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Survey on Dental Caries Experience of Students in Vientiane Province, Laos
Int J Clin Prev Dent 2023;19(4):86-93
Published online December 31, 2023;  https://doi.org/10.15236/ijcpd.2023.19.4.86
© 2023 International Journal of Clinical Preventive Dentistry.

Sun-Gil Park1, Ja-Won Cho1, Hyun-Jun Yoo1, Phommavongsa Nitthasack2, Ji-Hyeon Park3

1Department of Preventive Dentistry, College of Dentistry, Dankook University, Cheonan, Korea, 2Department of Pediatric Dentistry, Faculty of Dentistry, University of Health Science, Vientiane, Laos, 3Department of Dental Hygiene, Gang Neung YeongDong College, Gangneung, Korea
Correspondence to: Ji-Hyeon Park
E-mail: dipriban@hanmail.net
https://orcid.org/0000-0001-7692-6377
Received December 15, 2023; Revised December 21, 2023; Accepted December 27, 2023.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Objective: The purpose of this study is to assess the prevalence of dental caries among students in the Vientiane area of Laos.
Methods: We conducted an analysis of the oral examination outcomes for a cohort of 344 children in Vientiane, including 121 in primary school, 138 in middle school, and 85 in high school, to evaluate the prevalence of dental caries in this group.
Results: For 12-year-olds, equivalent to the first year of middle school, the index of experienced decay in permanent teeth was 3.30, with a decayed permanent tooth surface index of 6.01. The rate of caries experience in permanent teeth was 86.13%, the decay rate in permanent teeth was 92.09%, the treatment rate for permanent teeth was 1.98%, and the caries fatality rate was determined to be 12.09%.
Conclusion: The prevalence of dental caries experience among most age groups was significantly higher compared to other regions, with a permanent tooth decay rate ranging from approximately 88% to 91%. Notably, the primary tooth decay rate was found to be around 99%, indicating an exceptionally high level. The dental caries fatality rate was also estimated to be in the range of 5% to 12%, underscoring the need for simultaneous preventive measures and treatment programs in Laos to halt the progression of dental caries and reduce the dental caries fatality rate.
Keywords : dental caries, decay rate, dental caries among students
Introduction

Oral health status surveys are very important for planning oral health programs and establishing oral health policies through the statistical analysis of oral conditions. Thus, many countries have attempted to survey the oral health status in national programs [1-3] as it serves as fundamental information for establishing oral health plans within a country [4,5].

The World Health Organization (WHO) collects data on caries from most countries worldwide, which is regularly published in books and formatted into databases [6,7]. However, recent data on the caries incidence in Laos have not been formally reported to WHO, though there have been efforts to investigate the caries status in some regions [8-13].

Lao PDR (Lao People’s Democratic Republic) is located in Southeast Asia and shares borders with China, Myanmar, Vietnam, Cambodia, and Thailand. Laos is a landlocked country with an estimated population of around 6,500,000 in 2012 [6,7].

One-third of the population in Laos lives below the international poverty line. Laos is one of the lowest wage countries in the world and has a low-income economy. In 2013, Laos ranked 138th in the Human Development Index (HDI) and was noted for its limited media. According to the Global Hunger Index (2013), Laos is among the worst in terms of hunger situations and was rated the 25th poorest country in the national list [14-16].

There are approximately 500 dentists in Laos, with an estimated 14,000 patients per dentist. In the capital, Vientiane, there are 137 private dental clinics, and in the other 16 provinces, there are 38 private dental clinics [17-19].

With this in mind, the author intends to survey the status of dental caries experience among children in the Vientiane province area as part of the research for implementing public oral health projects by the Lao government and to use it as baseline data for Laos’s public oral health business.

Materials and Methods

1. Study subjects

This study focused on children aged 6 in elementary schools, 12 in middle schools, and 15 in high schools in the Vientiane Province of Laos. The research differentiated between urban and rural areas, selecting respective elementary, middle, and high schools in each region based on recommendations from the Lao Dental Association and the Lao Ministry of Education. Students from these schools were then designated as the research participants (Table 1).

