Locoregional recurrence rate and disease-specific survival following marginal vs segmental resection for oral squamous cell carcinoma with mandibular bone invasion.

BACKGROUND AND OBJECTIVES: To determine locoregional recurrence rate (LRR) and disease-specific survival (DSS) following marginal vs segmental mandibulectomy. METHODS: Included were 210 patients, who had marginal or segmental mandibulectomy between 2000 and 2017. Marginal resection was performed when complete removal of the tumor was deemed feasible on the condition that at least 1 cm bone height of the inferior border of the mandible could be preserved. Segmental resection was performed in case less than 1 cm bone height of the mandible would remain. Clinical and histopathological data were collected from medical records. LRR and DSS were computed using Kaplan-Meier analysis. Cox-regression analysis was used to identify risk factors for LRR and DSS. RESULTS: A total of 59 marginal and 151 segmental resections had been performed. There was no significant difference in 3- and 5-year LRR (P = .904) and no significant difference in 3- and 5-year DSS (P = .362) between the marginal and segmental resection group. Cox-regression analysis showed a trend for surgical margin less than equal to 1 mm, to affect LRR (P = .05) and surgical margin less than equal 1 mm, perineural invasion and lymph node metastasis to affect DSS (P < .05). CONCLUSIONS: There was no difference in outcome between the two types of mandibulectomy.

Global incidence and profile of ameloblastoma: A systematic review and meta-analysis.

OBJECTIVES: To evaluate the global incidence of ameloblastoma and to provide a profile of ameloblastoma patients. MATERIAL AND METHODS: A systematic review and meta-analysis was conducted. Searches were performed in PubMed, EMBASE, SCOPUS, and Web of Science for articles published from 1969 to 2018 for the global incidence and from 1995 to 2018 for the profile of ameloblastoma patients. RESULTS: Seven studies on the incidence rate of ameloblastoma were included in the meta-analysis. These studies only covered Europe, Africa, and Australia. The pooled incidence rate was 0.92 per million person-years (95% CI: 0.57-1.49), with significant heterogeneity between studies. Forty-two articles provided profile data of 6,446 ameloblastoma patients. Mean age was 34 years and the peak age incidence in the third decade of life. In Europe and North America, ameloblastoma mostly occurred at an older age when compared to Africa and South America. A slight male preference (53%) was found, and the mandible appeared to be the preferred site. The most common type of ameloblastoma was multicystic. The histopathologic patterns were mostly follicular and plexiform. CONCLUSIONS: This is the first study assessing the global incidence of ameloblastoma. The pooled incidence rate was determined to be 0.92 per million person-years.

Early and late complications in the reconstructed mandible with free fibula flaps.

BACKGROUND AND OBJECTIVES: Evaluation of mandibular reconstructions with free fibula flaps. Identification of factors associated with major recipient site complications, that is, necessitating surgical intervention under general anaesthesia. METHODS: Seventy-nine reconstructions were included. The following factors were analyzed: fixation type, number of osteotomies, site of defect (bilateral/unilateral), surgeon, sex, ASA classification, continuous smoking, pathological N-stage, age, defect size, flap ischemic time, and postoperative radiotherapy. Proportional hazards regression was used to test the effect on the time between reconstruction and intervention. RESULTS: Sixty-nine (87%) of the 79 fibula flaps were successful at the last follow-up. Forty-eight major recipient site complications occurred in 41 reconstructions. Nineteen complications required surgical intervention within six weeks and were mostly vascular problems, necessitating immediate intervention. These early complications were associated with defects crossing the midline, with an estimated relative risk of 5.3 (CI 1.1-20, P = 0.01). Twenty-nine complications required surgical intervention more than 6 weeks after the reconstruction. These late complications generally occurred after months or years, and were associated with smoking, with an estimated relative risk of 2.8 (CI 1.0-8.3, P = 0.05). CONCLUSIONS: Fibula flaps crossing the midline have a higher risk of early major recipient site complications than unilateral reconstructions. Smoking increases the risk of late complications.

Free vascularized flaps for reconstruction of the mandible: complications, success, and dental rehabilitation.

PURPOSE: To evaluate complications and success of mandibular reconstruction with free fibula flaps, iliac crest flaps, and forearm flaps with reconstruction plates and to evaluate dental rehabilitation after these reconstructions. PATIENTS AND METHODS: Eighty-three patients with segmental mandibular defects were included. Correlation analyses were used to determine the relationship between reconstruction type and clinical parameters with recipient-site complications and success. The dental rehabilitation was evaluated in successfully reconstructed survivors. RESULTS: Multivariate analyses showed significant correlations between flap type and success (P < .0001). Of the patients, 51 (61%) were alive 2 years after the reconstruction. Mandibular reconstruction with a free forearm flap and reconstruction plate was associated with higher complication rates at the recipient site and higher failure rates compared with reconstruction with free vascularized bone flaps. Of the 32 successfully reconstructed survivors, 14 (44%) had a complete dental rehabilitation, of which 10 had dental implants and 4 did not. Only 6 (29%) of the edentulous survivors ultimately had an implant-supported prosthesis. CONCLUSIONS: Reconstruction of the mandible with a free vascularized bone flap is superior to reconstruction with a free forearm flap with a reconstruction plate. Complete dental rehabilitation was reached in fewer than half of the surviving patients.

