Cleft lip and palate deformities constitute the most common congenital defects of the head.
The etiology of clefting is multifactorial. Its prevalence varies among ethnic groups and within families. Syndromes are common, especially among patients with cleft palate.
Surgical decisions should be based on careful analysis of the defects. The goals are restoring function such as lip closure, nasal airway, normal speech, eustachian tube function, and useful dental occlusion in addition to maximizing symmetry of the lip, nose, and midface.
Numerous surgical and medical approaches have been developed to address cleft lip and palate, and management strategies for patients with clefting may vary among teams at different institutions.
Patients with cleft lip or cleft palate are best managed using a multidisciplinary approach. A coordinated medical and surgical care plan provides optimal long-term outcomes because the patient’s medical and surgical needs change over time.
Cleft lip and cleft palate are among the more common congenital deformities. Patients with these deformities may often have associated problems that include otologic disease; speech and language problems, such as delayed onset of speech, articulation disorders, and velopharyngeal incompetence or insufficiency; dental deformities that include malocclusion and missing, malformed, or supernumerary teeth; facial growth deficiencies; and psychosocial issues. Some children have associated genetic syndromes or chromosomal abnormalities.
This chapter discusses some of these problems. Treatment strategies for the child with cleft lip and/or cleft palate are also discussed, emphasizing the need for a well-coordinated multidisciplinary approach to management.
Classification of Cleft Lip and Palate
A variety of classification systems have been proposed for cleft lip and palate, but few have found wide acceptance. The embryologic development of the lip and palate serves as the foundation for a number of cleft classification systems. Some useful terms and concepts for these classifications are described in this section.
The incisive foramen divides the palate into the primary palate and the secondary palate. The secondary palate develops after completion of development of the primary palate and extends from the incisive foramen anteriorly to the uvula posteriorly. The primary palate, which has the incisive foramen as its posterior border, consists of the premaxilla, lip, nasal tip, and columella.
Cleft lip is classified as unilateral or bilateral, and its extent may be classified as complete or incomplete. A complete cleft involves the entire vertical thickness of the upper lip and is often associated with an alveolar cleft because the lip and primary palate share the same embryologic origin ( Fig. 8-1 ). An incomplete cleft lip involves only a portion of the vertical height of the lip, with a variable segment of continuity across the cleft region. The variable continuous segment may present as a simple muscular diastasis with intact overlying skin or as a wide cleft with only a thin band of skin that crosses the region of the cleft ( Fig. 8-2 ). The Simonart band is a bridge or bar of lip tissue of variable size that bridges the cleft gap. The Simonart band usually consists of skin only, although some histologic studies have shown that some muscle fibers lie within the band. Unilateral clefts of the lip should include a designation of whether the right or the left side is involved.
Palatal clefts also are described as being unilateral or bilateral, and their extent may be classified as complete or incomplete. In addition, cleft palates are classified according to their location relative to the incisive foramen. Clefts of the primary palate occur anterior to the incisive foramen, and clefts of the secondary palate involve the segment posterior to the incisive foramen. Clefting patterns are highly variable; in a given embryologic region such as the primary palate, some structures may be completely cleft, whereas others manifest incomplete clefting. A unilateral cleft of the secondary palate is defined as one in which the palatal process of the maxilla on one side is fused with the nasal septum ( Fig. 8-3 ). A bilateral complete cleft of the secondary palate has no point of fusion between the maxilla and the nasal septum ( Fig. 8-4 ). A complete cleft of the entire palate involves both the primary and secondary palate and includes one or both sides of the premaxilla/alveolar arch and frequently involves a cleft lip. An isolated cleft palate usually involves the secondary palate only and has varying degrees of severity. The least severe incomplete cleft is the submucous cleft palate (SMCP), in which the underlying palatal musculature is deficient and inappropriately oriented. Associated features include a bifid uvula; a zona pellucida, a bluish midline region from the appearance of a mucosal layer with deficient muscle; and a notch in the posterior hard palate ( Fig. 8-5 ). However, the diagnosis of SMCP does not require all three elements.
