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.

Osseointegrated craniofacial implants in the rehabilitation of orbital defects: an update of a retrospective experience in the United States.

STATEMENT OF PROBLEM: Since their introduction, craniofacial implants have been used in prosthetic rehabilitation of facial defects. The literature, however, indicates marked variability in outcomes using implants for the retention of orbital prostheses. PURPOSE: A multicenter report updating the experience in the United States with the use of craniofacial implants for prosthetic rehabilitation of orbital defects is presented. MATERIAL AND METHODS: Surveys were sent to clinicians at 25 centers where maxillofacial prosthetic treatment is provided to obtain retrospective data regarding patients who completed implant-retained orbital prosthetic rehabilitation. Data on implant placement location, radiation treatment history, and use of hyperbaric oxygen therapy were collected and assessed in relationship to implant survival over time. The Kaplan-Meier life table and Wilcoxon analyses (alpha = .05) were used to assess the significance of the findings. RESULTS: Ten centers responded, providing data suitable for statistical analysis on 153 implants placed to retain 44 orbital prostheses and followed for a mean period of 52.6 months. Forty-one implant integration failures occurred during this follow-up period, resulting in an overall integration survival rate of 73.2%. No significant relationship was found between radiation treatment history, hyperbaric oxygen therapy history, or implant placement location and implant survival. Individual responses revealed large variability between reporting centers in treatment outcomes. CONCLUSION: Craniofacial implants may offer marked benefits in the prosthetic rehabilitation of orbital defects when compared to conventional adhesive retention designs. However, questions remain regarding long-term predictability and the impact specific factors may have on treatment outcomes. Insufficient data is currently available from which to draw statistically meaningful conclusions. The establishment of a national database designed to acquire adequate data to assess treatment outcomes is recommended.

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.

Dental extractions in the irradiated head and neck patient: a retrospective analysis of Memorial Sloan-Kettering Cancer Center protocols, criteria, and end results.

BACKGROUND: This study was designed to use our institutional experience with irradiated head and neck patients to evaluate 1) dental extraction incidence and sequelae; 2) those patients who developed osteoradionecrosis via extraction and the efficacy of hyperbaric oxygen therapy; and 3) guidelines for extraction protocols in this population. Materials and methods A group of 1,194 patients with a history of radiation to the head and neck, who were evaluated and treated in the Dental Service at Memorial Sloan-Kettering Cancer Center, were reviewed. The 187 who required dental extractions were analyzed using patient demographics, tumor location, staging, histopathology, radiation dosage, field, and timing, dental extraction indications, location, surgical methods, and sequelae. RESULTS: Almost 85% of the patients reviewed did not require extraction. Only 4 of those who underwent extractions at Memorial Sloan-Kettering Cancer Center developed osteoradionecrosis. CONCLUSIONS: The use of multidisciplinary team communications and careful extraction selection by prognosis and symptomatology regardless of preexisting dental pathologies, atraumatic extraction procedures, and meticulous follow-up can lower both extraction and osteoradionecrosis rates.

Hard palate resection, microvascular reconstruction, and prosthetic restoration: a 14-year retrospective analysis.

BACKGROUND: This retrospective analysis was conducted to evaluate self-reported patient and clinician assessed functional outcomes of patients who have undergone ablative hard palate oncologic resection and microvascular free-flap reconstruction with and without maxillofacial prosthetic intervention. METHODS: All Head and Neck Surgery Service, Plastic and Reconstruction Surgery Service, and Dental Service charts and progress notes entered into the Institutional Health Care Information System of 57 patients who underwent hard palate resection and microvascular reconstruction at Memorial Sloan-Kettering Cancer Center (MSKCC) between January 1, 1988, and December 31, 2001 were reviewed retrospectively by three maxillofacial prosthodontists (BJB, JMH, IMZ). Prosthetic and nonprosthetic rehabilitation outcomes for each patient were reported as having normal; limited; or poor esthetics and function according to each prosthodontist's clinical evaluations; patients' self-perceptions; and feedback from friends, family members, and/or spouse. Speech intelligibility was determined in the same manner but reported as normal, hypernasal, and hyponasal. RESULTS: Most of the 26 prosthetically rehabilitated patients were reported as having normal esthetics (81%), normal function (77%), normal speech (96%), and were able to return to per oral full diets (81%) without any restrictions. CONCLUSIONS: Acceptable oral rehabilitation outcomes were reported for most prosthetically rehabilitated free-flap patients. Normal speech can be anticipated with a high degree of certainty, and a high percentage of prosthetically restored free-flap patients achieved per oral diets.

