Craniofacial Surgery and Congenital Anomalies
What this domain tests
Timing decisions, suture-specific skull deformities, syndromic recognition and the staged cleft pathway.
Craniosynostosis
- Virchow's law: fusion of a suture restricts growth perpendicular to it, with compensatory growth parallel to it.
- Sagittal fusion (commonest) gives scaphocephaly; unilateral coronal gives anterior plagiocephaly with harlequin eye; bicoronal gives brachycephaly; metopic gives trigonocephaly; lambdoid gives posterior plagiocephaly.
- Syndromic forms: Apert (FGFR2, bicoronal with mitten syndactyly and midface hypoplasia), Crouzon (FGFR2, no limb anomaly), Pfeiffer, Saethre–Chotzen (TWIST1). Multiple-suture and syndromic cases risk raised intracranial pressure and need earlier intervention.
- Timing: endoscopic strip craniectomy with helmet therapy before 3–6 months of age; open cranial vault remodelling generally at 6–12 months.
Cleft lip and palate
- Embryology: lip fusion of medial nasal and maxillary prominences at 4–7 weeks; palatal fusion at 8–12 weeks.
- Cleft lip repair follows the "rule of tens" - about 10 weeks of age, 10 lb weight, 10 g/dL haemoglobin - via Millard rotation-advancement or Tennison–Randall.
- Palate repair at 9–12 months, before meaningful speech, by von Langenbeck, Bardach or Furlow double-opposing Z-plasty; aims are layered closure, restoration of the velar sphincter and normal speech.
- Alveolar bone grafting at 6–9 years in the mixed dentition. Velopharyngeal insufficiency after repair is managed by pharyngeal flap or sphincter pharyngoplasty.
Other anomalies
- Pierre Robin sequence: micrognathia, glossoptosis, U-shaped cleft palate. Airway management is positional, nasopharyngeal airway, tongue-lip adhesion, or mandibular distraction osteogenesis.
- Vascular anomalies (ISSVA): infantile haemangioma is GLUT-1 positive, appears after birth, proliferates then involutes, and responds to propranolol; malformations do not involute and are treated with sclerotherapy, embolisation or sirolimus.
Worked example
A baby born with a complete unilateral cleft lip and palate. Reasoning across time: lip repair at about 10 weeks once weight and haemoglobin allow (Millard); palate repair at 9–12 months for speech; grommets and audiology throughout; alveolar bone graft at 6–9 years as the permanent canine erupts; orthodontics in the mixed dentition; definitive rhinoplasty and orthognathic surgery only after facial growth is complete in late adolescence.
Traps
- Confusing positional plagiocephaly (parallelogram head, no suture ridge, responds to repositioning) with lambdoid synostosis.
- Applying the "rule of tens" to palate repair.
- Delaying palate repair past 18 months, compromising speech.
- Missing 22q11 deletion in isolated cleft palate with cardiac anomalies.
- Enucleating rather than resecting vascular anomalies.