Wryneck in the ancient Hawaiians.

A unique cranial asymmetry previously noted in the skeletal remains from Mokapu, O'ahu, Hawai'i, is described. The anomaly involves an indentation of one or both of the occipital condyles and facial and vault asymmetry. This examination of the asymmetry includes a search for other reported occurrences, a detailed description, and a differential diagnosis. A multiple working hypothesis approach is employed. Comparison of the osseous material with the expected clinical pictures in craniosynostosis, Kleippel-Feil syndrome, primary basilar impression, and torticollis results in the most likely explanation of congenital torticollis. A high rate of occurrence of the anomaly (1.8%) is found in the skeletal remains from the Hawaiian Islands, but it has been documented in only two instances outside Hawai'i. A survey of patients seen at The Shriner's Hospital for Crippled Children does not reveal a high rate of occurrence of torticollis in Hawaiians relative to other ethnic groups.