i 

Caries prevalence amongst pre-school 

children in Windhoek, Namibia. 

 

By 

 

Moses Aluteni 

 

Submitted in partial fulfilment of the requirements for the degree of 

 

Master of Science in Dentistry (Community Dentistry) 

 

In the 

 

School of Dentistry Faculty of Health Sciences University of the  

Witwatersrand 

 

Johannesburg 
 

Supervisor: Profs. Veerasamy Yengopal and Simon Nemutandani 



 ii 

 

 

 

 



 iii 

DEDICATION 

 

 

I dedicate this work to my Creator, the One who gives wisdom and direction in 

serving and helping those in need of care.  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 



 iv 

 

ACKNOWLEDGEMENTS: 

 

I would like to sincerely thank:  

 My Supervisors Profs Veerasamy Yengopal and Simon Nemutandani; H.O.D. 

Community Dentistry, Wits School of Oral Health Sciences and Head of 

School, Oral Health Sciences respectively, for their expertise, professionalism 

and guidance. 

 The Department of Community Dentistry, Wits Oral Health Sciences School. 

 Ethics Committee HREC from Wits University for approving the research 

protocol. 

 Ethics Committee from the Ministry of Health and Social Services (MoHSS, 

Namibia) in Namibia for approving the research protocol. 

 Dr. Bukola Olutola for helping with the statistical data analysis. 

 Mr. Thomas Ruiz for assisting with the logistics prior, during and after the data 

collection process. 

 Ms. Maggy Esterhuizen, who assisted with clinical data capturing during the 

clinical dental examinations. 

 Ms. Helena N. Nakale, who assisted me with information technology in 

computer software programming. 

 Falisana Oriental College, who assisted me with computer literacy training. 

 Ms. Neoentle Motsaathebe, who assisted with an oral health promotion play 

at one of the participating creches. 

 My family, for assisting me with computer literacy skills and endless support. 

 The management and school principals as well as the preschool teachers at 

the various participating creches, for their cooperation and assistance. 

  The participants of the study, both the parents as well as the learners. 

 

 

 



 v 

Abstract: 

 

Background: Early Childhood Caries (ECC) has been recognised as a disease of 

serious consequences in both industrialised as well as undeveloped nations of the 

world. Its widespread prevalence among children makes it ideal for assessing the 

risk factors and identifying specific strategies that could be implemented to prevent 

the disease. 

 

Aim: The aim of the present study was to determine the prevalence of dental caries 

and its untreated consequences among 2-6-year-old preschool children in 

Windhoek, Namibia.  

 

Objectives: The objectives were; 

(i) To determine the prevalence of caries amongst 2-6-year-old children 

attending selected crèches in Windhoek, Namibia. 

(ii) To assess the clinical consequences of untreated tooth decay amongst 2-6-

year-old children attending selected crèches in Windhoek using the pufa 

index. 

(iii) To investigate the strength of correlation between the dmft and pufa indices 

amongst 2-6years-old children attending selected creches in Windhoek, 

Namibia. 

(iv) To evaluate the correlation between oral hygiene practices and early 

childhood caries amongst 2-6-year-old children attending selected crèches in 

Windhoek, Namibia. 

Methods: The study design used was cross-sectional and descriptive. A random 

sample was used  to select children between the age group of 2-6 years attending 

selected creches represented within the 9 urban constituencies of Windhoek, 

Namibia. The sample size comprised 250  children whose parents had consented to 

be part of the  study. Data was collected by means of a dental clinical examination 

which focused on the diagnosis of dental caries using a World health organization 

(WHO) criteria for caries through the dmft and pufa indices. The dental examination 

was conducted at the respective crèches of the participants. An accompanying 

complementary oral health questionnaire was completed by the parents/care givers 



 vi 

of the participants prior to the clinical dental examination and data was collated 

accordingly. 

The examinations were done by a single examiner and the examiner was calibrated 

by a team from the Department of Community Dentistry at the Wits Oral Health 

Sciences School. Ten percent of each examination sample was randomly selected 

and re-examined as a means of ensuring intra examiner reliability and consistent 

clinical judgment. 

Results:  The caries and pufa prevalence amongst the study cohort was established 

at 55.77% and 6.54% respectively.  The mean age of the children was 4.7 years, the 

mean dmft index score was 2.38  and the mean pufa score was 0.11. There was an 

increase in caries prevalence from 30.77% amongst the 2-year-old children to 

66.67% amongst the 6-year-old children thus indicating an increase in caries 

prevalence with increasing age in both girls and boys.  

 

 

Conclusion: The caries and pufa prevalence of 55.77% and 6.54% for pre-school 

children of Windhoek  is high compared to similar studies from other countries and it 

was directly proportional to increasing age.  

 

 

 
 

 

 

 

 

 

 



 vii 

 

Table of contents: 

Declaration                                                                                                                   ii  

Dedication                                                                                                                   iii 

Acknowledgements                                                                                                     iv 

Abstract                                                                                                                        v 

List of Abbreviations                                                                                                     x 

 

Chapter 1: Introduction                                                                                             1              

1.1 Background                                                                                                            1 

1.2 Caries diagnostic index                                                                                          2 

1.3 PUFA/pufa diagnostic index                                                                                  3 

1.4 Research problem (Rationale)                                                                              5 

1.5 Literature review                                                                                                    5   

 

Chapter 2. Aims and Objectives                                                                            11     

2.1 Aim of the Study                                                                                                  11 

2.2 Objectives                                                                                                            11                                                                                        

 

 



 viii 

 

Chapter 3. Materials/Methods                                                                                 12 

3.1 Study design                                                                                                        12 

3.2 Study site and study population                                                                           12 

3.3 Sampling and sample size                                                                                   13 

3.4 Methodology                                                                                                        13            

3.5 Ethics consideration and clearance                                                                     15 

3.6 Data analysis                                                                                                       16 

Chapter 4. Results                                                                                                   17 

4.1 Socio-demographic  characteristics of the study participants                              17                   

4.2 Age distribution of the participants                                                                       19                                                                           

4.3 Early childhood caries in children                                                                        19                                    

 4.4 Correlation between dmft and pufa                                                                     20                                                                

4.5 Caries (cavities) observed by parents                                                                 20 

4.6 Prevalence of early childhood caries by oral hygiene practices                          20                      

4.7 Risk factors for early childhood caries                                                                 23 

4.8 Mean dmft by age of child                                                                                    25  

4.9  Prevalence of caries by demographic and socio-economic factors                    25 

4.10 Summary                                                                                                           26 

     



 ix 

 

Chapter 5. Discussion                                                                                            27 

5.1 Introduction                                                                                                          27 

5.2. Demographic composition                                                                                  28 

5.3 Prevalence of caries and pufa                                                                             29 

5.4 Age distribution versus caries prevalence                                                           31 

5.5 Clinical consequences of untreated tooth decay                                                 32 

5.6 Correlation between the dmft and pufa                                                                32 

5.7 Correlation of oral hygiene practises associated with early childhood caries      34 

5.8 Limitations of the study                                                                                        35 

Chapter 6. Conclusions and recommendations                                                   36  

6.1 Conclusions                                                                                                         36 

6.2 Recommendations                                                                                               36 

6.2.1 Preventive oral health promotion programmes                                                 37 

6.2.2 Studies on caries prevalence of pre-school children in rest of  

          Namibia                                        37 

6.2.3 Identification of communities and individuals with high caries risk                   37                                            

6.2.4 Toothbrushing With Fluoridated Toothpaste                                                     37 

6.2.5  Counselling to Reduce Harmful Behaviours                                                    38 

6.2.6 Dental Referral                                                                                                  38 



 x 

 

References                                                                                                               38 

Appendices                                                                                                             46 

Appendix 1:  Information cover letter for research on preschool                            47

            children. 

Appendix 2:   Parent’s/guardian’s/care giver’s consent form for dental                    49

  research involving a minor child. 

Appendix 3:   Oral health questionnaire for parent’s/guardian’s (care                      50

  givers), seeking information on behalf of and of    

  relevance to minor child. 

Appendix 4:   Oral health clinical assessment form.                                                 52 

Appendix 5:   Human Research Ethics Clearance Certificate (Wits).                        54 

Appendix 6:  Human Research Ethics Clearance Certificate (MoHSS).                    56 

 
List of Tables and figures: 
 
Table 1:  Socio-demographic  characteristics of the study participants              17 

Table 2:   Age distribution of the participants                                                       19 

Table 3:  Reported oral hygiene practices for the study cohort                           21 

Table 4:  Risk factors for early childhood caries                                                 24 

Table 5:   Percentage and mean dmft by age of child                                          25                                                               

Table 6:         Prevalence of caries by demographic and socio-economic factors     25 

Figure 1:  Caries (cavities) observed by parents                                                  20 

 
 
 
 
 
 
 
 



 xi 

List of abbreviations: 
 

AFRO:  African region. 
 
AMRO:  American region. 
 
CI:                 Confidence Interval 
 
EURO:  Europe region. 
 
dmft:   Count of decayed, missing and filled deciduous teeth. 
 
DMFT:  Count of decayed, missing and filled permanent teeth. 
 
ECC:   Early childhood caries. 
 
HREC:  Human Research Ethics Committee. 
 
MI:   Motivational interviews. 
 
MoHSS:  Ministry of Health and Social Services in Namibia 
 
MS:   Mutans Streptococci. 
 
OR:               Odds Ratio 
 
pufa:  pulp, ulcer, fistula and abscess formation due to untreated deciduous 

tooth decay. 
 
SEARO:  Southern Eastern Asian Region. 
 
 
Wits:   University of the Witwatersrand. 
  

 

          

 



  

 

 

1 

 

Chapter 1. Introduction 

 

1.1 Background  

Oral diseases are among the most prevalent non-communicable diseases worldwide 

and are regarded as one of the major components in the global burden of diseases 

affecting mankind (Marcenes et al., 2013). Among the commonest of dental 

conditions, dental caries is 10 times more prevalent than any other oral disease with 

a worldwide prevalence of between 60-90% amongst children (Kamran et al., 2017). 

In adults untreated tooth decay constitutes the most prevalent condition whereas in 

primary dentition it remains the 10th most untreated condition (Kassebaum et al., 

2015). This translates into 2.4 billion adults and 621 million children being affected 

by caries which has remained mostly untreated globally.  The recognised high global 

prevalence of dental caries has qualified it to be classified as a pandemic disease 

responsible for untold pain, suffering and increased morbidity. This disease has 

shown a strong association with  urbanisation and industrialisation amongst human 

populations across the world (Bedi, 2005). The disease has as a consequence 

impacted negatively on the general wellbeing of children in most developing nations 

and has had severe adverse effects on socio economic state within communities 

(Marcenes et al., 2013). Thus dental caries remains one of the most common unmet 

health care needs in both adults and children with no exception in preschool children 

(Mahejabeen et al., 2006). The high levels of caries and the increased morbidity 

caused by dental caries has placed oral health  as a priority on the agenda of public 

health authorities. 

Dental caries is a disease of multi factorial origin and ensues as a result of the  

interplay between host factors, environmental factors and causative bacterial agents 

(Struzycka, 2014). The disease has primarily a direct destructive effect on teeth 

which can have secondary  adverse systemic manifestations on the body such as  

on body weight, growth, poor quality of life in preschool children and permanent life 

lasting debilitating effects often requiring continuous maintenance and care 

(Ozdemir, 2013).  