For full appreciation of the variety of anatomic deformities that may be encountered in the patient with cleft lip and palate, an understanding of the normal embryologic development of the lip, palate, and nose is essential. At the end of the fourth embryonic week, the neural crest–derived facial prominences appear from the first pair of pharyngeal arches. The maxillary prominences are found laterally ( Fig. 8-6 ). The frontonasal prominences, formed by the proliferation of mesenchyme ventral to the forebrain, form the upper border of the stomodeum. On either side of the frontonasal prominences are local thickenings of surface ectoderm that form the nasal placodes.
During the fifth week of embryonic development, the nasal placodes invaginate to form the nasal pits. This invagination process creates a ridge of tissue around the pit, called the lateral nasal prominences laterally and the medial nasal prominences medially ( Fig. 8-7 ).
Over the sixth and seventh weeks of embryonic development, the paired maxillary prominences grow medially toward the paired medial nasal prominences ( Fig. 8-8 ). Over time, fusion of the paired medial nasal prominences and paired maxillary prominences occurs, thereby forming the upper lip. The medial nasal prominences fuse to form the philtrum, medial upper lip, nasal tip, and columella. The maxillary prominences form the lateral aspects of the upper lip; the lateral nasal prominences form the nose and are not involved in the formation of the upper lip ( Fig. 8-9 ).
The nose is formed from five facial prominences: the frontonasal prominence forms the bridge, the fused medial nasal prominences form the tip and columella, and the lateral nasal prominences form the nasal alae ( Table 8-1 ).
|Frontonasal *||Forehead, bridge of the nose, medial and lateral nasal prominences|
|Maxillary||Cheeks, lateral portion of the upper lip|
|Medial nasal||Philtrum of the upper lip, crest and tip of the nose|
|Lateral nasal||Alae of the nose|
Palatogenesis begins at the end of the fifth week, and complete fusion occurs by 12 weeks of development. As the maxillary prominences grow and push the medial nasal prominences medially, the medial nasal prominences fuse not only at the surface but also at deeper levels ( Fig. 8-10 ). Thus the intermaxillary segment, or primary palate—which includes the central maxillary alveolar arch that houses the four incisor teeth and the hard palate anterior to the incisive foramen—is formed by the deeper levels of fusion of the two medial nasal prominences. Once the primary palate is completely developed, the secondary palate begins to develop.
The secondary palate makes up the major portion of the palate. It is formed from the palatine shelves, which are two outgrowths of the maxillary prominences. In the sixth week of embryonic development, the palatine shelves are directed obliquely downward on either side of the tongue ( Fig. 8-11 ). By the seventh week, the palatine shelves migrate inferomedially to lie horizontally above the tongue. It is in this horizontal position that the palatine shelves fuse in the midline to form the secondary palate ( Fig. 8-12 ). The palatine shelves fuse with the previously formed primary palate anteriorly, and the nasal septum fuses with the newly formed secondary and primary palate. Palatal fusion occurs from anterior to posterior, beginning at the incisive foramen at 8 weeks of gestation and reaching completion by week 12 with uvular fusion ( Fig. 8-13 ). The degree of clefting noted clinically is a consequence of the point in fetal development at which the fusion process is interrupted.
Routine prenatal ultrasonography is now the standard practice in most communities, and improvements in imaging permit antepartum diagnosis of cleft lip and palate ( Fig. 8-14 ). More reliable prenatal diagnosis can be made of cleft lip than of cleft palate. Diagnostic accuracy is improved if two-dimensional ultrasonography is combined with three-dimensional ultrasonography. The diagnosis can be made as early as 18 weeks, although the accuracy improves with the age of the fetus. It is estimated that 12% of these fetuses will have other anomalies. The parents frequently will want additional information and often are referred to cleft teams for counseling. Most families find antenatal counseling helpful in planning for care of the child with an orofacial cleft.
