Frequency of malocclusion and condition of dental health among eight-year-old children in the municipality of Foča

Summary Introduction Caries and orthodontic anomalies in school-age children lead to disturbed aesthetics, oral functions (chewing, swallowing, and speech), predisposition to trauma and the onset of periodontal diseases. The aim was to assess dental health and frequency of orthodontic anomalies in children aged 8-9 years in the municipality of Foča. Methods The research was conducted in the primary school Sveti Sava in Foča, where the total of 112 children age 8-9 years were examined. An informed consent was obtained from parents and school director for each student. Dental examination was performed using standard dental method, a mirror and a probe under artificial lighting. Children received instructions on proper nutrition, oral hygiene, tooth protection and elimination of bad habits. Results Among 112 examined boys and girls of selected ages, very high person caries index (PCI) was found (78.57%). A total of 548 caries affected teeth were found (boys 331 (24.62%), girls 217 (16.14%) (p <0.05)). Fifty-nine children had caries lesions on permanent teeth (boys 39 (2.9%), girls 20 (1.5%) (p <0.05)). Sagital abnormalities of the bite were present in 39 (34.82%) children, while 38 (33.92%) anomalies were related to vertical bite irregularities, 10 (8.92%) of them had open bite and 28 subjects (25%) had deep bite (p> 0.05). Conclusion Large number of teeth was affected with caries lesions (548) in eighth-year-olds, while orthodontic anomalies, mostly sagital abnormalities of bite were found in 39 subjects.


INTRODUCTION
Oral diseases and disorders have an important place in human pathology and can negatively affect the quality of life in children [1]. Caries and periodontitis are the most prevalent diseases of modern age. Children are the most commonly affected with caries lesions that have profound effect on aesthetic and function of oro-facial region [2]. Different factors (general and local, internal and external) are related to the emergence of caries. These are: race, hereditary factors, individual lifespan, gender, endocrine gland function, nutrition, microorganisms, saliva, form and arrangement of teeth, iatrogenic factors, poor oral hygiene and others [3]. Maloclusion is disorder of normal occlusion [4]. It has multifactorial origin (genetic and hereditary components, irregular nutrition, teeth caries, overdose teeth and premature loss of teeth) [5].
Orthodontic anomalies and dental caries of the two most widespread dental diseases in children, and the fact that they are in constant rise, indicates their mutual relation and conditionality [6]. It is known that caries lesions and especially those on the proximal surfaces of primary teeth have major influence on orthodontic anomalies. In addition, any premature extraction of primary mo-lars causes secondary anxiety [7]. Since the best time to start orthodontic therapy is pre-puberty, the goal of our research was to determine oral status and the presence of malocclusion in eight-year-olds in the municipality of Foca, and compare obtained results with those from other parts of B & H, countries in the region, or some more developed countries in the world.

MATERIAL AND METHODS
This study was done in the municipality of Foča, where a total of 112 children aged 8-9 years were examined (second and third grade). The selected year is relevant because of the period of mixed dentition, teeth shifting and pre-puberty growth when treatment with orthodontic mobile devices provides the best effects. The study was conducted in 2017 in the elementary school Sveti Sava in Foča. Dentists from the Department of Pediatric and Preventive Dentistry with Orthodontics carried out the examinations. Prior to the beginning of examination, parents, the school director and the Ministry of Education and Culture of Repuplika Srpska signed written consent for participation in the study for each child. Children who did not have written consent from their parents were excluded from the study. The Ethics Committee of the Faculty of Medicine in Foca also approved the study. The main activities during the research were: health education of children, examination of mouth and teeth, dental card records, group health interview with children, individual health interview with parents and teachers on how to maintain oral hygiene and advise parents on correct diet.
Prior to each examination, children were lectured in the presence of teaching staff about the importance of healthy teeth for general health, the process of caries formation, the process of plaque formation, the effects of microorganisms from toothache, the importance of proper nutrition for the health of teeth, the way to maintaining proper oral hygiene, the importance and significance of fluoride prophylaxis, the importance of fissure sealants, the type of accessories necessary for the maintenance of oral hygiene, as well as the importance of control checkups. The proper maintenance of oral hygiene was also demonstrated to the students.
The examinations were carried out in classrooms under daylight using dental probe and mirror. The Klein-Palmer System (DMFT) was used to assess the prevalence of caries. For each child the presence or absence of orthodontic anomalies was recorded. Based on the occlusal relationship between the teeth of the upper and lower jaws, the class was determined by Angle. Vertical irregularities of the bite were measured using an orthodontic millimeter liner.
For the statistical data processing, the non-parametric test, Chi-square test, and the parametric test, t-test for independent samples were used, at a probability level of 5% (p <0.05).
Also, high percentage of orthodontic anomalies was found in examined children. Sagittal abnormalities were found in 34.82% of respondents (18.2% boys, 16.6% of girls, (p> 0.05). As per Angle classification the most common class found was class I in 65.17% of respondents (Table 3), where 47.32% had class I with no malocclusion while 17.85% had class I with malocclusion (p<0.05).
The most frequent irregularity of biting was the class II, which was registered in 26.78% of respondents. Class II/1 characterized by distal bite with protrusion of upper teeth was found in 16.96% of children, while class II/2 with distal bite and upper teeth retrusion was registered in 9.82% of children ( Table 3). The lowest number of bite irregularities was related to class III malocclusion that was found in 8.03% of subjects (p>0.05) ( Table 3). A dentoalveolar class III with simple inversed incisor contacts as the most form of class III was registered in 6.72% children ( Figure 1).
In relation to the vertical plane, bite irregularities were found in 33.92% of children. Open bite was present 10 (8.92%) subjects, while 28 (25%) of subjects had some form of deep bite (p>0.05) ( Figure 2) ( Table 4).

