| TITLE: CLEFT LIP AND PALATE SOURCE: Dept. of Otolaryngology, UTMB, Grand Rounds DATE: March 20, 1991 RESIDENT PHYSICIAN: Lane F. Smith, M.D. FACULTY: Karen H. Calhoun, M.D. DATABASE ADMINISTRATOR: Melinda McCracken, M.S. "This material was prepared by resident physicians in partial fulfillment of educational requirements established for the Postgraduate Training Program of the UTMB Department of Otolaryngology/Head and Neck Surgery and was not intended for clinical use in its present form. It was prepared for the purpose of stimulating group discussion in a conference setting. No warranties, either express or implied, are made with respect to its accuracy, completeness, or timeliness. The material does not necessarily reflect the current or past opinions of members of the UTMB faculty and should not be used for purposes of diagnosis or treatment without consulting appropriate literature sources and informed professional opinion." I. INTRODUCTION Cleft lip and palate represents the second most frequently occurring congenital deformity (after clubfoot deformity). Approximately 1 in 700-850 births suffer from cleft lip, cleft palate or both. Clefting is associated with many problems including cosmetic deformities, dental abnormalities, speech, swallowing and growth difficulties. II. ANATOMY A. Primary and secondary palate delineated according to embryologic development. 1. Primary palate or premaxilla is a triangular area of the anterior hard palate extending from anterior to the incisive foramen and to a point just lateral to each lateral incisor tooth. It includes the alveolar ridge containing the four incisor teeth. 2. Secondary palate: consists of all the remaining hard palate and all the soft palate. B. The Palate: consists of the hard and soft palate forming the roof of the mouth and the floor of the nose. 1. Hard Palate a. Formed by palatine processes of maxillae and by horizontal lamina of palatine bones. b. Blood supply chiefly from greater palatine a. which comes off the IMA and passes through the greater palatine foramen. c. Nerve supply from ant. palatine and nasopalatine nerves. 2. Soft Palate a. A fibromuscular shelf made up of several muscles attached like sling to the posterior portion of the hard palate. b. Functions to close off the nasopharynx by tensing and elevating. Contacts passavant's ridge. c. Consists of these muscles Muscle Nerve Action Tensor Veli Palatini V Tenses and depresses soft palate and opens eustachian tube Levator Veli Palatini X, IX Elevates palate Musculus Uvulae IX, X Pulls uvula up and forward Glossopalatine IX, X Draws palate down and narrows pharynx Palatopharyngeus IX, X Draws palate down and narrows pharynx III. Embryology and Genetics A. Genetics and Epidemiology 1. Multifactorial inheritance plays the major role. Familial inheritance occurs, but classic mendelian inheritance is rare. 2. Counseling for risk rates for future offspring. Cleft lip with or without cleft palate: a. One sibling with cleft and no parent with cleft 4% b. One sibling and one parent has cleft 10-17% c. No sibling with cleft and one parent with cleft 2% Cleft palate alone: d. One sibling has cleft and no parent with cleft 2% e. One sibling has cleft and one parent with cleft 17% f. No sibling with cleft and one parent with cleft 7% 3. Chromosomal aberrations such as trisomy D and E have increased incidence of clefts. 4. Environmental Factors: In humans only rubella virus, thalidomide and aminopterin have been proven to cause clefts. 5. Sex: Overall males are more affected than females. (K.J. Lee, pg 293 is wrong.) Isolated cleft lip and cleft lip and palate more common in males (2:1). Isolated cleft palate more common in females (2:1). The reason for this difference is because embryologically the mechanism for cleft palate is different than for cleft lip. (See below) 6. Race: "Highest in native Americans, then orientals, and whites, with lowest in blacks." 7. Increased paternal (not maternal) age associated with increased risk of clefts. 8. Cleft lip and palate 50% Cleft palate only 30% Cleft lip only 20% Cleft lip and alveolus 5% B. Embryologic Development 1. In general, children with clefts are suffering from a deficiency of tissue not merely a displacement of normal tissue. 2. Isolated cleft palate deformity (secondary palate) is embryologically derived in a different fashion than cleft lip (primary palate). 