The role of novel oncogenes squamous cell carcinoma-related oncogene and phosphatidylinositol 3-kinase p110alpha in squamous cell carcinoma of the oral tongue.

PURPOSE: Amplification at chromosome 3q26.3 is a common and crucial event in head and neck squamous cell carcinoma (HNSCC), impacting significantly on tumor progression and clinical outcome. Two novel oncogenes, namely squamous cell carcinoma (SCC)-related oncogene (SCCRO) and PIK3CA (gene encoding phosphatidylinositol-3 kinase catalytic alpha-polypeptide), have been identified as targets of 3q26.3 amplification. This study aimed to delineate the role of SCCRO and PIK3CA in the pathogenesis of oral tongue SCC. EXPERIMENTAL DESIGN: The association between gene copy number for SCCRO and PIK3CA measured by fluorescence in situ hybridization and level of mRNA expression quantitated by real-time reverse transcription-PCR was assessed in a panel of human HNSCC cell lines. In addition, gene expression in 49 consecutive primary SCCs of the oral tongue was determined and correlated with clinicopathological characteristics and outcome. RESULTS: The mRNA level of SCCRO and PIK3CA was significantly correlated to the gene copy number in nine HNSCC cell lines. In addition, the expression level of SCCRO and PIK3CA was significantly greater in malignant tissues compared with those in histologically normal mucosae (2.17- and 2.46-fold, respectively; P < 0.001). Matched tumor normal control analysis revealed that 24.5 and 69.4% of patients expressed high levels of SCCRO and PIK3CA, respectively. Univariate analyses demonstrated that SCCRO overexpression correlated with nodal metastases (P = 0.05) and advanced stage (P = 0.02), whereas PIK3CA overexpression was associated with vascular invasion (P = 0.04). Only SCCRO overexpression was associated with disease-specific (P = 0.04) and overall survival (P = 0.02). Furthermore, SCCRO overexpression remained an independent predictor for cervical nodal metastasis on multivariate regression analysis (chi(2) likelihood ratio = 4.38; P = 0.04). CONCLUSIONS: Although both SCCRO and PIK3CA may play a role in the pathogenesis of oral tongue SCC through amplification at 3q26, SCCRO appears to be a significant predictor of regional metastasis and may be a marker for tumor aggressiveness and clinical outcome.

Effects of therapy on dentofacial development in long-term survivors of head and neck rhabdomyosarcoma: the memorial sloan-kettering cancer center experience.

PURPOSE: To describe potential effects of multimodality therapy on dental and facial development in long-term survivors of head and neck rhabdomyosarcoma. PATIENTS AND METHODS: The medical records of all patients aged 20 years or less presenting between 1985 and 1996 with a diagnosis of rhabdomyosarcoma and treated by protocol were reviewed. Head and neck rhabdomyosarcoma patients who were followed in the Dental Service and were alive and free of disease with at least a 5-year follow-up were included in the review. Ten patients satisfied the inclusion criteria and form the basis of this report. The median age at diagnosis of the 10 patients was 4.3 years (range 10 months to 19.5 years). All patients were treated with chemotherapy, two patients underwent surgery, and all but one patient received external beam radiation therapy. RESULTS: Clinical or radiographic dentofacial abnormalities were observed in 8 of the 10 (80%) patients. Abnormalities included enamel defects, bony hypoplasia/facial asymmetry, trismus, velopharyngeal incompetency, tooth/root agenesis, and disturbance in root development. Bony hypoplasia and disturbance in root formation were the most common findings. CONCLUSIONS: Multimodality therapy for head and neck rhabdomyosarcoma can result in dentofacial abnormalities that affect the patient's quality of life. The care of the long-term survivor requires a multidisciplinary approach, including early involvement of the dental team.