Deformation usually begins just after birth for the next couple of years until the desired shape has been reached or the child rejects the apparatus (Dingwall, 1931; Trinkaus, 1982; Anton and Weinstein, 1999).
There is no established classification system of cranial deformations. Many scientists have developed their own classification systems, but none have agreed on a single classification for all forms that are seen
In Europe and Asia, three main types of artificial cranial deformation have been defined by E.V. Zhirov
Cranial deformation was probably performed to signify group affiliation, or to demonstrate social status. This may have played a key role in Maya society. It could be aimed at creating a skull shape which is aesthetically more pleasing or associated with desirable attributes. For example, in the Nahai-speaking area of Tomman Island and the south south-western Malakulan (Australasia), a person with an elongated head is thought to be more intelligent, of higher status, and closer to the world of the spirits