Table 1 . Age and gender distribution of study participants

AgeVientianeUrban areaRural area



TotalMaleFemaleTotalMaleFemaleTotalMaleFemale
Total344145198168709817575100
6-year-old1215269522131693138
12-year-old1385879743539632340
15-year-old853550 421428 432122


2. Methods

1) Composition of the research team

The research team consisted of a total of 13 individuals: 7 Korean dentists, 3 Laotian dentists, one individual for examination assistance and documentation, and two administrative personnel. Prior to the commencement of the survey, the team underwent training to unify and maintain consistent survey standards across all members.

2) Research schedule

The investigation took place over two sessions, and the timeline was as follows:

First phase (Urban region): February 4th, 2019

Second phase (Rural region): February 5th, 2019

3) Examination standards

The criteria for assessing the examined teeth are delineated as follows [20-23]:

0: Healthy teeth: No ongoing carious activity and no signs of previous caries treatment.

1: Decayed teeth: Presence of lesions with softened or exposed dentin.

3: Caries-experienced restored teeth: Teeth with permanent restorations without adjacent decay or with crowns placed due to caries.

4: Caries-related lost teeth: Permanent teeth extracted due to caries, including prosthetic teeth excluding the abutments.

5: Non-caries-related lost teeth: Permanent teeth lost due to non-caries causes (trauma, congenital absence, periodontal disease, orthodontic reasons) and excluded from caries-experienced count.

6: Sealed teeth: Teeth that have received fissure sealant treatment.

7: Non-caries-related restored teeth: Permanent teeth with crowns or bands for reasons other than caries (trauma, developmental issues, prosthetics, orthodontic treatments) and excluded from caries-experienced count.

8: Non-erupted teeth.

9: Non-recordable teeth.

4) Data analysis

Oral examination data were inputted using the statistical program EXCEL (Version 2016, Microsoft Inc, USA) and analyzed for descriptive statistics using SPSS version 24.0. For the 6-year-old elementary students, metrics such as the primary teeth decay and filling rate (df rate), primary decay and filling teeth index (dft index), primary decay and filling tooth surface index (dfs index), primary teeth decay rate (dt rate), and primary teeth filling rate (ft rate) were determined. For the 12-year-old middle and 15-year-old high school students, parameters like the permanent teeth decay, missing, and filling rate (DMF rate), permanent decay, missing, and filling teeth index (DMFT index), permanent decay, missing, and filling tooth surface index (DMFS index), permanent teeth decay rate (DT rate), and permanent teeth filling rate (FT rate) were also derived.

Results

1. Primary teeth caries experience among 6-year-old primary school students

The primary teeth caries experience among primary school students in the Vientiane region is presented in Table 2 and Table 3.

Table 2 . Primary teeth caries experience among vientiane primary school students (1)

IndexValueVientianeUrban areaRural area



TotalMaleFemaleTotalMaleFemaleTotalMaleFemale
stMean7.807.627.94 7.135.868.00 8.308.817.89
SD4.614.604.65 4.854.454.99 4.394.384.42
dtMean7.397.237.51 6.506.386.58 8.067.818.26
SD3.813.993.69 3.463.943.16 3.943.993.95
ftMean0.020.020.01 0.000.000.00 0.030.030.03
SD0.130.140.12 0.000.000.00 0.170.180.16
setMean0.000.000.00 0.000.000.00 0.000.000.00
SD0.000.000.00 0.000.000.00 0.000.000.00
utMean0.000.000.00 0.000.000.00 0.000.000.00
SD0.000.000.00 0.000.000.00 0.000.000.00
etMean1.401.291.49 1.250.951.45 1.521.521.53
SD2.632.342.85 2.091.242.50 2.992.853.14
dftMean7.407.257.52 6.506.386.58 8.097.848.29
SD3.824.033.68 3.463.943.16 3.964.053.92
df rate%95.8796.1595.65 94.2390.4896.77 97.10100.0094.74
dt rate%99.7899.7399.81 100.00100.00100.00 99.6499.5999.68
ft rate%0.220.270.19 0.000.000.00 0.360.410.32

st: number of sound primary teeth, dt: number of decayed primary teeth, ft: number of filled primary teeth due to caries, set: number of sealant treated primary teeth, ut: number of un-erupted primary teeth, et: number of primary teeth indicated for extraction, dft: number of decayed and filled primary teeth, df rate: primary teeth caries experience rate, dt rate: decay rate for primary teeth, ft rate: filling rate for primary teeth, SD: standard deviation.


