Anthropological study of ear tubercles in a Spanish sample.

The ear has been used since the 19th century as a valuable instrument in personal identification. Its special interest is due to the morphological complexity of the structures involved. The aim of the present investigation is to establish the morphological variability of the helix tubercles in a sample of the Spanish European population (303 individuals between 18 and 72 years old). The frequencies of appearance of each type of tubercle and its degree of expression, as well as the possible relationship with sex, age, and laterality, are determined. Three of the tubercles are relatively frequent in the sample: tubercle of the root of the superior helix (31.7%), tubercle of the anterior helix (27.6%), and the Darwin's tubercle (18.2%). The least frequent helix tubercles are those located on the superior helix (2.7%) and the inferior tubercles at the root of the helix (6%). For all sites, tubercles with the greatest degree of expression are the least frequent. No sexual dimorphism or age differences have been found except for the tubercle of the anterior helix. Overall, tubercles show good symmetry. A relation of dependency among some of the tubercles of the helix has been found.