Anatomical Variations in Clefts of the Lip with or without Cleft Palate

Objective. Few orofacial cleft (OFC) studies have examined the severity of clefts of the lip or palate. This study examined associations between the severity of cleft of the lip with cleft type, laterality, and sex in four regional British Isles cleft registers whilst also looking for regional variations. Design. Retrospective analysis of cleft classification in the data contained in these four cleft registers. Sample. Three thousand and twelve patients from cleft registers based in Scotland, East England, Merseyside, and Belfast were sourced from the period 2002-2010. Submucous clefts and syndromic clefts were included whilst stillbirths, abortuses, and atypical orofacial clefts were excluded. Results. A cleft of the lip in CLP patients is more likely to be complete in males. A cleft of the lip in isolated CL patients is more likely to be complete in females. Variation in the proportion of cleft types was evident between Scotland and East England. Conclusions. Association between severity of cleft of the lip and sex was found in this study with females having a significantly greater proportion of more severe clefts of the lip (CL) and CLP males being more severe (P < 0.0003). This finding supports a fundamental difference between cleft aetiology between CL and CLP.