Introduction:
The purpose of this study was to evaluate the prevalence of different types of dental malocclusions in the city of Neishabour.
Materials and Methods:
In this descriptive- cross sectional study, 469 students (215 girls and 254 boys) with ages ranging from 12 to 15 were randomly selected among 20130 junior high school students in the city of  Neishabour. The occlusal characteristics of these students including profile situation, molar and canine relationships on the basis of Angle classification, overjet, overbite, and the type of malocclusion, were recorded on data sheets. To compare the results between boys and girls, chi-square test was used.To compare the results of this study with other studies, Z statistical test was used. A confidence level of 95% was considered in this study.
Results:
The results of this study indicated that 13.7% of samples had normal occlusion, while 54% had class I malocclusion, 16.4% had class II Div 1 malocclusion, 6.8% had class II Div 2 malocclusion, and 9.2% demonstrated class III malocclusion. Except in overbite and anterior openbite (which revealed more reduction in boys), there was no significant difference in other types of malocclusions between boys and girls.
Conclusion:
Only 13.7% of the sample population had normal occlusion, and the remaining 86.3% had some type of malocclusion. Therefore considering the high prevalence of malocclusion, care should be taken for prevention and ontime treatment schedules.