Molecular Genetics of Orofacial Clefts
Both genetic and environmental factors contribute to cleft lip and/or palate. Monozygotic twins demonstrate a 40% to 60% concordance in clefts. The lack of 100% concordance in monozygotic twins suggests that genetics alone does not determine orofacial clefts. Embryology and genetics suggest that clefts of the primary palate, those that involve the lip with or without the remaining palate (CLP), arise from a different mechanism than do clefts that involve the secondary palate only (CP). Currently about 70% of CLP patients are thought to be nonsyndromic, whereas 50% of CP patients are nonsyndromic. Syndromic clefts may be the result of a single gene disorder with autosomal-dominant, autosomal-recessive, or X-linked inheritance. More than 500 syndromes have facial clefts as possible associations. The most common syndrome associated with cleft lip is van der Woude syndrome. Lower lip pits and CLP are the characteristic features of this syndrome, although CLP and isolated CP can be seen in the same family, and 10% lack lip pits. Genetic studies indicate that mutations of the interferon regulatory factor gene ( IRF6 ) are responsible for this autosomal-dominant disorder.
A number of genetic approaches have been used to search for candidate genes that affect isolated (nonsyndromic) CLP. Most studies of isolated clefts have focused on CLP, rather than on isolated cleft palate, largely because of the greater numbers of CLP patients and the heterogeneity of the isolated cleft palate group. Genome-wide association studies indicate that mutations in IRF6 may be responsible for nonsyndromic cleft lip. Variants in IRF6 have been shown to play a role in CLP in other populations. Several other genes have been identified that may be important to the development of the lip and palate. These include VAX1 , widely expressed in craniofacial development, MSX1 and BMP4 , and TGF-α and TGF-β3. Mutations in the gene, delay in expression of the gene product, or exposure to an environmental factor that affects the gene or its product may result in a cleft.
Several teratogens have been implicated in cleft development. These include alcohol, tobacco smoke, phenytoin, and retinoic acid. Meta-analysis did not find maternal age to be a factor. Multivitamin supplements have been shown to lower the risk for CLP and possibly isolated CP. Whether preconceptual folic acid supplementation alone can reduce clefting is controversial. Potential mechanisms of genetic, environmental, and biochemical interactions have been suggested and reviewed. However, human teratogen studies should be interpreted with caution because of the potential for confounding variables and recall bias.
Cleft lip and palate deformities are thought to be the most common congenital anomalies of the head and neck. Cleft lip with or without cleft palate must be distinguished from isolated cleft palate deformities because of different embryologic, etiologic, and epidemiologic factors. Cleft lip occurs in 1 in 1000 live births in the United States, whereas cleft palate deformity occurs in 1 in 2000 live births. Cleft lip deformities occur with the highest incidence among Native Americans (3.6 in 1000 births), Asians (2.1 in 1000), and whites (1 in 1000) and with the lowest incidence among blacks (0.41 in 1000). By contrast, the incidence of cleft palate is 0.5 in 1000 live births and does not differ among ethnic groups. Cleft lip occurs more commonly in boys than in girls, whereas cleft palate occurs more commonly in girls than in boys. Fusion of the palatine shelves 1 week later in girls than in boys is thought to be responsible for the higher frequency of cleft palate in girls.
Recurrent risk rates for cleft lip with or without cleft palate and for isolated cleft palate have been determined and may be useful in counseling parents about the risk of cleft in future pregnancies. Two unaffected parents with one child affected with a cleft have a 4.4% chance of having another child with a cleft lip and palate and a 2.5% chance of having a child with isolated cleft palate. One parent affected with a cleft has a 3.2% chance of having a child with cleft lip and palate and a 6.8% chance of having a child with isolated cleft palate. Presence of a cleft in one parent and in one sibling is associated with a 15.8% chance that the next child will have a cleft lip or palate and a 14.9% chance that the next child will have a cleft palate.
Multidisciplinary Cleft Team
Comprehensive care of the child with a cleft palate is best done within a team of health care professionals trained in the care of various disorders that accompany and develop as a result of the cleft lip or palate. This approach recognizes that no single discipline possesses all of the expertise needed for proper management of the many problems of these patients. The cleft team also addresses the needs of the patient and family. Standards have been recommended by the American Cleft Palate–Craniofacial Association. Specialties that often make up a cleft care team are listed in Box 8-1 . Members should meet face to face to discuss patient care at least six times a year. Continuing education for the care of patients with cleft deformities should be an integral part of membership in a cleft team.
