Before death:[as adjective]:the ante-mortem instructions of the dead leader...
So I think that it is not evidence of an ante-mortem kind of ligature.
The forensic odontologists compare the dental remains that we recover with the ante-mortem dental records in order to make a positive dental identification.
‘It has become an integral part of the ante-mortem process at factories and pre-export clearance for live exports,’ he added.