Chronic gingivitis, a nonspecific inflammatory reaction to dental biofilm bacterial challenge, is the most common oral health problem worldwide in both adults and children. While the disease is largely reversible in nature, it can develop in susceptible hosts into periodontitis, which is characterized by irreversible loss of periodontal attachment [
Epidemiological data on gingivitis in children are important for understanding the natural course of the disease, identifying its risk factors, and predicting its time trends [
Yemen is a poor developing country located South-West of Arabian Peninsula to Kingdom of Saudi Arabia. The country has twenty governorates distributed across four geographical zones that significantly vary with respect to cultural practices, social structure, and livelihood: the highland zone, the western coastal zone (Tehama), the southern coastal zone, and the eastern plateau [
Yemen has a total population of around 23 million with children under the age of 15 years making up 43%. However, these do not have access to primary dental healthcare and are not being targeted by any dental educational/preventive programs. Baseline data on oral health status itself are sparse. In a previous study limited to Sana’a city, the capital of the country, we assessed plaque and calculus accumulation and gingival inflammation in a sample of 1489, 6–14-year-old children, revealing gingivitis in 100% of the subjects [
This study was approved by the Ethical Committee of the Deanship of Scientific Research at Khartoum University. Permission to carry on the study was obtained from the Ministry of Education in Yemen as well as authorities of each of the sampled schools. In addition, informed consent was obtained from parents for kindergarten children.
The study was conducted during the period between April 2003 and October 2005 in five Yemeni governorates: Sana’a, Taiz, Hodeida, Hadramaut, and Hajjah. These were nonrandomly selected to represent the country’s geographical zones and according to population density. The five governorates are heterogeneous with respect to culture, social structure, and livelihood [
The population of the five selected governorates represents around 50% the total population of Yemen; they contain around 50% of the 12-year-old (sixth grade) school children and about 90% of the 5-year-old private kindergarten children [
Aiming at a sample size of at least 5000 subjects as recommended by WHO’s World Health Survey (WHS) [
No 5-year-old children were included from Hajjah, because there were no kindergartens in the whole governorate. Children were randomly selected from one class in each school (grade six for the 12-year olds). Age was confirmed by checking school records. Eventually, a total of 5396 children (4104 of 12 years and 1292 of 5 years) were recruited from 105 public primary schools and 52 private kindergartens. Their distribution by governorate, age group, gender, and area of residence is shown in Table
Distribution of the sample by governorate, age, gender, and area of residence.
Governorate | |||||
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Sana'a |
Taiz |
Hodeida |
Hajjah |
Hadramaut |
|
Age | |||||
5 years ( |
456 (35.3) | 456 (35.3) | 152 (11.8) | 000 (00.0) | 228 (17.6) |
12 years ( |
1216 (29.6) | 836 (20.4) | 684 (16.7) | 684 (16.7) | 684 (16.7) |
Total ( |
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|
|
|
|
Gender | |||||
Male ( |
836 (31.0) | 646 (23.9) | 418 (15.5) | 342 (12.7) | 456 (16.9) |
Female ( |
836 (31.0) | 646 (23.9) | 418 (15.5) | 342 (12.7) | 456 (16.9) |
Total ( |
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|
|
|
|
Area of residence (for 12 years) | |||||
Urban ( |
608 (40.0) | 228 (15.0) | 228 (15.0) | 228 (15.0) | 228 (15.0) |
Rural ( |
304 (23.5) | 304 (23.5) | 228 (17.6) | 228 (17.6) | 228 (17.6) |
Periurban ( |
304 (23.5) | 304 (23.5) | 228 (17.6) | 228 (17.6) | 228 (17.6) |
Total ( |
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Subjects with ongoing or previous orthodontic treatment, under current or previous periodontal treatment, or with history of diabetes, any syndrome, immunosuppression, or intake of immunosuppressive medications were excluded from the study.
Clinically, each child’s periodontal status was assessed using the plaque index (PI) according to Silness and Loe [
The examiner performed measurements of the clinical parameters (PI, CAI, and GI) for 20 subjects on 2 occasions two weeks apart. Intraexaminer variation (differences in mean PI, CAI, and GI between the two occasions) was assessed using paired
Data were summarized as means ± SD or percentages as appropriate. Significance of differences in clinical parameters by governorate, age group, gender, and area of residence was sought using independent Student’s
The PI and CAI scores, stratified by relevant factors for each age group separately, are shown in Tables
Mean ± SD plaque, gingival, and calculus indices for the 5-year-old age group by gender and governorate.
