Concerning the embryology of the nose and paranasal sinuses which of the following statements is FALSE?
ExplanationD. Branchio-oto-renal syndrome is characterized by abnormalities of the ear, branchial clefts, and renal dysplasia. The frontal sinus originates from pneumatization of the frontal recess into the frontal bone, and is not usually visible at birth. It is usually complete by the age of 20. The maxillary sinus undergoes two periods of rapid growth associated with dental development (3 years and 7-12 years). Initially the floor of the sinus is above that of the nasal floor, but later it is below the nasal floor. Prenatal markers for Down's syndrome include absent or hypoplastic nasal bones. Abnormal cilia function is seen in Kartagener's syndrome and primary ciliary dyskinesia.
