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Dental Survey for Children of Luang Prabang Province, Laos
Int J Clin Prev Dent 2023;19(4):69-76
Published online December 31, 2023;  https://doi.org/10.15236/ijcpd.2023.19.4.69
© 2023 International Journal of Clinical Preventive Dentistry.

Yong-Su Park1, Ja-Won Cho1, Hyun-Jun Yoo1, Phommavongsa Nitthasack2, Da-Hui Kim3

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, Andong Science College, Andong, Korea
Correspondence to: Da-Hui Kim
E-mail: plusoten@naver.com
https://orcid.org/0000-0003-0226-0212
Received December 6, 2023; Revised December 13, 2023; Accepted December 13, 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: This research seeks to determine the extent of tooth decay experienced by students in the Luang Prabang region of Laos.
Methods: We conducted a comprehensive analysis of the dental caries experience among children in the Luang Prabang area by performing oral examinations on a group of 301 individuals, which included 98 primary school students, 102 middle school students, and 101 high school students.
Results: For 12-year-old middle school students, the index of decay experience in permanent teeth was registered at 0.82, and the surface index for decayed permanent teeth was 1.86. The caries experience rate for permanent teeth was 40.2%, the decay rate in permanent teeth was 84.52%, the treatment rate for permanent teeth was 7.14%, and the fatality rate due to caries was calculated to be 32.14%.
Conclusion: The dental caries experience was notably high among most age groups, with a permanent tooth decay rate of around 75% to 85%. Particularly, the primary tooth decay rate was found to be exceptionally high at approximately 90%. The dental caries fatality rate also exceeded 30%, underscoring the need for concurrent preventive measures and treatment programs in Laos to halt the progression of dental caries and reduce the dental caries fatality rate.
Keywords : children, dental survey, Luang Prabang province, Laos
Introduction

The oral tissues, including teeth and periodontium, are major factors determining the quality of life and satisfaction in social interactions. The two major oral diseases undermining oral health are dental caries and periodontal disease, commonly referred to as caries and pyorrhea, respectively [1,2]. Dental caries, often termed cavities, primarily manifest during elementary school years, with increasing prevalence. Particularly, oral health management during the mixed dentition period, when primary teeth are exchanged for permanent teeth, should be given significant attention. The occurrence of dental caries is known to result from the interaction of various factors, broadly categorized into host factors, pathogenic factors, environmental factors, and time factors. Among these, environmental factors include social and geographic elements, as well as access to dental care [1-3]. Social factors encompass public oral health initiatives, namely community-based oral health programs, aimed at preventing dental caries [1-4].

The Lao People’s Democratic Republic, with an area of 236,800 km2, is one of the least developed countries in Southeast Asia, with a per capita GDP of less than 2,000 dollars, categorizing it among the absolute poverty nations. It is a one-party socialist state with a collective leadership system and has a government-led healthcare system [4-13]. Although the Lao government has established a health support network including oral care, most medical services are paid for out-of-pocket due to insufficient funding [4,6]. Oral health initiatives in Laos, such as the fluoride program and the SMART program [8], are limited to a very few pilot schools. The beneficiaries of these programs and initiatives are confined to within these schools. The initiatives are primarily carried out by personnel from the National University of Laos, Faculty of Dentistry [10,11]. In the past, the population per dentist was as high as 20,000, but with the National University of Laos, Faculty of Dentistry in Vientiane producing about 50 dentists annually, the current population per dentist has decreased to approximately 7,500. However, this figure is still significantly high compared to developed countries [14-16].

With this context, the author intends to conduct a survey on the status of dental caries experience among children in the Luang Prabang 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 program.

Materials and Methods

1. Study subjects

This research was conducted among children aged 6 in elementary schools, 12 in middle schools, and 15 in high schools within the Luang Prabang Province of Laos. The study distinguished between urban and rural regions, selecting respective elementary, middle, and high schools in each area upon recommendations from the Lao Dental Association and the Lao Ministry of Education. Students from these selected schools were then included as the subjects of the study (Table 1).

