Cleft lip and cleft palate

Cleft lip and cleft palate (CLP) are the most common congenital orofacial deformities. A combination of genetic predisposition and in-utero exposure to teratogens (nicotine, alcohol, antiepileptic drugs) can arrest the fusion of the facial processes required for normal facial development. Failure of fusion of the maxillary prominence with the medial nasal prominence causes cleft lip (CL). Failure of fusion of the palatine prominences causes cleft palate (CP). Cleft lip and/or palate may be unilateral or bilateral and complete or incomplete. In addition to facial deformity, infants with CLP have feeding, hearing, speech difficulties, and defects in the dentition. Infants with cleft lips and/or palate require special feeding techniques (feeding in upright position, special feeding bottles) since they cannot effectively create negative sucking pressure. Treatment should be initiated as early as possible and may involve an interdisciplinary team of plastic surgeons, oral maxillofacial surgeons, otolaryngologists, pediatricians, and speech therapists. Nasoalveolar molding and lip taping are non-surgical techniques used to decrease the size of the lip/palatal defects and should be initiated early (at 2 weeks of age). Repair of the cleft lip is done at 3 months of age and of the cleft palate at 6 months of age with the aim of optimizing feeding and speech development without interrupting normal maxillofacial growth.

• Incidence
  • Cleft lip with/without cleft palate is common: 1 case per in 1000 live births
  • Isolated cleft palate is less common: 1 case in 2000 live births
• Unilateral CLP is more common than bilateral CLP
• Majority of cases are non-syndromic.

References:^[1][2][3][4]

Epidemiological data refers to the US, unless otherwise specified.

• Face development: The face is formed by the fusion of 5 embryonic facial prominences that come from the first and second pharyngeal arch: the midline frontonasal prominence, the bilateral maxillary prominences, and the bilateral mandibular prominences.
• Development of the upper lip
  • The maxillary prominences grow medially and fuse first with the lateral nasal prominence, giving rise to the lateral parts of the upper lip.
  • The maxillary prominences continue to grow medially and fuse with the medial nasal prominence on either side, bringing the nostrils closer together at around 5 weeks' gestation; failure of this process leads to cleft lip.
  • Fusion of the medial nasal prominences → the philtrum and middle ⅓ of the upper lip, the primary palate, the central nose, and the nasal septum
• Development of the lower lip: Fusion of the right and left mandibular processes → the lower lip and the mandible
• Development of the palate: The palate develops in two parts, the anterior primary palate and the posterior secondary palate.
  • Fusion of the medial nasal prominences → the primary palate (median palatine process)
  • The two maxillary processes give rise to the lateral palatine processes (posteriorly) → fusion of the lateral palatine processes around 8–12 weeks' gestation → the secondary palate
  • Partial or total failure of primary palate formation leads to cleft lip, and failed formation of the secondary palate leads to cleft palate.

References:^[5][6][7]

The development of CLP is dependent on the interaction of environmental factors and genetic predisposition

• Genetic predisposition
  • Family history: multifactorial inheritance pattern (Mendelian inheritance is rare)
  • Part of chromosomal abnormalities: Pierre Robin sequence, Patau syndrome (trisomy 13), Edwards syndrome (trisomy 18)
• Environmental factors: exposure to teratogenic substances in utero
  • Nicotine and/or alcohol
  • Drugs: antiepileptics; (e.g., phenytoin, sodium valproate, carbamazepine, phenobarbital), folate antagonists (e.g., methotrexate, trimethoprim), and excessive vitamin A intake during pregnancy

References:^[8][9]

• Facial deformities: See “Subtypes and variants” below.
• Feeding difficulties: depends on the type and severity of the cleft
  • CL: minimal feeding difficulties; may have suckling difficulties
  • CP: difficulty in suckling; nasal regurgitation of milk; choking/coughing during feeds; excessive aerophagia
• Speech difficulties (hypernasality, unintelligible speech): due to velopharyngeal insufficiency
• Dentition defects (in CP): due to gaps in the upper jaw at the sites of the clefts
• Hearing loss: due to recurrent/persistent otitis media with effusion (OME)

References:^[10][11]

Types of cleft lip

• Microform cleft lip: notch on vermillion border of the upper lip; fibrous tissue band from the notch to the nostril; drooping of the ipsilateral nasal ala
• Incomplete cleft lip: cleft on the upper lip which does not extend into the nostril (unilateral/bilateral)
• Complete cleft lip: cleft on the upper lip which extends into the nose (unilateral/bilateral); more often associated with cleft palate

Types of cleft palate

• Submucosal cleft palate(occult cleft palate): the palatine mucosa is intact; an underlying muscular and/or bony palatal defect is present
• Incomplete cleft palate: clefting only of the secondary palate
• Complete cleft palate: clefting of the entire hard palate, soft palate, and the uvula; often associated with cleft lip

References:^[2][12]

• Prenatal
  • CLP may be diagnosed on prenatal ultrasound (after 12 weeks of gestation)
  • If detected prenatally, amniocentesis for karyotyping is offered, to detect other chromosomal abnormalities
• Postnatal: clinical diagnosis; children with a submucosal cleft palate may present in later life with abnormal speech and/or OME

References:^[9][13]

Approach

• Interdisciplinary management is required (oral maxillofacial surgeons. plastic surgeons otolaryngologists, pediatricians, and speech therapists)
• All cleft lips and palates should be surgically repaired.

Conservative measures before surgery

• Proper feeding techniques: feeding in upright position to prevent nasal regurgitation; use of specialized feeding bottles ; frequent burping
• Nasoalveolar molding: Use of a custom made orthodontic prosthesis to bridge and reduce the palatal gap and passively mold the maxillary, palatal, and nasal structures into a normal shape
• Nasal stent: to lift the drooping nostril and shape the nose
• Lip taping: use of adhesive tape to reduce the defect; makes definitive surgery easier
• Lip adhesion: suturing the edges of the cleft lip, in conjunction with NAM can be done in infants with complete CL/CP who are not responding well to lip taping

Surgical repair

• Cleft lip repair (chelioplasty)
  • Goals: achieving normal lip contour and nose, improve oral competence
  • Timing: 3 months, surgery is usually staged with cleft lip being the first surgery and cleft palate done at a later time due to risk of surgery to infant
  • Tympanostomy tubes are placed at the same sitting: in children with OME causing hearing loss/recurrent infections
• Cleft palate repair (palatoplasty)
  • Goals include closure of the defect, optimal speech development, and normal maxillofacial growth
  • Timing: 6–9 months: palatoplasty
• Further surgeries are often required as the child grows older.
• Speech assessment and therapy

References:^{[14][15][16][17][18][19]}