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

• A. 85%
• B. 70%
• C. 60%
• D. 90%

Answer: (A)

A high cephalic index indicates a brachycephalic head shape. The cephalic index is calculated by dividing the skull's maximum width by its maximum length and multiplying by 100. When the width-to-length ratio is large, the head is broad, which is described as brachycephalic. Values in the mid-80s fall into this category, whereas lower values describe dolichocephaly (long, narrow heads). Therefore, 85% is the brachycephalic range and best matches this head shape. The lower values (70% or 60%) point to dolichocephaly, and while 90% would also be brachycephalic, the given option aligns with the common range used to define brachycephaly.