Surgical margins in the resection of oral squamous cell carcinoma under local versus general anesthesia.

OBJECTIVES: This study analyzes the influence of the surgical setting, i.e. resection under local anesthesia versus resection under general anesthesia, on surgical margins in tumor resection of stage I and II oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Retrospective study on tumor resections of stage I or II OSCC performed between 2014 and 2020. Potential predictors associated with surgical margins were identified. Multinomial logistic regression was used to analyze the effect of type of anesthesia on surgical margins, adjusted for potential predictors. RESULTS: In total, 109 cases were included: 54 tumor resections were performed under local anesthesia and 55 under general anesthesia. Histopathological examination showed 19 clear surgical margins, 54 close surgical margins, and 36 positive surgical margins. Compared to resection under general anesthesia, resection under local anesthesia increased the risk of close margins (adjusted OR = 6.26; 95 %CI 1.66-23.58; p = .01) and positive margins (adjusted OR = 6.81; 95 %Cl 1.70-27.27; p = .01). Tumor resection of the floor of mouth, buccal mucosa, gingiva, retromolar trigone, hard palate, and soft palate had a higher risk of close and positive margins than tumor resection of the tongue. Tumor resection of the tongue under local anesthesia was associated with an increased risk of positive margins compared to resection under general anesthesia. CONCLUSION: Tumor resection under local anesthesia of stage I and II OSCC increases the risk of close and positive surgical margins compared to tumor resection under general anesthesia.

Reconstruction of the alveolar cleft: can growth factor-aided tissue engineering replace autologous bone grafting? A literature review and systematic review of results obtained with bone morphogenetic protein-2.

The alveolar cleft in patients with clefts of lip, alveolus and palate (CLAP) is usually reconstructed with an autologous bone graft. Harvesting of autologous bone grafts is associated with more or less donor site morbidity. Donor site morbidity could be eliminated if bone is fabricated by growth factor-aided tissue engineering. The objective of this review was to provide an oversight on the current state of the art in growth factor-aided tissue engineering with regard to reconstruction of the alveolar cleft in CLAP. Medline, Embase and Central databases were searched for articles on bone morphogenetic protein 2 (BMP-2), bone morphogenetic protein 7, transforming growth factor beta, platelet-derived growth factor, insulin-like growth factor, fibroblast growth factor, vascular endothelial growth factor and platelet-rich plasma for the reconstruction of the alveolar cleft in CLAP. Two-hundred ninety-one unique search results were found. Three articles met our selection criteria. These three selected articles compared BMP-2-aided bone tissue engineering with iliac crest bone grafting by clinical and radiographic examinations. Bone quantity appeared comparable between the two methods in patients treated during the stage of mixed dentition, whereas bone quantity appeared superior in the BMP-2 group in skeletally mature patients. Favourable results with BMP-2-aided bone tissue engineering have been reported for the reconstruction of the alveolar cleft in CLAP. More studies are necessary to assess the quality of bone. Advantages are shortening of the operation time, absence of donor site morbidity, shorter hospital stay and reduction of overall cost.

Oral squamous cell carcinoma involving the maxillae: Factors affecting local recurrence and the value of salvage treatment for overall survival.

OBJECTIVE: To determine factors associated with local recurrence (LR) of oral squamous cell carcinoma involving the maxillae (MSCC) and overall survival (OS) after salvage treatment. SUBJECTS AND METHODS: Retrospective study of MSCC operated between 2000 and 2015. Kaplan-Meier survival and Cox regression were used for analysis of MSCC-associated clinical and histopathological factors. RESULTS: Ninety-five patients were included. LR occurred in 24% of patients. Vascular invasion significantly increased the risk of LR (hazard ratio 4.595, P = .003). Local salvage surgery, in the area of the original tumor, significantly prolonged OS, compared to palliative treatment (P = .001) and extensive salvage surgery (P = .013). Extensive salvage surgery, requiring resection of adjacent facial structures, did not prolong OS compared to palliative treatment (P = .186). CONCLUSIONS: MSCC with vascular invasion has higher risk of LR. Salvage surgery may prolong OS in small recurrences but might have dubious value for larger recurrences infiltrating adjacent facial structures.

Nonvascularized bone grafts for segmental reconstruction of the mandible--a reappraisal.

