Dental extractions for preradiation dental clearance and incidence of osteoradionecrosis in patients with nasopharyngeal carcinoma treated with intensity-modulated radiotherapy.

AIM: The aims of the present retrospective study were to evaluate the outcomes of dental extractions in nasopharyngeal carcinoma patients who had undergone dental clearance pre- and post-radiotherapy (RT) with intensity-modulated RT, and to report on the incidence and timing of osteoradionecrosis (ORN) in these patients. METHODS: A total of 231 patients were seen pre-, mid-, and postradiation therapy. Information on patient demographics, smoking history, staging, treatment modalities, dental extraction indications, and number and site of dental extractions was gathered. Wilcoxon two-sample tests and Fisher's exact test were used to test the association between groups for patient variables. RESULTS: The mean number of teeth removed was 4.1 teeth per patient. A total of 334 (35.2%) teeth were removed for periodontal reasons, 322 (34.03%) were removed prophylactically, and the remaining teeth were removed because of deep caries, retained roots, partial impaction, endodontic lesions, and prosthodontic reasons. Patients had an average of 19.6 teeth remaining after dental clearance, and only 97 (42%) required prosthetic intervention. The statistical analysis showed that there was no correlation between dental extractions pre- or post-RT and the development of ORN. CONCLUSIONS: No specific parameter was directly associated with dental extractions, although smoking and increased number of teeth removed preradiation seemed to be prevalent in patients who developed ORN.

Implant prosthodontic rehabilitation of fibula free-flap reconstructed mandibles: a Memorial Sloan-Kettering Cancer Center review of prognostic factors and implant outcomes.

PURPOSE: This study aimed to estimate the cumulative survival rates (CSRs) of implants placed in reconstructed mandibles and to identify prognostic factors that may influence implant survival. MATERIALS AND METHODS: The charts of 24 patients (10 male, 14 female) who had undergone mandibular resection and reconstruction with fibula free-flaps treated with implant-supported prostheses from April 1986 through December 2001 were reviewed. Information on demographics, surgical characteristics, treatment modalities, dentition, implant parameters, prostheses, and hyperbaric oxygen therapy (HBO) was gathered. Kaplan-Meier survival estimates were generated for the 100 implants that satisfied the inclusion criteria. Multivariate Cox proportional hazards regression models accounting for correlated implants within subjects were developed to identify prognostic factors for implant survival. RESULTS: Ninteen implants had been placed in native mandible (3 in irradiated bone) and 81 in fibula bone flap. Six implants failed during the follow-up period (mean 51.7 months). The overall 5- and 10-year CSRs were 97.0% and 79.9%, respectively. In the univariate analysis, variables associated with implant survival were age, gender, chemotherapy, radiation therapy, HBO, irradiated bone, implant diameter, xerostomia, trismus, opposing dentition, and type of prosthesis. At 5 years, the CSR of implants in patients with HBO was 86.7%; HBO was statistically associated with an increased risk for implant failure (P = .005, hazard ratio = 19.79, 95% CI: 2.42 to 161.71). DISCUSSION: The CSR was lower when implants were placed in a previously irradiated mandible. There is still a lack of reliable clinical evidence to support the effectiveness of HBO in these patients. CONCLUSIONS: A high survival rate was demonstrated for implants placed in fibula free-flap reconstructed mandibles. The finding that HBO was a risk factor can probably be attributed to the small sample size; further study is needed in this patient population.

Prosthetic intervention in the era of microvascular reconstruction of the mandible--a retrospective analysis of functional outcome.

PURPOSE: The purpose of this retrospective study was to compare the functional outcomes of patients who had mandibular resection and reconstruction with and without prosthetic intervention, and to identify predictive factors that may have an impact on functional outcomes. MATERIALS AND METHODS: Two hundred twenty head and neck cancer patients who had undergone mandibular resection and reconstruction with at least 6 months of postoperative convalescence formed the basis of this retrospective review. Patients who did not receive prosthetic intervention formed group I (n = 142); those who received prosthetic intervention formed group II (n = 78). Functional outcomes were measured using four individual assessments (nutritional status, swallowing, masticatory performance, and speech) and one that combined the information from these assessments, the global measure of functional outcome (GMFO). Statistical analyses were used to compare the baseline characteristics and functional outcome between groups I and II and to analyze independent predictors for GMFO. RESULTS: Of the 220 patients reviewed, 78 (35%) had prosthetic intervention; group II patients had better individual functional outcome measures and GMFO. Use of a prosthesis remained associated with GMFO after controlling for other significant predictors; other independent predictors were xerostomia, number of remaining mandibular teeth, number of tooth-to-tooth contacts, type of reconstruction, flap interference, and tongue defect. Patients who had fewer mandibular teeth and received a smaller prosthesis had better overall outcome than patients who received a larger prosthesis. CONCLUSION: Patients who had prosthetic intervention after mandibular reconstruction had significantly better functional outcomes than patients who did not receive prosthetic intervention, even after adjusting for confounding variables.