RISK INDICATORS FOR FUTURE CLINICAL ATTACHMENT LOSS IN ADULT PERIODONTITIS - TOOTH AND SITE VARIABLES

IN AN EARLIER REPORT, WE EXAMINED the relationship of patient-derived clinical and epidemiological variables to the risk for future clinical attachment loss (CAL) in chronic adult periodontitis. We determined that the extent of the patient's existing periodontal disease as measured by mean attachment loss (MAL) and the patient's age were the most important patient-derived risk indicators for CAL among those factors evaluated. In this study, we examined the tooth and site variables that were associated with CAL. Seventy-five patients with chronic adult periodontitis were followed for 6 months. Clinical data at baseline, including attachment level and probing depth, were obtained from six sites per tooth. The hazard rate for CAL at all sites was 2.0%, and 4.1% of teeth displayed at least one site with CAL. Mandibular and maxillary molars and maxillary premolars displayed the highest incidence of CAL (6.1%, 5.6%, 5.5%, respectively), while maxillary anterior teeth (1.8%) and mandibular premolar teeth (2.1%) demonstrated the incidence. The greatest number of sites demonstrating CAL had an existing attachment level of 4 to 7 mm and a probing depth of less-than-or-equal-to 5 mm. When the data were converted to hazard rates, however, an increase in hazard rate was seen with increasing existing attachment loss or probing depth. When MAL was considered, patients with mild and moderate periodontitis demonstrated a relatively low incidence of CAL at sites with less-than-or-equal-to 7 mm of existing attachment loss. Patients with severe periodontitis exhibited greater hazard rates for sites with 0 to 3, 4 to 5 and 6 to 7 mm of existing attachment loss. Regardless of the patient category, all sites with greater-than-or-equal-to 8 mm of existing attachment loss demonstrated a significantly higher incidence of CAL. Similar results were seen for probing depth. When age was considered as a patient variable, all sites in patients who were in the 30 to 49 year-old group demonstrated low hazard rates for CAL. For patients who were 50 to 59 years old, the hazard rate gradually rose with increasing existing attachment loss or increasing probing depth. For patients in the 60 to 69 year-old group, sites with less-than-or-equal-to 5 mm of existing attachment loss and less-than-or-equal-to 3 mm probing depth did not differ in hazard rate from that seen in patients who were 50 to 59 years old. In the oldest group, sites with greater-than-or-equal-to 6 mm of existing attachment loss and greater-than-or-equal-to 4 mm of probing depth demonstrated hazard rates that were significantly greater than what was observed in the younger groups. These results suggest that both patient-derived and site-derived variables should be considered when developing a risk profile for CAL. These data may be useful in both treatment planning and selection of appropriate therapeutic modalities.