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The following terminology is used when describing orofacial clefts (OFCs): cleft lip alone without cleft palate (CL); cleft lip with or without cleft palate (CL/P), which includes cleft lip only and cleft lip with cleft palate; cleft lip with cleft palate (CLP); posterior cleft palate without cleft lip (CPO); syndromic and nonsyndromic; and familial and nonfamilial (or simplex).
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Prevalence is the suggested measure of disease frequency.
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The source population, the time period of data collection,
Classification, Epidemiology, and Genetics of Orofacial Clefts
Section snippets
Key points
Historical perspective: terminology and classification
There is considerable ambiguity in the use of terminology when referring to orofacial clefts (OFCs). Many clinicians incorrectly refer to OFCs as deformities, which are said to be the result of disrupted embryologic development. In 1982, an international working group proposed our currently used concepts and terms to describe errors of morphogenesis, which include OFCs.1 The term malformation should be used for a “morphologic defect of an organ, part of an organ, or larger region of the body
Classification
Several different classification systems for OFCs have been proposed in the surgical and dental literature. These systems are primarily divided into anatomic systems useful for surgeons and embryology-based systems useful for genetic counseling and research. The disciplines of surgery, genetic counseling, and research require and use different types of OFC data, which has hindered the development of a universally acceptable and useable classification system.12
Modern concepts of classification
Incidence Versus Prevalence
Incidence and prevalence are traditional epidemiologic measures used to quantify the occurrence of disease in a population. Incidence reflects the transition from health to disease where prevalence reflects both the presence of disease as well as how long a person lives with the disease.46 Incidence is defined as the number of new cases of disease in a population of individuals at risk for developing the disease in a given time period. This measure can be expressed as either a proportion, with
Sex, Race, and Ethnicity
Prevalence of OFCs differs by sex, race, and maternal age. The prevalence of CL/P among males is approximately twice that of females, whereas the prevalence for CPO is about two-thirds that of females.55, 56
The prevalence of all OFCs is less for non-Hispanic blacks compared with non-Hispanic whites.57 African Americans are 44% less likely to have CL/P compared with non-Hispanic whites. Moreover, the prevalence of CPO was approximately 30% less for African American and Hispanic children when
Pierre Robin sequence
The Robin sequence (commonly referred to as the Pierre Robin Syndrome [PRS]) deserves special mention. Current concepts classify this as a malformation complex or a sequence, in recognition of the embryologic sequence of events involved.1 PRS is usually defined by the triad of micrognathia/retrognathia,147 cleft palate (usually U shaped but may be V shaped), and glossoptosis (abnormal posterior placement of the tongue); but there is a significant precedent for using this term to refer to only
Patient evaluation and family counseling
Most parents who have a child with an OFC wonder why this happened to their child and whether they caused it by doing something they should not have done or by not doing something that they should have done. Parents may also be worried about their chance of having the same or more severe malformations affect future pregnancies. Patients with OFCs may have similar concerns about the health of their offspring. Health professionals who care for patients with OFCs should be alert to their patients'
References (162)
- et al.
Errors of morphogenesis: concepts and terms. Recommendations of an international working group
J Pediatr
(1982) 2006 ASHG Award for Excellence in Human Genetics Education. GeneTests: integrating genetic services into patient care
Am J Hum Genet
(2007)Anatomical classification facial, cranio-facial and latero-facial clefts
J Maxillofac Surg
(1976)- et al.
Cleft malformation of lip, alveolus, hard and soft palate, and nose (LAHSN)–a critical view of the terminology, the diagnosis and gradation as a basis for documentation and therapy
Br J Oral Maxillofac Surg
(1995) - et al.
Cleft lip and palate
Lancet
(2009) - et al.
Breakthroughs in the genetics of orofacial clefting
Trends Mol Med
(2011) - et al.
Maternal periconceptional alcohol consumption and risk for orofacial clefts
J Pediatr
(1999) - et al.
Risks of orofacial clefts in children born to women using multivitamins containing folic acid periconceptionally
Lancet
(1995) - et al.
