Patient Eligibility for Standardized Treatment of the Edentulous Mandible: A Retrospective CBCT-Based Assessment of Mandibular Morphology

The aim of the study was to evaluate the proportion of patients recommended for full-arch mandibular restoration that would be eligible for treatment with a recently developed premanufactured full-arch prosthesis (Trefoil™, Nobel Biocare) based on the morphology of their lower jaw. Anonymized cone beam computed tomography (CBCT) data from 100 partially and fully edentulous patients referred for full-arch mandibular restoration were retrospectively collected from an imaging center database. Using custom-built software, CBCTs of mandibles were registered to a reference CBCT of a patient treated previously with a premanufactured full-arch prosthesis to determine if patients had adequate horizontal width and vertical height for implant placement. Bone height and thickness around simulated implants and distances to the incisive canal were evaluated. Mandibular arch width and semi-automated volume calculations were also performed. Using the system-specific 5.0 mm diameter implants with lengths of 13 and 11.5 mm, 85% and 86% of patients, respectively, were eligible for treatment with the standardized prosthesis. Eligibility was higher for men than women (odds ratio = 3.9, p = 0.045) due to increased bone volume. Based on mandibular morphology, our results suggest that the standardized treatment concept could serve a large percentage of patients with edentulous mandibles or failing dentition in the mandible.