Indian Journal of Dental Research

ORIGINAL RESEARCH
Year
: 2013  |  Volume : 24  |  Issue : 1  |  Page : 1--7

Malocclusion status among 15 years old adolescents in relation to fluoride concentration and area of residence


Byalakere Rudraiah Chandra Shekar1, Shankarappa Suma2, Sudarshan Kumar3, Jagadeeswara Rao Sukhabogi4, Bhadravathi Cheluvaiah Manjunath5,  
1 Department of Public Health Dentistry, People's Dental Academy, Bhanpur, Bhopal, India
2 Department of Orthodontics, People's Dental Academy, Bhanpur, Bhopal, India
3 Department of Community Dentistry, Kamineni Institute of Dental Sciences, Narketpally, India
4 Department of Orthodontics, Government Dental College and Hospital, Hyderabad, India
5 Department of Orthodontics, Postgraduate Institute of Dental Sciences, PGIMS Campus, Pt.BD Sharma University of Health Sciences, Rohtak, Haryana, India

Correspondence Address:
Byalakere Rudraiah Chandra Shekar
Department of Public Health Dentistry, People«SQ»s Dental Academy, Bhanpur, Bhopal
India

Abstract

Objectives: To compare the overall dental aesthetic index scores between rural and urban areas, males and females, and to correlate dental aesthetic index score with fluoride concentration in drinking water. Settings and Design: The study was cross sectional and conducted among 15 year old adolescents in the rural and urban areas of Nalgonda district, Andhra Pradesh, India (an endemic fluoride belt). Materials and Methods: Six out of 59 mandals in Nalgonda district were first selected by simple random sampling technique. Then 24 secondary schools were selected from these six selected mandals. All eligible grade X children from these sixteen rural and eight urban schools, having different fluoride concentrations in drinking water, selected by simple random sampling, were considered for the study. Dentofacial anomalies with criteria of dental aesthetic index were used for assessing malocclusion. The information on the dietary habits, orthodontic treatment history, parafunctional habits, continuous residence etc., was collected using a pre-designed questionnaire. The examination was carried out by three trained and calibrated dentists. The Dental Aesthetic Index (DAI) scores, in areas with below optimal, optimal and above optimal fluoride concentrations, between urban and rural areas were compared and analyzed using SPSS windows version 16. Results: The mean DAI scores, for the rural and urban population were 21.37 ± 5.845 (mean ± SD) and 22.26 ± 6.115, for males and females, it was 20.86 ± 5.100 and 22.70 ± 6.713 respectively. The mean DAI scores in areas with below optimal, optimal and above optimal fluoride concentration were 23.42 ± 7.205 (mean ± SD), 20.85 ± 4.658 and 19.93 ± 4.312 respectively. Conclusion: The prevalence and severity of malocclusion was more in urban than rural areas, more among females than males, and it decreased with increasing concentration of fluoride in drinking water.



How to cite this article:
Chandra Shekar BR, Suma S, Kumar S, Sukhabogi JR, Manjunath BC. Malocclusion status among 15 years old adolescents in relation to fluoride concentration and area of residence.Indian J Dent Res 2013;24:1-7


How to cite this URL:
Chandra Shekar BR, Suma S, Kumar S, Sukhabogi JR, Manjunath BC. Malocclusion status among 15 years old adolescents in relation to fluoride concentration and area of residence. Indian J Dent Res [serial online] 2013 [cited 2020 Nov 23 ];24:1-7
Available from: https://www.ijdr.in/text.asp?2013/24/1/1/114910


Full Text

India, a developing country, faces many challenges in rendering oral health needs. The majority of Indian population resides in rural areas of which more than 40% constitute children. [1] It is necessary to know the prevalence and distribution of oral health problems and understand the dental health practices that people follow. Such information is basic for formulation of oral health policies and appropriate programmes, to improve awareness and knowledge of general public about the preventive and promotive aspects of oral health, to create the required services and to train the necessary dental manpower to meet these needs. [2] Lack of awareness about dental diseases has resulted in gross neglect of oral health. There is no component of oral health in the present health care system in India. The grass-root level health workers and doctors do not have adequate knowledge about prevention of oro-dental problems. All the above factors have resulted in poor oro-dental health of our population. [2] Among the dental conditions, malocclusion is the second commonest in children and young adults, next to dental caries. [3]

To distinguish between those whose malocclusion is severe enough to require orthodontic treatment and those with minor deviations, one needs to establish certain criteria to rank patients properly according to the severity of the case. [4] Several indices have been used since the 1950 s to assess the prevalence and severity of malocclusion. Some of these indices are Mal-alignment Index by Van Kirk and Pennell EH, [5] Handicapping labio-lingual deviations (HLD) by Draker HL, [6] Malocclusion severity assessment by Salzmann JA, [7] The occlusal index by Summers CJ, [8] Bjork's method by Bjork A et al., [9] Index of tooth position by Massler M and Frankel JM. [10] However, none of these methods has become a universally accepted method for assessing malocclusion reliably. [11] More recently index of orthodontic treatment priority, [12] Peer Assessment Rating Index (PAR) [13] were cited as the two most commonly used indices of occlusion. The authors claim, the indices could be used to assess severity of malocclusion and its treatment needs but still these indices too lack universal acceptance.

