- Cleft lip
- The presence of one or two vertical fissures (clefts) in the upper lip — cleft lip can be on one side only (unilateral) or on both sides (bilateral) — resulting from failure of the normal process of fusion of the lip to come to completion during embryonic life. Cleft lip is one of the most common physical birth defects. On the average, one baby per 1,000 is born with a cleft lip. The lip should normally fuse by 35 days of uterine age. Since failure of lip fusion can impair the subsequent closure of the palatal shelves, cleft lip often occurs in association with cleft palate. The cleft lip in this situation is the direct cause of the cleft palate. In dysmorphology (the study of birth defects), this disorder is called "cleft lip +/- (plus or minus) cleft palate." It is distinct from "cleft palate only." Cleft lip is corrected today by plastic surgery. The repair should be cosmetically good. The repair of a cleft palate can be more difficult. Cleft lip can be isolated or be part of a syndrome. By isolated is meant that the child is otherwise normal. Cleft lip is a part of many syndromes, for example, the trisomy 13 syndrome. If normal parents have an otherwise normal child with a cleft lip +/- cleft palate, there is an increased risk (4-5%) for their other children to be affected with this disorder. And if a second child has cleft lip, the risk for each subsequent sibling jumps to 9%.
* * *cleft lip n a birth defect characterized by one or more clefts in the upper lip resulting from failure of the embryonic parts of the lip to unite called also cheiloschisis, harelip
* * *the congenital deformity of a cleft in the upper lip, on one or both sides of the midline. It occurs when the three blocks of embryonic tissue that go to form the upper lip fail to fuse and it is often associated with a cleft palate. Medical name: cheiloschisis.
* * *a congenital cleft or defect in the upper lip, usually due to complete or partial failure of migration and deposit of mesoderm around or over the head in the embryo, with consequent failure of the maxillary prominence to merge with the merged medial nasal prominences. It may be unilateral, bilateral, or median, and may be accompanied by maxillary and palatal defects. Called also cheiloschisis, harelip, and stomatoschisis.
Bilateral cleft lip.
Medical dictionary. 2011.