Time of fusion of the basisphenoid with the basilar part of the occipital bone in northwest Indian subjects.

To find out the time of fusion of the basisphenoid with the basilar part of the occipital bone in Northwest Indian subjects, a quadrilateral piece of bone extending from the posterior clinoid processes to the jugular tubercles was removed from 50 male and 34 female autopsy subjects between the ages of 10 and 20 years. The piece of bone was X-rayed and then macerated. In addition CT scan cuts of the basisphenoid were obtained in 46 male and 27 female living subjects between the age of 10 and 19 years. In the males, partial fusion was seen at 13 years while a complete fusion was noticed at 15 years in 25% of the subjects. The age of a boy showing complete fusion should be 15 years or above. If there is no fusion or partial fusion he should be below 19 years as complete fusion is seen in all male subjects at 19 years. In females, the earliest partial fusion was noted at 12 years and complete fusion was present at 13 years in 16.6%. All female subjects showed complete fusion at 17 years. The minimum age of a girl showing complete fusion should be 13 years; if no fusion or partial fusion is seen, her age should be below 17 years.