Bone resorption processes in patients wearing overdentures. A 6-years retrospective study.

OBJECTIVES 1. - To measure the alveolar resorption processes that occur in patients wearing mandibular overdentures on 2 implants and fully-removable maxillary dentures, and to evaluate the same process on patients wearing fully-removable dentures on both arches. 2.- To verify whether Kelly's Combination Syndrome occurs in the group of patients wearing overdentures. METHOD AND MATERIAL Forty patients were evaluated, of which a "cases" group was formed by 25 patients wearing mandibular overdentures on 2 lower jaw implants and fully-removable dentures on the opposite arch. The other 15 patients formed a control group that wore fully-removable dentures on both arches. Each one of the patients underwent orthopantograms from the moment the dentures were inserted until an average of 6 years later, which were assessed based on the Xie et al. method to estimate vertical bone loss. Once the data was collected, it was subjected to statistical analysis. RESULTS In terms of the maxillary midline, we observed a greater loss in patients wearing overdentures, which was statistically significant, as it registered 0.32 mm/year. Mandibular bone loss was 2.5 times less in patients in the cases group. The rest of the clinical criteria for Kelly's Combination Syndrome were not observed. CONCLUSIONS Kelly's Combination Syndrome did not occur in the patients in the cases group. In spite of the greater bone loss on a premaxillary level in this group, the placing of the overdenture on the implants significantly reduced mandibular bone resorption.