Your examination reveals a probing pocket depth of 6 mm on the facial surface of tooth 30. The free gingival margin is 2 mm apical to the CEJ (there is 2-mm recession on the facial). How much attachment loss has there been on the facial of this tooth?

When the free gingival margin is apical to the CEJ, recession has occurred. Attachment loss is the measure from the CEJ to the base of the periodontal pocket. With the free gingival margin 2 mm apical to the CEJ and the probing pocket depth measurement 6 mm, there has been 8 mm loss of attachment.