Defects of OMF

Question 1

Orofacial clefts

Answer 1

•Most common craniofacial malformations of the newborn (1:690 births)

–CL/P: cleft lip with or without palate (~60%)

–CP: cleft palate (~40%)

•May be isolated or syndromic

–50-70% isolated

•CL/P and CP differ in regards to embryology, etiology, candidate genes, and other features

Question 2

CL vs. CP

Answer 2

Cleft lip:

• Unilateral (left side most common presentation)
• Bilateral
• Median (rarely)

Cleft palate:

• May occur in isolation because:
• Lip closure accomplished by 35 days post-conception
• Palatal closure not completed until 56-58 days post-conception

Some cleft palates may present as submucosal clefts alone

Bifid uvula: minimal manifestation of cleft palate

Question 3

Uncommon Clefts

Answer 3

• Oblique facial cleft: lack of fusion of lateral nasal/maxillary processes
• Lateral facial cleft: lack of fusion of maxillary/mandibular processes
• Median cleft of upper lip: lack of fusion of medial nasal processes

Question 4

Etiology of orofacial clefts

Answer 4

•Genetics

–Usually a genetically complex event: 2-20 genes involved in most cases

–Single Mendelian disorders less common

•Environmental agents

–Medications: phenytoin, sodium valproate, methotrexate

–Cigarette smoking

–Alcohol consumption

–Folate deficiency