Page 2 of 5 9th weeks of gestation, as the palatal shelves change from a vertical to horizontal position and fuse. The tongue must migrate away from t

Transcription

1 Page 1 of 5 TITLE: Cleft Lip and Palate SOURCE: UTMB Dept. of Otolaryngology Grand Rounds DATE: January 28, 1998 RESIDENT PHYSICIAN: Greg Young, M.D. FACULTY: Ronald Deskin, M.D. SERIES EDITOR: Francis B. Quinn, Jr., M.D., F.A.C.S. Return to Grand Rounds Index "This material was prepared by physicians in partial fulfillment of educational requirements established for Continuing Postgraduate Medical Education activities and was not intended for clinical use in its present form. It was prepared for the purpose of stimulating group discussion in a interactive computer mediated 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 subscribers or other professionals and should not be used for purposes of diagnosis or treatment without consulting appropriate literature sources and informed professional opinion." INTRODUCTION Cleft lip and palate represents the second most frequently occurring congenital deformity (after clubfoot deformity). Cleft lip, cleft palate or both affects approximately 1 in 750 births. Clefting is associated with many problems including cosmetic and dental abnormalities, as well as speech,, hearing and facial growth difficulties. The otolaryngologist is uniquely qualified to identify and manage many of these problems, and holds a key role on the cleft palate team. ANATOMY The palate consists of the hard palate and soft palate, which together form the roof of the mouth and the floor of the nose. The palatine processes of the maxilla and horizontal lamina of the palatine bones form the hard palate. Its blood supply is mainly from the greater palatine artery, which passes through the greater palatine foramen. The nerve supply is via the anterior palatine and nasopalatine nerves. The soft palate is a fibromuscular shelf made up of several muscles attached like a sling to the posterior portion of the hard palate. It closes off the nasopharynx by tensing and elevating, thereby contacting Passavants ridge posteriorly. The soft palate consists of the tensor veli palatini, the levator veli palatini, the musculus uvulae, the palatoglossus, and palatopharyngeus muscles. CN V supplies the tensor veli palatini, while CN IX and CN X innervate the others. The levator veli palatini is the primary elevator of the palate. EMBRYOLOGY The primary and secondary palates are delineated according to embryological development. The primary palate or premaxilla is a triangular area of the anterior hard palate extending from anterior to the incisive foramen to a point just lateral to the lateral incisor teeth. It includes that portion of the alveolar ridge containing the four incisor teeth. The secondary palate consists of the remaining hard palate and all of the soft palate. The primary palate forms during the 4th to 7th weeks of gestation as the two maxillary swellings merge and the two medial nasal swellings fuse to form the intermaxillary segment. The intermaxillary segment is composed of a labial component (forms the philtrum), a maxilla component (forms alveolus and 4 incisors), and palatal component (forms the triangular primary palate). Normally during development of the primary palate, a cleft does not exist (unlike the secondary palate in which cleft formation occurs as a natural stage of development). The secondary palate forms during the 6th to

2 Page 2 of 5 9th weeks of gestation, as the palatal shelves change from a vertical to horizontal position and fuse. The tongue must migrate away from the shelves in an antero-inferior direction for palatal fusion to occur. CLEFT FORMATION In general, patients with clefts have a deficiency of tissue and not merely a displacement of normal tissue. A cleft lip occurs when an epithelial bridge fails, due to lack of mesodermal delivery and proliferation from the maxillary and nasal processes. Clefts of the primary palate occur anterior to the incisive foramen. Clefts of the secondary palate are due to lack of fusion of the palatal shelves, and always occur posterior to the incisive foramen. The secondary palate closes 1 week later in females, which may explain why isolated clefts of the secondary palate are more common in females. A cleft of the lip increases in probability of a cleft palate developing. The cleft of the lip occurs earlier and inhibits tongue migration, which may then prevent horizontal alignment and fusion of the palatal shelves. In the unilateral cleft lip, the floor of the nose communicates freely with the oral cavity, the maxilla on the cleft side is hypoplastic, the columella is displaced to the normal side, and the nasal ala on the cleft side is laterally, posteriorly, and inferiorly displaced. The lower lateral cartilage of the nose is lower on the cleft side, its lateral cruz is longer, and the angle between the medial and lateral cruz in more obtuse. The muscles of the orbicularis oris do not form a complete sphincter but instead are directed superiorly to the ala nasi laterally and the base of the columella medially. In the bilateral cleft lip, the central portion of the alveolar arch is rotated anteriorly and superiorly. The medial or prolabial segment of skin contains no muscle or vermillion. In palatal clefts, the muscles of the soft palate are hypoplastic and insert in the posterior margin of the remaining hard palate rather than the midline raphe. Associated dentition abnormalities include supernumerary teeth (20%), dystrophic teeth (30%), congenitally missing teeth (50%), and malocclusion (almost 100%). GENETICS Nonsyndromic inheritance of facial clefting is multifactorial. Familial inheritance of both cleft lip and palate occurs with varying frequency, depending on whether a parent or sibling is affected. For cleft lip with or without cleft palate, the risk rate for future offspring is 2% with only one parent affected, 4% with only one sibling affected, 9% with two siblings affected, and 10-17% with one parent and one sibling affected. For cleft palate alone, the risk rate for future offspring is 7% with only one parent affected, 2% with only one sibling affected, 1% with two siblings affected, and 17% with one parent and one sibling affected. Chromosome aberrations such as trisomy D and E have increased incidence of clefts. Facial clefts are associated with a syndrome 15-60% of the time. More than 200 recognized syndromes may include a facial cleft as a manifestation. Common syndromes with cleft palates include Apert's, Stickler's and Treacher Collins. Van der Woude's and Waardenberg's syndromes are associated with cleft lip with or without cleft palate. EPIDEMIOLOGY Clefts of the lip and combined lip and palate are twice as common in males. Isolated cleft palates are twice as common in females. Cleft lips, with or without cleft palate, are most common in Native Americans, then Orientals and Caucasians, and least common in Blacks. Conversely, the rate of isolated cleft palate is constant among ethnic groups. Environmental factors found to cause clefts in humans are ethanol, rubella virus, thalidomide, and aminopterin. Maternal diabetes mellitus and amniotic band syndrome are associated with clefts. Increased paternal, but not maternal age is also associated with clefts. Combined cleft lip and palate is the most common presentation (50%), followed by isolated cleft palate (30%), isolated cleft lip (20%) and least common is cleft lip and alveolus (5%). MANAGEMENT