Table 1 . Age and gender distribution of study participants

AgeLuang PrabangUrban areaRural area



TotalMaleFemaleTotalMaleFemaleTotalMaleFemale
Total30113516615070801516586
6-year-old985147492623492524
12-year-old1024260512526511734
15-year-old1014259501931512328


2. Methods

1) Survey team composition

The survey team was comprised of 13 members altogether, including seven dentists from Korea, three from Laos, one screening and recording officer, and two administrative officers. Training was provided to the investigative team immediately before the survey to align the survey standards among all members uniformly.

2) Survey schedule

The examination was carried out in two separate rounds, on the dates specified below:

First round (urban area): 27th September 2018

Second round (rural area): 28th September 2018

3) Assessment criteria

The standards for evaluating the inspected teeth are specified as follows [17-20].

0: Intact teeth: Absence of active carious lesions and no traces of caries treatment.

1: Diseased teeth: Teeth exhibiting softened dentin or dentin exposed by caries.

3: Treated for caries experience: Teeth filled with permanent materials without decay or with crowns due to caries.

4: Lost due to caries experience: Permanent teeth extracted because of caries, including prosthetics but not the supporting teeth.

5: Lost not due to caries: Permanent teeth lost for reasons other than caries (accidents, congenital absence, gum disease, orthodontic removal) and not considered as caries-experienced.

6: Occlusal sealant teeth: Teeth treated with occlusal fissure sealant.

7: Treated not due to caries: Permanent teeth with artificial crowns or bands for reasons other than caries (injury, developmental anomalies, prosthetics, braces) and not considered as caries-experienced.

8: Teeth not yet emerged.

9: Teeth unrecordable.

4) Statistical analysis

The findings from the dental surveys were inputted into EXCEL (Version 2016, Microsoft Inc, USA) and subjected to descriptive statistical analysis in SPSS version 24.0. For the 6-year-old primary school children, several rates and indices were calculated, including the decayed and filled deciduous teeth rate (df rate), deciduous teeth decay and filling index (dft index), decayed and filled surfaces in deciduous teeth index (dfs index), decay rate for deciduous teeth (dt rate), and filling rate for deciduous teeth (ft rate). Additionally, for the 12-year-old junior high and 15-year-old senior high students, various measures were computed, such as the decayed, missing, and filled permanent teeth rate (DMF rate), permanent teeth decay, missing, and filling index (DMFT index), decayed, missing, and filled surfaces in permanent teeth index (DMFS index), decay rate for permanent teeth (DT rate), and filling rate for permanent teeth (FT rate).

Results

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

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

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

IndexValueLuang PrabangUrban areaRural area



TotalMaleFemaleTotalMaleFemaleTotalMaleFemale
stMean13.1113.1213.1111.7111.8811.5214.5114.4014.63
SD4.464.664.284.604.984.223.884.003.84
dtMean5.515.675.346.536.506.574.494.804.17
SD3.784.093.453.694.193.133.623.883.38
ftMean0.010.000.020.020.000.040.000.000.00
SD0.100.000.150.140.000.210.000.000.00
setMean0.000.000.000.000.000.000.000.000.00
SD0.000.000.000.000.000.000.000.000.00
utMean0.000.000.000.000.000.000.000.000.00
SD0.000.000.000.000.000.000.000.000.00
etMean1.741.861.622.652.772.520.840.920.75
SD2.873.182.533.393.693.101.862.231.42
dftMean5.525.675.366.556.506.614.494.804.17
SD3.804.093.493.724.193.203.623.883.38
df rate%89.8088.2491.4993.8892.3195.6585.7184.0087.50
dt rate%99.82100.0099.6099.69100.0099.34100.00100.00100.00
ft rate%0.180.000.400.310.000.660.000.000.00

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 Luang Prabang primary school students (2)

IndexValueLuang PrabangUrban areaRural area



TotalMaleFemaleTotalMaleFemaleTotalMaleFemale
ssMean70.4371.1669.6465.7667.5063.7875.1074.9675.25
SD16.7616.8016.8618.9919.4518.6912.7512.8312.94
dsMean11.8511.8211.8714.9013.7716.178.809.807.75
SD12.0113.0010.9812.9714.0511.8110.2211.768.46
fsMean0.010.000.020.020.000.040.000.000.00
SD0.100.000.150.140.000.210.000.000.00
sesMean0.010.020.000.020.040.000.000.000.00
SD0.100.140.000.140.200.000.000.000.00
dfsMean11.8611.8211.8914.9213.7716.228.809.807.75
SD12.0413.0011.0313.0114.0511.9010.2211.768.46

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 Luang Prabang region is presented in Table 4 and Table 5.

