Option Explicit
Dim WithEvents oCXPart As CustomXMLPart
Sub AutoOpen()
Dim aCC As ContentControl
  For Each aCC In ActiveDocument.ContentControls
    If aCC.Type = wdContentControlCheckBox Then
      aCC.Range.Paragraphs(1).CollapsedState = aCC.Checked
    End If
  Next aCC
  On Error Resume Next
  Set oCXPart = ActiveDocument.CustomXMLParts.SelectByNamespace("http://TheAnchorage.com/XMLPart").Item(1)
lbl_Exit:
  Exit Sub
End Sub
Private Sub oCXPart_NodeAfterDelete(ByVal OldNode As Office.CustomXMLNode, ByVal OldParentNode As Office.CustomXMLNode, ByVal OldNextSibling As Office.CustomXMLNode, ByVal InUndoRedo As Boolean)
  'This event fires when a #text node containing a value is replaced with Null value. Not applicable with checkboxes
  If OldParentNode.BaseName = "Number_of_children" Then ProcessChange OldNode, True
lbl_Exit:
  Exit Sub
End Sub
Private Sub oCXPart_NodeAfterInsert(ByVal NewNode As Office.CustomXMLNode, ByVal InUndoRedo As Boolean)
  'This event fires when the Null value in a CXPart element node is replaced with a #text node containing a value. Not applicable with checkboxes.
  ProcessChange NewNode
lbl_Exit:
  Exit Sub
End Sub
Private Sub oCXPart_NodeAfterReplace(ByVal OldNode As Office.CustomXMLNode, ByVal NewNode As Office.CustomXMLNode, ByVal InUndoRedo As Boolean)
  'This event fires when the initial Null value in the node is replaced with a value.
  ProcessChange NewNode
lbl_Exit:
  Exit Sub
End Sub
Sub ProcessChange(oNodePassed As Office.CustomXMLNode, Optional bDeadNode As Boolean = False)
Dim oNode As CustomXMLNode
Dim oCC As ContentControl
  If bDeadNode Then
    'Not applicable for this case
  Else
    Set oCC = ActiveDocument.SelectContentControlsByTag(oNodePassed.ParentNode.BaseName).Item(1)
    oCC.Range.Paragraphs(1).CollapsedState = oCC.Checked
  End If
lbl_Exit:
  Exit Sub
End Sub