Immediate Implants in Fibulas: Does the Implant to Fibula Osteotomy Distance Impact Early Implant Failure?

[BACKGROUND] When placing dental implants in the free fibula flap, the osteotomy cut edge poses a unique challenge in that an optimal distance has not yet been established.

[PURPOSE] The study aimed to measure the association between implant-to-fibula osteotomy edge distance and early implant failure in patients who received free fibula flap reconstruction with immediate implants.

[STUDY DESIGN, SETTING, SAMPLE] A retrospective cohort study was designed and implemented. The study population was composed of patients who underwent free fibula flap transfer with immediate dental implant placement for the treatment of benign or malignant conditions of the head and neck from 2015 to 2022 at John Peter Smith Hospital. Subjects were excluded if the implant was in the middle of the free flap bordered by adjacent implants, was >10 mm from the osteotomy edge, or had insertional torque values of ≤30 Ncm.

[PREDICTOR VARIABLE] Primary predictor variable was the implant distance in millimeters from the fibula osteotomy edge.

[MAIN OUTCOME VARIABLE] Primary outcome variable was early implant failure, defined as implant exfoliation noted by the patient or failure due to implant movement or pain necessitating explantation within 6 months of placement.

[COVARIATES] The covariates were age, sex, diabetes diagnosis, American Society of Anesthesiologists classification, smoking status, history of head and neck radiation, pathology treated, and if postoperative radiation treatment was received.

[ANALYSES] A generalized estimating equations model was used to assess the relation between the primary predictor and outcome. A P value of <.05 was considered statistically significant.

[RESULTS] The sample was composed of 48 subjects who had 130 implants placed, with early failures occurring in 5 implants (3.9%) in 3 subjects. The mean age of the sample was 49 years (standard deviation [SD] 20) and 29 (60%) were male. The mean implant distances for early failures and nonfailures were 3.5 mm (SD 1.04) and 4.3 mm (SD 1.5), respectively. There was a statistically significant relation between implant distance and early implant failure (P = .005, odds ratio 0.6, 95% confidence interval 0.39 to 0.85).

[CONCLUSION AND RELEVANCE] This study found that shorter distances between the implant and the edge of the fibula osteotomy are associated with early implant failure.