Letter to the Editor

Eide M.G. , Skjaerven R. , Irgens L.M. , Bjerkedal T. , Oyen N. Associations of birth defects with adult intellectual performance, disability and mortality: population-based cohort study. Pediatr Res. 2006; 59: 848–853.

Lewallen S. , Courtright P. Epidemiology in practice: case-control studies. Community Eye Health. 1998; 11: 57–58.

OECD. From Education to Work: A Difficult Transition for Young Adults With Low Levels of Education. Paris: OECD Publishing; 2005.

Persson M. , Becker M. , Svensson H. Academic achievement in individuals with cleft: a population-based register study. Cleft Palate Craniofac J. 2012; 49: 153–159.

Richman L.C. , McCoy T. , Conrad A. , Nopoulos P. Neuropsychological, behavioral, and academic sequelae of cleft: early developmental, school age, and adolescent/young adult outcomes. Cleft Palate Craniofac J. 2012; 49: 387–396.

Sarkozi A. , Wyszynski D.F. , Czeizel A.E. Oral clefts with associated anomalies: findings in the Hungarian congenital abnormality registry. BMC Oral Health. 2005; 5: 4.

Schulz K.F. , Grimes D.A. Case-control studies: research in reverse. Lancet. 2002; 359: 431–434.