A 9-ONTH-OLD infant appears to have the right side of her mouth pulled downward when she cries. The facial asymmetry has been noted by her mother, only on crying, since she was 2 months old. On her discharge examination from the newborn nursery, the right-sided asymmetry was also noted. Her birth history was unremarkable, her developmental milestones have been achieved appropriately, and her health has been excellent.
The physical and neurological examinations are unremarkable except for a drooping of the right corner of the mouth when crying. The eyelid closure, nasolabial fold depths, and forehead elevation are intact and symmetric. Results of a renal ultrasound examination, a voiding cystourethrogram, and a complete cardiac evaluation are normal.
Denouement and Discussion
Congenital Hypoplasia of the Depressor Anguli Oris Muscle
Congenital hypoplasia of the depressor anguli oris muscle is a minor anomaly characterized by a failure of one corner of the mouth to
Franco SM, Tunnessen WW. Picture of the Month. Arch Pediatr Adolesc Med. 1996;150(3):325-326. doi:10.1001/archpedi.1996.02170280095019