There have been many studies on dental caries and periodontal diseases but only a few studies were available on the prevalence and severity of malocclusion and orthodontic treatment needs in India. The isolated studies carried out in Punjab, Delhi, Trivandrum and Bangalore suggest that about 30% school going children suffer from some degree of malocclusion and half of these require comprehensive orthodontic treatment. [3] The results obtained from these studies have shown wide variations in prevalence and distribution of malocclusion and one of the major factors for this widespread variation was lack of consensus on the index to be applied for assessing malocclusion. [14]

The use of fluorides in systemic as well as topical forms have substantially reduced dental caries prevalence in most of the developed countries and played a vital role in the control of the most common dental disease of mankind. [15] Where there is a pronounced reduction in the incidence of dental caries among school children, it is therefore, logical to assume there might also be a reduction in the prevalence of malocclusion. Dental decay is considered by some to exert a detrimental effect on occlusion; however, there is no complete agreement in the literature establishing the amount of dental malocclusion stemming from the early loss of tooth material. [16] Some studies in the past have shown the prevalence of certain malocclusion traits to be lesser in fluoridated areas than in non fluoridated areas [17],[18],[19] where as others found no such difference. [16] Community water fluoridation which is not even being considered till now in a developing country like India, in spite of its demonstrated benefits in the prevention of dental caries may be strongly recommended as the most cost effective dental preventive procedure for combating the two most common dental conditions if such benefits exist. However, studies to determine the severity of malocclusion in relation to area of residence as well as fluoride concentration in drinking water in India were scanty. With regard to the minimal data available on severity of malocclusion in relation to area of residence and fluoride concentration in this part of the world, the present study made an attempt to correlate malocclusion status with area of residence and fluoride concentration in drinking water. Due to lack of consensus on the index to be used for assessing malocclusion, the severity of malocclusion in the present study was assessed using an index (Dentofacial Anomalies with the criteria of Dental Aesthetic Index) accepted by WHO [20] for epidemiological studies on malocclusion. The Dental Aesthetic Index (DAI) looks into the aesthetic aspects of occlusion. The DAI links clinical and aesthetic components, mathematically, to produce a single score. This score reflects the malocclusion severity. By using cut-off points, index was subsequently used to determine the need for orthodontic treatment. The DAI is based on a social acceptability scale of occlusal conditions. The DAI highlights the importance of physical attractiveness and by considering societal defined norms for dental appearance, it recognizes conditions that are potentially handicapped psycho-socially. [21]

 Materials and Methods



The study was cross sectional in nature and ethical clearance for the study was obtained from the institutional ethics committee. The information on the total number of secondary schools in the district of Nalgonda was obtained from the office of concerned District Education Officer. Among the 59 mandals (administrative divisions within a district) in the district, six mandals were selected by simple random sampling technique. All the secondary schools in these selected six mandals were listed out into urban and rural schools separately, based on the official government notifications. Then four secondary schools (three rural schools and one urban school) from each of these selected mandals were again selected at random. All grade X children in these twenty four selected schools (eighteen rural and six urban) who were available on the day of examination and who were continuous residents in these areas were considered for the study [Figure 1]. A total of 1364 fifteen years old adolescents were examined in the study. Among these, 1268 adolescents fulfilled the inclusion criteria and hence their data only was considered for final analysis. The sex distribution of the study population in relation to the area of residence and fluoride concentration in the drinking water is illustrated in [Table 1]. The exclusion criteria and the number of participants excluded due to various exclusion parameters in denoted in [Table 2]. The permission for conducting oral examination of these adolescents was obtained from head masters of the concerned schools and district education officer (DEO). Examination was conducted by three trained and calibrated dentists under natural day light on a foldable chair using mouth mirror and CPI probe. The training and calibration of the examiners was carried out using the trial forms (consisting of questionnaire and Dental Aesthetic index) on a group of 40 patients. The Kappa co-efficient for inter-examiner agreement was found to be 0.82. The data on demographic and other characteristics like source of drinking water, history of orthodontic treatment, any habits was collected using a pre-designed questionnaire [Appendix 1] through personal interview of the study subjects after completion of oral examination by the same examiners to ensure uniformity in data collection. The data on malocclusion was collected using the criteria of dental aesthetic index (WHO oral health assessment form -1997). [20] The data was then entered onto a personal computer and DAI score (Dental Aesthetic Index score) was computed using the regression equation described by WHO (Basic Oral Health Surveys 1997). [20] Based on the DAI score, the subjects were assigned to one of the four categories suggesting a severity grade and a particular treatment need. The various occlusal traits assessed in DAI, the regression equation used in computing the DAI score, the categorization based on severity and treatment need is denoted in [Table 3]. Assistance from three trained interns was taken for making the entries in the data collection sheet following the examination of the subjects and their interview. Once the oral examination of all the eligible adolescents was complete, 500 ml of water sample from the common source was collected using a clean plastic bottle, coded and sent to laboratory for estimation of fluoride concentration. The range of optimum fluoride concentration for community water fluoridation is suggested to be 0.7-1.2 ppm in the literature. [22],[23] Based on the fluoride concentration in drinking water, the areas were divided into three categories viz, below optimal (with a fluoride concentration of less than 0.7 ppm), Optimal (0.7-1.2 ppm) and above optimal (>1.2 ppm). The instruments were sterilized using hot water sterilizer and chemical disinfectant (Cidex-2.45% Glutaraldehyde) in the absence of electricity.{Figure 1}{Table 1}{Table 2}{Table 3}

