Cleft lip and palate are congenital deformities of variable severity. The face begins to develop around the fourth week of life in the womb, from five different parts of the developing fetal tissue — a central one and two on each side. These embryonic cellular components normally migrate and fuse to give rise to the nose, the sides and centre of the upper lip, and the palate and the lower jaw. Any failure of fusion of these parts can result in a cleft. The severity may vary from a barely detectable groove or ridge with a gap in the underlying muscles, to a complete cleft on each side of the lip associated with clefts extending back through the gums and the palate. Although genetic factors are implicated, the causes of such deformities are considered to be multi-factorial. Cleft lip and palate (CL/P) and cleft palate alone (CP) are different entities with varying incidence, epidemiology, and genetics.
Clefts of the lip, with or without clefts of the palate, occur in 1 in 750 live births, as compared with 1 in 2000 for clefts of the palate alone. CL/P is commoner in boys and CP alone is commoner in girls. There are racial variations in incidence of CL/P, with a decreasing order of frequency in Orientals, Europeans, and Africans, but there is no heterogeneity in the incidence of CP.
The problems associated with clefts of the lip and palate are both aesthetic and functional.
Aesthetic problems — those related to appearance — are mainly in patients with clefts of the lip. These may be on one side of the central part or on both sides. Clefts of the lip are also associated with deformity of the nose and asymmetry of the underlying facial skeleton which contribute to the problems of abnormal facial appearance.
Functional problems are minor in unrepaired clefts of the lip except in the infant, when there may be difficulty in sucking due to inability to achieve an efficient lip seal, or later, when clarity of speech or whistling may be affected. Unrepaired clefts of the palate, especially the soft palate, cause significant functional problems associated with speech and swallowing. Eustachian tube malfunction in CP patients may result in middle ear infections and hearing loss.
The earliest repairs recorded in history were in China circa 390 ad; in Europe the first report was of surgical repair by a French dentist, le Monier, in 1764. Advances in surgical techniques, and especially anaesthesia, now allow anatomical correction with great precision in restoration of form and function. Traditional repair of the cleft lip is recommended at around the age of 3 months or at a weight of 10 lbs, and of the cleft palate at about 18 months — but various protocols and techniques exist. Current techniques are very successful but there is considerable controversy regarding the effects of surgery and possible adverse influences on facial growth and function.
— Arup K. Ray
See also congenital abnormalities.
The Oxford Companion to the Body. Copyright © 2001, 2003 by Oxford University Press. All rights reserved.
