The proponents of bite mark evidence would like you to believe that bite marks are as distinctive as fingerprints, and that is pure bullsh!t.
A bite mark may rule out someone as making it, but can never be absolute proof that a specific person did made it. The best that can be said is that the mark is consistent with the suspected individual and could have been made by that person.
It’s also possible that in the months or years between the crime and his lawyers grandstanding display that he either had his teeth pulled or his dentures changed.