Table 3 . Primary teeth caries experience among vientiane primary school students (2)

IndexValueVientianeUrban areaRural area



TotalMaleFemaleTotalMaleFemaleTotalMaleFemale
ssMean50.8849.9251.59 46.9242.0550.23 53.8655.2652.71
SD18.8218.4519.20 18.9115.9920.24 18.3218.3118.50
dsMean17.0616.4217.54 14.8113.7115.55 18.7518.2619.16
SD13.5313.2113.84 11.6711.1212.14 14.6414.3315.06
fsMean0.020.020.01 0.000.000.00 0.030.030.03
SD0.130.140.12 0.000.000.00 0.170.180.16
sesMean0.000.000.00 0.000.000.00 0.000.000.00
SD0.000.000.00 0.000.000.00 0.000.000.00
dfsMean17.0716.4417.55 14.8113.7115.55 18.7818.2919.18
SD13.5313.2413.83 11.6711.1212.14 14.6414.3815.03

ss: number of sound primary tooth surfaces, ds: number of decayed primary tooth surfaces, fs: number of filled primary tooth surfaces due to caries, ses: number of sealant treated primary tooth surfaces, dfs: number of decayed and filled primary tooth surfaces, SD: standard deviation.



2. Permanent teeth caries experience among 12-year-old middle school students

The permanent teeth caries experience among middle school students in the Vientiane region is presented in Table 4 and Table 5.

Table 4 . Permanent teeth caries experience among vientiane middle school students (1)

IndexValueVientianeUrban areaRural area



TotalMaleFemaleTotalMaleFemaleTotalMaleFemale
STMean20.8521.3420.49 21.0021.9420.15 20.6820.4320.83
SD3.863.584.07 4.063.674.25 3.683.303.91
DTMean3.042.833.18 2.962.713.18 3.113.003.18
SD2.392.102.60 2.512.122.83 2.272.112.38
FTMean0.070.050.08 0.040.030.05 0.100.090.10
SD0.420.290.50 0.260.170.32 0.560.420.63
MTMean0.200.120.25 0.150.030.26 0.250.260.25
SD0.560.420.65 0.540.170.72 0.590.620.59
ATMean0.010.000.03 0.000.000.00 0.030.000.05
SD0.170.000.23 0.000.000.00 0.250.000.32
SeTMean0.000.000.00 0.000.000.00 0.000.000.00
SD0.000.000.00 0.000.000.00 0.000.000.00
XTMean0.010.030.00 0.000.000.00 0.030.090.00
SD0.170.260.00 0.000.000.00 0.250.420.00
UTMean7.837.627.97 7.857.298.36 7.798.137.60
SD3.533.483.61 3.873.674.02 3.163.183.17
ITMean0.190.140.23 0.180.090.26 0.210.220.20
SD0.610.610.62 0.530.370.64 0.700.850.61
DMFTMean3.303.003.51 3.152.773.49 3.463.353.53
SD2.472.222.65 2.522.102.83 2.442.392.49
DMF rate%86.1384.4887.34 82.4380.0084.62 90.4891.3090.00
DT rate%92.0994.2590.61 93.9997.9491.18 89.9189.6190.07
FT rate%1.981.722.17 1.291.031.47 2.752.602.84
MT rate%5.934.027.22 4.721.037.35 7.347.797.09
Mortal rate%12.098.6214.44 10.304.1214.71 14.2214.2914.18

ST: number of sound permanent teeth, DT: number of decayed permanent teeth, FT: number of filled permanent teeth due to caries, MT: number of missing permanent teeth due to caries, AT: number of missing permanent teeth not due to caries, SeT: number of sealant treated permanent teeth, XT: number of permanent teeth with non-caries treatments, UT: number of un-erupted permanent teeth, IT: number of permanent teeth indicated for extraction, DMFT: number of decayed, missing, and filled permanent teeth, DMF rate: permanent teeth caries experience rate, DT rate: decay rate for permanent teeth, FT rate: filling rate for permanent teeth, MT rate: missing rate for permanent teeth due to caries, SD: standard deviation.


