A 2-day-old male presents with micrognathia, malformed malleus and incus, and underdeveloped muscles of mastication causing feeding difficulty. Vital signs show HR 145 bpm, RR 48, and normal oxygen saturation on room air. Physical examination reveals small mandible with normal maxilla. Imaging confirms ossicular abnormalities. The child has no cleft palate. Which embryologic structure's maldevelopment most likely accounts for this constellation of findings?
- A)First pharyngeal pouch
- B)Third pharyngeal arch
- C)Second pharyngeal arch
- D)Fourth and sixth pharyngeal arches
- E)First pharyngeal archGABARITO
Explicação
The first pharyngeal arch gives rise to the maxilla, mandible, malleus, incus, and muscles of mastication. Combined abnormalities of jaw development, first ossicles, and chewing muscles point strongly to a first arch defect. Ver explicação completa e trilha adaptativa →