Private Clinic of Obstetrics and Gynecology, Varna, Bulgaria.
Introduction
Cleft lip (cheiloschisis) and cleft palate (palatoschisis) are variations of a type of clefting congenital deformity caused by abnormal facial development during gestation. Approximately 1 in 700 children are born with cleft lip or palate anomalies.
Clefts can also affect other parts of the face, such as the eyes, ears, nose, cheeks, and forehead. In 1976, Paul Tessier described fifteen different lines of clefting. Most of these craniofacial clefts are even more rare and are frequently described as Tessier clefts using the numerical locator devised by Tessier.
Cleft lip is formed at the top of the lip as either a small gap or the indentation in the lip (partial or incomplete cleft) or it continues into the nose (complete cleft). Lip cleft can be unilateral or bilateral. It is caused by the failure of fusion of the maxillary and medial nasal processes. A mild form of a cleft lip is a microform cleft. A microform cleft can appear as small as a little dent in the red part of the lip or look like a scar from the lip up to the nostril. In some cases, the muscle tissue in the lip underneath the scar is affected and might require reconstructive surgery.
Cleft palate is a condition in which the two plates of the skull that form the hard palate (roof of the mouth) are not completely joined. The soft palate is in these cases clefted as well. In most cases, cleft lip is also present.
Cleft palate can occur as complete (soft and hard palate, possibly including a gap in the jaw) or incomplete (a 'hole' in the roof of the mouth, usually as a cleft soft palate). When cleft palate occurs, the uvula is usually split. It is caused by the failure of fusion of the lateral palatine processes, the nasal septum, and/or the median palatine processes.
A direct result of an open connection between the oral cavity and nasal cavity is a velopharyngeal incompetency. Because of the gap, air leaks into the nasal cavity resulting in a hypernasal voice resonance and nasal emissions.Secondary effects include speech articulation errors and compensatory misarticulations. Possible treatment options include surgical procedures, speech therapy, prosthetics.
Submucous cleft palate is a midline cleft defect covered by the mucous membrane of the roof of the mouth. It is usually characterized by the bifid uvula, a notch or depression in the midline of the soft palate, and a notch in the posterior margin of the hard palate.
Etiology
The development of the face is coordinated by complex morphogenetic events and rapid proliferative expansion, and it is thus highly susceptible to environmental and genetic factors. During the first six to eight weeks of pregnancy, the shape of the embryo's head is formed. Five primitive tissue lobes grow to form the upper and lower lip and the palate:
1) Frontonasal prominence; from the top of the head down towards the future upper lip
2) Maxillar prominence;Â 2 lobes from the cheeks; meet the first lobe forming the upper lip
3) Mandibular prominence (Meckel's cartilage); 2 lobes growing from each side forming the chin and lower lip
Formation of the palate is the last step in joining the five embryonic facial lobes, and involves the back portions of the maxillary and mandibular prominence. These portions are called palatal shelves, which grow towards each other until they fuse in the middle.This process is very vulnerable to multiple toxic substances, environmental pollution, and nutritional imbalance.
Genetic factors contributing to cleft lip and cleft palate formation have been identified for some syndromic cases. Genetic factors which contribute to the isolated cleft lip and palate are still not clear.
The Van der Woude Syndrome is caused by a specific variation in the gene IRF6 that significantly (threefold) increases the occurrence of cleft anomalies. Siderius X-linked mental retardation, is caused by mutations in the PHF8 gene. In addition to cleft lip and palate, symptoms include facial dysmorphism and mild mental retardation.
Stickler's Syndrome can cause cleft lip and palate, joint pain, and myopia. Loeys-Dietz syndrome can cause cleft palate or bifid uvula, hypertelorism, and aortic aneurysm. Cleft lip and palate may be present in many different chromosomal disorders including Trisomy 13.
Current research continues to investigate the effect of the folic acid on reduction of the incidence of clefting.
Case report
This is a case of a 22-year-old G1 P0 with unremarkable family and personal history. The karyotype was normal 46 XY. Patient was referred to our department at 26 weeks of gestation. We diagnosed a cleft lip and palate on the right side. Parents decided to continue the pregnancy.
Images 1-5: 26 weeks; 3D images of the fetus with the right sided cleft lip and palate.