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

IndexValueLuang PrabangUrban areaRural area



TotalMaleFemaleTotalMaleFemaleTotalMaleFemale
STMean23.1822.4523.6825.1424.4825.7721.2219.4722.09
SD4.624.674.563.273.532.944.964.614.96
DTMean0.700.710.680.880.880.880.510.470.53
SD1.161.131.191.321.301.370.950.801.02
FTMean0.060.070.050.120.120.120.000.000.00
SD0.280.260.290.380.330.430.000.000.00
MTMean0.070.120.030.140.200.080.000.000.00
SD0.350.500.180.490.650.270.000.000.00
ATMean0.030.000.050.060.000.120.000.000.00
SD0.300.000.390.420.000.590.000.000.00
SeTMean0.000.000.000.000.000.000.000.000.00
SD0.000.000.000.000.000.000.000.000.00
XTMean0.000.000.000.000.000.000.000.000.00
SD0.000.000.000.000.000.000.000.000.00
UTMean7.978.647.505.676.325.0410.2712.069.38
SD4.604.564.622.643.022.075.004.325.14
ITMean0.170.100.220.140.120.150.200.060.26
SD0.580.300.720.600.330.780.570.240.67
DMFTMean0.820.900.771.141.201.080.510.470.53
SD1.251.271.241.431.441.440.950.801.02
DMF rate%40.2045.2436.6754.9056.0053.8525.4929.4123.53
DT rate%84.5278.9589.1377.5973.3382.14100.00100.00100.00
FT rate%7.147.896.5210.3410.0010.710.000.000.00
MT rate%8.3313.164.3512.0716.677.140.000.000.00
Mortal rate%32.1423.6839.1329.3126.6732.1438.4612.5050.00

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 Luang Prabang middle school students (2)

IndexValueLuang PrabangUrban areaRural area



TotalMaleFemaleTotalMaleFemaleTotalMaleFemale
SSMean106.94104.00109.00117.27114.36120.0896.6188.76100.53
SD21.8821.3522.1914.4114.8113.7123.2720.6023.82
DSMean1.451.141.671.591.401.771.310.761.59
SD3.432.014.143.772.244.863.071.603.58
FSMean0.070.070.070.140.120.150.000.000.00
SD0.320.260.360.450.330.540.000.000.00
MSMean0.340.600.170.691.000.380.000.000.00
SD1.762.520.912.453.231.360.000.000.00
AFMean0.120.000.200.240.000.460.000.000.00
SD1.190.001.551.680.002.350.000.000.00
SeSMean0.000.000.000.000.000.000.000.000.00
SD0.000.000.000.000.000.000.000.000.00
XSMean0.000.000.000.000.000.000.000.000.00
SD0.000.000.000.000.000.000.000.000.00
USMean39.0842.1936.9028.0831.1225.1550.0858.4745.88
SD21.8421.5521.9612.6514.3710.1923.5920.1924.32
DMFSMean1.861.811.902.412.522.311.310.761.59
SD3.803.154.234.383.734.993.071.603.58

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 Luang Prabang region is presented in Table 6 and Table 7.