  

 

 

2 

 

Most deleterious oral care habits associated with early childhood caries are 

developed during the pre-school period and pre-school children presents a 

convenient and easily accessible population where dental epidemiological surveys 

can be conducted to establish baseline prevalence data information aimed at early 

identification and continuous management of the disease within populations.  

 

1.2 Caries Diagnostic Index  

 

The DMFT index is a well-established and one of the simplest and most commonly 

used indices in epidemiologic surveys of dental caries and has been in use for 

almost 80 years. It quantifies dental health status based on the number of carious, 

missing and filled teeth (Anaise, 1984).  

 

The DMF Index when applied to the permanent dentition is expressed as the total 

number of teeth or surfaces that are decayed (D), missing (M), or filled (F) in an 

individual. When written in lowercase letters, the dmf index is a variation that is 

applied to the primary dentition. When the index is applied to teeth specifically, it is 

called the DMFT index, and scores per individual can range from 0 to 28 or 32, 

depending on whether the third molars are included in the scoring. When the index is 

applied only to tooth surfaces (five per posterior tooth and four per anterior tooth), it 

is called the DMFS index, and scores per individual can range from 0 to 128 or 148, 

depending on whether the third molars are included in the scoring.  

  

The caries experience for a child is expressed as the total number of teeth or 

surfaces that are decayed (d), missing (m), or filled (f). The dmft index expresses the 

number of affected teeth in the primary dentition, with scores ranging from 0 to 20 for 

children. Because of the difficulty in distinguishing between teeth extracted due to 

caries and those that have naturally exfoliated, missing teeth may be ignored 

according to some protocols. In such cases, it is then referred to as the df index. The 

teeth not counted are unerupted teeth, congenitally missing teeth or supernumerary 

teeth, teeth removed for reasons other than dental caries, and primary teeth retained 

in the permanent dentition.  



  

 

 

3 

 

Counting the third molars is optional. When a carious lesion(s) or both carious 

lesion(s) and a restoration are present, the tooth is recorded as a D. When a tooth 

has been extracted due to caries, it is recorded as an M. When a permanent or 

temporary filling is present, or when a filling is defective but not decayed, this is 

counted as an F. Teeth restored for reasons other than caries are not counted as an 

F.  

 

  

1.3 PUFA/pufa diagnostic index 

 

The PUFA/pufa index was developed as an adjunct to the DMFT/dmft index (Monse 

et al., 2010a). The PUFA/pufa index records the presence of severely decayed teeth 

with visible pulpal involvement (P/p), ulceration caused by dislocated tooth fragments 

(U/u), fistula (F/f) and abscess (A/a).  PUFA is an index used to assess the presence 

of oral conditions resulting from untreated caries. The index is recorded separately 

from the DMFT⁄dmft and scores the presence of either a visible pulp, ulceration of 

the oral mucosa due to root fragments, a fistula or an abscess. Lesions in the 

surrounding tissues that are not related to a tooth with visible pulpal involvement as 

a result of caries are not recorded.  

 

The assessment is made visually without the use of an instrument. Only one score is 

assigned per tooth. In case of doubt concerning the extent of odontogenic infection, 

the basic score (P ⁄ p for pulp involvement) is given. If the primary tooth and its 

permanent successor tooth are present and both present stages of odontogenic 

infection, both teeth will be scored. Uppercase letters are used for the permanent 

dentition and lowercase letters used for the primary dentition.  

 

The codes and criteria for PUFA index are as follows:  

P⁄p: Pulpal involvement is recorded when the opening of the pulp chamber is visible 

or when the coronal tooth structures have been destroyed by the carious process 

and only roots or root fragments are left. No probing is performed to diagnose pulpal 

involvement.  

 



  

 

 

4 

 

U⁄u: Ulceration due to trauma from sharp pieces of tooth is recorded when sharp 

edges of a dislocated tooth with pulpal involvement or root fragments have caused 

traumatic ulceration of the surrounding soft tissues, e.g., tongue or buccal mucosa.  

 

F⁄f: Fistula is scored when a pus releasing sinus tract related to a tooth with pulpal 

involvement is present.  

 

A⁄a: Abscess is scored when a pus containing swelling related to a tooth with pulpal 

involvement is present.  

 

The PUFA ⁄ pufa score per person is calculated in the same cumulative way as for 

the DMFT ⁄ dmft and represents the number of teeth that meet the PUFA ⁄ pufa 

diagnostic criteria. The PUFA for permanent teeth and pufa for primary teeth are 

reported separately. Thus, for an individual person the score can range from 0 to 20 

pufa for the primary dentition and from 0 to 32 PUFA for the permanent dentition. 

The prevalence of PUFA⁄pufa is calculated as percentage of the population with a        

PUFA ⁄pufa score of one or more.  

 

The PUFA index is used in evaluating clinical consequences of untreated caries 

such as pulpal involvement and dental abscess, which may be more serious than the 

caries lesions themselves. Thus the index defines four different clinical stages of 

advanced caries that have different implications on general health status of 

individuals thus providing ‘a face of the reality’ to the prevailing and often ignored 

oral conditions. Use of DMFT/dmft index combined with the PUFA/pufa index for 

dental epidemiologic studies provides more accurate information on the magnitude 

of the disease prevalence (Monse et al., 2010a). 

 

Exposing decision makers to both DMFT/dmft and PUFA/pufa data, gives them a 

more comprehensive picture of the severity, magnitude and health impact that 

untreated caries may have on the quality of life of individuals and communities. 

 

 

 



  

 

 

5 

 

1.4 Research problem (Rationale) 

This study aims to determine the factors that contribute to the increased incidence of 

early childhood caries amongst 2 – 6 year old children in Windhoek urban area, and 

to contribute towards an understanding of measures that could remedy the prevailing 

situation. 

From the phletora of dental caries prevalence studies done worldwide very few have 

focused on the pre-school population as is the focus on in this study cohort. 

The purpose of this study is to contribute to an understanding of the causes of the 

increased incidence of early childhood caries and its clinical consequences amongst 

2-6 year old children within the urban Windhoek area. The findings of the study may 

be used by policy makers to make informed decisions on which intervention 

strategies to utilize in the elimination of early childhood caries. 

  

1.5 Literature review  

 

From review of current available epidemiological research data regarding the 

prevalence of dental caries, results have shown conclusively that there is a noted 

increase in the prevalence of dental caries worldwide. This observed worldwide 

increasing trend is seen in both children as well as adult populations thus affecting 

both primary as well as permanent dentition, posing a public health crisis in the 

absence of any intervention (Bagramian, Garcia-Godoy and Volpe, 2009). The very 

high prevalence of dental caries in children which has remained  largely untreated 

especially has become a serious challenge to public healthcare delivery in 

developing countries where it has remained a cause of debilitating pain and suffering 

in both children and adult populations (Çolak et al., 2013). 

 

Dental pain is a common consequence of untreated dental caries and it invariably 

has a direct influence on an individual’s quality of life. In a study of Head Start Dental 

programme, it was reported that among children with caries, 16.6% complained of 

toothache and 8.9% cried because of a toothache (Tinanoff and Reisine, 2009a).  



  

 

 

6 

 

Children's dental pain affected regular activities, such as eating, sleeping, school 

attendance and playing. Amongst the most extreme of consequences, 

Cassamassimo and colleagues recently summarized the human and economic costs 

of ECC, finding reports of several deaths associated with sepsis., (Tinanoff and 

Reisine, 2009a). 

 

Great efforts to achieve improvements in oral health have been implemented in 

recent decades by both governmental and nongovernmental agencies worldwide. 

Subsequent World Health Organization (WHO) findings suggest that prevalence of 

caries experience has declined in many locations in the world. The largest decline 

namely a 90% reduction in the number of decayed, missing, and filled (DMFT) teeth 

for 12-year old children occurred in the early 1970’s to mid-1990’s in the United 

States and Western and Nordic European high-income countries. The decline was 

less obvious in low-income countries (Lagerweij and van Loveren, 2015). In Africa, 

higher caries prevalence is to be found amongst the higher socio-economic groups 

in the urban areas reflecting, perhaps, the increasing ”westernization” of the diet of 

these high-income groups and the increasing availability of refined carbohydrates.  

 

Dental caries prevalence levels in developed countries has been low mainly due to 

the presence of children's preventative oral health programmes, availability of dental 

clinics and affordable health insurance (Sheiham, 1984), whereas in most 

developing countries such programmes and facilities are non-existent (Bagramian R. 

A., Garcia-Godoy, F. and Volpe, A. R., 2009). In the U. S. A. it is estimated that 

children 5 to 7 years of age lose more than 7 million school hours annually because 

of dental problems and/or visits, many of which are consequences of caries that 

began when they were preschoolers (Tinanoff and Reisine, 2009a).   

 

Marked improvements have been achieved in so far as betterment of oral health of 

children is concerned. Significant strides have been made in recent years in 

developing and applying oral health related quality of life measures for young 

children. Most studies have relied on caregiver reports of the impact of severe caries 

on their children or on the family, although some studies included self-reports from 

children.    



  

 

 

7 

 

 

In a study of 4-year olds with severe caries and those with no caries conducted in 

Brazil, caregivers were interviewed and asked to assess the impact of caries on their 

children. The children also had rated how they felt about their teeth using a happy 

face and sad face. Caregivers of children with severe caries stated that their children 

were more likely to be absent from school (26%), were ashamed to smile (31%), and 

had problems eating (49%). Children with severe caries were also more likely to 

select the sad face (34%) compared with caries-free children (22%), (Bönecker et 

al., 2012). 

 

A pilot study of children ages 35 to 66 months referred for treatment under general 

anaesthesia was conducted in Montreal, Canada. Caregivers interviewed before and 

after treatment reported that before treatment, 48% of the children complained of 

pain, 43% had problems eating, 35% had problems sleeping, and 5% had negative 

reports from school. After treatment, most of the problems resolved, and the authors 

concluded that severe caries had a serious impact on the children's quality of life and 

that treatment eliminated many of these problems (Tinanoff and Reisine, 2009a).  

Another study in the United Kingdom found that 22% of parents of children aged 5  

under reported at least one impact of oral conditions among their children, the most 

common being pain (16%) and limitations in oral function (6%), (Tinanoff and 

Reisine, 2009a). 

 

In the United States, Filstrup et al. (2003) included self-reports from children on the 

impact of caries on quality of life. Forty-three percent of children aged 36 to 47 

months were able to respond to questions such as, “Do your teeth hurt you now?” 

and “Does a hurting tooth wake you up at night?”  

 

In most of the developing countries in South East Asia, children had a high 

prevalence of dental caries in the primary dentition, often in contrast to the situation 

in the permanent dentition. The reasons for this difference were not obvious but may 

have been linked to differences in diet. In a study done by Monse et al. (2010a) the 

prevalence of fistulae and abscesses of 18% among 6-year-old Filipino children was 

consistent with the findings for 5-year-old Scottish children, where the prevalence of 



  

 

 

8 

 

sepsis was reported to be 11% for children living in the most deprived areas in 

Scotland (Pine et al., 2006).  

