Nasolabial Fold Discontinuity During Speech as a Possible Extended Cleft Phenotype.

Abstract Objective: This exploratory research sought to extend the cleft phenotype by identifying movement related soft tissue appearance changes in the midfacial region in individuals with cleft lip/palate or those with genetic susceptibility to cleft lip/palate (unaffected relatives). The cleft phenotype (clinically identified orofacial cleft or subclinical orbicularis oris defect) was hypothesized to be associated with movement related appearance changes in the midfacial region, e.g. with furrowing and dimpling during speech. Design: Changes in the appearance of skin in the midfacial region, including a newly identified phenotypic feature, nasolabial fold discontinuity (NLF discontinuity), were described and compared across groups. Participants: Individuals with cleft lip (n= 42), unaffected relatives of persons with a cleft (n = 57) and healthy controls (n= 41) were compared. Results: Frequencies of NLF discontinuity differed across cleft, relative, and control groups. NLF discontinuities were observed more frequently in individuals with a cleft phenotype (overt cleft or previously identified orbicularis oris muscle defect) than in those with no underlying muscular defect (Fisher Exact test, p = .014). Conclusion: Results suggest that the appearance of facial soft tissue during movement of the midface is moderated at least in part by underlying cleft risk factors, indicating certain facial movements as candidate physical markers for extension of the cleft phenotype. Key words: facial movement, mid facial region, cleft lip, phenotypes, phenomics.\ud \u