[INLINE:1]

Statistical methods

Statistical analysis was done using SPSS windows version 16. The mean DAI score between males and females, rural and urban areas in each fluoride area was computed using independent sample t-test. The mean DAI score between different fluoride areas was compared using one way Analysis of Variance (ANOVA). Wherever ANOVA yielded significant difference, the multiple pair wise comparison was done using Tukey's post hoc test. The percentage distribution of the population based on DAI scores between different categories was compared using Pearson's Chi-square test. The statistical significance was fixed at 0.05.

 Results



Malocclusion status in relation to area of residence

15.5% of the study subjects (12.4%-males, 19.4%-females) in rural areas and 22.9% in urban areas (15.4%-males, 30.8%-females) had a DAI (Dental Aesthetic Index) score of more than 25. The prevalence and severity of malocclusion was more among the urban population than the rural. The difference was statistically significant [P = 0.003, [Table 4]. The mean DAI score for the rural and urban population was 21.37 ± 5.845 (mean ± SD) and 22.26 ± 6.115 respectively. The urban population had a statistically significant higher mean DAI value than the rural population [P = 0.000, [Table 5].{Table 4}{Table 5}

Gender differences in malocclusion status

13.5% of the males and 23.9% of the females had a DAI score of more than 25. The prevalence and severity of malocclusion was more among females than males. This difference was statistically significant even when a separate comparison was made between the genders in rural and urban areas [ P = 0.000, [Table 4]. Mean DAI score for males and females in the study population was 20.86 ± 5.100 and 22.70 ± 6.713 respectively. Females had a statistically significant higher mean DAI score than males [ P = 0.00,0 [Table 5].

Malocclusion status in relation to fluoride concentration

27.6% of the study subjects (17.6%-males, 39%-females) in areas with below optimal fluoride concentration, 13.6% (13.4%-males, 13.8% - females) in the areas having optimal fluoride concentration, and 8.8% (6.7%-males, 11.7% - females) in the areas with above optimal fluoride concentration had DAI score of more than 25. This difference in the prevalence and severity of malocclusion between different fluoride areas was statistically significant even when the comparison was made among males and females in different fluoride areas [ P = 0.000, [Table 6]. The mean DAI score in areas with below optimal, optimal and above optimal fluoride concentration was 23.42 ± 7.205, 20.85 ± 4.658 and 19.93 ± 4.312 respectively. The mean DAI score decreased with increasing concentration of fluoride in drinking water and the finding was statistically significant even when the comparison was made between different fluoride areas among the rural and urban population separately [ P = 0.000, [Table 5]. The mean DAI score decreased with increasing concentration of fluoride in drinking water [r = - 0.202, P = 0.000, [Table 5]. The difference in the mean DAI score was more dramatic between below optimal and optimal fluoride concentration than between optimal and above optimal fluoride concentration.{Table 6}