In the Middle East (Abu Dhabi), studies have shown that the prevalence of ECC 

ranged from 71 to 86% among 4 year olds and 82 to 94% among 5 year old children 

(AlKhayat, 2018), while in Indian studies, the reported prevalence was 37.7, 47.3 

and 47.4% amongst 3,-4 and 5 year olds respectively (Gupta et al., 2015).   

 

A large variation has been seen in the trends of dental caries among the index age 

groups as suggested by WHO worldwide. It was observed that the American Region 

(AMRO) and the Europe Region (EURO) presented a risk of 1.14 and 1.10 times 

higher than the average in the world. The African Region (AFRO) was with 19% 

lower risk compared to the average of all countries surveyed, followed by Southern 

Eastern Asian Region SEARO region. In most highly developed countries like USA, 

UK, and Japan, there was a precipitous increase in prevalence and incidence of the 

disease during 1920’s to 1950. Recently there was a dramatic reduction in caries in 

countries of the western world, primarily due to the increased use of fluorides from a 

variety of sources, especially toothpastes. A decrease in dental caries among 

children in highly developed countries started to emerge around 1970, and the 

percentage of caries free children in different age categories have increased since 

then (Silveira Moreira, 2012).  

 

A changing trend has been observed in developing countries like India and Thailand, 

where there has been a reported increase in dental caries. This could be ascribed to 

the increased availability and use of processed sugars and underutilization of 

preventive services in these developing countries (Kundu et al., 2015).  In 1940, the 

prevalence of dental caries in 5 and 12-year-old schoolchildren in India was 55.5% 

and it jumped to 68% in the 1960 and climbed to 89% in subsequent years. 

Prevalence of dental caries was about 50% in 5 year old children and close to 84.1% 

in older age population as reported by National oral health survey and fluoride 

mapping 2002-2003 (Kundu et al., 2015).  Notwithstanding the observation of 

increased prevalence of dental caries worldwide, such conclusive results have  not 

been established for sub Saharan Africa, due to a lack of research studies on this 



  

 

 

9 

 

topic and in particular amongst the age group cohort of 2-6 year old children 

(Cleaton-Jones and Fatti, 1999).  

 

 

In Africa, dental caries prevalence in the preschool child seems to be increasing 

somewhat in countries or parts of countries where there is an increase in sugar 

intake, while it stays low in countries where a poor economy restricts sugar intake. 

However the prevalence in Africa does not seem to be as high as in South East Asia 

(Holm, 1990).  

 

In most industrialized countries in northern Europe, in North America, in Australia 

and New Zealand, dental caries is decreasing, often linked to an increasing use of 

fluoride coupled with various types of dental health education programmes. In many 

European countries, the prevalence in preschool children is, however, still high and 

caries in primary teeth is often left untreated. In Scandinavia, where all preschool 

children are included in an organized dental care programme, dental caries has been 

decreasing markedly during the 1970s and at the beginning of the 1980s (Holm, 

1990).  

 

From a systematic review study of published information regarding prevalence of 

dental caries for the period 1967–1997 which was done online from 35 countries in 

sub‐Saharan mainland Africa, the study showed a predominantly downward trend in 

dental caries which was statistically significant for dmft at age 5 to 6 years and for 

DMFT at 35 to 44 years over  a period of two decades between 1967 to 1987 

(Cleaton-Jones, Fatti and Bönecker, 2006). 

Studies done in the past on caries prevalence for 5-year-old children in Namibia 

have found a mean dmft of 1.4 nationally and 1.23 for  Khomas region in which 

Windhoek is located (Schier and Cleaton‐Jones, 1995). In another closely related 

study by Hofstedt and Stillerman (1990) on 6-7 year old children of both rural and 

urban Windhoek, only 20% of the urban children and 35% of the rural children were 

caries free and the mean dmft in the urban area was 3.36 (SD 2.93) and in the rural 

area 2.43 (SD 3.18).  The goal set by WHO was to have more than 80% of the 6-

year-olds  caries free by the year of 2015 (Hofstedt and Stillerman, 1990).  



  

 

 

10 

 

 

This review of the literature serves to highlight an alarming situation for Namibian 

children where dental caries has been found to be severe (Thopil, 2013) and the fact 

that many children will be confronted by caries even in their permanent dentition.  

This assumption has been proven by previous studies that have shown a high 

correlation between high caries frequency in deciduous dentition followed by high 

caries frequency in the permanent dentition (Çolak and Dülgergil, 2012).   

Given the scarcity of information on the oral health status of 2-6 years old preschool 

children in Namibia and the fact that oral health surveys done before have focused 

mainly on primary or secondary school children and as such there is not enough 

data available for the pre-school population for Windhoek and the rest of Namibia; it 

was with this background that the present study sought to determine the magnitude 

of early childhood caries among children aged between 2-6 years in the urban 

setting of Windhoek in Namibia.  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 



  

 

 

11 

 

Chapter 2.  Aims and Objectives 

 

2.1 Aim of the Study 

 

The aim of this study was to determine the caries prevalence of pre-school children 

aged 2-6 years in Windhoek, Namibia. 

 

 

 

2.2 Objectives  

 

(i) To determine the prevalence of caries amongst 2-6-year-old children 

attending selected crèches in Windhoek, Namibia. 

(ii) To assess the clinical consequences of untreated tooth decay amongst       

2-6-year-old children attending selected crèches in Windhoek using the 

pufa index. 

(iii) To investigate the strength of correlation between the dmft and pufa 

indices amongst 2-6 years-old children attending selected creches in 

Windhoek, Namibia. 

(iv) To evaluate the correlation between oral hygiene practices and early 

childhood caries amongst 2-6-year-old children attending selected crèches 

in Windhoek, Namibia. 

 

 

 

 

 

 

 

 

 

 

 

 



  

 

 

12 

 

Chapter 3: Materials/Methods 

 

 

3.1 Study Design  

 

A descriptive, cross sectional survey was chosen for this study as it best suited the 

study aims and objectives.  

 

The examination was done under natural light and caries was diagnosed according 

to WHO criteria as cited by (Assaf et al., 2004).  

 

 

3.2 Study Site and Study Population 

 

The sample was selected by random sampling method and the sample size was 

subdivided proportionally according to the total population of early childhood 

development and pre-primary learners in each of the 9 constituencies of Windhoek. 

A total of 27 randomly selected crèches were identified to participate in the survey 

and 586 children between the ages of 2-6 years were to be examined. However, due 

to formalities that had to be met before in terms of obtaining permission from the 

respective school boards and parental consent from would be participants, only 24 

creches and 250 parents gave permission and consent. 

 

The study site was comprised of 24 randomly selected creches within Windhoek’s 9 

urban constituencies  (Namibia Statistics Agency. Namibia Inter-censal Demographic 

Survey 2016 Report. Namibia Statistics Agency, Windhoek. (2017) [accessed 21 

August 2018] - Google Search,2017). With the permission from the school 

management participating creches were identified. With the assistance of the 

respective school principals and the individual class teachers of the respective 

learners per age group, prospective learners were identified, and their parents were 

sent the necessary consent forms as well as an oral health questionnaire that they 

had to complete on behalf of their children.  



  

 

 

13 

 

The prospective learners’ parents were informed of their rights to either allow or 

withhold their children from participating in the study.  

 

From the total of 586 a total of 250 parents gave consent and completed the issued 

consent and oral health questionnaire forms. From the 27 earmarked creches that 

were selected  to be participants in the research, only 24 accepted and as such 

these comprised the total number of creches that participated in the research study. 

 

The study population comprised of 2-6 year old learners attending various creches in 

Windhoek’s 9 urban constituencies (Namibia Statistics Agency. Namibia Inter-censal 

Demographic Survey 2016 Report. Namibia Statistics Agency, Windhoek. (2017) 

[accessed 21 August 2018] - Google Search,2017). 

 

 

3.3  Sampling and sample size  

 

Using the sample size calculator from The Survey System 

(https://www.surveysystem.com/sscalc.htm) at 95% confidence level and a margin of 

error (confidence interval) of 4%, a random sampling method was used to select the 

children from the chosen participating creches.  The sample size was subdivided 

proportionally according to total population of early childhood development and pre-

primary learners in each of the 9 constituencies of Windhoek, Namibia.  

 

The sample comprised of a total of 250 participants of which 48% (119) were 

females and 52% (131) were males. Age distribution amongst the participants was 

as follows: 2-year old 6.2% (16), 3-year old 11.6% (30), 4-year old 20.5% (53), 5-

year old 32.5% (84) and 6-year old 29.1% (75). 

 

 

3.4  Methodology 

 

The study instrument consisted of two components: 

https://www.surveysystem.com/sscalc.htm


  

 

 

14 

 

 Clinical examination of children was performed using the WHO dmft and pufa 

index for the assessment of dental caries and untreated decay in primary 

dentition.                                                                                                                      

The clinical assessment was made by visual inspection without the use of any 

instruments except for gauze pads that were used only to remove loose food 

debris from the surface of the teeth. Infection control barrier measures like 

nonsterile, single use disposable gloves and face masks were worn during the 

dental examination. The gloves and used gauze were disposed of in a red 

colour coded medical waste disposal bag. Hand disinfection sanitizer was 

used by the examiner after each child’s clinical examination.  

 A complementary oral health questionnaire was completed prior to the clinical 

dental examination and the forms contained 19 questions that consisted of 

demographic details such as age, gender, place of birth, occupation, level of 

education, living conditions and the parent’s or care giver’s oral health and 

dietary habits as well as questions related to the child regarding his/her oral 

health and dietary habits. This questionnaire was similar to that used in a 

study by Thopil (Thopil, 2013)  and was modified for use in this study (see 

appendix 3) 

 

Training and calibration of the single examiner Dr. Aluteni was done by the team 

from the Department of Community Dentistry at the Wits Oral Health Sciences 

School. A short lecture covering dental caries and clinical diagnosis using WHO 

criteria as described in the WHO Basic Methods Manual, was presented to the 

researcher (World Health Organization, 2013). Extracted primary teeth were 

mounted in plaster (approximately 30) and placed on a display table.  After going 

through the criteria that the WHO uses for caries diagnosis, the researcher examined 

the mounted extracted teeth in the plaster mould for the presence or absence of 

caries using visual inspection under good light. His diagnosis and findings were 

assessed and checked for any discrepancies from the “model answer”. Correct 

diagnoses were discussed with the researcher and consensus/agreement was 

reached with the researcher on the correct diagnosis. The mounted teeth were then 

re-arranged in a different order from the 1st round of the exercise and the whole 

process of examining the mounted teeth for the presence or absence of caries was 



  

 

 

15 

 

repeated. After this, a Kappa score was calculated to determine the intra-examiner 

variability. The target was to obtain a Cohen Kappa score of 0.8 or more in order to 

ensure good reliability and standardization for caries diagnosis. An intra-rater 

reliability score of 0.91 was attained. 

The  dental clinical examinations were done by a single examiner. The clinical 

findings during the clinical examination were recorded in a modified WHO form for 

dmft and pufa recording. Each participant’s clinical examination form was attached to 

the corresponding completed oral health questionnaire.  

 

The examiner was assisted by a dental assistant whose task was that of recording 

the clinical findings onto the relevant form for each participant and filing the 

completed forms in  designated registry.  

