stomaeduj 2 SEJ_1-2017_screen | Page 71

Prevalence of malocclusions in a sample of 4-5-year-old Bulgarian children
Table 5 . Percentage prevalence of malocclusions in primary dentition .
Type of malocclusion
Children with malocclusion
Percentage (%)
Class II canine occlusion
142
30.1 %
Class III canine occlusion
45
9.6 %
Anterior open bite
34
7.2 %
Posterior open bite
6
1.3 %
Deep overbite
127
27 %
Deep overbite with gingival contact
40
8.5 %
Anterior cross bite
30
6.4 %
Posterior cross bite
Unilateral - 15 Bilateral - 7
3.2 % 1.5 %
Posterior edge-to-edge bite
9
1.9 %
Mandible lateral deviation
12
2.5 %

General

4 . Discussion The overall prevalence of malocclusions is high - 64.4 %. According to the scientific literature , the prevalence of malocclusions in primary dentition varies from 22 % to 93 % 9 , 10 due to racial characteristics and different occlusion recording methods . We found a higher prevalence of malocclusions as compared to some previous studies conducted on the Bulgarian population by Nikolov & Atanasov , 11 who found 44.5 % prevalence . The difference in prevalence is probably due to the fact that at that time a mass orthodontic prevention program was held . The generalized spacing in this sample is 78.2 % and it is corresponding to the findings of Foster & Hamilton 8 with 70 %. The prevalence of no spacing and crowding concurs with other studies , 4 , 12 , 13 but it is much lower than the results for the British children . 8 Our results for the prevalence of several concurrent malocclusions in primary dentition are in agreement with other studies . 14 The canine sagittal relationships showed that 60 % of the children have Class I , 30 % have Class II and 10 % have Class III and the results are corresponding to the findings for the European
4 , 10 , 15
population . Our study conducted on the Bulgarian population showed a percentage distribution of a flush terminal molar relation in 70.1 % of the subjects on the right side and 72.4 % on the left , which is similar to studies done by Nanda et al . 16 A mesial step and a distal step in this sample are equally distributed in 14.4 % and 14.5 %, respectively . Our results for the mesial step are in agreement with the findings of Baume 17 and Ravn , 18 but in disagreement with the results of Johannsdottir et al ., 19 who found that 60 % of their sample had mesial step occlusal relationships in primary dentition . Our results for the distal step are similar to the findings by Grabowski et al ., 10 who found 15.5 % “ distalization ” in primary dentition . The normal overjet is in agreement with the results by Berneburg et al ., 14 but the increased overjet was assessed in 9.5 % of this sample , which is lower than their findings . Our results for the decreased overjet are higher than other studies 10 , 14 but similar to the findings of Müssig . 15 An anterior crossbite was observed in 6.4 % of the sample , which resembles a study conducted by Kerouso 20 for the Finnish children . The prevalence of a normal overbite is 30.1 %. We also found 27.2 % of an anterior edge-to-edge bite and , at the age of 5 , it is a norm according to Hotz . 21 The findings are in agreement with the results by Nanda et al ., 16 Müssig 15 and Berneburg et al . 14 But on the other hand , the high frequency may be due to the self-correction of an anterior open bite after interrupting the action of external factors . 22 In this sample , a moderate anterior open bite (< 3mm ) and a severe anterior open bite (> 3mm ) were registered respectively in 6.8 % and 0.4 % of the children , which is in agreement with Berneburg et al ., 14 who found 4.6 % prevalence of an anterior open bite . The prevalence of an anterior open bite in this sample is significantly less than the findings of Müssig 15 and Tschill et al . 4 Our results showed prevalence of a deep bite and a deep bite with gingival contact , 27 % and 8.5 %, respectively , which is similar to the studies done by Müssig 15 and Grabowski et al . 10 In this sample , boys have more severe deep bites and there is also a statistically significant increase in prevalence of a deep bite with gingival contact with the increasing of the age , which concurs with other studies ’ results , 10 , 22 but it is in disagreement with the results of Berneburg et al . 14 A posterior cross-bite was seen in 4.7 % and a posterior edge-to-edge bite in 1.9 % of all the children in this study . Other investigators report that a deciduous
8 , 10 , 18 posterior cross bite ranges between 7-12 %. But our findings are similar to Hensel ( 12 ) and Stahl & Grabowski , 6 who report 5.1 % and 4 % respectively . Available literature suggests that the development of the occlusion and oral functions in primary dentition is a continuum for the further
Stomatology Edu Journal

71