Prevalence of malocclusions in a sample of 4-5-year-old Bulgarian children
General
Table 1 . Prevalence of spacing , no spacing and crowding in primary dentition . |
Gender |
Type 1 |
Type 2 |
Type 3 |
Total |
Girls |
172 ( 74.8 %) |
50 ( 21.7 %) |
8 ( 3.5 %) |
230 ( 100 %) |
Boys |
196 ( 81.3 %) |
26 ( 10.8 %) |
19 ( 7.9 %) |
241 ( 100 %) |
Total |
368 ( 78.2 %) |
76 ( 16.1 %) |
27 ( 5.7 %) |
471 ( 100 %) |
Table 2 . Prevalence of normal , increased and decreased overjet in 4- and 5-year old children . |
Age |
Overjet 0-3mm |
Overjet 3-6 mm |
Overjet > 6 mm |
Overjet < 0 mm |
Total |
4 years |
138 ( 87.9 %) |
10 ( 6.4 %) |
2 ( 1.3 %) |
7 ( 4.5 %) |
157 ( 100 %) |
5 years |
265 ( 84.4 %) |
31 ( 9.9 %) |
2 ( 0.6 %) |
16 ( 5.1 %) |
314 ( 100 %) |
Total |
403 ( 85.6 %) |
41 ( 8.7 %) |
4 ( 0.8 %) |
23 ( 4.9 %) |
471 ( 100 %) |
Table 3 . Primary canine sagittal relationships . |
Age
4 years
5 years
Total
Class I Class II Class III Right Left Right Left Right Left
92 ( 58.6 %)
181 ( 57.6 %)
273 ( 58.0 %)
102 ( 65.0 %)
187 ( 59.6 %)
289 ( 61.4 %)
45 ( 28.7 %)
103 ( 32.8 %)
148 ( 31.4 %)
37 ( 23.6 %)
100 ( 31.8 %)
137 ( 29.1 %)
20 ( 12.7 %)
30 ( 9.6 %)
50 ( 10.6 %)
18 ( 11.5 %)
27 ( 8.6 %)
45 ( 9.6 %)
Total
157 ( 100 %)
314 ( 100 %)
471 ( 100 %)
Table 4 . Second molar sagittal relationships .
Age
4 years
5 years
Total
Flush terminal Mesial step Distal step Right Left Right Left Right Left
117 ( 74.5 %)
213 ( 67.8 %)
330 ( 70.1 %)
119 ( 75.8 %)
222 ( 70.7 %)
341 ( 72.4 %)
21 ( 13.4 %)
52 ( 16.6 %)
73 ( 15.5 %)
19 ( 12.1 %)
43 ( 13.7 %)
62 ( 13.2 %)
19 ( 12.1 %)
51 ( 16.2 %)
70 ( 14.9 %)
19 ( 12.1 %)
47 ( 15.0 %)
66 ( 14.0 %)
Total
157 ( 100 %)
314 ( 100 %)
471 ( 100 %) and a mesiocclusion in 10 %. A distribution of a flush terminal molar relationship in percentages is 70.1 % on the right side and 72.4 % on the left side of the examined subjects . The mesial step was assessed as 15.5 % on the right side and 13.2 % on the left side . And the distal step was assessed as 14.9 % on the right side and respectively 14 % on the left side . There are no statistically significant differences between gender in the primary canine relationships and the second primary molar relationships . But we found a statistically significant increase in Class II canine relationships between the age groups ( χ2 = 3.479 , p = 0.062 ). A normal overbite was found in 30.1 % of the sample and an anterior edge-to-edge bite existed in 27.2 % of all the children , with no significant differences between gender and age in the subgroups . A moderate anterior open bite (< 3mm ) and a severe anterior open bite (> 3mm ) were registered respectively in 6.8 % and 0.4 %. A posterior open bite was documented in 1.3 % of all children . A deep overbite was found in 127 children ( 27.0 %) and a deep overbite with gingival contact in 40 children ( 8.5 %). Statistically significant was the fact that boys showed more deep bites with gingival contact ( χ2 = 3.347 , p = 0.067 ) and also the difference between the age groups was statistically significant ( χ2 = 3.497 , p = 0.061 ) - an increase of the frequency was observed with the increasing of the age . A unilateral posterior cross-bite was observed in 3.2 % of the sample and a bilateral posterior cross-bite in 1.5 %. An edge-to-edge bite in the posterior region was found in 9 cases with a statistically significant difference in age comparison ( χ2 = 8.156 , p = 0.004 ), the 4-year-olds showed more edge-to-edge bites than the 5-year-olds . In this sample , a scissor bite was not registered . The total percentage of mandible lateral deviation was 2.5 %. A mandible deviation to the right side was found in two cases and 10 cases to the left side . The percentage prevalence of malocclusions in primary dentition is shown in Table 5 .
70 Stoma Edu J . 2017 ; 4 ( 1 ): 68-73 . http :// www . stomaeduj . com