Summary
Cleft palate is an embryofoetopathy occurring between the 7th and 12th week of pregnancy as a result of a defect in fusion of the palatine processes, which normally fuse to form the velum or soft palate and the hard palate. Although cleft of the soft and hard palate and cleft lip can occur in association, cleft palate and cleft lip have different embryological origins, with cleft lip occurring at between 4 and 7 weeks. As a result, isolated clefts of the hard and soft palate (without cleft lip) should be considered as separate entities from those associated with cleft lip or a labial maxillary cleft. Isolated clefts of the hard and soft palate account for between 25 and 30% of all cleft cases (between 1 in 3,300 and 1 in 10,000 births). The clinical spectrum of cleft palate ranges from bifid uvula, to incomplete or complete cleft of the soft palate, through to complete or incomplete cleft of both the soft and hard palate. Clefts of the hard and/or soft palate lead to an opening between the oral cavity and the nasal canals. Cleft of the soft palate leads to alterations in the physiology of the Eustachian tube leading to middle ear anomalies and hearing difficulties. The principle manifestations are speech problems with hypernasality due to the velopharyngeal insufficiency. In the more severe forms, compensatory phenomena such as glottal production and heavy breathing may occur. Another variant, submucosal cleft palate, consists of a muscular and sometimes osseous cleft covered by a normal mucosal layer. Although submucosal clefts are barely visible in some cases, they are associated with the same risk of speech problems as other forms of cleft palate. Cleft of the soft and hard palate is more common in girls than in boys and 20% of cases are hereditary. Syndromic forms have also been described: Pierre-Robin syndrome, Stickler syndrome, van der Woude syndrome, X-linked otopalatodigital syndrome and velocardiofacial syndrome (see these terms). The prognosis depends on the syndrome and the nature of the cleft as micrognathia, muscular hypoplasia and/or neurogenic deficiency of the soft palate may also be present. Clefts of the soft and hard palate occurring in association with cleft lip or a labial maxillary cleft represent 45% of all cleft palate cases (1 in 2000-5000 births). Cleft of the hard palate leads to communication between the oral cavity and one or both of the nasal canals. In around 70% of cases cleft lip/palate occurs as an isolated, nonsyndromic malformation. Genetic, environmental and toxic factors appear to be responsible for these cases. In the remaining 30% of patients, the cleft/lip palate occurs as part of a syndrome: van der Woude syndrome, EEC syndrome, and faciogenitopopliteal syndrome (see these terms). Although cleft of the soft and hard palate leads to sucking and swallowing problems in the neonatal period, normal feeding (including breast feeding under close medical supervision) is possible in nonsyndromic forms. Treatment is surgical with reconstruction of the soft palate recommended at between 3 and 7 months of age. Speech problems can be avoided by initiating educative programmes and speech therapy as early as possible and, if necessary, by further surgical intervention (velopharyngoplasty). *Author: Prof. M-P. Vazquez (July 2007)*.
