Predisposing factors for malocclusion in 7-year-old children with special reference to atopic diseases.

The relationships between malocclusion and atopic diseases (familial allergy) and other usual predisposing factors were studied clinically and biometrically in a nonselected cohort of 217 7-year-old children. Normal Class I occlusion was more common in children with atopic respiratory symptoms than in nonatopic children. Posterior crossbites were found in children with atopic dermatitis (P less than 0.05), those with frequent infections (P less than 0.05), and in those sucking their fingers or a dummy beyond the age of 4 years (P less than 0.05) more often than in other children. The present results provide further support for the view that atopic hyperreactivity is a predisposing factor for posterior crossbites.