Cleft Lip and/or Palate happen early on in pregancy. Between 6-9 weeks the lips fuse and get covered with 'reinforcing' tissue. If something interrupts the reinforcement, the weak lip will eventually give way to a cleft lip. At about 8 weeks gestation, the oral and nasal cavities are one continuous structure, with the palatal tissue growing downward along the tongue. By 12 weeks gestation the tongue drops down and the palatal shelves fuse in the middle, creating a division between the oral and nasal cavities. Cleft Palate is what happens when the palatal tissue fails to fuse in the middle, leaving an open gap between the mouth and nose. Since two different processes are responsible for the fusion of the lip and the palate, it is possible to have a cleft of one and not the other.
Syndromic Clefts of the Lip / Palate are commonly associated with syndromes such as Apert Syndrome, Down Syndrome, Goldenhar Syndrome, Pierre-Robin Sequence, Treacher Collins, van der Woude Syndrome, and Velocardiofacial Syndrome, amongst others. They are due to or associated with a specific syndrome and represent 30% of the CL+/- P cases and 50% of just CP cases.
Non-Syndromic Clefts of the Lip / Palate are attributed to genetics and enviromental factors and represent 70% of the CL+/- P cases and 50% of just CP cases.There is a tremendous amount of research being conducted to find and name the specific genes that are to blame for Cleft Lip/Palate. There is also research into enviromental factors that are believed to put the fetus at risk for Cleft Lip/ Palate. Some maternal risks that have been identified include smoking, alcohol consumption, use of crack/cocaine, use of anticonvulsant medication and lack of folic acid. Due to findings of many scientists that folic acid reduces neural tube defects, doctors strongly recommend women to take folic acid in the preconception period up until delivery. Also, women are reminded once again about the hazards tetragenic agents such as nicotine and alcohol pose to fetus and are advised to abstain from them during pregnancy... |
"Cleft palate is more frequently associated with a syndrome, whereas Cleft Lip is most often an isolated defect." (Merritt, |