 

The dental examination were performed with both the child and examiner seated on 

ordinary classroom school chairs and under normal day light conditions in a 

designated enclosure as was provided or indicated by the school coordinator of each 

respective creche. The examiner adopted a systematic approach to the examination 

for dental caries, proceeding in an orderly manner from one tooth or tooth space to 

the adjacent tooth or tooth space.  

  

To ensure consistent clinical judgment, 10% of each examination sample was 

randomly selected and re-examined in order to ensure intra examiner reliability. A 

Cohen’s Kappa score of 0.8 or more was achieved each time thus ensuring intra-

examiner reliability and consistency. 

 

 

3.5 Ethics consideration and clearance 

 

Ethics clearance and approval to conduct the research  study was applied for prior to 

commencement of the research study and was duly obtained from both the Ministry 

of Health and Social services in Namibia and from the Human Research Ethics 

Committee from the University of the Witwatersrand. A letter was sent to parents of 

children attending selected participating creches explaining the aims of the study and 



  

 

 

16 

 

asking them for their consent. Signed informed consent was obtained from each 

participant’s parent or care giver prior to conducting the clinical dental examinations. 

Participation in this study was entirely voluntary and the participants were allowed to 

withdraw from the study at any time should they wish to do so without any untoward 

consequences.  

Parents and care givers were assured that strict confidentiality would be maintained 

at all times and that none of their names or personal details would be mentioned in 

the write up of the study.  

 

Anonymity was achieved by not using the participant's names on the questionnaire 

and the questionnaires were recorded with coded numbers.  

 

 

3.6 Data analysis 

 

Data was analysed using STATA version 12. Quantitative variables were 

summarized as proportions, frequencies and percentages. Because both the dmft 

and pufa indices were not normally distributed, Spearson’s test for correlation was 

used to determine the strength of the association between both indices (dmft & 

pufa).  Multi-variable adjusted logistic regression was carried out using a backward 

deletion approach starting with a full model of factors significantly associated with 

early childhood caries. The level of significance was set at P<0.05.   

 

 

 

 

 

 

 

 

 

 

 



  

 

 

17 

 

 

Chapter 4. Results 

 

 

4.1 Socio-demographic  characteristics of the study participants ( n=250) 

 

From the total number of 586 questionnaires distributed 250 signed forms were 

returned equating to a response rate of 43% for the earmarked target population 

sample.  Gender distribution by the participants was 48% (119) females and 52% 

(131) males. 

    

 Table 1:  Socio-demographic characteristics of the study participants ( n=250) 

Characteristics %(n) 

Gender of child  

Female 47.60 (119) 

Male 52.40 (131) 

Level of education of mother  

No schooling 3.49 (8) 

Secondary school 24.02 (55) 

High school 21.83 (50) 

College/university 50.66 (116) 

Level of education of father  

No schooling 3.40 (5) 

Secondary school 21.77 (32) 

High school 28.57 (42) 

College/university 46.26 (68) 

Self-rated oral hygiene by parents  

Good 67.19 (170) 

Fair 28.85 (73) 

Poor 3.95 (10) 

Parent brushing child’s teeth  

No 6.10 (15) 



  

 

 

18 

 

Yes 93.90 (231) 

Flossing by child  

Once/day 18.85 (46) 

2 or 3 times a day 11.89 (29) 

Never 69.26 (169) 

Quantity of toothpaste applied  

Full length of bristles 26.14 (63) 

About size of a grain of rice 4.56 (11) 

About the size of a pea 26.56 (64) 

Half-length of bristles 42.74 (103) 

Duration of brushing  

About 30seconds 19.68 (49) 

About  1 minute 32.53 (81) 

About  2 minutes 32.53 (81) 

Don’t know 15.26 (38) 

Use of pacifier  

No  93.36 (211) 

Yes 6.64 (15) 

Thumb sucking  

No 86.00 (215) 

Yes 14.00 (35) 

Mouth pain  

No 80.32 (200) 

Yes 19.68 (49) 

Child going to bed with a baby bottle  

No  85.83 (212) 

Yes 14.17 (35) 

Parent’s rating of oral hygiene status of 

child 

 

Good 47.58 (118) 

Fair 38.31 (95) 

Poor 14.11 (35) 

 



  

 

 

19 

 

4.2 Age distribution of the participants  

 

Table  2 below depicts the age distribution of the child participants. Two hundred and 

fifty- (250) children were examined and the majority of the participants were five-year 

olds at 32.5% followed by six-year olds and the least were 2-year olds at 6.2%. The 

mean age of the study population was 4.70 years (SD 1.16).    

 

Table 2 age distribution of the participants.  (n=250) 

2-year-old 16 6.2% 

3-year-old 29 11.6% 

4 years old 51 20.5% 

5 years old 81 32.5% 

6 years old 73 29.1% 

 

 

4.3 Early childhood caries in children  

 

Early childhood caries was calculated by adding decayed, missing and filled teeth to 

generate dmft. Most of the children had a dmft of 3 and the mean dmft from the 

study population was 2.38. Prevalence for the study was 55.77%. The pufa score 

was a minimum of 0 and a maximum of 3 with a mean of 0.11(SD=0.45) thus 

resulting in a  mean pufa score of 0.11.  and a prevalence of 6.54% for the study 

population. This implies that on average there was about a 1 in 10 chance of the 

child who had tooth decay presenting with symptoms such as p u f or a. 

 

 

4.4 Correlation between dmft and pufa 

 

Spearman’s correlation was used instead of Pearson’s test because both dmft and 

pufa were not normally distributed. Also, the variables were ordinal not continuous 

which is one of the indicators for the use of Pearson’s test. The dmft and pufa 

variables have shown a direct proportional relation thus therefore a positive 



  

 

 

20 

 

correlation of 0.2838 i.e. 28.3%  (p<0.001) between pufa and dmft was established, 

meaning that the higher the dmft, the higher is pufa. 

 

 

4.5 Caries (cavities) observed by parents 

 

From figure 1 below it is observed that prevalence of parent-reported caries/cavities 

was established at 33.88%. 

 

 

 

Figure 1: Caries (cavities) observed by parents 

 

 

4.6 Prevalence of early childhood caries by oral hygiene practices 

 

Table 3 below shows reported oral hygiene practices for the study cohort. 

 

 As observed in table 3 below, a higher proportion of children whose parents 

reported having cavities had early childhood caries (65.85% vs. 50.63%; p=0.029). 

The lower the duration of tooth-brushing, the more the proportion of early childhood 

caries was (p=0.024). There was no significant difference in the proportion of caries 

with other oral hygiene practices such as the frequency of child’s tooth brushing, 

66.12% 

33.88% 

No Yes



  

 

 

21 

 

frequency of flossing in a day, quantity of toothpaste used, use of pacifiers and 

thumb sucking. 

Table 3: Reported oral hygiene practices for the study cohort n=250 

Characteristics Prevalence %(n) P-value 

Oral health of parent  0.731 

Good 53.53 (91)  

Fair 58.90 (43)  

Poor 60.00 (6)  

Cleaning of child’s teeth 

by parent 

 0.693 

No 51.72 (15)  

Yes 56.50 (126)  

Use of toothbrush to 

clean child’s teeth 

 0.815 

No 60.00 (12)  

Yes 55.07 (125)  

Use of toothpaste to 

clean child’s teeth 

 0.637 

No 57.89 (11)  

Yes 50.88 (116)  

Parent helps child to 

clean teeth 

 0.856 

No  52.94 (18)  

Yes 51.17 (109)  

Overall parent cleaning for 

child 

 0.794 

No 60.00 (9)  

Yes 55.41 (128)  

Materials used to clean 

child’s teeth 

 0.673 

Toothbrush + toothpaste + 

dental floss 

50.00 (10)  



  

 

 

22 

 

Toothbrush + Toothpaste 

only 

56.56 (125)  

Don’t know 66.67 (6)  

Frequency of child’s 

tooth brushing 

 0.460 

Less than once a day 40.00 (6)  

Once a day 56.38 (84)  

Twice a day 57.50 (46)  

More than twice a day 80.00 (4)  

Time tooth brushing was 

normally done 

 0.682 

In the morning 56.38 (84)  

In the evening 42.86 (6)  

Both morning and evening 59.76 (49)  

Don’t know 60.00 (3)  

Frequency of 

flossing/day 

 0.120 

Once a day 41.30 (19)  

2 or 3 times/day 58.62 (17)  

Never 57.99 (98)  

Quantity of toothpaste  0.401 

Full length of bristles 63.49 (40)  

About size of a grain of 

rice/size of a pea 

53.33 (40)  

Half-length of bristles 53.40 (55)  

Duration of brushing  0.024* 

About 30seconds 59.18 (29)  

About 1 minute 55.56 (45)  

About 2 minutes 46.91 (38)  

Don’t know 76.32 (29)  

Use of pacifier  0.791 

No  54.03 (114)  



  

 

 

23 

 

Yes 60.00 (9)  

Thumb sucking  0.464 

No 56.74 (122)  

Yes 48.57 (17)  

Cavities/caries observed 

by parents 

 0.029* 

No 50.63 (81)  

Yes 65.85 (54)  

Mouth pain  0.079 

No 53.00 (106)  

Yes 67.35 (33)  

Bottle to bed  0.857 

No  55.19 (117)  

Yes 57.14 (20)  

Parent’s rating of oral 

hygiene status of child 

 <0.001* 

Good 43.22 (51)  

Fair 63.16 (60)  

Poor 82.86 (29)  

*p<0.05 

 

 

4.7 Risk Factors  for early childhood caries ECC  

 

Table 4 provides information on the possible risk factors associated with ECC in the  

study cohort.  

 

It was found that children whose parents rated their oral hygiene either as fair Odds 

Ratio - OR: 2.71; 95% Confidence Interval - CI: [1.49-4.92] or poor Odds Ratio - OR: 

9.65; 95% Confidence Interval - CI: [3.10-30.06] were significantly more likely to 

have early childhood caries when compared to children whose parents rated their 

oral hygiene as good . Also, female children were more likely to have early childhood 



  

 

 

24 

 

caries compared to male children Odds Ratio - OR: 1.94; 95% Confidence Interval - 

CI: [1.09-3.43]. 

   

Children who were either 5 years Odds Ratio - OR: 4.36; 95% Confidence Interval - 

CI: [1.02-18.57] or 6 years Odds Ratio - OR: 5.05; 95% Confidence Interval - CI: 

[1.18-21.61] were more likely to have early childhood caries than 2-year olds. 

However, there was no difference in the odds ratio of between the 3- and 4-year olds 

and the 2-year olds. 

  

Table 4: Risk factors for ECC n=240 

Characteristic Odds ratio (OR) 95% Conf. Interval P-value 

Parent’s rating of 

oral hygiene 

status of child 

   

Good 1.0   

Fair 2.71 1.49-4.92 0.001 

Poor 9.65 3.10-30.06 <0.001 

Gender of child    

Male 1.0   

Female 1.94 1.09-3.43 0.024 

Age of child (year)    

2 1.0   

3 2.53 0.53-12.09 0.246 

4 3.16 0.72-13.95 0.129 

5 4.36 1.02-18.57 0.046 

6 5.05 1.18-21.61 0.029 

 

 

4.8 Mean dmft by age of child 

 

Results in table 5 clearly shows that children within the 2-year age group had the 

lowest dmft score. The 3-4-year-old age group had almost similar dmft scores and 

the 5-year-old children had the highest dmft score followed by the 6-year olds that 



  

 

 

25 

 

was marginally lower. The mean dmft scores show an increasing trend with age 

except for an inverse relation trend between the 5 and 6-year-old age group. The 

overall mean dmft from the study population was established at 2.38. 