Plaque index | Calculus index | Gingival index | |
---|---|---|---|
Gender | |||
Male ( |
0.34 ± 0.46 | 0.00 ± 0.00 | 0.22 ± 0.02 |
Female ( |
0.35 ± 0.48 | 0.00 ± 0.01 | 0.17 ± 0.01 |
Total ( |
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Governorate | |||
Sana'a ( |
0.51 ± 0.47 | 0.00 ± 0.10 | 0.39 ± 0.49 |
Taiz ( |
0.11 ± 0.28 | 0.00 ± 0.00 | 0.06 ± 0.20 |
Hodeida ( |
0.35 ± 0.50 | 0.00 ± 0.00 | 0.11 ± 0.28 |
Hadramaut ( |
0.50 ± 0.57 | 0.00 ± 0.00 | 0.13 ± 0.33 |
Total ( |
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Mean ± SD plaque, gingival, and calculus indices for the 12-year-old age group by gender, area of residence, and governorate.
Plaque index | Calculus index | Gingival index | |
---|---|---|---|
Gender | |||
Male ( |
1.17 ± 0.60 | 0.09 ± 0.18 | 1.03 ± 0.64 |
Female ( |
1.06 ± 0.49 | 0.04 ± 0.13 | 0.91 ± 0.62 |
Total ( |
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Area of residence (for 12 years) | |||
Urban ( |
1.12 ± 0.53 | 0.07 ± 0.19 | 1.01 ± 0.56 |
Rural ( |
1.19 ± 0.54 | 0.07 ± 0.15 | 1.02 ± 0.69 |
Periurban ( |
1.04 ± 0.57 | 0.05 ± 0.14 | 0.88 ± 0.65 |
Total ( |
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Governorate | |||
Sana'a ( |
1.26 ± 0.49 | 0.03 ± 0.12 | 1.38 ± 0.31 |
Taiz ( |
0.71 ± 0.56 | 0.02 ± 0.08 | 0.54 ± 0.59 |
Hodeida ( |
1.01 ± 0.67 | 0.10 ± 0.20 | 0.61 ± 0.63 |
Hajjah ( |
1.33 ± 0.34 | 0.04 ± 0.11 | 1.43 ± 0.31 |
Hadramaut ( |
1.25 ± 0.69 | 0.16 ± 0.25 | 0.69 ± 0.63 |
Total ( |
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Governorate-wise, the 12-year olds of Hajjah had the highest PI scores followed by those of Sana’a and Hadramaut, then Hodeida, finally Taiz. CAI, however, showed the highest mean in Hadramaut followed by Hodeida, then Hajjah and Sana’a, and finally Taiz. With the exclusion of Hajjah, similar pattern was seen for the 5-year old children with respect to the mean PI, but there were no significant differences in CAI.
The mean GI and categorical gingival status are presented in Tables
Level of gingival inflammation in the 5-year olds by gender and governorate.
None |
Mild |
Moderate |
Severe |
|
---|---|---|---|---|
Gender | ||||
Male ( |
455 (70.4) | 173 (26.8) | 18 (2.8) | 0 (0.0%) |
Female ( |
485 (75.1) | 139 (22.5) | 22 (3.4) | 0 (0.0%) |
Total ( |
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|||
Governorate | ||||
Sana'a ( |
221 (48.5) | 195 (42.8) | 40 (8.8) | 0 (0.0%) |
Taiz ( |
400 (87.7) | 56 (12.3) | 0 (0.0) | 0 (0.0%) |
Hodeida ( |
126 (82.9) | 26 (17.1) | 0 (0.0) | 0 (0.0%) |
Hadramaut ( |
193 (84.6) | 35 (15.4) | 0 (0.0) | 0 (0.0%) |
Total ( |
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Level of gingival inflammation in the 12-year olds by gender, area of residence, and governorate.
