The results highlight that infants across the spectrum of CL/P have a high risk of SDB symptoms and obstructive respiratory events before palate surgery. Clinicians should enquire about symptoms of SDB and consider investigation with polysomnography in all infants with CL/P.

Preschool children with cleft lip and/or palate have a risk of obstructive sleep apnea that is as much as five times that of children without cleft. Obstructive sleep apnea appears to be underrecognized in this group of children. Further research is needed to investigate important risk factors for obstructive sleep apnea in children with cleft lip and/or palate.

Children with cleft palate appear to have a significant risk of SDB. A prospective study of a population of children with cleft palate is needed to further define the characteristics of this risk and important risk factors.

Orofacial clefting is a common birth defect with wide phenotypic variability. Many systems have been developed to classify cleft patterns to facilitate diagnosis, management, surgical treatment, and research. In this review, we examine the rationale for different existing classification schemes and determine their inter-relationships, as well as strengths and deficiencies for subclassification of clefts of the lip. The various systems differ in how they describe and define attributes of cleft lip (CL) phenotypes. Application and analysis of the CL classifications reveal discrepancies that may result in errors when comparing studies that use different systems. These inconsistencies in terminology, variable levels of subclassification, and ambiguity in some descriptions may confound analyses and impede further research aimed at understanding the genetics and etiology of clefts, development of effective treatment options for patients, as well as cross-institutional comparisons of outcome measures. Identification and reconciliation of discrepancies among existing systems is the first step toward creating a common standard to allow for a more explicit interpretation that will ultimately lead to a better understanding of the causes and manifestations of phenotypic variations in clefting.