3 Page 3 of 5 A team approach is needed to manage the wide variety of problems common to the patient with cleft lip and palate. In addition to the reconstructive surgeon, a typical team consists of an otolaryngologist, dentist, speech pathologist, audiologist, geneticist, nurse, psychiatrist, social worker, and prosthodontist. Teams may vary depending on available resources and individual interest. The otolaryngologist has a pivotal role in the diagnosis and management of all disorders relating to the head and neck. Cleft lip and palate patients are particularly prone to speech disorders and ear disease, and may have significant airway abnormalities. The otolaryngologist is uniquely qualified to oversee the management of these disorders, and at times is the primary reconstructive surgeon as well. INITIA L H EA D A ND NEC EXA MINA TION The otolaryngologist performs a complete head and neck examination on new patients in the cleft palate clinic. The head is inspected for symmetry, the auricle and external canal for development and location. A facial analysis is helpful to identify abnormalities of facial symmetry and harmony. Otologic examination includes pneumatic otoscopy and tuning forks. Anterior and posterior rhinoscopy will identify clefting, septal abnormalities, intranasal masses, and choanal atresia. Oral cavity examination will identify any cleft, dental arch abnormalities and tongue anomalies such as bifid tongue, macroglossia, glossoptosis, or lingual thyroid. In addition, malocclusion, hemifacial hypertrophy or atrophy, and facial clefting are documented. The upper airway tract is evaluated by assessing the adequacy of phonation, cough, and deglutition, and by auscultating and palpating the neck. SPEECH DISOR DER S Errors in articulation are common in cleft palate patients, especially those involving affricates and fricatives. Other errors include stop, glides, and nasal semivowels. Velopharyngeal incompetence is associated with an audible escape of air from the nose during production of pressure sounds and is termed nasal emission or snort. It is estimated that 75% of patients have velopharyngeal competence following primary cleft palate surgery, and this can be increased to 90-95% with directed secondary procedures. Velopharyngeal competence is the most important determinant of articulation performance and listener understanding of speech in cleft palate patients. Others factors include dentition, associated hearing loss, and muscular and neurologic deficits. Velopharyngeal competence can be estimated by direct examination of the nasopharyngeal depth, palatal length, and palate movement during phonation. Flexible fiberoptic nasopharyngoscopy has the added advantage of direct visualization of palatal motion and pharyngeal wall motion with both single sounds and connected speech. EA R DISEA SE Patients with an isolated cleft lip have an incidence of hearing loss similar to that in the normal population. In contrast, cleft palate is very often associated with eustachian tube dysfunction and a resulting conductive hearing loss. Eustachian tube dysfunction in these patients is due to an abnormal insertion of the levator and tensor veli palatini muscles into the posterior margin of the hard palate. In addition to middle ear effusion, the patients also appear to have an increased incidence of cholesteatoma (7%). With increasing age, the incidence of eustachian tube dysfunction decreases, and in many cases normal eustachian tube function develops by mid adolescence. Otologic goals in the cleft palate patient are to provide adequate hearing, maintain ossicular continuity and adequate middle ear space, and prevent deterioration of the tympanic membrane. Patients with eustachian tube dysfunction are evaluated every 3-4 months until it resolves. Indications for myringotomy and tube insertion include a significant conductive hearing loss or persistent middle ear effusion, recurrent otitis media, or tympanic membrane retraction. In practice, almost all patients with cleft palate will require multiple sets of tubes from 3-4 months of age until the beginning of the second decade of life. In contrast, patients with an isolated cleft lip do not have a significantly increased rate of myringotomy and tubes.