 Discussion



A wide variation in the prevalence of malocclusion in different parts of the country was observed in a review conducted on the malocclusion studies in India. Lack of uniformity in data collection and variations in the indices used for assessing the severity of malocclusion was one among the many major factors for such widespread variations. [14] The present study was taken up with the objectives of comparing the severity of malocclusion between rural and urban areas, between males and females as well to correlate the mean DAI score with concentration of fluoride in drinking water among 15 years old adolescents in the district of Nalgonda. The study found the distribution of definite, severe and very severe malocclusion with a DAI score of more than 25, to be higher in urban than in rural areas. The consumption of softer and more refined food is part of the modern day lifestyle, seen predominantly in urban areas. The relatively primitive rural population will have less refined foods than the urban population. [24] Consistency of diet plays a vital role in the development of jaw musculature and dentition. It has been demonstrated in some animal studies that consumption of soft and refined foods results in less biting force and less biting duration which in turn affects stimulation of the jaw bones and oral musculature leading to inadequate development of jaws and oral musculature along with improper eruption of teeth. [25],[26],[27],[28],[29] The nature of the diet in man also plays a vital role in the evolution of the form and function of the dentition and of the whole masticatory mechanism. The consumption of soft and refined diet will fail to produce the attritional wear. This results in lack of mesial migration of the teeth and ultimately lack of space for accommodating all the teeth in the jaws which may predispose to crowding in the dental arches. [30] The population in urban areas also has a less rigid caste system than in rural areas. This may facilitate a relatively higher frequency of inter-caste and inter-religious marriages creating a more heterogeneous population in urban than in rural areas. [31] A higher prevalence of malocclusion in heterogeneous population than in the primitive homogenous population was found in a study conducted by Lauc T et al. [32] The differences in the consistency of food consumed and the homogeneity of the population between urban and rural areas may be contributory to the differences in the severity of malocclusion. This finding was consistent with the findings of other studies by Corruccini RS et al. [33] and Jalili VP et al. [34] who also found a higher prevalence of malocclusion among the urban population than in the rural population. A higher mean DAI score was noticed among females than in males. The differences in the nutritional status, amount of food and consistency of food consumed between males and females may again be the possible explanation for a higher prevalence of malocclusion among females. This finding was consistent with results of studies conducted by Jalili VP et al[34] in India and Helms S et al., in Denmark. [35] Traditionally, Indian females have poor nutritional status, less choice for selecting their food than males and also they prefer food items which are softer and more refined than that consumed by males. [36] The prevalence and severity of malocclusion decreased with increasing concentration of fluoride in the drinking water. Experimental studies in the past have demonstrated that a systemic ingestion of fluoride during the developmental stages of the teeth results in smaller teeth with wider but less deep fissures. [37] Since the teeth size may be smaller in optimal and above optimal fluoride areas, the jaw and tooth size discrepancies resulting in maxillary and mandibular irregularity may be less in these areas than that found in below optimal fluoride areas where the teeth size may be relatively larger. Moreover, children in optimal and above optimal fluoride areas will have less premature loss of teeth than that found in below optimal fluoride areas. This may give a possible explanation for the observed difference in the severity of malocclusion between the areas with different fluoride concentrations. The results of studies by Kirzioglu Z et al., [17] Ast DB.et al. [18] and Plater WR [19] found the prevalence of certain malocclusion traits to be significantly less, in optimum fluoride areas than low fluoride areas. Although a statistically significant negative correlation existed between mean DAI score and fluoride concentration in drinking water, the result may not be convincingly conclusive as the areas were divided into three categories only. The fluoride concentration that offered maximum reduction in malocclusion could not be precisely defined as all the areas above 1.2 ppm fluoride concentration were considered under above optimal fluoride area. So, will further increase in the Fluoride concentration above optimal levels reduce malocclusion as a linear relation, or will it become stable after a certain level just like its influence on dental caries remain unanswered as the difference in the DAI scores between optimal and above optimal fluoride areas was less dramatic than that between below optimal and optimal fluoride areas. This necessitates the need for further studies with larger sample and with wider range of fluoride concentrations (more categories) in drinking water to validate the results of this study. The present study used Dento facial anomalies with criteria of dental aesthetic index for assessing the severity of malocclusion, as this index is included in the WHO oral health assessment form 1997. We recommend the use of this WHO accepted index in all epidemiological studies on malocclusion, at least for the simple reason of having international uniformity in data collection. This may facilitate the comparison of data obtained from different regions of the world. Though malocclusion is a multifactorial disease with heredity, hormonal differences, habits etc., playing a major role, these factors cannot be easily modified. Promotion of appropriate diet for healthy life through well planned health education and a cost effective preventive procedure like water fluoridation at least in areas where feasible, will go a long way in the promotion of health and dental health of the population in a developing country like India. The benefits which accrue from public water fluoridation programs may be measured not only in terms of significant protection against dental caries but also with respect to a reduced hazard of malocclusion, especially severe malocclusion which may be regarded as physically handicapping. The dental associations and dental professionals have a huge responsibility of convincing the authorities concerned for the implementation of community water fluoridation - A noble preventive procedure in the history of dental public health.

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