The normal calvaria indices of the human skull. 1. Absolute measurements. 2. Proportional measurements.

Using the bony reference points: Nasion (N), Tuberculum sellae (Ts), Bregma (B), Lambda (L) as well as Twining's line (Tw) the normal position of bregma, lambda and internal occipital protuberance can be expressed in proportional measures by the ratios: N-Ts/B, N-Ts/L and N-Ts/Tw. Thus the growth rate of the human calvaria is expressed as a proportion of the anterior cranial base and found to be independent of the shape and age of the skull.