Background: Little is known about the effect of non-nutritive sucking habits (pacifier and digital sucking) in the prevalence of molar Class in mixed dentition. The aim of this study was determinate the relation between non-nutritive sucking habits, and Angle´s molar Class, in the horizontal plane, and it´s relation with gender. A convenience sample of 326 children with ages between 6 and 12 years was selected from three schools of Oporto.
Material and methods: To collect the epidemiologic data, was used a method recommended by the WHO. An indirect questionnaire about the medical history, dental habits, was used. It was adapted from Sanchez-Molins and validated by Clinical Dental III of Integrated Dental University Institute Health Sciences, Gandra, Portugal.
Results: In this study, 326 infants were examined in order to determine the prevalence of non-nutritive sucking habits. Only 45 observed children did not mentioned any kind of non-nutritive sucking habit; the remaining 281 children mentioned at least one potential bad habit. Children with non-nutritive sucking habits show a higher molar Class II percentage in females, while molar Class III is more frequent among males compared with children with no sucking habits.
Conclusions: Children with non-nutritive sucking habits, presented a higher-Class II prevalence with statistically significance. It was detected a direct relationship between Angle´s molar Class and gender. Key words:Finger sucking, pacifier sucking, Angle Class malocclusion.