Which cephalic index value is typically associated with a brachycephalic head shape?

Which cephalic index value is typically associated with a brachycephalic head shape?

• A. 85%
• B. 70%
• C. 60%
• D. 90%

Answer: (A)

The cephalic index measures how broad the head is relative to its length by calculating CI = (maximum skull width / maximum skull length) × 100. A higher index means a shorter, wider head, which is characteristic of brachycephaly. In practical terms, values above about 80 indicate brachycephalic shape, with the mid-80s being a common representative range. Therefore, 85% is a typical example of brachycephalic head shape because the skull is relatively wide for its length. Values such as 70% or 60% describe longer, narrower heads (dolichocephalic), and while a 90% value would still be brachycephalic, it represents a more extreme end rather than the usual presentation.

The cephalic index measures how broad the head is relative to its length by calculating CI = (maximum skull width / maximum skull length) × 100. A higher index means a shorter, wider head, which is characteristic of brachycephaly. In practical terms, values above about 80 indicate brachycephalic shape, with the mid-80s being a common representative range. Therefore, 85% is a typical example of brachycephalic head shape because the skull is relatively wide for its length. Values such as 70% or 60% describe longer, narrower heads (dolichocephalic), and while a 90% value would still be brachycephalic, it represents a more extreme end rather than the usual presentation.