Table 5 . Permanent teeth caries experience among vientiane middle school students (2)

IndexValueVientianeUrban areaRural area



TotalMaleFemaleTotalMaleFemaleTotalMaleFemale
SSMean103.27105.09101.97 103.80107.37100.59 102.70101.61103.33
SD16.9616.2017.59 18.0517.0818.50 15.8614.4216.79
DSMean4.934.595.15 4.594.294.87 5.295.045.43
SD4.744.764.75 4.724.095.25 4.805.714.26
FSMean0.090.090.10 0.080.090.08 0.110.090.13
SD0.580.470.65 0.490.510.48 0.670.420.79
MSMean0.980.601.27 0.740.141.28 1.271.301.25
SD2.822.113.25 2.700.853.58 2.973.102.94
AFMean0.060.000.10 0.000.000.00 0.130.000.20
SD0.680.000.90 0.000.000.00 1.010.001.26
SeSMean0.000.000.00 0.000.000.00 0.000.000.00
SD0.000.000.00 0.000.000.00 0.000.000.00
XSMean0.010.030.00 0.000.000.00 0.030.090.00
SD0.170.260.00 0.000.000.00 0.250.420.00
USMean38.6537.6039.41 38.7836.1141.18 38.4839.8737.68
SD16.8616.4817.31 18.5017.5019.26 15.0214.8715.23
DMFSMean6.015.286.52 5.424.516.23 6.676.436.80
SD5.615.575.65 5.164.095.90 6.107.225.45

SS: number of sound permanent tooth surfaces, DS: number of decayed permanent tooth surfaces, FS: number of filled permanent tooth surfaces due to caries, MS: number of missing permanent tooth surfaces due to caries, AS: number of missing permanent tooth surfaces not due to caries, SeS: number of sealant treated permanent tooth surfaces, XS: number of permanent tooth surfaces with non-caries treatments, US: number of un-erupted permanent tooth surfaces, DMFS: number of decayed, missing, and filled permanent tooth surfaces, SD: standard deviation.



3. Permanent teeth caries experience among 15-year-old high school students

The permanent teeth caries experience among high school students in the Vientiane region is presented in Table 6 and Table 7.

Table 6 . Permanent teeth caries experience among vientiane high school students (1)

IndexValueVientianeUrban areaRural area



TotalMaleFemaleTotalMaleFemaleTotalMaleFemale
STMean22.8922.8622.92 22.4821.9322.75 23.3023.4823.14
SD4.204.424.09 4.725.284.49 3.643.753.60
DTMean4.404.434.38 4.935.364.71 3.883.813.95
SD4.034.373.81 4.595.184.34 3.373.753.05
FTMean0.510.370.60 0.500.570.46 0.510.240.77
SD1.150.971.26 1.111.400.96 1.200.541.57
MTMean0.080.110.06 0.120.140.11 0.050.100.00
SD0.320.320.31 0.400.360.42 0.210.300.00
ATMean0.000.000.00 0.000.000.00 0.000.000.00
SD0.000.000.00 0.000.000.00 0.000.000.00
SeTMean0.000.000.00 0.000.000.00 0.000.000.00
SD0.000.000.00 0.000.000.00 0.000.000.00
XTMean0.000.000.00 0.000.000.00 0.000.000.00
SD0.000.000.00 0.000.000.00 0.000.000.00
UTMean4.124.234.04 3.984.003.96 4.264.384.14
SD0.910.770.99 0.560.000.69 1.140.971.28
ITMean0.190.200.18 0.260.210.29 0.120.190.05
SD0.570.530.60 0.700.580.76 0.390.510.21
DMFTMean4.994.915.04 5.556.075.29 4.444.144.73
SD4.154.483.95 4.755.284.54 3.443.803.12
DMF rate%80.0077.1482.00 78.5778.5778.57 81.4076.1986.36
DT rate%88.2190.1286.90 88.8488.2489.19 87.4391.9583.65
FT rate%10.147.5611.90 9.019.418.78 11.525.7516.35
MT rate%1.652.331.19 2.152.352.03 1.052.300.00
Mortal rate%5.426.404.76 6.875.887.43 3.666.900.96

