Ramus frame dental implant functional survival and safety in severely atrophic edentulous human mandibles.

Abstract

Ramus frame dental implants were retrospectively studied in 360 adults with severely atrophic edentulous mandibles. Patient records up to 12 years post-treatment were independently reviewed after a single clinician surgically placed titanium long-arm (“Tatum”) ramus frame implants and immediately loaded them with a mandibular overdenture. A total of 11 ramus frames were removed at 19 to 109 months post-treatment, mostly due to supramucosal bar fracture (N = 6) or mobility (N = 3). Kaplan-Meier product-limit analysis revealed the post-treatment survival probability for functional ramus frame implants to be 99.3% at 2 years (266 patients), 98.9% at 3 years (223 patients), 97.9% at 4 years (198 patients), 96.9% at 5 years (160 patients), 96.9% at 6 years (123 patients), 95.0% at 7 years (86 patients), 95.0% at 8 years (67 patients), 93.3% at 9 years (43 patients), and 91.1% at 10 years (25 patients). No statistically significant differences in functional ramus frame implant survival were found relative to patient gender, smoking, presence of natural maxillary teeth, or compliance with semi-annual maintenance care. Fracture of endosseous anterior feet/posterior arms was the most frequent implant-related complication on 29 implants, which were left in place, repaired, or replaced in situ without implant removal. At 5 years, the ramus frame implant functional survival probability without any implant-related biological or mechanical complication was 88.9%. Ramus frame dental implants, immediately loaded with a fully implant-borne mandibular overdenture, exhibited a high degree of long-term functional survival and safety in severely atrophic edentulous human mandibles.