*3.2.3. Low-set ears*

Low-set ears refer to malpositioned auricles, located anteriorly to the horizontal line drawn at the level of the inner canthus (**Figure 3E**).The size of a low-set ear is usually smaller compared to that in a normally developed embryo, with the angle posteriorly rotated [22]. Low-set ears accompany a variety of congenital chromosomal defects, including Turner's syndrome, Patau syndrome, Treacher-Collins syndrome, trisomy 18, trisomy 13, Cri du chat syndrome, and Down syndrome. It is often observed along with micrognathia.

Malformations of the ear can be recognized earliest at CS 18, although it can be estimated earlier by observing the auricle hill. Besides being low-set, the auricles may also be malformed as shown in **Figure 3E**.