ST: number of sound permanent teeth, DT: number of decayed permanent teeth, FT: number of filled permanent teeth due to caries, MT: number of missing permanent teeth due to caries, AT: number of missing permanent teeth not due to caries, SeT: number of sealant treated permanent teeth, XT: number of permanent teeth with non-caries treatments, UT: number of un-erupted permanent teeth, IT: number of permanent teeth indicated for extraction, DMFT: number of decayed, missing, and filled permanent teeth, DMF rate: permanent teeth caries experience rate, DT rate: decay rate for permanent teeth, FT rate: filling rate for permanent teeth, MT rate: missing rate for permanent teeth due to caries, SD: standard deviation.


Table 7 . Permanent teeth caries experience among vientiane high school students (2)

IndexValueVientianeUrban areaRural area



TotalMaleFemaleTotalMaleFemaleTotalMaleFemale
SSMean119.51118.51120.20 119.52118.29120.14 119.49118.67120.27
SD8.568.778.43 8.709.808.21 8.538.268.91
DSMean6.897.376.56 7.408.296.96 6.406.766.05
SD7.138.266.29 8.1910.037.26 5.987.054.90
FSMean0.650.460.78 0.600.710.54 0.700.291.09
SD1.381.171.50 1.331.681.14 1.440.641.85
MSMean0.410.570.30 0.600.710.54 0.230.480.00
SD1.581.611.57 1.981.822.08 1.071.500.00
AFMean0.000.000.00 0.000.000.00 0.000.000.00
SD0.000.000.00 0.000.000.00 0.000.000.00
SeSMean0.000.000.00 0.000.000.00 0.000.000.00
SD0.000.000.00 0.000.000.00 0.000.000.00
XSMean0.000.000.00 0.000.000.00 0.000.000.00
SD0.000.000.00 0.000.000.00 0.000.000.00
USMean20.5421.0920.16 19.8820.0019.82 21.1921.8120.59
SD4.453.734.89 2.810.003.46 5.564.726.32
DMFSMean7.958.407.64 8.609.718.04 7.337.527.14
SD7.538.416.92 8.609.808.06 6.367.475.28

SS: number of sound permanent tooth surfaces, DS: number of decayed permanent tooth surfaces, FS: number of filled permanent tooth surfaces due to caries, MS: number of missing permanent tooth surfaces due to caries, AS: number of missing permanent tooth surfaces not due to caries, SeS: number of sealant treated permanent tooth surfaces, XS: number of permanent tooth surfaces with non-caries treatments, US: number of un-erupted permanent tooth surfaces, DMFS: number of decayed, missing, and filled permanent tooth surfaces, SD: standard deviation.


Discussion

National data on caries experience is crucial for understanding the dental health status of the population and establishing oral health policies. Laos is a landlocked Southeast Asian country bordered by Burma and the People’s Republic of China to the northwest, Vietnam to the east, Cambodia to the south, and Thailand to the west. Its population was estimated to be around 6.5 million in 2012 [24-29].

Vientiane is the capital and largest city of Laos, situated along the Mekong River adjacent to the Thai border. Due to fear of Burmese invasion, Vientiane became the capital in 1563, and recently, it has maintained its administrative capital status from the French colonial period due to economic growth. Currently, Vientiane is the economic center of Laos, with an urban population estimated at 754,000 in 2009 [24-29].

