The extremely resorbed mandible, 10-year results of a randomized controlled trial on 3 treatment strategies

Abstract

Objectives: To prospectively compare the clinical and radiographic results of three modes of implant treatment for implant-retained mandibular overdentures in patients with extremely resorbed mandibles. The three treatment strategies used were (1) a transmandibular implant, (2) augmentation of the mandible with an autologous bone graft followed by placement of four endosseous implants, and (3) placement of four short endosseous implants.

Materials and methods: Sixty edentulous patients met the inclusion criteria and were assigned according to a balanced allocation method to 1 of the 3 treatment strategies. Implant survival, surgical retreatment rates, and peri-implant bone loss were assessed according to a standardized protocol during a 10-year evaluation period.

Results: During the evaluation period, significantly more implants were lost in the transmandibular implant (cumulative 10-year implant survival rate, 76.3%) and the augmentation groups (88%) compared to the group provided with short endosseous implants (98.8%). The 10-year retreatment rate was significantly more favorable in the endosseous implants only (0%) and augmentation groups (5%) compared to the transmandibular group (30%). In all three groups, there was minor peri-implant bone loss.

Discussion: Although implant loss is a frequently used outcome measure for success, the necessity of surgical retreatment seems to be of more relevance for both the patient and the clinician.

Conclusion: Considering the favorable clinical and radiographic parameters and the fact that patients can be treated in outdoor clinic setting, the use of short endosseous implants in combination with an overdenture is the first choice of treatment in patients with extremely resorbed mandibles.

Keywords: augmentation; dental implant; edentulous mandible; healthy aging; overdenture; transmandibular implant.