is less than that observed in previous reports (Li et al, 1995; Lunardelli and Peres, 2005). Among the different types of defects examined; demarcated opacities were those most commonly found in primary teeth. These findings are similar to those reported by Slayton et al (2001) and Mackay and Thomson (2005). Enamel hypoplasia was found in 2.3% of the examined primary teeth. Needleman et al (1991) examined 509 exfoliated primary teeth and reported that 33.3% of the canines were affected by hypoplasia. Their findings are in sharp contrast to the present findings of 2.1% hypoplastic canines. Diffuse opacities were less frequently observed. This could be explained by the difficulty in observing the changes in colour in cases of diffuse opacities due to the white appearance of the enamel of primary teeth. Without a precise border, diffuse opacities cannot be distinguished from the adjacent normal enamel. In the present study, children with enamel defects had a significantly higher level of caries compared to those without enamel defects. This strong significant association between enamel defects and caries corroborates the findings of several other studies (Kanchanakamol et al, 1996; Montero et al, 2003; Lunardelli and Peres, 2005). These data support the hypothesis of Li et al (1994) that hypoplastic enamel permits the adherence of cariogenic bacteria, facilitating caries onset and progress. Seow (1991) suggested that enamel defects of any kind make the tooth less caries resistant due to the presence of imperfect enamel. The present study suggests that DED is a high risk factor associated with dental caries and highlights the importance of establishing priority programmes for prevention of DED and early treatment of children with DED for aesthetic function, thus minimising the risk of dental caries.
pyrig No Co Farsi t fo • The most prevalent enamel defect wasr P demarub lica cated opacity. tio • The presence of enamel defects was associated n te ss e n c e with increased caries. • The results of the present study provided further insight into the reasons for the susceptibility of Saudi children to high dental caries.
ACKNOWLEDGEMENTS The author acknowledges the help of Dr Leena Merdad in data collection and Dr Suliman Merdad in data analysis. The present study was supported by the Scientific Research Council, King Abdulaziz University Grant No. 428-053.
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