Objective: Presence of all the normal ear components and the median longitudinal length more than 2 SD below the meanComments:
The definitions of microtia below follow a widely used, surgically based, classification of ear anomalies outlined by Weerda . As microtia indicates at least both decreased length and width, and in more severe forms it includes abnormal shape of structures, all forms are acknowledged to be bundled terms, but are retained here because they are well established.
See Short ear for a discussion of altered ear length. A better assessment of size would include both length and width (i.e., an estimate of surface area). Normal values for width and length measurements are available [Farkas, ; Hall et al., ].