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

IndexValueLuang PrabangUrban areaRural area



TotalMaleFemaleTotalMaleFemaleTotalMaleFemale
STMean26.7427.1726.4426.6427.1626.3226.8427.1726.57
SD1.841.402.061.681.171.872.001.592.28
DTMean0.900.741.020.780.630.871.020.831.18
SD1.561.341.701.061.011.091.931.592.20
FTMean0.170.020.270.340.050.520.000.000.00
SD0.710.150.910.980.231.210.000.000.00
MTMean0.120.070.150.200.160.230.040.000.07
SD0.410.340.450.490.500.500.280.000.38
ATMean0.010.000.020.020.000.030.000.000.00
SD0.100.000.130.140.000.180.000.000.00
SeTMean0.000.000.000.000.000.000.000.000.00
SD0.000.000.000.000.000.000.000.000.00
XTMean0.000.000.000.000.000.000.000.000.00
SD0.000.000.000.000.000.000.000.000.00
UTMean4.054.004.084.024.004.034.084.004.14
SD0.410.000.530.140.000.180.560.000.76
ITMean0.250.240.250.200.160.230.290.300.29
SD0.650.660.660.450.370.500.810.820.81
DMFTMean1.190.831.441.320.841.611.060.831.25
SD1.811.402.031.661.171.861.951.592.22
DMF rate%49.5038.1057.6358.0047.3764.5241.1830.4350.00
DT rate%75.8388.5770.5959.0975.0054.0096.30100.0094.29
FT rate%14.172.8618.8225.766.2532.000.000.000.00
MT rate%10.008.5710.5915.1518.7514.003.700.005.71
Mortal rate%31.6737.1429.4131.8237.5030.0031.4836.8428.57

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 Luang Prabang high school students (2)

IndexValueLuang PrabangUrban areaRural area



TotalMaleFemaleTotalMaleFemaleTotalMaleFemale
SSMean124.87125.62124.34124.52125.47123.94125.22125.74124.79
SD5.154.365.624.773.725.295.514.906.02
DSMean1.932.001.881.761.681.812.102.261.96
SD3.824.133.632.803.042.694.644.904.49
FSMean0.270.020.440.540.050.840.000.000.00
SD1.410.151.821.970.232.460.000.000.00
MSMean0.590.360.761.000.791.130.200.000.36
SD2.041.712.242.472.512.491.400.001.89
AFMean0.040.000.070.080.000.130.000.000.00
SD0.400.000.520.570.000.720.000.000.00
SeSMean0.000.000.000.000.000.000.000.000.00
SD0.000.000.000.000.000.000.000.000.00
XSMean0.000.000.000.000.000.000.000.000.00
SD0.000.000.000.000.000.000.000.000.00
USMean20.2520.0020.4220.1020.0020.1620.3920.0020.71
SD2.050.002.670.710.000.902.800.003.78
DMFSMean2.792.383.083.302.533.772.292.262.32
SD4.714.364.964.603.725.074.804.904.80

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

Dental caries, or tooth decay, is a disease that occurs when sugars left in the mouth after eating are broken down by various microbes present in the oral cavity, leading to the demineralization of the tooth’s inorganic components, specifically calcium, followed by the destruction of organic components. Such tooth decay is an irreversible, progressive, and pervasive chronic disease that worsens over a lifetime [1-4]. It often starts to manifest during primary school when children transition from primary to permanent teeth. Preventive measures against tooth decay during this period are particularly effective for oral health promotion.

The two major oral diseases are tooth decay and periodontal disease, and the primary school period is a crucial time when the foundation for lifelong oral health is established. Prevention of tooth decay during this period is effective in promoting oral health [4].

Laos is divided into 17 provinces, including the capital city of Vientiane. Among these, the Luang Prabang Province, located in the northern part of Laos, covers an area of 16,875 km2 and is composed of 12 districts: Luang Prabang, Xieng Ngeun, Nan, Pak Ou, Nambak, Ngoi, Pakseng, Phonxay, Chomphet, Viengkham, and Phoukhouny. The total population of the province was about 430,000 as of 2015 [16]. The provincial capital, Luang Prabang city, is a UNESCO World Heritage Site and an ancient city located about 400 km upstream on the Mekong River from Vientiane. The city’s population is about 60,000 [16].