Oral maxillofacial surgeon
Pediatric or prosthodontic dentist
Developmental or general pediatrician
Team care begins when an infant is identified as having a cleft. Within the context of a cleft care team approach, the nursing staff or the pediatrician monitor feeding, growth, and development of the child. Parents are provided counseling, genetic information as needed, and verbal and written instructions regarding care plans. Most teams develop protocols for the management of children with cleft lip and palate deformities; these algorithms for care are based on the experience of the team members, and they assign care for the anticipated needs of the child. A sample management protocol is outlined in Table 8-2 . The otolaryngologist carries the roles of airway management, otologic care, and evaluation of velopharyngeal insufficiency and may also serve as the facial reconstructive surgeon.
|Neonatal (0-1 month)|
Special problems encountered in care of the patient with a cleft deformity include initial feeding, postoperative airway and feeding management, and family care issues centered on significant medical and surgical needs. Nurses often provide an additional and, for some parents, a more secure source of information regarding treatment plans. Parents may feel more comfortable revealing to nursing staff their concerns or frustrations related to their child, and the participation of dedicated and skilled nurses is valuable within the cleft care team.
Infants with a cleft palate are limited in their ability to suck. The common cavity between the nose and the mouth allows air to leak as the infant tries to suck. Cleft lip alone usually does not cause feeding problems. Accordingly, a number of strategies have been devised, and different feeders have been created for feeding the infant with a cleft palate. Generally, breast feeding is ineffective. Alternately, expressed (pumped) breast milk can be delivered using one of the specialized feeders. The three most commonly used cleft palate feeders are the Mead-Johnson, Haberman, and Pigeon bottles ( Figs. 8-15 through 8-17 ). Each allows for parent-controlled delivery of the meal (expressed breast milk or formula). Parents and caregivers need to be taught how to properly use the feeder and should be observed for the first feeding to ensure proper use of the feeder. Trial and error may be needed to discover the best technique and feeder for the infant. Children with cleft palate generally swallow much more air during feeds. Frequent burping often is necessary, which should be explained to parents. Attention should be paid to the child’s growth; following weight and length gains using standardized growth charts is very useful to ensure that the infant stays on the appropriate growth curves.
Nurses can help families find the best position and technique for feeding after surgery. Oral and facial wounds affect placement of a feeding nipple. Often, the same cleft feeder can be used as before surgery, although the feeding technique may need to be modified owing to pain and swelling. Wound care can also be taught by nursing staff. Fresh lip wounds should be kept clean with soap and water and should be kept moist with ointments. Often, padded elbow restraints that prevent flexion of the elbow but permit other arm and hand motion are placed after surgery. Children are discouraged from placing fingers or other things into their mouth that may potentially disrupt the suture line. Restraints also may be used after palatoplasty; restraints are left on until the intraoral wounds have epithelialized. Close monitoring by nursing staff will facilitate a return to normal activities after surgery.
Anatomy of the Cleft Lip Deformity
The normal upper lip is divided into red and white components. The red lip is a mucous membrane, whereas the white lip is a cutaneous structure. The mucocutaneous junction at the vermilion border between the red and white lips is an important anatomic boundary that must be reconstructed meticulously in cleft lip repair for a natural-looking result. Failure to do so will draw attention to the irregularity at the vermilion border and will create a poor cosmetic result.
In unaffected persons, the orbicularis oris muscle forms a complete sphincter around the oral cavity and provides the substrate for proper form and function of the lips and mouth. All patients with cleft lip deformities have muscular deficiencies and irregularities of varying degrees that lead to the abnormal appearance and function of the lip and mouth ( Figs. 8-18 and 8-19 ). For proper correction of cleft lip deformities, it is essential not only to create symmetry of the lip superficially, at the skin level, but also to re-create the complete orbicularis muscular sling for long-lasting cosmetic and functional results. In addition, complete mucosal coverage must be reestablished to ensure optimal healing and to prevent distorting wound contracture. The muscle fibers in cleft lip deformities run in an inferior-to-superior direction along the margins of the cleft. They insert into the columella medially and along the nasal alae laterally. These fibers must be detached from their insertions and reoriented in a horizontal direction to bridge the cleft and create a complete muscular sling around the entire circumference of the oral cavity.