The teratogenic effect of carbamazepine: a meta-analysis of 1255 exposures
Reprod Toxicol
(2002) - et al.
Congenital malformations among infants whose mothers had gestational diabetes or preexisting diabetes
Early Hum Dev
(2001)
Diabetes mellitus and birth defects
Am J Obstet Gynecol
Amniotic band syndrome with significant orofacial clefts and disruptions and distortions of craniofacial structures
J Pediatr Surg
Racial and ethnic variations in the prevalence of orofacial clefts in California, 1983-1992
Am J Med Genet
The further epidemiological differentiation of cleft lip and palate: a population study of clefts in King Country, Washington, 1856-1965
Teratology
Anomalies associated with cleft lip, cleft palate, or both
Am J Med Genet
Genetic services at a center for craniofacial anomalies
Cleft Palate J
Etiology of facial clefts: prospective evaluation of 428 patients
Cleft Palate J
Associated malformations in cases with oral clefts
Cleft Palate Craniofac J
Epidemiology of cleft palate in Europe: implications for genetic research
Cleft Palate Craniofac J
Associated anomalies in multi-malformed infants with cleft lip and palate: an epidemiologic study of nearly 6 million births in 23 EUROCAT registries
Am J Med Genet A
A systematic review of associated structural and chromosomal defects in oral clefts: when is prenatal genetic analysis indicated?
J Med Genet
Classification of orofacial clefting
A new classification for cleft lip and cleft palate
Plast Reconstr Surg Transplant Bull
A classification of cleft lip and cleft palate
Plast Reconstr Surg Transplant Bull
On cleft lip and palate classification
Plast Reconstr Surg
A proposed modification for the classification of cleft lip and cleft palate
Cleft Palate J
Classification and birth prevalence of orofacial clefts
Am J Med Genet
Diagnosis and classification of congenital craniofacial cleft deformities
J Craniofac Surg
New neonatal classification of unilateral cleft lip and palate-part 1: to predict primary lateral incisor agenesis and inherent tissue hypoplasia
Cleft Palate Craniofac J
New neonatal classification of unilateral cleft lip and palate part 2: to predict permanent lateral incisor agenesis and maxillary growth
Cleft Palate Craniofac J
Classifying common oral clefts: a new approach after descriptive registration
Cleft Palate Craniofac J
Use of two cleft lip and palate classification systems by nonsubspecialized health care providers
Cleft Palate Craniofac J
Mouse genetic models of cleft lip with or without cleft palate
Birth Defects Res A Clin Mol Teratol
Gene/environment causes of cleft lip and/or palate
Clin Genet
Langman's medical embryology
Orofacial embryogenesis: a framework for understanding clefting sites
A cohort study of recurrence patterns among more than 54,000 relatives of oral cleft cases in Denmark: support for the multifactorial threshold model of inheritance
J Med Genet
Mutations in IRF6 cause Van der Woude and popliteal pterygium syndromes
Nat Genet
MSX1 mutation is associated with orofacial clefting and tooth agenesis in humans
Nat Genet
The origin of the term “harelip”
Cleft Palate J
Gorlin's syndromes of the head and neck
Prenatal sonographic diagnosis of median facial cleft should alert holoprosencephaly with premaxillary agenesis and prompt genetic investigations
Ultrasound Obstet Gynecol
Perspectives on holoprosencephaly: part II. Central nervous system, craniofacial anatomy, syndrome commentary, diagnostic approach, and experimental studies
J Craniofac Genet Dev Biol
Phenotypic variability in human embryonic holoprosencephaly in the Kyoto Collection
Birth Defects Res A Clin Mol Teratol
Genotypic and phenotypic analysis of 396 individuals with mutations in Sonic Hedgehog
J Med Genet
Congenital healed cleft lip
Am J Med Genet
22q11.2 Deletion syndrome
Morphologic significance of bifid uvula
Pediatrics
Cleft lip and palate versus cleft lip only: are they distinct defects?
Am J Epidemiol
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Disclosures: The authors report no conflicts of interest.