<prompt> Which of the fontalle is the last to close after birthAnterior fontanellePosterior fontanelleSphenoidal fontanelleMastoid fontanelle  <response>: Ref. The Short Textbook of Pediatrics. Pg 550 Anterior fontanelle closes around 10-18 monthsPosterior fontanelle closes around 8 weeksPersistent posterior fontanelles is earliest sign of hypothyroidism 