Conditions of iliac bone grafts application in mandibular defects replacement: a retrospective study of 11-years’ experience

Abstract

Background: This study aimed to clarify the occurrence and causes of postoperative complications in patients with continuous mandibular defects, reconstructed with free iliac bone grafts. Patients and methods: Patients with mandibular continuity defect with bone tissue loss, resulting in a 2 cm gap or more underwent reconstruction with non-vascularized iliac crest bone graft. The outcome variable was graft failure which was defined as its loss due to the postoperative infection, graft exposure, full resorption or non-unition of the graft. The predictors were timing of reconstruction, length of the bone defect, preoperative presence of mucosa defect and/or dehiscence and fixation method. All explanatory and predictor variables were analyzed with univariate binomial logistic regression. Results: The study included the results of 50 mandibular reconstructions with non-vascularized iliac crest bone graft which were observed retrospectively. The follow-up of included patients ranged from 6 months to 11 years. 34 patients (68 %) had successful surgery results. In 16 patients (32 %) the bone grafts were lost. All of them due to the infection development, suppuration and/or graft exposure during the first 6-months of the observation period. In univariate analysis, the main failure predictor variables were smoking (OR 5.8, CI 1.48-22.7, p = 0.002), timing of reconstruction (OR 7.94, CI 1.88-33.5, p = 0.004) and mucosa defect or dehiscence (OR 8.49, CI 2.21-32.6, p = 0.002). The multivariate analysis also revealed symphyseal involvement of defect (OR 5.63, CI 1.14-27.8, p = 0.034) as the significant failure predictor in a case of immediate reconstruction. The length of defect and fixators type remained statistically non-significant for mandibular reconstruction with NVICG (p < 0.05). Conclusion: The incidence of graft failure in patients with continuous mandibular defects reconstructed with non-vascularized iliac crest graft is determined by the risk factors, associated with timing of reconstruction, smoking and presence of the mucosal defect and/or dehiscence. No significant influence on the surgical outcomes was demonstrated for the large defects (more than 6 cm in comparison to less than 6 cm). Immediate reconstructions with iliac crest graft could not be recommended also in a case of symphyseal localization of a defect due to the significant increase in graft failure rates. In these categories of patient's other treatment modalities should be considered.