3. Closure of the primary palate. a. Fusion of the two maxillary swellings and two medial swellings merge to form the intermaxillary segment. This occurs during the 4th to 7th week. b. The intermaxillary segment is composed of a labial component (forms philtrum of upper lip), upper jaw component (alveolus and 4 incisor teeth), and palatal component (triangular primary palate). c. At no time during normal development of the lip and primary palate does a cleft exist (unlike the secondary palate). d. Cleft lip results from a failure to maintain an epithelial bridge due to lack of mesodermal delivery and proliferation from the maxillary and nasal processes. There is a breakdown of epithelium in this weakened area. e. Isolated clefts of the primary palate always occur anterior to the incisive foramen. 4. Closure of the secondary palate. a. Normal closure occurs from weeks 6-9 (some say 7-12) and requires 3 things: (1) Palatal shelves change from vertical to horizontal direction. (2) Migration of the tongue out of the way in antero-inferior direction away from the shelves. (3) Fusion of the palatal shelves. b. Clefts of the secondary palate are due to lack of fusion of the palatal shelves. c. Isolated clefts of the secondary palate always occur posterior to incisive foramen. d. In one study the female palate was shown to close one week later in the female than in the male. This may explain why isolated clefts are more common in females than males. 5. Cleft lip with cleft palate most common deformity. A cleft of the lip increases the probability of a cleft palate developing. The cleft of the lip occurs at an earlier age in embryologic development and this lip discontinuity results in obstruction of tongue migration. The tongue then prevents horizontal alignment and fusion of the palatal shelves. IV. Classification Numerous systems, but none universally accepted. A. Grouped according to cleft lip or palate. 1. Cleft lip a. Unilateral or bilateral. b. Complete or incomplete. A complete cleft involves the entire lip and usually the alveolar arch. An incomplete cleft of the lip involves only part of the lip. (Often only small band of tissue call Simonart's bar remains.) 2. Cleft palate a. Unilateral or bilateral. b. Complete or incomplete. A complete cleft of the entire palate involves all of the palate and one or both sides of the premaxilla (alveolar arch). An incomplete cleft involves only the secondary palate. B. Classification according to groups (Iowa System). Group I - clefts of lip only Group II - clefts of palate only Group III - clefts of lip, alveolus and palate Group IV - clefts of the lip and alveolus Group V - miscellaneous V. Anatomy of the Deformity The degree of the deformity depends on the severity of the cleft lip or palate. A. Defects associated unilateral cleft lip. 1. Floor of nose communicates freely with the oral cavity. 2. The maxilla is hypoplastic on the cleft side. 3. The columella is displaced to the normal side. 4. The columella is shortened on the side of the cleft. 5. Nasal ala on cleft side is laterally and inferiorly displaced and retrodisplaced. 6. The lower lateral cartilage of the nose is lower on the cleft. 7. The lateral crus of the lower cartilage is longer on the cleft side than the non-cleft side. 8. The angle between the medial and lateral crus of the lower nasal cartilage is more obtuse than on the normal side. 9. The muscles of the obicularis oris do not form a complete sphincter but instead are directed upward parallel to the margins and terminate beneath the ala nasi (laterally) and the base of the columella (medially). Frequently excessive muscle exists in the lateral segment. 10. Inferior turbinate often hypertrophied on cleft side. B. Defects associated with bilateral cleft lip. 1. Floor of nose is absent bilaterally. 2. Central portion of the alveolar arch is rotated forward and upward out of the area. 3. Obicularis oris muscle deformity similar to unilateral cleft lip in lateral segments (ie inserts beneath the alanasi) but there are no muscle fibers in the prolabial (medial) segment. 4. Prolabium skin for lip is underdeveloped. 5. Central portion of the lip contains no lip muscle or lip vermillion. 6. The columella is short. 7. Nasal tip is widened and flattened. 8. Septum and nasal spine are forward in relation to the retrodisplaced alar bases. C. Defects associated with the cleft palate. 