Table 5:Percentage and mean dmft by age of child 

 

 

 

 

 

 

 

 

4.9 Prevalence of caries by demographic and socio-economic factors 

 

Table 6 shows that there was no significant difference in the prevalence of caries 

between male and female children. Also, the level of education of either the mother 

or father did not affect the prevalence of caries. However, the older a child was the 

higher the prevalence of early childhood caries (p=0.030).   

 

Table 6:  Prevalence of caries by demographic and socio-economic factors 

n=250 

Characteristic Prevalence % (n) p-value 

Gender of child  0.094 

Male 52.10 (62)  

Female 62.60 (82)  

Age of child (year)   0.030 

2 30.77 (4)  

3 46.67 (14)  

4 47.17 (25)  

5 61.90 (52)  

6 66.67 (50)  

Level of education of 

mother 

 0.220 

Age (Year) Dmft =0 (%) Dmft>0 (%) Mean dmft (Standard deviation) 

2 69.2 30.8 0.77 (1.48) 

3 53.3 46.7 1.53 (1.91) 

4 54.7 45.3 1.81 (3.02) 

5 38.1 61.9 3.02 (3.56) 

6 33.3 66.7 2.84 (3.09) 



  

 

 

26 

 

No schooling  87.50 (7)  

Secondary school 63.64 (35)  

High school 62.00 (31)  

College/University 54.31 (63)  

Level of education of 

father 

 0.992 

No schooling 60.00 (3)  

Secondary school 56.25 (18)  

High school 54.76 (23)  

College/University 57.35 (39)  

 

 

4.10 Summary    

 

The mean age of the children was 4.7 years, the mean dmft index score was 2.38  

and the mean pufa score was 0.11. There was an increase in caries prevalence from 

30.77% amongst the 2-year-old children to 66.67% amongst the 6-year-old children 

thus indicating an increase in caries prevalence with increasing age in both girls and 

boys.   

 

The caries and pufa prevalence amongst the study cohort was established at 

55.77% and 6.54% respectively. There was a positive correlation of 0.2838 i.e. 

28.3%  (p<0.001) between pufa and dmft, meaning as dmft score increased so did 

the pufa score, thus conferring a direct proportional relation between the two 

variables. 

 

 

 

 

 

 

 

 



  

 

 

27 

 

Chapter 5. Discussion 

 

5.1 Introduction  

 

Dental caries is a major health problem in Namibian school children, especially in 

low income populations, however, very few studies have been done on the 

prevalence of the disease, treatment needs as well as the associated risk factors in 

this age group. The recognized high global prevalence of dental caries from various 

studies done by researchers such as (Bagramian and colleagues 2009,; Kassebaum 

et al., 2015) and from the few studies done in Namibia by (Thopil, 2013,; Priwe and 

Herunga, 1997,;  Hofstedt and Stillerman, 1990) a trend can be deduced 

corroborating and suggestive of an increased incidence of early childhood caries for 

Windhoek and Namibia. Although the few studies done have focused on older age 

groups and generally have not included children younger than 6 years of age. This 

study is amongst the first to provide detailed epidemiological data on caries 

prevalence on children younger than 6 years of age in Windhoek, Namibia. 

 

From the results of this study, it was established that caries prevalence in pre-school 

children of urban Windhoek was 55.77% with a mean dmft of 2.38 and there was a 

positive correlation of 0.2838 i.e. 28.3%  (p<0.001) between pufa and dmft. The 

findings of this study can be used as baseline knowledge on the oral health status of 

preschool children  from against which  future studies on this topic for other towns 

and cities in Namibia can be referenced against.  The risk factors for ECC included 

age of children and parental rating of children’s oral hygiene status. Children whose 

parents rated their oral hygiene as poor were more likely to have early childhood 

caries when compared to children whose parents rated their oral hygiene as good.  A 

higher proportion of children whose parents reported having cavities had early 

childhood caries.  

 

The relationship between early childhood caries and associated risk factors 

especially, in relation to oral hygiene habits, feeding habits and socio-economic 

conditions has been well documented (Prakash et al., 2012a).  

 



  

 

 

28 

 

The common indicators used for assessing risk factors in most studies have been 

the child‘s feeding habits and patterns, oral hygiene habits and practices followed by 

the education and employment status of the parents or care givers. In the present 

study, feeding and oral hygiene habits and practices along with the education and 

socio-economic conditions of parents and care givers were assessed.  

 

Although dental caries has been declining globally in general, especially among 

older children, the contrary has been observed in developing nations. (Mahejabeen 

et al., 2006).  Most oral health surveys have targeted school going children because 

of their easy accessibility which is not the case in preschool children. The oral health 

of pre-school children has remained an overlooked and neglected aspect which has 

rendered them a vulnerable sector of the population. 

 

 

5.2. Demographic composition 

 

In this study there was a response rate of 43% for the earmarked target population 

sample amounting to two hundred and fifty (250) children that  were examined with a 

gender distribution of 48% (120) females and 52% (130) males; showing that the 

gender representation in the study population was comparable with the 

representation of the total preschool learners population of Windhoek (Namibia 

Statistics Agency. Namibia Population and Housing Census 2011.N [accessed 21 

August 2018] - Google Search, no date).  

 

Female children were observed to have an increased likelihood of early childhood 

caries compared to male children Odds Ratio - OR: 1.94; 95% Confidence Interval - 

CI: [1.09-3.43].  The majority of participants were 4 years and older with a mean age 

of 4.70 years  and there was not a significant difference in the number of participants 

amongst the 5- and 6-year olds.  

 

Low maternal education was related to higher caries prevalence in their children. In 

the study sample of 250 children, 87.5% of children whose mothers had no schooling 

were affected with caries.  



  

 

 

29 

 

This was statistically significant when compared to those children whose mothers 

had received higher education. The results of this study are similar to other studies, 

which showed a strong association between mother’s education and presence of 

caries in their children as was the findings in  a study done in central Trinidad (Naidu, 

Nunn and Kelly, 2013). This may be attributed to the lack of information and 

awareness about oral health care for children in uneducated mothers. Mothers are 

the primary care givers of children and thus any tangible efforts aimed at curbing the 

disease should involve mothers forthwith. There are a number of studies that have 

found separate but overlapping findings in different settings on the effects of dietary 

feeding practices as well as parental factors and their influence on early childhood 

caries development (Rai and Tiwari, 2018; Evans et al., 2013; Feldens et al., 2010;  

Qin et al., 2008; Ersin et al., 2006;  Schroth and Moffatt, 2005) 

 

 

5.3 Prevalence of caries and pufa 

 

The prevalence of parent-reported caries/cavities was 33.88% and the prevalence of 

clinically diagnosed caries was 51.54%. Most of the children had a dmft of 3 (n=27; 

18.6%)  and the mean dmft from the study was 2.38. The mean pufa score for this 

study  was 0.11 and the prevalence pufa score was 6.54% (n=17). These findings 

were substantially lower than was found in a related study in north east Poland by 

Bagińska et al (2013) were the mean dmft was 5.56 and the pufa 

experience/prevalence was 2.20/43.4%.  

 

Results from the Namibian National Oral Health Survey of 2010/11 found a caries 

prevalence of 41.67% for Khomas region and a weighted national average of 

42.95% for the age group 5-6 year olds. Although the results from the National Oral 

Health Survey of 2010/11 provide baseline information especially for the 5-6 year old 

age group the two studies are not exactly comparable as the one was a national 

study with specific age groups of which the only relevance was the 5-6 year old age 

group; (Ministry of Health and Social Services Republic of Namibia, 2013).  



  

 

 

30 

 

Similarly in a study done by Hofstedt and colleagues (1990) which included 6-7 year 

old children it was found that the caries prevalence among the urban children was 

higher than the rural children of Windhoek (Hofstedt and Stillerman, 1990).  

 

Another study done in the past on caries prevalence for 5-year-old children in 

Namibia  found a mean dmft of 1.4 nationally and 1.23 for Khomas region in which 

Windhoek is located (Schier and Cleaton‐Jones, 1995).  From past  studies done a 

strong association between urbanization/industrialization and increased prevalence 

of caries has been posited by Bedi (2005) and therefore Windhoek being a major 

urban city in Namibia with a heterogeneous population, the findings from this study 

could be used to provide useful baseline knowledge that can be used by healthcare 

planners. 

   

The increased caries prevalence findings from this study are indicative that 

increased morbidity as a consequence is to be expected in the near future and as 

such oral health should become a high priority on the agenda of Namibian public 

health authorities as is advocated for globally (Kassebaum et al., 2015). Therefore 

the increased morbidity will have a concomitant effect on the quality of life of children 

and an increased financial burden on families as was the findings in a study by 

(Çolak et al., 2013; Tinanoff and Reisine, 2009). Findings from this study indicate a  

high caries prevalence and a low pufa prevalence. Thus, with the appropriate 

intervention strategies the disease progression process can be successfully thwarted 

and optimum oral health can be attained among the preschool population of 

Windhoek.  

 

 

5.4 Age distribution versus caries prevalence 

 

Children within the 2-year age group had the lowest dmft score. The 3-4 year-old 

age group had almost similar dmft scores and the 5-year-old children had the highest 

dmft score followed by the 6-year olds that was marginally lower than of the 5 year 

old. The mean dmft scores showed an increasing trend with age except for an 

inverse relation trend between the 5 and 6-year-old age group. The difference in the 



  

 

 

31 

 

caries prevalence was significant (<0.05) between the age groups of 3-4 years and 4 

and 5 years, and highly significant (<0.001) between the age groups of 2 and 5 

years.  

This increase in caries prevalence with increasing age was consistent with findings 

in similar studies done in Bangalore, India (Prakash et al., 2012b) and Riyadh, Saudi 

Arabia (Al-Meedani and Al-Dlaigan, 2016). Therefore the  older a child was the 

higher the prevalence of early childhood caries was (p=0.030). This could be due to 

increased exposure of the dentition to cariogenic assault in older teeth than in 

younger teeth.  

 

Goals set by the WHO to have a 20% caries prevalence in 6 year old children by the 

year 2015 as cited by Hofstedt and Stillerman (1990) it is evident that from this study 

the caries prevalence for Windhoek’s pre-school population is high. An extrapolation 

can then be deduced that the disease prevalence would even be higher in the 

permanent dentition given the postulation that caries onslaught in the primary 

dentition is a precursor for disease affliction in the permanent dentition (Çolak and 

Dülgergil, 2012). 

 

Results from this study and previous studies done in Namibia are suggestive of 

increasing caries levels for Namibia as a country contrary to the trend seen in 

developed nations such as the USA, UK, Japan where there has been a noted 

decrease in caries levels for the past few decades (Lagerweij and van Loveren, 

2015; Silveira Moreira, 2012). Despite this good strides made in the developed 

countries a paradoxical situation is found in sub Saharan Africa where caries 

prevalence is on the increase due to increased consumption of refined 

carbohydrates as a consequence of improved socioeconomic status (Holm, 1990). 