4 Page 4 of 5 AIRWAY PROBLEMS Airway problems may arise in children with cleft palates, especially those with concomitant structural or functional anomalies. For example, Pierre-Robin sequence is the combination of micrognathia, cleft palate, and glossoptosis. Affected patients may develop airway distress from their tongue becoming lodged in the palatal defect. SURGICAL REPAIR Cleft Lip Cleft lips are repaired at about 10 weeks of age at most institutions. Lip adhesions can be performed at 2 weeks of age. They convert a complete cleft to an incomplete cleft, and serve as a temporizing measure for those infants with certain feeding problems. Adhesions may interfere with definitive lip repair and are less often needed in recent years due to the wider variety of specialty feeding nipples available. The rotation advancement method of cleft lip repair is the most commonly used in The United States. Initially, nine landmarks on the lip are identified with a vital dye. These are 1) the non-cleft side nasal ala base, 2) The non-cleft side high point of lateral cupid's bow, 3) The low point of cupid's bow, 4) The non-cleft side high point of medial cupid's bow (equal to distance between #2 and #3), 5) the cleft side high point of cupid's bow (placed where white roll attenuates along vermillioncutaneous junction), 6) superior extent of advancement flap(length of #5 to #6 equal height of non-cleft lip(#4 to #8), 7) point on cleft side alar crease such that length of #5 to #7 equals length of #1 to #2, 8) And 9) the superior extent of the rotation incision. Through and through cuts are made for the non-cleft side rotation flap, allowing # 4 to drop down with # 2. (The small remaining triangular tissue attached to the columella is Millard's C flap). The cleft side advancement flap is now made, with distance #5 to #6 corresponding to distance #8 to #4 in its newly rotated position. Next, the cleft and non- cleft lip segments are separated in a supraperiosteal plane from the maxilla. The cleft side nasal ala incision is then made (#6 to #7), and the external and vestibular skin is separated from the cleft side lower lateral cartilage. Next, the tip of the advancement flap (#6) is brought to point #9(base of the columella). The remaining sutures are then placed to complete the repair. Bilateral cleft repair, although more complex, is performed using similar principles. Cleft Palate Several techniques for cleft palate repair have been developed over the past 3 decades. The current trend is toward procedures that involve less denuding and scarring of the hard palate, and less tension on the soft palate. Although controversial, many authors believe there is a relationship between scar formation of the palatal repair and the impaired mid-facial growth that is observed in most patients with cleft

5 Page 5 of 5 palate. Bony abnormalities that develop include collapse of the alveolar arches, midface retrusion, and malocclusion. Facial growth may also be affected by the age when the repair is performed. Some surgeons advocate later repair, because facial growth is less affected when surgery is delayed until months of age. Others advocate an earlier repair, stating that feeding, speech and socialization are improved if the surgery is performed by the 1st year of life, and that facial growth problems can be minimized with less traumatic palate repairs. Several methods of cleft palate repair have been described. The two-flap techniques, such as those described by Bardach or Furlow are used commonly in the U nited States today. In the Bardach repair, a single posteriorly based mucoperiosteal flap is developed over each palatal shelf. In this repair, medial incisions are made which separate the oral and nasal mucosa, and lateral incisions are made at the junction of the palate and alveolar ridge. The mucoperiosteal flaps are elevated, taking care to identify and preserve the neurovascular bundle containing the greater palatine artery. Next, the velar muscle is detached from its attachment to the posterior border of the palatal shelves. The palate is then closed in three layers, 1st nasal mucosa, then velar muscle, and finally oral mucosa. The lateral palate incisions are closed loosely. Bilateral cleft palate repairs are performed in similar fashion. Cleft palate patients at high surgical risk or who refuse surgical treatment may use a dental obturator to obtain velopharyngeal competence. Disadvantages of dental obturators include the necessity of wearing a prosthesis and the need for modification of the prosthesis as the patient grows. BIBLIOGRAPHY 1. Bardach J, Morris H L, eds. Multidisciplinary management of cleft lip and palate. Philadephia: WB Saunders, Bumsted R M. Cleft lip and palate. In: Cummings CW, et al.,eds. Otolaryngology-H ead and Neck Surgery. St. Louis: CV Mosby, Crockett DM, Seibert R W, and Bumsted R M. Cleft lip and palate: the primary deformity. In: Bailey BJ, et al, eds. H ead and Neck Surgery- Otolaryngology. Philadelphia: Lippincott Co., Crockett DM. Velopharyngeal incompetence. In: H ealy G B, ed. Common problems in pediatric otolaryngology. Chicago: Y ear Book, H olt G R and Watson MJ. The otolaryngologist's role in the craniofacial anomalies team. Otolaryngol H ead Neck Surg 92:406, Seibert R W. Lip adhesion in bilateral cleft lip. Arch Otol H ead Neck Surg 109:434, 1983.