Cleft Lip and Palate: Embryology & Incidence

• Cleft lip and palate are craniofacial anomalies.

Embryology

• The frontonasal process, formed by mesenchyme proliferation from the ventral surface of the developing brain, creates the nose, the philtrum (central upper lip), and the central part of the alveolar process (which holds the central and lateral incisors).
• The first pharyngeal arch develops into the maxillary and mandibular processes, from the former develops the lateral parts of the upper lip, the lateral parts of the alveolus, and palatine shelves.
• The mandibular processes fuse to form the lower lip and the mandible.
• Cleft lip and alveolus happen because the frontonasal process doesn't fuse with either one or both maxillary processes, resulting in a left, right, or bilateral cleft.
• Cleft palate results from the non-fusion of the palatine shelves.

Incidence

• The incidence of cleft lip or cleft palate is 1 in 750 births.
• Cleft lip or palate constitutes 2/3 of all craniofacial anomalies.
• The incidence of cleft lip is two times that of cleft palate.
• Cleft lip affects the left side in 60% of cases, the right side in 30%, and is bilateral in 10%.
• Cleft lip is more common in males, while cleft palate is more common in females.
• Isolated cleft palate is associated with other syndromes in 30% of cases.

Etiology

• The cause is unknown: non-hereditary factors encompass vitamin deficiency in pregnancy (folic acid), steroid use, gestational viral infections or irradiation, and loss of amniotic fluids.

Cleft Lip

• Usually associated with nasal deformity, it is an aesthetic problem that can be corrected at birth or later and repaired at 3 months of age.

Cleft Alveolus

• It may lead to abnormal teething, especially of the lateral incisors and canines.
• Orthodontic treatment may be needed to correct the alignment of the alveolar arch.
• Children may need an alveolar bone graft at 8-9 years to allow the eruption of the permanent canine

Cleft Palate

• Cleft palate is associated with many functional problems, including feeding, speech, regurgitation of food from the nose, and potential hearing loss from recurrent ear infections.
• Cleft palate patients often have Eustachian tube dysfunction due to abnormal muscle insertion, leading to fluid accumulation and secretory otitis media.
• Fluid is treated by an ENT specialist by drugs as anti-histamines, or drainage of the fluids surgically by puncturing the ear drum and putting tubes (Gromet tubes) for continuous drainage.
• Untreated secretory otitis media can lead to bacterial acute otitis media and hearing loss.
• Hearing loss in cleft palate patients is acquired, not congenital, due to repeated ear infections.

Function Of The Soft Palate

• The soft palate (velum) is formed of muscles that elevate the soft palate and push it backward to meet the posterior pharyngeal wall to separate the nasopharynx from the oropharynx.
• Velopharyngeal competence defines the soft palate (velum) and pharynx's ability to act as a valve.
• This valve should be open for breathing and closed for swallowing to prevent nasal regurgitation.
• Normal speech needs closure of the port between the mouth and nose to create positive pressure for consonants.
• During suckling, the port should be closed to create negative pressure.

Velopharyngeal Incompetence

• Failure of the valve mechanism.
• Cleft palate is the most common cause, attributed to mechanical defects, hypoplasia of the palate, and abnormal muscle insertion.
• Surgical correction aims to restore the valve function.

Family Counseling

• Parents of cleft babies should be counseled, reassured, and informed about feeding challenges and other functional deficits like nasal regurgitation and speech abnormalities, and ear infections.
• The importance of follow-up with an ENT specialist should be emphasized.
• The Cleft Palate Team includes a plastic surgeon, pediatrician, ENT surgeon, dentist, orthodontist, speech therapist, cleft palate nurse, and social worker.

Feeding

• Babies with cleft palate have defective sucking due to the inability to create negative pressure, making breastfeeding hard.
• Swallowing is normal, but weight loss can occur.
• Special nipples can help close the cleft during feeding.
• Passively introducing milk by widening the bottle nipple is a simple solution.
• The mother is the best nurse and should be involved from the beginning.
• Nasogastric feeding shouldn't be permanent.
• Babies should be nursed in a semi-sitting position and burped well.
• Feeding takes more time, so patience is important.
• Breastfeeding is difficult but not contraindicated; the mother can assist by pressing her breast.

Speech

• Normal speech needs air from the lungs to create positive pressure in the oral cavity for consonants.
• Patients with cleft palate and velopharyngeal incompetence can't create this pressure, leading to nasal escape and abnormal speech.
• Surgical correction helps restore speech, but speech therapy is also needed.

Recurrent Otitis Media and Hearing Loss

• Eustachian tubes need to be open to balance pressure.
• Cleft palate patients have non-patent tubes due to abnormal muscle insertion, causing fluid accumulation and recurrent otitis media.
• Lack of management can cause hearing loss.
• The ENT surgeon treats secretory otitis media.

Nasal Regurgitation

• Children with cleft palate may have nasal regurgitation.

Timing of Surgical Repair of Cleft Palate

• Speech therapists favor early repair for better speech outcomes.
• Facial surgeons believe early repair can interfere with facial bony growth.
• The compromise is to operate around 1 year of age.

Cleft lip and palate are craniofacial anomalies arising from issues during embryological development. Cleft lip/alveolus occurs due to the frontonasal process not fusing with the maxillary processes. Cleft palate results from non-fusion of the palatine shelves. Incidence is approximately 1 in 750 births.