 

 

5.5 Clinical consequences of untreated tooth decay 

 

Using the pufa index as developed by Monse et al (2010) to assess the clinical 

consequences of untreated decay among the 2-6 year old children attending 

selected crèches the pufa score was a minimum of 0 and a maximum of 3 with a 



  

 

 

32 

 

mean of 0.11(SD=0.45). The mean pufa was determined to  be 0.11. with a total 

prevalence of 6.54% for the study population which was comparable with a related 

study done in suburban school children in Nigeria where the mean pufa score was 

0.16 (Oziegbe and Esan, 2013).  

Though the dmft prevalence was high the clinical consequences as a result were 

moderate and of relatively low severity which is consistent with a study done in Brazil 

by Figueiredo et al. (2011) where the mean pufa score was 0.4. Thus the mean pufa 

score from this study was comparable to both studies done in children in suburban 

Nigeria and Brazil where the mean pufa scores were 0.16. and 0.4 respectively.  

 

In another study by Mehta and Bhalla (2014) on the clinical consequences of 

untreated tooth decay even though their study was on 5-6 year old children in an 

urban population in India their findings were comparable to this study for the 

particular age group where their findings were 0.9 for pufa index and 2.54 for dmft 

compared to 0.11 pufa and an average of 2.93 dmft respectively from this study.  . 

 

 

5.6 Correlation between dmft and pufa  

 

Spearman’s correlation was used instead of Pearson’s test because both dmft and 

pufa were not normally distributed. Also, the variables were ordinal not continuous 

which is one of the indicators for the use of Pearson’s test (Bishara and Hittner, 

2012).  

 

There was a positive correlation of 0.2838 i.e. 28.3%  (p<0.001) between pufa and 

dmft as the two variables being studied were showing a direct proportional increase.  

Statistical analysis revealed a strong relation between dmft and pufa in especially the 

4,5 and 6 year age groups. The presence of non-treated tooth decay (dmft) in this 

study population had a direct proportion on the presence of clinical consequences 

(pufa).  

 

Even though the pufa prevalence of 6.54% and a mean pufa score  of 0.11 were 

fairly low in comparison to the dmft prevalence of 55.77% and mean dmft score of 



  

 

 

33 

 

2.38 respectively for this study. When compared to other similar or related studies 

from north east of Poland (Bagińska et al., 2013).; where prevalence and mean 

scores for dmft and pufa were 43.4% and 5.56 for 5year olds and 72.4% and  6.69 

for 7 year olds with  pufa scores of 2.2 for 5year olds and 2.44 for 7 year olds 

respectively, still a positive correlation was found between caries prevalence and 

clinical consequences.  

 

The work of Mehta and Bhalla (2014) showed positive and significant correlation of 

dental caries and clinical manifestations as a consequence. Though the findings 

from their study were higher than this study it should be noted that their study was 

only on 5-6 year old children, whereas this study’s findings are on 2-6 year old 

children. 

 

 Findings from this study should be cautiously weighed as the study population 

differed from their study population, however there were commonalities worth noting. 

From the results it can be deduced that given enough time, more than half of the 

children from the study group would at least develop pain as a consequence of 

untreated tooth decay and  as a consequence healthcare planners need to design 

appropriate curative programmes soon. 

  

 

5.7 Correlation of oral hygiene practises and early childhood caries - ECC  

 

Despite the fact that parents/care takers indicated that they actively assisted their 

children in the execution of their daily oral hygiene duties prevalence of early 

childhood caries by oral hygiene practices ranged between 50-66%.   

 

From the research findings a higher proportion of children whose parents reported 

having cavities had early childhood caries (65.85% vs. 50.63%; p=0.029).  The lower 

the duration of tooth-brushing, the more the proportion of early childhood caries was. 

There was no significant difference in the proportion of caries with other oral hygiene 

practices such as the frequency of child’s tooth brushing, frequency of flossing in a 

day, quantity of toothpaste used, use of pacifiers and thumb sucking.  



  

 

 

34 

 

 

Results from this study have shown a strong association between  parent’s rating of 

oral hygiene status of child and an increased presence of early childhood caries.  

Children whose parents rated their oral hygiene as poor were more likely to have 

early childhood caries when compared to children whose parents rated their oral 

hygiene as good.  

This was consistent with similar results from a Brazilian study done by Corrêa-Faria 

et al ( 2016) were the prevalence of early childhood caries was 53.6% due to poor 

oral hygiene practises.   

 

Children who were either 5 years Odds Ratio - OR: 4.36; 95% Confidence Interval - 

CI: [1.02-18.57] or 6 years Odds Ratio - OR: 5.05; 95% Confidence Interval - CI: 

[1.18-21.61] were more likely to have early childhood caries than 2-year olds.  

 

From this study a strong congruence can be inferred with studies done in India and 

Brazil, where similarities in socio-economic conditions are a prevailing common 

denominator (Kundu et al., 2015; Holm, 1990). It has thus emerged from this study 

that poor oral hygiene practices due to a lack of appropriate dental health knowledge 

had a major contributory effect on the increased prevalence of early childhood 

caries. 

 

 

5.8 Limitations of the study  

 

This study was a cross-sectional study and cross-sectional studies are inherently 

flawed in the sense that their findings are period specific and cannot be used to 

analyze behavior over an extended period. They fail to prove the temporal 

relationship between exposure and outcome and they are beset with a high 

propensity for potential bias.  

 

The lack of use of diagnostic intra oral radiographs, the challenging settings in which 

the clinical examinations were conducted and difficulties in obtaining optimum 

cooperation from the patients being examined, has made it difficult to conduct this 



  

 

 

35 

 

dental research examinations under ‘ideal’ clinical settings. Therefore, the results of 

this study may have an inherent under estimation of dental caries. Dental caries 

prevalence would probably have been higher had probes/explorers and intra oral 

radiographs been used.   

 

Populations of young children at risk for dental caries were difficult to recruit because 

they were not enrolled in large numbers in institutional settings where they would be 

easily accessible for research related studies.  

Lack of understanding regarding the importance and relevance of dental research 

from parents/caregivers and owners of creches which influenced their decision 

making resulting in refusal to participate in the study.  

 

In this study,  a small randomly selected urban population sample was selected and 

as such the research results found should be cautiously interpreted as 

representative of populations other than the one being studied if comparisons are 

made against incongruent national and discordant sized population studies. 

 

The lack of other studies with which to compare the results from this research study 

for preschool learners of Windhoek may be a limitation but certainly the findings from 

this study can be used as baseline knowledge for future similar or related studies. 

 

 

 

 

 

 

 

 

 

 

 

 

 



  

 

 

36 

 

Chapter 6. Conclusions and recommendations 

 

6.1 Conclusion 

 

This study sought to determine the caries prevalence of pre-school children aged 2-6 

years in Windhoek, Namibia. 

 

From the results of this study, it was established that caries prevalence in pre-school 

children of urban Windhoek was 55.77% with a mean dmft of 2.38  which is 

considered high when compared with other countries. An increase in age was 

positively correlated with an increase in dmft. The pufa prevalence was determined 

at 6.54% with a mean of 0.11 and the study showed that there was a positive 

correlation of 0.2838 i.e. 28.3%  (p<0.001) between pufa and dmft meaning that a 

direct proportional relation was exhibited between the two variables  which means as 

the dmft variable increased so also did the pufa variable increase. 

 

Correlation of oral hygiene practises associated with early childhood caries was 

established and a 50-66% caries presence in children was found despite parents 

indicating that they were actively involved with daily oral hygiene practises of their 

children. Children whose parents rated their oral hygiene as poor had increased 

prevalence of early childhood caries than children whose parents rated their 

children’s oral hygiene as good.  

 

This study has conclusively proven that there is a high caries prevalence among the 

preschool population of Windhoek which could have deleterious effects on the 

general health in this population  

 

 

 

 

 

 

 



  

 

 

37 

 

6.2 Recommendations  

The following recommendations are made on the basis of the findings:  

 

6.2.1 Preventive oral health promotion programmes 

Oral health promotion programmes aimed at prevention of early childhood caries 

must be developed and actively promoted via all available platforms such as for 

example radio, television, newspapers, magazines, and social media.  

  

6.2.2 Studies on caries prevalence of pre-school children in rest of Namibia 

 

From the findings of this study dental researches, policy makers and dental 

healthcare practitioners should focus on future studies that will shed more 

knowledge on the caries prevalence of preschool children population of Namibia in 

order to devise an encompassing national oral health policy programme.  

 

6.2.3 Identification of communities and individuals with high caries risk 

 

Dental professionals should establish systematic continuous periodic dental 

screenings within the various communities and pay special attention to families with 

mothers with low education levels, whereby early detection of groups of children at 

increased risk  of early childhood caries development can be done.  

 

6.2.4 Toothbrushing with fluoridated toothpaste 

 

Brush in programmes at all creches must be established where all preschool children 

can be taught the correct tooth brushing methods using fluoridated toothpaste.  

 

6.2.5 Counselling to Reduce Harmful Behaviours  

 

Counselling aimed at parents to change their behaviours and adopt preventive 

dental behavioural practices that will result in reducing the risk of early childhood 

caries development . 



  

 

 

38 

 

6.2.6 Dental Referral 

 

Children identified with early childhood caries should be immediately referred to 

dental professionals for prompt treatment.   

 

 

 

 

References 

 

Al-Meedani, L. A. and Al-Dlaigan, Y. H. (2016) ‘Prevalence of dental caries and 

associated social risk factors among preschool children in Riyadh, Saudi Arabia’, 

Pakistan Journal of Medical Sciences. doi: 10.12669/pjms.322.9439. 

 

AlKhayat, M. (2018) ‘Caries Survey in 3-5 Year Old Children in Dubai Schools’, 

Interventions in Pediatric Dentistry Open Access Journal, 1(1). doi: 

10.32474/ipdoaj.2018.01.000101. 

 

Anaise, J. Z. (1984) ‘Measurement of dental caries experience-modification of the 

DMFT index’, Community Dentistry and Oral Epidemiology. Wiley, 12(1), pp. 43–46. 

doi: 10.1111/j.1600-0528.1984.tb01408.x. 

 

Assaf, A. V. et al. (2004) ‘Assessment of different methods for diagnosing dental 

caries in epidemiological surveys’, Community Dentistry and Oral Epidemiology, 

32(6), pp. 418–425. doi: 10.1111/j.1600-0528.2004.00180.x. 

 

Bagińska, J. et al. (2013) ‘Index of clinical consequences of untreated dental caries 

(pufa) in primary dentition of children from north-east Poland’, Advances in Medical 

Sciences. Medical University of Bialystok, 58(2), pp. 442–447. doi: 10.2478/v10039-

012-0075-x. 

 

Bagramian R. A., Garcia-Godoy, F. and Volpe, A. R. (2009) ‘The global increase in 

dental caries’, Am J Dent, 21(1), pp. 3–8. 



  

 

 

39 

 

 

Bedi, R. (2005) ‘A futures study of dental decay in 5 and 15 year olds in England’, 

Health Education Journal. 

 

Bishara, A. J. and Hittner, J. B. (2012) ‘Testing the significance of a correlation with 

nonnormal data: Comparison of Pearson, Spearman, transformation, and resampling 

approaches’, Psychological Methods, 17(3), pp. 399–417. doi: 10.1037/a0028087. 

