“…The absence of randomized controlled trials and reliance on cohort or case study methodology is in line with previous systematic reviews and surveys in the area of cleft lip and palate (de Ladeira & Alonso, 2012;Gilleard et al, 2014;Karri, 2006 (Dixon, Marazita, Beaty, & Murray, 2011;Smyth, 2014;Sommerlad et al, 2004).…”