DISCUSSION
In our study, high prevalence of caries was observed among school children in the municipality of Foča. Based on previous studies and reviewed literature, it is known that socio-demographic factors, parents and cooperation with dental service have an impact on children general health. According to the obtained high values of person caries index (PCI-78.57%), Foča municipality is among leading ones with frequent occurrence of caries lesions. These results are in accordance with the results of   2000) found high values of PCI (89%) in Sarajevo municipality [9]. These findings are typical for underdeveloped or developing countries to have high values of PCI (87-91%) [10], compared to developed countries where PCI is significantly lower (28.8%) [11,12]. The above results can be related to number of carious teeth in mixed dentition in some European countries [13], where higher values of carious teeth (44.6%) were found in school children. However, European countries have significantly higher (55.4%) number of children with all healthy teeth, whereas in our country only 21.4% of children are reported with all healthy teeth. Considering that significantly large number of eight-year-olds has high frequency of carious and extracted then filled teeth, it is clear that long-term preventive programs and systematic dental care are non-existing in our country.
Previous research in the area of Bosnia and Herzegovina and neighboring countries [8,9,10] showed high prevalence of caries of permanent teeth in schoolchildren (45-88.35%). Our study showed significantly lower (4.1%) frequency of caries at this age compared to previous studies, which can be explained by the fact that it was period of early mixed dentition and only recently erupting permanent teeth were present. But when we look at the distribution of DMFT, we noticed significantly more carious teeth compared to filled teeth, especially in boys, with clear indication of weaker preventive and prophylactic measures and cooperation with dentist.
In addition, orthodontic anomalies were found in 52.67% children and that was the highest frequency found compared to other similar research in domestic and foreign literature, where the percentage of these anomalies varied from 29.42-81% [8,14].
In our study, the most common form of malocclusion according to Angle Classification was Class I (65.17%), and that is consistent with the results from earlier studies (62.9%) [14,15,16]. 47.32% of subjects had normal occlusion class I, which is significantly higher than in the results of other studies (6.5-10%), while malocclusion of the class I with crowding in the anterior teeth accounted for a total of 17.85%, that is lower than in the world population [14]. The frequency of the class II (26.78%) was lower in our study compared to the results of other studies where the percentage of these anomalies was significantly higher (58-65%) [17,18]. This could be explained by the lower prevalence of bad habits and successful application of preventive and interceptive orthodontic measures in the period of deciduous dentition. Also, results showed that II/1 was more pronounced in relation to the class II/2, which is in line with previously published studies where class II/1 (35%) was more prevalent than the class II/2 (17%) [8].
Class III malocclusion was present in 8.03%, which is more than in European countries (2.5%) [19]. As higher percentage (6.72%) of this malocclusion relates to children with simple inversion of incisors, this percentage can be explained by poor application of interceptive and preventive measures at an early age that has great effect in the treatment of orthodontic anomalies [20].
Vertical bite irregularities in this study were found in a total of 33.92% subjects. In relation to the world population, where deep bite malocclusion is found in 30-50% of children, in our study deep bite was found in 25%, which is less compared to other studies [20]. Our results are similar to the study conducted by Jovic et al. [21] that showed bite depth is changing at intervals and bite becomes deeper in the period of 7-10 years. These data also coincide with the prevalence of the class II/2, which is associated with deep and distal bite. Open bite was registered in a total of 8.92% of children, which is significantly lower compared to other studies where the prevalence of this anomaly was considerably higher (26.7%) [22]. This can be explained with lower incidence of bad habits in the eighth year olds that are the main etiological factor in the onset of open bite.

CONCLUSION
The prevalence of orthodontic anomalies in the selected sample of school children in the municipality of Foča was high. The most commonly registered was class II, deep bite, anterior crowding, open bite and inverted bite of incisors. The frequency of caries in the total sample (PCI) was very high, and higher for boys than girls. In order to preserve deciduous teeth as a protector of space and supporting zone, it is necessary to introduce mandatory restoration of deciduous teeth before enrolling in schools, as well as regular preventive-prophylactic and interceptive measures in order to prevent the occurrence of serious orthodontic problems at a later age.