1. Open roof of mouth communicating with nasal cavity. 2. Mucosal deficiency always present except in a submucous cleft palate. 3. The muscles of the soft palate are usually hypoplastic. 4. The soft palate muscles have an abnormal insertion into the posterior margin of the remaining bony palate rather than the midline raphe. D. Facial skeleton defects associated with clefts. 1. Hypoplastic maxilla on cleft side. 2. Malalignment of alveolar arches. 3. With bilateral cleft, premaxilla often grossly deficient in bone. E. Dentation abnormalities. 1. Supernumerary teeth 20% 2. Dystrophied teeth 30% 3. Congenitally missing teeth 50% 4. Malocclusion (nearly all patients) a. The most common orthodontic deformity involves an anterior and/or post. crossbite usually occurring on the side of the cleft. b. The teeth of the maxillary arch contact the mandibular teeth medial to the normal anatomic position. VI. Facial Growth with Cleft Palate A. The majority of clefts are capable of developing an essentially normal facial skeleton except in the area of the cleft defect. B. While the cleft deformity is associated with some abnormal facial growth, the surgical procedures performed to repair the cleft appear to play the greatest role in abnormal facial growth. 1. Repair of the cleft palate has greater effects on future growth than repair of the lip. 2. Repair of palate shown to cause impaired maxillary growth producing midface retrusion. 3. Facial growth related to age of repair. The earlier the repair, the more inhibited facial growth. 4. Type of repair. a. Better growth with less traumatic procedure. b. Better growth with less tension on palate. c. Amount of scar tissue on denuded palate inhibits facial growth. 5. Optimal timing of cleft palate repair with regards to facial growth varies with author. a. Surgery on palate best done after the deciduous molars are in proper occlusion. b. Surgery for small clefts done earlier 12-18 months. c. Surgery on larger clefts 18-24 months of age, with occasional delay to 30 months of age. d. Surgery on isolated soft palate cleft done age 6-12 months. C. In general, the cleft nose deformity becomes more apparent with increasing age. (See above for anatomic abnormalities.) VII. General Management A. Team approach needed to handle complex problem. 1. Reconstructive surgeon 2. Otologist 3. Dentist 4. Speech pathologist 5. Audiologist 6. Geneticist 7. Nurse 8. Psychiatrist 9. Social Worker 10. Prosthodontist B. Parent counseling important. Geneticist and psychiatrist help. C. Feeding. 1. One of the immediate problems associated with cleft palate. 2. Breast feeding usually not successful and should not be attempted. 3. Feed baby with a Montgomery nipple, bulb syringe or a preemie nipple. 4. Infant should be fed in the slightly upright position. 5. Aerophagia a problem in these infants and requires more frequent burping and slower feeding. 6. After feeding, mouth needs to be cleaned and rinsed with water. D. Orthodontics: usually 3 phases of care. 1. Phase I involves expansion of the maxillary segments when the child is 3-4 years old. 2. Phase II involves specific treatment of mixed dentation abnormalities. 3. Phase III occurs after permanent dentation has erupted and corrections are treated with full-band appliance. VIII. Non-surgical Treatment of Cleft Palate Deformities A. Prosthodontic devices can provide an alternative to surgery for obtaining velopharyngeal competence. B. Speech production with prosthodontic device as good or better than with surgery (ie velopharyngeal competence). C. Indications 1. Patient does not want surgery. 2. Patients at high risk for surgery. 3. Patients who are surgical failures. 4. Patients who would benefit from presurgical orthopedics to better align the maxillary segments prior to definitive surgery. D. Disadvantages 1. The major disadvantage is that the prosthesis must be readjusted every two weeks until growth is finished. 2. Need for an external appliance. 3. Sometimes difficult to clean the prosthesis. 4. Because it requires cooperation of the child obturation only really practical at age 3-4 years old. E. Advantages 1. As high or higher rate of obtaining velopharyngeal competence than surgery. 2. Avoidance of surgical effects on facial growth. END- | |
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