Introduction
Morphological changes in Japanese cranial and facial form over time were described by Suzuki (1967). He examined a sample (n = 542) from the Jomon (Neolithic) through the Early Modern (Historic) period. These cranial materials were identified as adult males free from any congenital malformations or artificial deformations.
Suzuki described the face of a typical protohistoric Japanese as long headed, with a broad face, wide and flat nasal roots, and a fairly strong prognathism. These morphological aspects gradually changed becoming round-headed, displaying a more constricted face, and narrower and higher nasal roots, and less prognathous jaws. Nevertheless, two characteristics associated with the protohistoric period, dolichocephaly and prognathism, remained quite pronounced.
Some of the contributing factors influencing these chronological changes in skull morphology were hypothesized to be socioeconomic and environmental (Suzuki, 1967). Another presumed factor was the choice of mate. Finally, he also suggested that differences in Japanese physiognomy (as seen in these craniofacial or physical characteristics) from prehistoric to modern times were due to diverse origins. His studies were based on metrical and nonmetrical observations as well as physical measurements taken from the Martin and Saller (1957) handbook.
Traditionally, skull form has been described with ratios or indices as introduced by Martin and Saller (1957).