A retroauricular incision in children less than 2 years may cause damage to which cranial nerve?

"Choanal atresia should be suspected in any infant who develops cyanosis that occurs with feeding or rest but is relieved by crying"Choanal atresiaPathology - Persistence of bucconasal membraneU/L atresia is more common than B/L atresiaMC in females and on the right sideDiagnostic criteriaPresence of mucoid discharge in the noseThe absence of air bubbles in nasal dischargeFailure to pass catheter from nose to pharynxPassage of methylene blue dye into pharynx from the noseIOC for choanal atresia - CT scan (Diagnosed if posterior choanal orifice <0.34 cm or posterior vomer >0.55 cm)Treatment - Correction of atresia by transnasal or transpalatal approach at 1 1/2 years or Mc Govern's technique for B/L choanal atresiaRef: PL Dhingra, Diseases of Ear, Nose & Throat, 7th edition, pg no. 183