PURPOSE: To evaluate the success rate and complications of segmental mandibular reconstructions with autogenous nonvascularized iliac crest bone grafts, and to refine treatment strategies. PATIENTS AND METHODS: Seventy-four patients with segmental mandibular defects were included. Malignant lesion, immediate reconstruction, smoking habit, radiotherapy, site of the defect, surgical approach, and method of graft fixation were analyzed as factors of influence on success. Success was defined as maintenance of bone continuity and stability, and absence of infection 1 year after reconstruction upon clinical and radiographic examination. Complications were divided into recipient and donor-site complications and classified as minor or major. The reconstruction was considered functionally complete if prosthetic rehabilitation was accomplished or if there was a sufficient remaining dentition for mastication. RESULTS: In 56 (76%) patients, the initial reconstruction was successful. Multivariate analyses showed that symphyseal involvement (SI) and intraoral approach (IA) were significantly associated with failure (P(SI) = .022, P(IA) = .038) and major recipient-site complications (P(SI) = .022, P(IA) = .038). Thirty-two (43%) patients showed complications in the first postoperative year: 27 recipient-site complications and 6 donor-site complications. Nineteen (70%) recipient-site complications were classified as major. The reconstruction was functionally complete in 48 (86%) of the 56 patients with a successful initial reconstruction. CONCLUSIONS: Nonvascularized iliac crest bone grafts for segmental reconstruction of the mandible is the method of choice on the condition that the defect is truly lateral and only an extraoral approach is used. In these cases, microvascular tissue transfer is not necessary.

Predicting individualized mortality probabilities for patients with squamous cell carcinoma of the maxilla: Novel models with clinical and histopathological predictors.

BACKGROUND: The aim of this article was to develop prediction models that calculate postoperative 2- and 5-year mortality probabilities of patients with squamous cell carcinoma of the maxilla (MSCC). METHODS: Data were collected from the medical records of patients who had been operated between 2000 and 2015 for MSCC. Potential clinical and histopathological predictors were identified. Confounding-(un)adjusted multivariate Cox and logistic regression models were computed with stepwise backward selection. Internal validation was performed to assess calibration and discriminatory ability. RESULTS: Ninety-five patients with MSCC were included. Two-year follow-up was complete, and 85 patients had 5-year follow-up. Age, neck treatment, surgical margins, bone invasion, spindle growth, and vasoinvasive growth were associated with mortality. Models were adjusted for confounding with Charlson's comorbidities index. C-indexes were .841 and .770 respectively, and .838 and .749 after bootstrapping. CONCLUSION: The MSCC-specific mortality probability can be calculated with new prediction models.

Bone SPECT reduces the number of unnecessary mandibular resections in patients with squamous cell carcinoma.

High percentages (35-78%) of resected mandibles without bone invasion have been reported in squamous cell carcinoma (SCC), adjacent or fixed to the mandible, stressing the need for accurate imaging methods. The aim of this study is to determine the value of bone single photon emission computed tomography (SPECT) for the evaluation of mandibular invasion by SCC. Seventy-nine patients with SCC, adjacent or fixed to the mandible, were included. The results of bone SPECT were compared to the histology of the resection specimens. Bone SPECT was positive in all 50 patients with mandibular invasion and negative in 17 of 29 patients without mandibular invasion. In conclusion, a negative bone SPECT rules out mandibular invasion. Important clinical implications are then that further imaging is not necessary and that the resection can be kept limited. Inclusion of SPECT in the preoperative assessment of these patients will lead to a considerable reduction of unnecessary mandibular resections.

Health related quality of life after mandibular resection for oral and oropharyngeal squamous cell carcinoma.

The impact of several clinical parameters on health related quality of life (HrQOL) was evaluated in patients with squamous cell carcinoma adjacent or fixed to the mandible with special emphasis on postoperative radiotherapy and type of mandibular resection. One-hundred and five returned EORTC-questionnaires were available for this study. Correlation analyses were used to determine the relationship between clinical parameters and HrQOL. Postoperative radiotherapy was the clinical parameter that affected HrQOL most. The type of mandibular resection had no influence on HrQOL. The affected QOL-items were all associated with eating problems, i.e. use of a feeding tube, use of nutritional supplements, swallowing, social eating, mouth opening and dry mouth. Postoperative radiotherapy should only be applied if strictly indicated. This implies that the application of postoperative radiotherapy may need reconsideration in cases without strict criteria for postoperative radiotherapy.

The effect of exercise therapy in head and neck cancer patients in the treatment of radiotherapy-induced trismus: A systematic review.

