p. 36: In addition,the PSR Index provides a more detailed picture of periodontal status by recording the presence of furcation involvement, tooth mobility, mucogingival problems, and gingival recessions exceeding3.5mm. When at least one of the above conditions is present, an asterisk (*) is recorded with the PSR score for that given sextant.
p. 37: In addition, sextants with fewer than two teeth are scored with an ‘X’and are not considered in the overall evaluation
p. 37: However, if a sextant has only one functional tooth, it is included in the preceding sextant