Vientiane Province (Lao ແຂວງ ແຂວງ ວຽງ ຈັນ) is located in the northwest of Laos, with a total population of 419,090 as of 2015. The province covers an area of 15,927 km2 in the central region of northwestern Laos. It borders Luang Prabang Province to the north, Xangkhouang Province to the northeast, Bolikhamxai Province to the east, Thailand to the south, and Xaignabouli Province to the west. Major towns include Vang Vieng and Muang Phôn-Hông [30].

To create baseline data for the implementation of public oral health programs in Laos, the author aimed to investigate the extent of dental caries experience among children in the Vientiane Province, surrounding the capital city of Vientiane. The oral examination of a total of 344 individuals, including 121 primary school students, 138 middle school students, and 85 high school students, was analyzed. The results indicated that the decayed primary teeth index for 6-year-olds was 7.40, the decayed primary tooth surface index was 17.07, the primary teeth caries experience rate was 95.87%, the decayed primary teeth rate was 99.78%, and the treated primary teeth rate was 0.22%.

Furthermore, the decayed permanent teeth index for 12-year-olds was 3.30, the decayed permanent tooth surface index was 6.01, the permanent teeth caries experience rate was 86.13%, the decayed permanent teeth rate was 92.09%, the treated permanent teeth rate was 1.98%, and the caries fatality rate was 12.09%. For 15-year-olds, the decayed permanent teeth index was 4.99, the decayed permanent tooth surface index was 7.95, the permanent teeth caries experience rate was 80%, the decayed permanent teeth rate was 88.21%, the treated permanent teeth rate was 10.14%, and the caries fatality rate was 5.42%.

The decayed permanent teeth index of 3.30 for 12-year-olds in the Vientiane region was higher than the national average of 2.18 for 12-year-olds in Laos in 2009, and the index of 4.99 for 15-year-olds was also higher than the national average of 3.20 for all children in 2009, indicating an increase in dental caries experience [9,10].

In comparisons between urban and rural areas, the decayed permanent teeth index for 12-year-olds was 3.15 in urban areas and 3.46 in rural areas, showing no significant difference. However, for 15-year-olds, the index was higher in urban areas at 5.55 compared to 4.44 in rural areas. The caries experience rate was very high across most age groups, with the decayed permanent teeth rate being high at around 88-91%, and notably, the decayed primary teeth rate was as high as approximately 99%. The caries fatality rate was also substantial at 5-12%. In Laos, it seems necessary to conduct treatment programs alongside prevention programs to halt further progression of caries and lower the caries fatality rate.

Laos is a developing country receiving international support, and it’s true that access to dental care proportional to income levels is somewhat lacking. However, when the government implements oral health programs, smooth manpower recruitment seems possible. Statistically significant, a two-year project using 2% sodium fluoride topical application has shown to have a significant effect on dental caries.

Conclusion

The researchers conducted an analysis of the oral examination outcomes for a cohort of 344 children in Vientiane, including 121 in primary school, 138 in middle school, and 85 in high school, to evaluate the prevalence of dental caries in this group. The following conclusions were drawn:

(1) For 6-year-olds corresponding to the first year of primary school, the index of experienced decay in primary teeth stood at 7.40, and the index for decayed primary tooth surfaces was 17.07. The rate of caries experience in primary teeth was found to be 95.87%, with a decay rate in primary teeth of 99.78% and a treatment rate for primary teeth at 0.22%.

(2) For 12-year-olds, equivalent to the first year of middle school, the index of experienced decay in permanent teeth was 3.30, with a decayed permanent tooth surface index of 6.01. The rate of caries experience in permanent teeth was 86.13%, the decay rate in permanent teeth was 92.09%, the treatment rate for permanent teeth was 1.98%, and the caries fatality rate was determined to be 12.09%.

(3) For 15-year-olds in their first year of high school, the index for experienced decay in permanent teeth was recorded at 4.99, and the index for decayed permanent tooth surfaces was 7.95. The caries experience rate in permanent teeth was 80%, the decay rate in permanent teeth was 88.21%, the treatment rate for permanent teeth was 10.14%, and the caries fatality rate was observed to be 5.42%.

Conflict of Interest

No potential conflict of interest relevant to this article was reported.

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