Spektrum Bibir Sumbing (Labioskisis)

01Pathophysiology

The development of the lip and palate involves two embryologically distinct processes, and understanding this separation is the key to answering questions about these conditions correctly.

During weeks 4 through 7 of gestation, the primary palate forms. This structure includes the upper lip, the alveolar ridge, and the hard palate anterior to the incisive foramen. The primary palate develops when the medial nasal processes fuse with each other and with the maxillary processes of the first pharyngeal arch. If this fusion fails on one or both sides, the result is a cleft lip (labioschisis), which may extend through the alveolus. A unilateral failure produces a unilateral cleft; bilateral failure produces a bilateral cleft. The side of the defect reflects which medial nasal-maxillary junction failed to fuse.

During weeks 7 through 12, the secondary palate forms. The two palatine shelves grow medially from the maxillary processes. Initially oriented vertically alongside the tongue, they elevate to a horizontal position once the tongue descends, and then fuse in the midline from anterior to posterior. This fusion also joins the secondary palate to the primary palate at the incisive foramen and to the nasal septum superiorly. Failure of this process results in a cleft palate, which can involve the soft palate alone, or extend anteriorly through the hard palate.

When both fusion events fail, the patient presents with a combined cleft lip and palate (labiopalatoschisis). This is the most common combined form and represents the most functionally significant defect because it disrupts oral competence, nasal airway anatomy, and the velopharyngeal mechanism simultaneously.

Why the patient presents the way they do: The cleft lip creates a visible structural defect and distorts the nasal cartilage on the affected side. The cleft palate eliminates the partition between the oral and nasal cavities, which prevents the infant from generating negative intraoral pressure (suction). This is why feeding difficulty is the hallmark functional complaint. Because the palate also serves as the floor of the nasal cavity, feeds reflux into the nose, causing nasal regurgitation. The abnormal palatal anatomy distorts the insertion of the tensor veli palatini muscle into the Eustachian tube, impairing middle ear ventilation. This leads to chronic Eustachian tube dysfunction, recurrent otitis media, and eventually conductive hearing loss. Later in childhood, the velopharyngeal valve cannot close properly, producing the classic hypernasal speech.

The etiology is multifactorial. There is a polygenic genetic component (with a recurrence risk of approximately 4% for first-degree relatives after one affected child), and environmental modifiers include maternal smoking, alcohol, folate deficiency, and teratogenic medications such as phenytoin, valproic acid, and isotretinoin (retinoic acid). Folic acid supplementation before and during early pregnancy is protective.

02Classification and Clinical Manifestation

Veau Classification of Cleft Palate:

A high-yield distinction: isolated cleft palate (without cleft lip) is more frequently associated with syndromic conditions (e.g., Pierre Robin sequence, 22q11.2 deletion syndrome, Stickler syndrome) compared to cleft lip with or without cleft palate, which is more often nonsyndromic. On a vignette, when an infant has an isolated cleft palate, you must think about evaluating for an underlying syndrome.

03Diagnostic Workup

The diagnosis of cleft lip is predominantly clinical. In the prenatal period, the best initial test is the routine anatomy ultrasound at 18 to 20 weeks of gestation, which can reliably detect cleft lip as a discontinuity in the upper lip echogenicity. However, isolated cleft palate is notoriously difficult to identify on prenatal ultrasound and is frequently missed, making it a postnatal diagnosis. When prenatal ultrasound raises concern, 3D ultrasound or fetal MRI can provide additional anatomical detail.

At birth, the diagnosis is confirmed by direct physical examination. The lip is inspected for any degree of clefting, from a subtle notch to a full-thickness defect extending into the nose. The palate must be both visually inspected and palpated, because a submucous cleft palate can be missed if only visual inspection is performed. The classic triad of a submucous cleft palate includes a bifid uvula, a midline zona pellucida (a translucent area where mucosa covers the cleft but muscle is absent), and a palpable notch in the posterior hard palate.

Once the cleft is identified, the next critical step is to evaluate for associated anomalies and syndromic features. Approximately 30% of cleft palate cases and 15% of cleft lip and palate cases are associated with a recognized syndrome. The presence of micrognathia should raise suspicion for Pierre Robin sequence. Cardiac murmurs, hypocalcemia, or thymic hypoplasia should prompt evaluation for 22q11.2 deletion syndrome. Lower lip pits are pathognomonic for Van der Woude syndrome. When syndromic features are identified, genetic testing (chromosomal microarray, fluorescence in situ hybridization for 22q11.2, or targeted gene panels) is indicated.