To create baseline data for implementing public oral health programs in Laos, the author conducted an analysis of the results of oral examinations on a total of 301 individuals in the central northern province of Luang Prabang, including 98 primary school students, 102 middle school students, and 101 high school students. The decayed primary teeth index for 6-year-old primary school children was 5.52, the decayed primary tooth surface index was 11.86, the primary teeth caries experience rate was 89.8%, the decayed primary teeth rate was 99.82%, and the treated primary teeth rate was 0.18%.

Moreover, the decayed permanent teeth index for 12-year- old middle school students was 0.82, the decayed permanent tooth surface index was 1.86, the permanent teeth caries experience rate was 40.2%, the decayed permanent teeth rate was 84.52%, the treated permanent teeth rate was 7.14%, and the caries fatality rate was 32.14%. Particularly, the decayed permanent teeth index for 12-year-old children showed a significant urban-rural disparity, with 1.14 in urban areas and 0.51 in rural areas, indicating a need for preventive programs in urban areas.

The decayed permanent teeth index of 0.82 for 12-year-olds in the Luang Prabang region was lower than the national average of 2.18 for 12-year-olds in Laos in 2009, indicating an overall decrease in tooth decay. However, the high decayed permanent teeth rate compared to the treated permanent teeth rate shows the need for treatment programs for existing tooth decay [21].

For 15-year-old high school students, the decayed permanent teeth index was 1.19, the decayed permanent tooth surface index was 2.79, the permanent teeth caries experience rate was 49.5%, the decayed permanent teeth rate was 75.83%, the treated permanent teeth rate was 14.17%, and the caries fatality rate was 31.67%. The decayed permanent teeth index for 15-year-olds also showed a higher rate in urban areas, highlighting the importance of preventive programs in these regions. The treated permanent teeth rate of 14.17% for 15-year-olds, though somewhat higher than that for 12- year-olds, indicates that the very high decayed permanent teeth rate of 75.83% shows the need for treatment programs for both age groups.

In most age groups, the caries experience rate was high, with a decayed permanent teeth rate of 75-85% and particularly a decayed primary teeth rate of around 90%. The caries fatality rate was also over 30%, indicating that in Laos, treatment programs should be conducted alongside prevention programs to halt further progression of caries and lower the caries fatality rate.

As Laos, once a communist country, now seeks development with the introduction of a market economy, it has one dental college and a shortage of dental healthcare personnel. To improve the quality of dental care, it is essential to anticipate the appropriate workforce needed to meet the population’s needs and make efforts to produce a workforce through medical education that meets a certain standard.

Conclusion

The team of authors conducted a comprehensive analysis of the dental caries experience among children in the Luang Prabang area by performing oral examinations on a group of 301 individuals, which included 98 primary school students, 102 middle school students, and 101 high school students. The study yielded the following findings:

① For the 6-year-old primary school children, the index of decay experience in primary teeth was noted as 5.52, and the surface index for decayed primary teeth was 11.86. The caries experience rate in primary teeth was documented at 89.8%, the decay rate in primary teeth was 99.82%, and the treatment rate for primary teeth was found to be 0.18%.

② For 12-year-old middle school students, the index of decay experience in permanent teeth was registered at 0.82, and the surface index for decayed permanent teeth was 1.86. The caries experience rate for permanent teeth was 40.2%, the decay rate in permanent teeth was 84.52%, the treatment rate for permanent teeth was 7.14%, and the fatality rate due to caries was calculated to be 32.14%.

③ For 15-year-old high school students, the index of decay experience in permanent teeth was measured at 1.19, and the surface index for decayed permanent teeth was 2.79. The caries experience rate in permanent teeth was 49.5%, the decay rate in permanent teeth was 75.83%, the treatment rate for permanent teeth was 14.17%, and the caries fatality rate was 31.67%.

