R.O.E. Records of Exotics
The lower tusks are the onlt ones measured. They must be pulled to measure.
Measure the entire length along the long side. Measure the circumference of the tusk at the base. Measure both tusks. Add all 4 measurements together for the total. Here's a link to R.O.E. http://www.roe.texaswildlife.net/Manual.htm
SCI measures the same except they measure the circumference at the widest point on the tusk, not necessisarily at the base.
SCI score sheet http://www.scifirstforhunters.org/docs/Method12.pdf