 

Bönecker, M. et al. (2012) ‘Impact of dental caries on preschool children’s quality of 

life: An update*’, Brazilian Oral Research, 26(SPL. ISS.1), pp. 103–107. doi: 

10.1590/S1806-83242012000700015. 

 

Cleaton-Jones, P. and Fatti, P. (1999) ‘Dental caries trends in Africa’, Community 

Dentistry and Oral Epidemiology. Blackwell Munksgaard, 27(5), pp. 316–320. doi: 

10.1111/j.1600-0528.1999.tb02027.x. 

 

Cleaton-Jones, P., Fatti, P. and Bönecker, M. (2006) ‘Dental caries trends in 5- to 6-

year-old and 11- to 13-year-old children in three UNICEF designated regions - Sub 

Saharan Africa, Middle East and North Africa, Latin America and Caribbean: 1970-

2004’, International Dental Journal. Wiley-Blackwell Publishing Ltd, pp. 294–300. doi: 

10.1111/j.1875-595X.2006.tb00104.x. 

 

Çolak, H. et al. (2013) ‘Early childhood caries update: A review of causes, 

diagnoses, and treatments’, Journal of Natural Science, Biology and Medicine, pp. 

29–38. doi: 10.4103/0976-9668.107257. 

 

Çolak, H. and Dülgergil, C. (2012) ‘Do the more caries in early primary dentition 

indicate the more caries in permanent dentition? Results of a 5-years follow-up study 

in rural-district’, Journal of International Society of Preventive and Community 

Dentistry. Medknow, 2(2), p. 48. doi: 10.4103/2231-0762.109364. 

 

Corrêa-Faria, P. et al. (2016) ‘Incidence of dental caries in primary dentition and risk 

factors: a longitudinal study’, Brazilian oral research, 30(1). doi: 10.1590/1807-



  

 

 

40 

 

3107BOR-2016.vol30.0059. 

 

Ersin, N. K. et al. (2006) ‘Association of maternal-child characteristics as a factor in 

early childhood caries and salivary bacterial counts’, Journal of Dentistry for 

Children. 

 

 

Evans, E. W. et al. (2013) ‘Dietary intake and severe early childhood caries in low-

income, young children’, Journal of the Academy of Nutrition and Dietetics. doi: 

10.1016/j.jand.2013.03.014. 

 

Figueiredo, M. J. et al. (2011) ‘Prevalence and severity of clinical consequences of 

untreated dentine carious lesions in children from a deprived Area of Brazil’, Caries 

Research, 45(5), pp. 435–442. doi: 10.1159/000330531. 

 

Filstrup, L. et al. (2003) ‘Early childhood caries and quality of life: Child and parent 

perspectives’, Pediatric Dentistry, 25(5). 

 

Gupta, D. et al. (2015) ‘Dental caries and their treatment needs in 3-5 year old 

preschool children in a rural district of India’, North American Journal of Medical 

Sciences. doi: 10.4103/1947-2714.156010. 

 

Hofstedt, H. and Stillerman, E. (1990) ‘Oral health status , knowledge and dietary 

habits among urban and rural 6-7 year old children in the Windhoek area , Namibia’, 

(1985), pp. 229–239. 

 

Holm, A. K. (1990) ‘Caries in the preschool child: international trends.’, Journal of 

dentistry, 18(6), pp. 291–5. doi: 10.1016/0300-5712(90)90125-x. 

 

Kamran, R. et al. (2017) ‘Clinical consequences of untreated dental caries assessed 

using PUFA index and its covariates in children residing in orphanages of Pakistan’, 

BMC Oral Health. BioMed Central Ltd., 17(1). doi: 10.1186/s12903-017-0399-9. 

 



  

 

 

41 

 

Kassebaum, N. J. et al. (2015) ‘Global burden of untreated caries: A systematic 

review and metaregression’, Journal of Dental Research, pp. 650–658. doi: 

10.1177/0022034515573272. 

 

 

Kundu, H. et al. (2015) ‘Dental caries scenario among 5, 12 and 15-year-old children 

in India- A retrospective analysis’, Journal of Clinical and Diagnostic Research. 

Journal of Clinical and Diagnostic Research, 9(7). doi: 

10.7860/JCDR/2015/12439.6150. 

 

Lagerweij, M. D. and van Loveren, C. (2015) ‘Declining Caries Trends: Are We 

Satisfied?’, Current Oral Health Reports. Springer Science and Business Media LLC, 

2(4), pp. 212–217. doi: 10.1007/s40496-015-0064-9. 

 

Mahejabeen, R. et al. (2006) ‘Dental caries prevalence among preschool children of 

Hubli: Dharwad city.’, Journal of the Indian Society of Pedodontics and Preventive 

Dentistry, 24(1), pp. 19–22. Available at: 

http://www.ncbi.nlm.nih.gov/pubmed/16582526 (Accessed: 2 October 2019). 

 

Mahejabeen, R. et al. (no date) ‘Dental caries prevalence among preschool children 

of Hubli: Dharwad city’, jisppd.com. Available at: 

http://www.jisppd.com/article.asp?issn=0970-

4388;year=2006;volume=24;issue=1;spage=19;epage=22;aulast= (Accessed: 1 

October 2019). 

 

Marcenes, W. et al. (2013) ‘Global burden of oral conditions in 1990-2010: A 

systematic analysis’, Journal of Dental Research, 92(7), pp. 592–597. doi: 

10.1177/0022034513490168. 

 

Mehta, A. and Bhalla, S. (2014) ‘Assessing consequences of untreated carious 

lesions using pufa index among 5-6 years old school children in an urban Indian 

population’, Indian Journal of Dental Research, 25(2), p. 150. doi: 10.4103/0970-

9290.135906. 



  

 

 

42 

 

 

Ministry of Health and Social Services Republic of Namibia (2013) National Oral 

Health Survey 2010/11. Windhoek, Namibia: Republic of Namibia: Ministry of Health 

and Social Services. Available at: 

http://www.mhss.gov.na/documents/119527/364677/NATIONAL+ORAL+HEALTH+S

URVEY.pdf/58b2346f-11d4-4d8f-857d-441da6a3a2f4. 

 

Monse, B. et al. (2010a) ‘PUFA - An index of clinical consequences of untreated 

dental caries’, Community Dentistry and Oral Epidemiology, pp. 77–82. doi: 

10.1111/j.1600-0528.2009.00514.x. 

Monse, B. et al. (2010b) ‘PUFA - An index of clinical consequences of untreated 

dental caries’, Community Dentistry and Oral Epidemiology, 38(1), pp. 77–82. doi: 

10.1111/j.1600-0528.2009.00514.x. 

 

Naidu, R., Nunn, J. and Kelly, A. (2013) ‘Socio-behavioural factors and early 

childhood caries: A cross-sectional study of preschool children in central Trinidad’, 

BMC Oral Health, 13(1). doi: 10.1186/1472-6831-13-30. 

 

Namibia Statistics Agency. Namibia Inter-censal Demographic Survey 2016 Report. 

Namibia Statistics Agency, Windhoek. (2017) [accessed 21 August 2018] - Google 

Search (no date). Available at: 

https://www.google.com/search?hl=en&ei=q7OUXeecAdaV1fAP6tyi-

AI&q=Namibia+Statistics+Agency.+Namibia+Inter-

censal+Demographic+Survey+2016+Report.+Namibia+Statistics+Agency%2C+Wind

hoek.+%282017%29++%5Baccessed+21+August+2018%5D&oq=Namibia+Statistic

s+Agency.+Namibia+Inter-

censal+Demographic+Survey+2016+Report.+Namibia+Statistics+Agency%2C+Wind

hoek.+%282017%29++%5Baccessed+21+August+2018%5D&gs_l=psy-

ab.12...0.0..230...0.0..0.0.0.......0......gws-

wiz.mVAZEf9k9dk&ved=0ahUKEwinnpGU5P3kAhXWShUIHWquCC8Q4dUDCAs 

(Accessed: 2 October 2019). 

 

 



  

 

 

43 

 

 

Namibia Statistics Agency. Namibia Population and Housing Census 2011.N 

[accessed 21 August 2018] - Google Search (no date). Available at: 

https://www.google.com/search?hl=en&ei=a7aUXbu8Ao2P1fAPlq65wAE&q=Namibi

a+Statistics+Agency.+Namibia+Population+and+Housing+Census+2011.N+%5Bacc

essed+21+August+2018%5D&oq=Namibia+Statistics+Agency.+Namibia+Population

+and+Housing+Census+2011.N+%5Baccessed+21+August+2018%5D&gs_l=psy-

ab.3...413701.418630..420228...0.5..0.329.329.3-1......0....1j2..gws-

wiz.....0..0i71.kZANPa2JL-

o&ved=0ahUKEwj7nevj5v3kAhWNRxUIHRZXDhgQ4dUDCAs&uact=5 (Accessed: 2 

October 2019). 

 

Organization, W. H. (2013) Oral health surveys: basic methods. Available at: 

https://books.google.com/books?hl=en&lr=&id=8rEXDAAAQBAJ&oi=fnd&pg=PP1&d

q=World+Health+Organization.+Oral+health+surveys-

basic+methods.+5th+ed.+Geneva:+Oral+health+surveys:+basic+methods.+(2013)&

ots=fCKDS_wG2s&sig=W68qOW--GBmsd1xB0IagXeAm3vs (Accessed: 3 October 

2019). 

 

Ozdemir, D. (2013) ‘Dental Caries : The Most Common Disease Worldwide and 

Preventive Strategies’, International Journal of Biology, 5(4), pp. 55–61. doi: 

10.5539/ijb.v5n4p55. 

 

Oziegbe, E. O. and Esan, T. A. (2013) ‘Prevalence and clinical consequences of 

untreated dental caries using PUFA index in suburban Nigerian school children’, 

European Archives of Paediatric Dentistry, 14(4), pp. 227–231. doi: 10.1007/s40368-

013-0052-5. 

 

Pine, C. M. et al. (2006) ‘An investigation of the relationship between untreated 

decayed teeth and dental sepsis in 5-year-old children’, British Dental Journal, 

200(1), pp. 45–47. doi: 10.1038/sj.bdj.4813124. 

 

 



  

 

 

44 

 

 

Prakash, P. et al. (2012a) ‘Prevalence of early childhood caries and associated risk 

factors in preschool children of urban Bangalore, India: A cross-sectional study’, 

European Journal of Dentistry, 6(2), pp. 141–152. 

 

Prakash, P. et al. (2012b) ‘Prevalence of early childhood caries and associated risk 

factors in preschool children of urban Bangalore, India: A cross-sectional study’, 

European Journal of Dentistry, 6(2), pp. 141–152. Available at: 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3327493/ (Accessed: 9 October 

2019). 

 

Priwe C, Herunga, N (1997). Oral Health Among Primary School Children in Namibia 

IADR First Joint Congress of the South African division. Cape Town. - Google 

Search (no date). Available at: 

https://www.google.com/search?hl=en&sxsrf=ACYBGNQxMJaU0JJJQLT5Ng8OwV

DogCE4CA%3A1574091052685&source=hp&ei=LLnSXcqOJ8vWwAL_9pvgBg&q=

Priwe+C%2C+Herunga%2C+N+%281997%29.+Oral+Health+Among+Primary+Scho

ol+Children+in+Namibia+IADR+First+Joint+Congress+of+the+South+African+divisio

n.+Cape+Town.&oq=Priwe+C%2C+Herunga%2C+N+%281997%29.+Oral+Health+

Among+Primary+School+Children+in+Namibia+IADR+First+Joint+Congress+of+the

+South+African+division.+Cape+Town.&gs_l=psy-

ab.3...11899.11899..14161...0.0..0.0.0.......1....2j1..gws-

wiz.&ved=0ahUKEwjK1KWQivTlAhVLK1AKHX_7BmwQ4dUDCAY&uact=5 

(Accessed: 18 November 2019). 