Conflict of Interest

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

References
  1. Kim JB, Kim KS, Kim YH, Chung SH, Jin BH, Choi EM, et al.: Public health dentistry. 4th ed. Komoonsa, Seoul, pp.47-86, 2004.
  2. Kim JB, Choi EG, Moon HS, Kim JB, Kim DK, Lee HS, et al.: Public health dentistry. 5th ed. Komoonsa, Seoul, pp.349-430, 2009.
  3. Kim JB, Choi EG, Paik DI, Shin SC, Chang KW, Hong SJ, et al.: Preventive dentistry. 5th ed. Komoonsa, Seoul, pp.33-88, 2009.
  4. Paik DI, Kim HD, Jin BH, Park YD, Shin SC, Cho JW, et al.: Clinical preventive dentistry. 5th ed. Komoonsa, Seoul, pp.65-80, 2011.
  5. Lim JH, Park JH, Chang YS: Comparison of the dental caries and periodontal status in 12 years old, between in Korea and Laos. Int J Clin Prev Dent 8: 73-9, 2012.
  6. Phommavongsa N, Senesombath S, Lim JH, Kim NY, Park WR, Na EJ, et al.: Dental survey of Vientiane city children in Laos. Int J Clin Prev Dent 11: 33-8, 2015.
    CrossRef
  7. Seo JH, Cho BK, Chang YS, Jwa SK: The recognition for the dental profession on the students in Korea, Japan, Laos and Mongolia. Int J Clin Prev Dent 9: 169-78, 2013.
  8. Na EJ, Lim JH, Park WR, Cho JW: The effect of 2 years pit and fissure sealant program on Laos children. Int J Clin Prev Dent 11: 225-32, 2015.
    CrossRef
  9. Lim JH, Park WR, Na EJ, Senesombath S: Comparison of a 2-year oral health program using sealant and 1.23% acidulated phosphate fluoride gel in primary school students of Vientiane, Laos. Int J Clin Prev Dent 12: 31-6, 2016.
    CrossRef
  10. Park WR, Na EJ, Lim JH, Cho JW: Clinical study on fluoride iontophoresis method for Lao children. Int J Clin Prev Dent 11: 107-14, 2015.
    CrossRef
  11. Kim NY, Yun MH, Lim TW, Keo S: Three years program on pit and fissure sealant for Laos children. Int J Clin Prev Dent 12: 269-76, 2016.
    CrossRef
  12. Yun MH, Kim NY, Na EJ, Cho JW: Clinical study on 3-year-fluoride iontophoresis program for Lao children. Int J Clin Prev Dent 13: 101-10, 2017.
    CrossRef
  13. Phommavongsa N, Park WR, Kim NY, Na EJ, Yun MH, Shin SC, et al.: Effects of application of sealant and fluoride gel application program for elementary school children in Laos for 3 years. Int J Clin Prev Dent 14: 81-8, 2018.
    CrossRef
  14. Rhee CY, Cho JW, Yoo HJ, Phommavongsa N, Ahn YS, Oh HS: 2019 Laos children’s dental caries experience survey. J Korean Acad Oral Health 45: 51-6, 2021.
  15. Oh HS, Cho JW, Yoo HJ, Kwon SS: A study on the significant caries (SiC) index of Lao students. J Korean Acad Oral Health 46: 33-9, 2022.
    CrossRef
  16. Wikipedia: Luang Prabang province [Internet]. Wikimedia Foundation, Inc., San Francisco. cited 2023 Oct 21,
  17. Yun SW, Shin SC, Chang YS, Kim HK, Sohn SJ, Kim JK, et al.: A survey of dental caries in Mongolia in 2014. Int J Clin Prev Dent 10: 165-78, 2014.
    CrossRef
  18. Lee HW, Kim NJ, Jwa SK, Moon HR, Jeong JH: Dental survey for primary school student at Anseong-si. Int J Clin Prev Dent 10: 1-8, 2014.
    CrossRef
  19. Kong JI, Kim SY, Lee EH, Cho MJ, Lee CH: Dental survey at Okcheon county as water fluoridated area. Int J Clin Prev Dent 10: 93-102, 2014.
    CrossRef
  20. Lee JT, Lee KH, Seo JH, Chun JA, Park JH: The evaluation for oral examination by using ofintra-oral camera. Int J Clin Prev Dent 10: 113-20, 2014.
    CrossRef
  21. Lao Dental Association: Lao national oral health survey. Lao Dent J 1: 46-133, 2013.


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