All infants with cleft palate should receive a baseline hearing evaluation because the risk of chronic otitis media with effusion and resultant conductive hearing loss is extremely high.

04Management and Treatment

Immediate Postnatal Management:
The first priority is to establish adequate feeding. Infants with a cleft palate cannot generate suction effectively, so standard breastfeeding and regular bottles are often unsuccessful. The intervention is a squeeze-delivery bottle such as the Haberman feeder, which allows the caregiver to control milk flow by compressing the bottle. The infant should be fed in an upright or semi-upright position to reduce nasal regurgitation. Weight gain must be closely monitored; failure to thrive is an important early complication.

Surgical Timing:
The single most tested concept in this section is the Rule of 10s for cleft lip repair: the infant must be at least 10 weeks of age, weigh at least 10 pounds (approximately 4.5 kg), and have a hemoglobin of at least 10 g/dL. These criteria ensure that the child can safely tolerate general anesthesia and that tissue volume is adequate for a good repair. The most commonly tested technique for unilateral cleft lip is the Millard rotation-advancement flap.

Palatoplasty is performed at 9 to 12 months, and the rationale is that the palate must be anatomically closed before the child begins producing meaningful speech. If repair is delayed beyond 12 to 18 months, the child develops compensatory speech patterns (glottal stops, pharyngeal fricatives) that are difficult to correct even with later surgery and therapy.

Middle Ear Management:
Because almost all infants with cleft palate develop middle ear effusion from Eustachian tube dysfunction, myringotomy with tympanostomy tube placement is frequently performed at the time of palatoplasty or even earlier if hearing loss is documented. Serial audiometric testing is continued throughout childhood.

Long-Term Management:
The management of cleft lip and palate extends over many years and requires a multidisciplinary team. Alveolar bone grafting at the mixed dentition stage (ages 6 to 9) fills the bony cleft and supports the permanent canine tooth. Orthodontic treatment addresses dental alignment and maxillary arch form. Secondary procedures such as pharyngoplasty or pharyngeal flap may be needed for persistent velopharyngeal insufficiency after palatoplasty. Definitive rhinoplasty and orthognathic surgery (typically a Le Fort I advancement) are deferred until skeletal maturity, because the midface continues to grow throughout adolescence.

Contraindications and Cautions:
Surgical repair should be postponed in the setting of active upper respiratory infection, uncorrected anemia, or failure to meet the Rule of 10s criteria. Pierre Robin sequence patients may require airway management (prone positioning, nasopharyngeal airway, or tongue-lip adhesion) before addressing the palatal cleft.

05Differential Diagnosis and Distractors

06Traps and High-Yield Pearls

The most common way students lose points on cleft lip and palate questions is by confusing the timing and criteria for surgical repair. The Rule of 10s (10 weeks, 10 lbs, 10 g/dL) applies to cleft lip repair (cheiloplasty), not palatoplasty. Palatoplasty is timed to be completed before speech onset, at 9 to 12 months. If a vignette describes an infant who meets the Rule of 10s but only has a cleft palate without a cleft lip, the answer is not immediate surgery; the palatoplasty is still performed at the 9-to-12-month window.

Another frequent trap is failing to recognize a submucous cleft palate. A vignette may describe an older child with hypernasal speech and recurrent otitis media but no visible palatal cleft. The key is to look for the triad of bifid uvula, zona pellucida, and a notched posterior hard palate. If you see "bifid uvula" in a stem, think submucous cleft.

Students also commonly miss the association between isolated cleft palate and syndromic diagnoses. When a vignette pairs cleft palate with cardiac anomalies, hypocalcemia, or immune deficiency, the answer is 22q11.2 deletion. When it pairs cleft palate with micrognathia and airway obstruction, the answer is Pierre Robin sequence. When it adds lower lip pits, the answer is Van der Woude syndrome. The core competency being tested is pattern recognition: matching the constellation of associated findings to the correct syndromic diagnosis, rather than treating the cleft as an isolated finding.

Finally, do not overlook the importance of Eustachian tube dysfunction. Any time a vignette presents a child with cleft palate and recurrent ear infections or hearing loss, the mechanism is tensor veli palatini dysfunction leading to chronic middle ear effusion. The treatment is tympanostomy tube placement, not antibiotics alone.