Bilateral clefts also have abnormally oriented muscle fibers that run along the edges of the lateral aspect of the cleft ( Fig. 8-20 ). Typically, the prolabial segment does not contain any useful muscle but is filled with connective tissue. In addition to the muscle and cutaneous irregularities, patients with bilateral cleft deformities have premaxillary and alveolar protrusion relative to the nasal septum. The premaxillary bony deformity may push the lip so far anteriorly and superiorly toward the nasal tip that the columella is severely diminished in strength and height and may even be obliterated completely ( Fig. 8-21 ). Often, length to the medial crura is inadequate, and consequently, columellar skin is inadequate; one of the major challenges in bilateral cleft repair is columellar reconstruction.
The anatomic characteristics of the unilateral cleft lip nasal deformity include irregularities of the tip, columella, nostril, alar base, septum, and skeleton ( Fig. 8-22 ). The nasal tip is deflected toward the noncleft side with a relatively short medial crus and long lateral crus on the cleft side. In addition, the lateral crus of the lower lateral cartilage is caudally displaced on the cleft side. The columella is shorter than normal on the cleft side; the columella lies on the noncleft side because of the unopposed action of the intact orbicularis oris muscle. The nostril on the cleft side is horizontally oriented rather than lying in the normal vertical orientation. Similarly, the nasal septum is deflected to the noncleft side. The alar base on the side of the cleft is displaced laterally, inferiorly, and posteriorly. Finally, there is a deficiency of maxillary bone on the cleft side, and the nasal floor is often absent.
The bilateral cleft lip nasal deformity differs from the unilateral deformity in several aspects other than laterality. The degree of nasal deformity relates to the severity of the cleft lip deformity, whether the cleft lip is complete or incomplete. It also is affected by the degree of premaxillary protrusion. Bilateral cleft lip nasal deformities are symmetric, which makes the repair of the nose somewhat simpler with regard to achieving tip symmetry. The challenging aspect of the bilateral cleft lip nasal deformity is the lack of adequate columellar tissue as a result of deficient length of the lower lateral cartilages and a deficiency of skin that overlies these shortened cartilages. The tip usually is broad and flat, and the alae are laterally displaced with resultant horizontally oriented nostrils.
Cleft Palate Deformity
Various degrees of deformity that involves all tissue layers are seen in cleft palate. With soft palate cleft, deficiencies of the muscle and mucosal layers also are characteristic.
Five muscle pairs contribute to the soft palate. Normally, the levator veli palatini (LVP) muscle has a transverse orientation and occupies the midportion of the soft palate, thereby creating a muscular sling for the velum. This muscular sling is the principal structural component in closure of the nasopharynx during speech and swallowing. Other muscles that contribute to the velopharyngeal sphincter include the palatopharyngeus, superior constrictor, and musculus uvulae. The musculus uvulae runs beneath the nasopharyngeal musculus and extends from the tensor aponeurosis to the base of the uvula. During speech, musculus uvulae contraction increases the midline bulk of the posterior edge of the soft palate. Deficiency of the musculus uvulae, such as that seen in submucous cleft palate, may lead to velopharyngeal insufficiency and speech disorders (see Chapter 9 ). The tensor veli palatini (TVP) muscle runs from its origins at the skull base and eustachian tube, wraps around the hamulus, and inserts into the posterior edge of the hard palate and forms an aponeurosis in the anterior midline of the soft palate. Its functions are dilation of the eustachian tube and support for the soft palate during contraction.
In patients with cleft palate, the muscles of the soft palate may be hypoplastic in addition to exhibiting misdirection and abnormal insertions into the posterior hard palate ( Fig. 8-23 ). Mucosa that envelops these muscles is deficient, except in the case of a submucous cleft palate. If the cleft involves the hard palate, a midline bony deficiency of variable degree will extend toward the incisive foramen. The vomer usually is unattached in isolated cleft palate but may or may not be attached if a cleft lip is present. Abnormal muscle insertions, combined with tissue absence or hypoplasia, lead to palatal dysfunction. Palatoplasty aims to restore function by reorienting the muscles and reconstructing the continuity of the tissues.