None |
Mild |
Moderate |
Severe |
|
---|---|---|---|---|
Gender | ||||
Male ( |
367 (17.9) | 625 (30.5) | 1059 (51.6) | 1 (0.00%) |
Female ( |
513 (25.0) | 635 (30.9) | 904 (44.1) | 0 (0.00%) |
Total ( |
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Area of residence (for 12 years) | ||||
Urban ( |
239 (15.7) | 487 (32.0) | 794 (52.2) | 0 (0.00%) |
Rural ( |
301 (23.3) | 349 (27.0) | 641 (49.9) | 1 (0.00%) |
Periurban ( |
340 (26.3) | 424 (32.8) | 528 (40.9) | 0 (0.00%) |
Total ( |
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Governorate | ||||
Sana'a ( |
0 (0.0) | 129 (10.6) | 1086 (89.3) | 1 (0.01%) |
Taiz ( |
392 (46.9) | 351 (42.0) | 93 (11.1) | 0 (0.0%) |
Hodeida ( |
269 (39.3) | 339 (49.6) | 76 (11.1) | 0 (0.0%) |
Hajjah ( |
0 (0.0) | 52 (7.6) | 632 (92.4) | 0 (0.0%) |
Hadramaut ( |
219 (32.0) | 389 (56.9) | 76 (11.1) | 0 (0.0%) |
Total ( |
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The 12-year olds from Hajjah and Sana’a demonstrated the highest GI means and rates of moderate gingivitis (around 90%). In comparison, the rates did not exceed 11% in other governorates. In the 5-year olds, there were significant differences among the governorates in mean GI, with Sana’a ranking first and Taiz last; however, moderate gingivitis was observed only in Sana’a (in 9%).
In the 12-year-old children, independent risk factors of gingivitis severity were mean PI (OR = 35; CI: 27–45), mean CAI (OR = 7.7; CI: 4.4–13.8), male gender (OR = 1.6; CI: 1.3–1.9), living in rural areas (OR = 1.4; CI: 1.1–1.7), and being from Hajjah (OR = 589; CI: 338–668) or Sana’a (OR = 493; CI: 381–875) in comparison with being from Hadramaut. For the 5-year olds, the determinants were mean PI (OR = 122; CI: 76–208), the male gender (OR = 1.4; CI: 1.0–2.0), and living in Sana’a (OR = 47; CI: 25–85) or Taiz (OR = 17; CI: 8.3–34) in contrast with being from Hadramaut.
To the best of our knowledge, this is probably the first country-wide survey to assess oral hygiene and gingival health status among Yemeni preschool and school children. The work was driven by the need for baseline data that highlight the magnitude of the problem and can be used to mobilize authorities towards introducing primary dental healthcare service for children across the country. The indices used are simple, non-time consuming, and easy to use and have proven validity [
The PI mean was 0.34 for the 5-year-old children and 1.12 for the 12-year-old children. The latter is comparable to findings from a previous study conducted on 6–14-year children in Sana’a [
Plaque-induced gingivitis is almost a universal finding in children. It begins with primary dentition and reaches a pick around puberty [
Indeed, the regression analysis in the current study demonstrates clearly that in addition to plaque and calculus accumulation, gender, and level of urbanization as classical risk factors of gingivitis, geographical location also acted as an independent determinant, which provides some sort of evidence for ethnic and possibly genetic variations. Prevalence/severity of poverty did not seem to account for any of the observed intergovernorate variation.
Overall, Yemeni preschool and school children suffer from bad oral hygiene and high prevalence of moderate gingivitis, particularly in the older age group. Certain geographical areas of high risk were identified. These findings should drive future research and be used as a basis for planning national preventive program.
The authors declare that they have no conflict of interests.
Khalid A. Al-Haddad, as the principle investigator, was involved throughout the study. He made all data collection, entry, analysis, and presentation and wrote the first draft of the paper. Yahia T. Ibrahim and Ahmed M. Al-Haddad were involved in the study design, supervised its execution throughout, and helped with data analysis and presentation. Nezar N. Al-Hebshi provided guidance on writing the first draft, performed the advanced statistical analysis, and wrote the second version of the paper.
The authors wish to thank Sana’a University for financially supporting the present study. Special thanks are due to school children and their parents, authorities of schools and kindergartens, and Ministry of Education in Yemen for facilitating data collection.