Trismus is characterized by a reduced ability to open the mouth, directly affecting many aspects of daily life, such as chewing, swallowing, speaking and maintaining oral hygiene. Several studies have shown that trismus affects health related quality of life. Radiotherapy in the head and neck area is identified as one of the most frequent causes of trismus in head and neck cancer (HNC) patients. Currently, there is no standard treatment for trismus. Several stretching techniques and jaw mobilizing devices are available, but their effect in radiotherapy-induced trismus is still largely unknown. With this review we give an overview of the present relevant literature and compare the effect of exercise therapy versus no exercise therapy on jaw mobility, expressed in millimeters mouth opening, in HNC patients with radiotherapy-induced trismus. A systematic literature search in four electronic bibliographic databases was conducted in July 2014. Selected articles were critically appraised on relevance and validity. Best available evidence was analyzed and compared. Three of the four selected articles show a significant increase (p-value<0.05) in maximal interincisal opening (MIO) after exercise therapy using a jaw-mobilizing device. One article reports a significant decrease in MIO. However, this decrease is less in the intervention group, which implies a positive effect of exercise therapy. Based on this current best clinical evidence, it can be assumed that exercise therapy with a jaw-mobilizing device yields better results than no exercise, with regards to opening of the mouth in HNC patients with radiotherapy-induced trismus.

An epidemiological study of maxillofacial fractures requiring surgical treatment at a tertiary trauma centre between 2005 and 2010.

The epidemiology of maxillofacial fractures shows considerable regional variation as a result of local demographic and socioeconomic factors. We have assessed the epidemiological characteristics of such fractures at our centre in The Netherlands. The medical records of 394 patients who were treated surgically for maxillofacial fractures between 1 January 2005 and 31 December 2010 were analysed retrospectively. The male:female ratio was 3:1. There was a peak incidence in the second and third decades of life among men. The number of injured patients/year remained stable during the selected period. The incidence was highest in the spring and at weekends. Fractures of the mandible and zygoma were the most common. Road traffic crashes were the most common cause of injury (42%) and mainly involved bicycles. A total of 165 (15%) of the patients were intoxicated, and 142 patients (36%) had other serious injuries. Most patients (n=248, 63%) were treated within a day of presentation. Two hundred and thirty-two patients (59%) spent 4 days or fewer in hospital. The presence of other injuries was associated with a prolonged stay in hospital. Groups at particular risk of maxillofacial fractures are young men and cyclists. The use of helmets by cyclists could achieve a large reduction in injuries to the brain and upper face.

Donor site complications in bone grafting: comparison of iliac crest, calvarial, and mandibular ramus bone.

PURPOSE: To compare the donor site complication rate and length of hospital stay following the harvest of bone from the iliac crest, calvarium, or mandibular ramus. MATERIALS AND METHODS: Ninety-nine consecutively treated patients were included in this retrospective observational single-center study. RESULTS: Iliac crest bone was harvested in 55 patients, calvarial bone in 26 patients, and mandibular ramus bone in 18 patients. Harvesting of mandibular ramus bone was associated with the lowest percentages of major complications (5.6%), minor complications (22.2%), and total complications (27.8%). Harvesting of iliac crest bone was related to the highest percentages of minor complications (56.4%) and total complications (63.6%), whereas harvesting of calvarial bone induced the highest percentage of major complications (19.2%). The length of the hospital stay was significantly influenced by the choice of donor site (P = .003) and age (P = .009); young patients with the mandibular ramus as the donor site had the shortest hospital stay. CONCLUSIONS: Harvesting of mandibular ramus bone was associated with the lowest percentage of complications and the shortest hospital stay. When the amount of bone to be obtained is deemed sufficient, mandibular ramus bone should be the first choice for the reconstruction of maxillofacial defects.

Quantitative dynamic contrast-enhanced MRI for the assessment of mandibular invasion by squamous cell carcinoma.

The objective of this study was to determine the value of dynamic contrast-enhanced MRI (DCE-MRI) for the preoperative assessment of mandibular invasion in squamous cell carcinomas (SCC), adjacent or fixed to the mandible. DCE-MRI was performed with gadolinium diethylene triamine pentaacetic acid (Gd-DTPA). Data were obtained from 25 patients. From pharmacokinetic analysis of the tissue uptake of Gd-DTPA, the DCE-MRI parameters (k(ep), K(trans) and v(e)) were determined, with k(ep) representing the exchange rate constant, K(trans) the volume transfer constant and v(e) the volume of extracellular space per unit volume of tissue. The histology of the resection specimens was used as gold standard for the extent of mandibular invasion. SCC with medullary invasion showed higher mean k(ep) and K(trans) compared with SCC without medullary invasion (ANOVA, p<0.001). ROC analysis of k(ep) and K(trans) revealed reliable threshold values for medullary invasion. In conclusion, DCE-MRI can discriminate SCC with medullary invasion from SCC without medullary invasion and may serve as a valuable tool in preoperative tumour staging with regard to the delineation of medullary invasion.