 

Qin, M. et al. (2008) ‘Risk factors for severe early childhood caries in children 

younger than 4 years old in Beijing, China’, Pediatric Dentistry. 

Schier, M. and Cleaton‐Jones, P. (1995) ‘Dental caries in Namibia – the first national 

survey’, Community Dentistry and Oral Epidemiology, 23(5), pp. 262–265. doi: 

10.1111/j.1600-0528.1995.tb00245.x. 

 

Schroth, R. J. and Moffatt, M. E. K. (2005) ‘Determinants of Early Childhood Caries 

(ECC) in a rural Manitoba community: A pilot study’, Pediatric Dentistry. 



  

 

 

45 

 

 

Sheiham, A. (1984) Changing Trends in Dental Caries, International Journal of 

Epidemiology © International Epidemiological Association. Available at: 

http://ije.oxfordjournals.org/ (Accessed: 9 October 2019). 

 

Silveira Moreira, R. da (2012) ‘Epidemiology of Dental Caries in the World’, in Oral 

Health Care - Pediatric, Research, Epidemiology and Clinical Practices. InTech. doi: 

10.5772/31951. 

 

Struzycka, I. (2014) ‘The oral microbiome in dental caries’, Polish Journal of 

Microbiology, pp. 127–135. Available at:  

https://www.researchgate.net/publication/264797835 (Accessed: 1 October 2019). 

 

Thopil, A. (2013) RISK FACTORS ASSOCIATED WITH EARLY CHILHOOD 

CARIES: AN EPIDEMIOLOGICAL SURVEY IN MARIENTAL, NAMIBIA. 

 

Tinanoff, N. and Reisine, S. (2009a) ‘Update on Early Childhood Caries Since 

the Surgeon General’s Report’, Academic Pediatrics. Elsevier Ltd, 9(6), pp. 396–

403. doi: 10.1016/j.acap.2009.08.006. 

 

Tinanoff, N. and Reisine, S. (2009b) ‘Update on Early Childhood Caries Since 

the Surgeon General’s Report’, Academic Pediatrics, 9(6), pp. 396–403. doi: 

10.1016/j.acap.2009.08.006. 

 

World Health Organization, W. H. O. (2013) Oral health surveys: basic methods. 

Available at: 

https://books.google.com/books?hl=en&lr=&id=8rEXDAAAQBAJ&oi=fnd&pg=PP1&d

q=World+Health+Organization.+Oral+health+surveysbasic+methods.+5th+ed.+Gene

va:+Oral+health+surveys:+basic+methods.+(2013)&ots=fCKDS_wG2s&sig=W68qO

W--GBmsd1xB0IagXeAm3vs (Accessed: 3 October 2019). 

 

 

 



  

 

 

46 

 

Appendices 

 

Appendix 1.  Information leaflet for research on preschool children. 

 

Appendix 2.  Parent’s/guardian’s/care giver’s consent form for dental research  

  involving a minor child. 

 

Appendix 3.  Oral health questionnaire for parent’s/guardian’s/care givers, seeking 

  information on behalf of and of relevance to minor child.  

 

Appendix 4.  Oral health clinical assessment form.  

 

Appendix 5. Human Research Ethics Clearance Certificate ( Wits). 

 

Appendix 6. Human Research Ethics Clearance Certificate (MoHSS).  

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 



  

 

 

47 

 

Appendix 1: Information cover letter for research on preschool children.   

 
Caries prevalence amongst pre-school children in Windhoek, Namibia 
 
Your child is being invited to participate in a research study. Participation in this 
research study is voluntary and confidentiality is assured.  No individual data will be 
reported.  
 
Thank you for taking the time to read this information leaflet.  
 
RESEARCH TEAM: Dr. Moses Aluteni, currently a registered student for the  
MSc Dentistry degree at the University of the Witwatersrand, School of Oral Health 
Science; is leading this research project. Our contact details are included at the end 
of this document.  
 
WHAT ARE THE OBJECTIVES OF THIS STUDY? The purpose of the study is to 
determine the prevalence of early childhood caries amongst 2 – 6-year-old children 
in Windhoek urban area.  
 
WHY HAVE I BEEN INVITED TO TAKE PART? You have been approached to 
participate in this research, as you are a parent/guardian of a pre-school/ crèche-
going learner. 
 
WHAT WILL HAPPEN IF YOU VOLUNTEER? Your participation is entirely 
voluntary. If you agree to participate, your child will be invited to take part in a 
dental/oral clinical examination. This would involve a basic examination of the mouth. 
The instruments we would be using would be a disposable wooden spatula, light 
disposable gloves and a mask. We would want to count the number of decayed 
(rotten) teeth and the number of healthy teeth. We would also assess the state of the 
gums and other soft tissues. You will be asked to complete an oral health 
questionnaire on behalf of your child and this information may have direct relevance 
to your child’s prevailing oral health status. 
There is neither cost nor payment to the participants involved in this study. 
 
CONFIDENTIALITY:  
Your child’s name will not be used when data from this study is published. Every 
effort will be made to keep clinical records, research records and other personal 
information confidential. 
 
WHAT ARE THE BENEFITS OR RISKS ASSOCIATED WITH THE STUDY? While 
there will be no direct benefit to you from the study, the findings have the potential to 
make a contribution to our understanding of the oral disease prevalence (the extent 
of the number of children who have rotten teeth) and associated risk factors for early 
childhood caries amongst the pre-school age population in Windhoek urban area (we 
will determine this from the response you provide in the questionnaire that you as the 
parent/caregiver will be asked to fill in). As such, the findings from this study will be 
presented at university level and at national and international conferences. The 
findings will also be submitted for publication in peer-reviewed journals.  



  

 

 

48 

 

However, no individual participant will be identified in any publication or presentation 
and only anonymised quotes will be used in these reports and publications. There 
are no known risks associated with participation. 
 
RIGHT TO WITHDRAW: You can decide to withdraw from the study at any point 
without any consequence. You can contact the researchers to request this.  
 
HOW WILL YOUR INFORMATION BE USED? Your responses that we receive from 
the filled-out questionnaires, together with the results we obtain from the clinical oral 
examination, of your child, will be combined and reported as part of the finding of this 
study. They may be compared to findings of studies done in other parts of the 
country, or to other international studies. However, it is important to indicate that 
individuals will remain anonymous.  
 
NEXT STEPS: If you are willing to take part in the study, we would ask you to please 
return the attached ‘Parent’s/guardian’s permission (consent) form for dental 
research involving a minor child’ Appendix 2 to the principal’s office at your child’s 
crèche.  
 
FURTHER INFORMATION & CONTACT DETAILS: If you have any further 
questions about the research or would like information on the findings, you can 
contact: 
 
Principal researcher: Dr. Moses Aluteni  
Tel. +26461304180, +26461304188 
Fax. +26461304155 
Cell. +264811402612, +264811244590 
Email. mosesaluteni@gmail.com 
 
Research supervisor: Prof. Veerasamy Yengopal  
Tel. +27117172593 
Fax. +27117172625 
Cell. +27827818188 
Email. Veerasamy.Yengopal@wits.ac.za 
  
Co-supervisor: Prof. Simon. M. Nemutandani  
Tel. +27114884864,+27117172447 
Fax. +2711717 
Cell. +27835775050 
Email. Simon.Nemutandani@wits.ac.za 

 
This study has been approved by the Human Research Ethics Committee (Medical) 
of the University of the Witwatersrand, Johannesburg (“Committee”). A principal 
function of this Committee is to safeguard the rights and dignity of all human subjects 
who agree to participate in a research project and the integrity of the research. 
If you have any concern over the way the study is being conducted, please contact 
the Chairperson of this Committee who is Dr. Clement Penny, who may be contacted 
on telephone number 011 717 2301, or by e-mail on Clement.Penny@wits.ac.za. 
The telephone numbers for the Committee secretariat are 011 717 2700/1234 and 
the e-mail addresses are Zanele.Ndlovu@wits.ac.za and 
Rhulani.Mukansi@wits.ac.za  
 
Thank you for reading this Study Information Sheet. 

mailto:mosesaluteni@gmail.com
mailto:Veerasamy.Yengopal@wits.ac.za
mailto:Simon.Nemutandani@wits.ac.za
mailto:Clement.Penny@wits.ac.za
mailto:Zanele.Ndlovu@wits.ac.za
mailto:Rhulani.Mukansi@wits.ac.za


  

 

 

49 

 

 
Appendix 2:   Parent’s/guardian’s/care giver’s consent form for dental  
   research involving a minor child. 

 
 Title of project:  

Caries prevalence amongst preschool children in Windhoek, Namibia 
 

1. I have been given a Participant Information Sheet which explains the nature and processes 
involved in this study; 

2. I was given time to read it, or had it read to me, in the language I best understand; 
3. I was given time to ask any questions I wanted to and found any answers given to me to be 

reasonable and satisfactory; 
4. I believe I fully understand why the study is being conducted and what the intended outcomes 

will be; 
5. I understand that there will be no immediate benefit to me or my child, should I agree to 

participate, nor will I receive any payment; conversely, participation will not cost me anything 
but my time; 

6. I understand that, even if I initially consent to take part in the study, I may subsequently 
withdraw my child from the study at any time and would not be required to give any reasons; 
if that happened, any data collected about me for the purposes of the study would 
immediately be destroyed, unless I give consent for it to be retained 

7. I have been given a range of contact details, listed below. If I require further information or 
become concerned about any aspect of this study, I am free to speak to any of these 
contacts.  

 
Contact details: 
 
Dr. M Aluteni, Principal Investigator, telephone no. 26461304180/8, or by e-mail at 
mosesaluteni@gmail.com 
 
Professor V Yengopal, Supervisor, on telephone no. +27 11 717 2593, or by e-
mail at Veerasamy.Yenugopal@wits.ac.za 
 
Professor CB Penny, Chairperson of the Human Research Ethics Committee (Medical) at the 
University of Witwatersrand, on telephone no. +27 11 717 2301, or by e-mail at 
Clement.Penny@wits.ac.za 

 
Name of Parent/Guardian/Caregiver of Participant (please print):  
 
________________________________________ 
 
Name of Child Participant (please print): 
 
________________________________________ 
 
Date:          ________________________________________ 
Place:    ________________________________________  
Signature or mark    ________________________________________ 
 
Witnessed by: 
Name of Witness: ________________________________________ 
Signature:             ________________________________________ 
Date:           ________________________________________ 

mailto:Veerasamy.Yenugopal@wits.ac.za
mailto:Clement.Penny@wits.ac.za


  

 

 

50 

 

Appendix 3:   Oral health questionnaire for parent’s/guardian’s (care  
   givers), seeking information on behalf of and of   
   relevance to minor child. 
 
Name of child: (enter code only) .............................................................