Malar Hypoplasia, with or without cleft in zygomatic bone

Cleft in zygomatic bone

Hypoplasia of the facial bones may be the first indicator of Treacher Collins Syndrome (TCS). The cheek (malar or zygomatic) bone is smaller or absent. A cleft in the malar bone is not uncommon. 

The malar surface is convex and perforated near its centre by a small aperture, the zygomatic foramen, for the passage of the zygomaticofacial nerve and vessels.

Radiographs and CT may be of value for evaluation of craniofacial abnormalities.

Other symptoms of TCS:

  • Mandibular Hypoplasia
  • Antimongoloid slanting palpebral fissures
  • Lower eye lid coloboma
  • malformation of auricles
  • External ear canal defect
  • Cleft Palate
  • Hearing loss
  • Visual impairment
  • Palate malformation
Last modified
26 May 2019

Small cheekbones or Malar Hypoplasia and/or cleft in the zygomathic bone may occur in:

Rare Condition

Treacher Collins Syndrome

Treacher Collins Syndrome is a genetic disorder characterized by hypoplasia of facial bones (mandible, maxilla and cheek bone), antimongoloid slant of palpebral fissures, coloboma of...


Dysgenesis of the hard and soft tissues of the first...