The Relationship Between Tyre Pressure and Tyre Wear

Some of Tyre Wear is very Strange, some of wear two side, But Middle Condition is good, but Some of Tyre weared Middle part, but two side Condition is good, Why? Some Repair People think the reason of Tyre wear is Wheel alginment angles Problem, well yes but that is only one reason, Have others Reasons can result in Tyre Wear Also Now Let's See one of them--Tyre Pressure