A novel nomogram and risk classification system for predicting overall survival in head and neck squamous cell cancer with distant metastasis at initial diagnosis.

INTRODUCTION: Head and neck squamous cell carcinoma (HNSCC) is one of the most invasive cancer types globally, and distant metastasis (DM) is associated with a poor prognosis. The objective of this study was designed to construct a novel nomogram and risk classification system to predict overall survival (OS) in HNSCC patients presenting with DM at initial diagnosis. METHODS: HNSCC patients with initially diagnosed DM between 2010 and 2015 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. Firstly, all patients were randomly assigned to a training cohort and validation cohort (8:2), respectively. The Cox proportional hazards regression model was used to analyze the prognostic factors associated with OS. Then, the nomogram based on the prognostic factors and the predictive ability of the nomogram were assessed by the calibration curves, receiver operating characteristic (ROC) curves and decision curve analysis (DCA). Finally, a risk classification system was established according to the nomogram scores. RESULTS: A total of 1240 patients initially diagnosed with HNSCC with DM were included, and the 6-, 12- and 18-month OS of HNSCC with DM were 62.7%, 40.8% and 30%, respectively. The independent prognostic factors for HNSCC patients with DM included age, marital status, primary site, T stage, N stage, bone metastasis, brain metastasis, liver metastasis, lung metastasis, surgery, radiotherapy and chemotherapy. Based on the independent prognostic factors, a nomogram was constructed to predict OS in HNSCC patients with DM. The C-index values of the nomogram were 0.713 in the training cohort and 0.674 in the validation cohort, respectively. The calibration curves and DCA also indicated the good predictability of the nomogram. Finally, a risk classification system was built and it revealed a statistically significant difference among the three groups of patients according to the nomogram scores. CONCLUSIONS: Factors associated with the overall survival of HNSCC patients with DM were found. According to the identified factors, we generated a nomogram and risk classification system to predict the OS of patients with initially diagnosed HNSCC with DM. The prognostic nomogram and risk classification system can help to assess survival time and provide guidance when making treatment decisions for HNSCC patients with DM.

Technical procedures for template-guided surgery for mandibular reconstruction based on digital design and manufacturing.

BACKGROUND: The occurrence of mandibular defects caused by tumors has been continuously increasing in China in recent years. Conversely, results of the repair of mandibular defects affect the recovery of oral function and patient appearance, and the requirements for accuracy and high surgical quality must be more stringent. Digital techniques--including model reconstruction based on medical images, computer-aided design, and additive manufacturing--have been widely used in modern medicine to improve the accuracy and quality of diagnosis and surgery. However, some special software platforms and services from international companies are not always available for most of researchers and surgeons because they are expensive and time-consuming. METHODS: Here, a new technical solution for guided surgery for the repair of mandibular defects is proposed, based on general popular tools in medical image processing, 3D (3 dimension) model reconstruction, digital design, and fabrication via 3D printing. First, CT (computerized tomography) images are processed to reconstruct the 3D model of the mandible and fibular bone. The defect area is then replaced by healthy contralateral bone to create the repair model. With the repair model as reference, the graft shape and cutline are designed on fibular bone, as is the guide for cutting and shaping. The physical model, fabricated via 3D printing, including surgical guide, the original model, and the repair model, can be used to preform a titanium locking plate, as well as to design and verify the surgical plan and guide. In clinics, surgeons can operate with the help of the surgical guide and preformed plate to realize the predesigned surgical plan. RESULTS: With sufficient communication between engineers and surgeons, an optimal surgical plan can be designed via some common software platforms but needs to be translated to the clinic. Based on customized models and tools, including three surgical guides, preformed titanium plate for fixation, and physical models of the mandible, grafts for defect repair can be cut from fibular bone, shaped with high accuracy during surgery, and fixed with a well-fitting preformed locking plate, so that the predesigned plan can be performed in the clinic and the oral function and appearance of the patient are recovered. This method requires 20% less operating time compared with conventional surgery, and the advantages in cost and convenience are significant compared with those of existing commercial services in China. CONCLUSIONS: This comparison between two groups of cases illustrates that, with the proposed method, the accuracy of mandibular defect repair surgery is increased significantly and is less time-consuming, and patients are satisfied with both the recovery of oral function and their appearance. Until now, more than 15 cases have been treated with the proposed methods, so their feasibility and validity have been verified.

Efficacy of bone grafts in jaw cystic lesions: A systematic review.

BACKGROUND: Bone grafts have been applied for many years in orthopedic surgery to assist with bone repair for defects or bone discontinuity caused by trauma and tumors as well as periodontal defects. Jaw cysts are another common benign disease of the maxillofacial region which may lead to pathological bone fracture, loss of teeth, and infection. However, whether bone grafts are beneficial for bone regeneration in jaw cystic lesions and when bone grafts should be used remains unclear. AIM: To study the efficacy of bone grafts compared to spontaneous healing in the treatment of jaw cystic lesions. METHODS: A literature search was performed in Medline, Cochrane Library and Embase to identify related articles published in English in the last ten years. The following key words and MeSH terms were used: "jaw cyst", "cystic lesion", "odontogenic cyst", "periapical cyst", "dentigerous cyst", "follicular cyst", "keratocyst", "treatment", "surgery", "bone graft", "enucleation", "cystectomy", and "bone regeneration". Case reports, clinical trials, clinical studies, observational studies and randomized controlled trials were included. Study quality was evaluated. RESULTS: Ten studies (n = 10) met the inclusion criteria. Five studies reported spontaneous bone healing after enucleation, three studies investigated the efficacy of various bone grafts, and two randomized comparative studies focused on the comparison between spontaneous healing and bone grafting. Over 90% of bone regeneration occurred within 6 mo after bone grafting. The bone regeneration rate after cystectomy showed great variation, ranging from 50% to 100% after 6 mo, but reaching over 90% after 12 mo. CONCLUSION: While the long-term superiority of bone grafting compared with spontaneous healing after cystectomy is unclear, bone grafts accelerate the process of healing and significantly increase bone quality.

Development and validation of novel nomograms to predict survival of patients with tongue squamous cell carcinoma.

BACKGROUND: There is no unified standard to predict postoperative survival in patients with tongue squamous cell carcinoma (TSCC), hence the urgency to develop a model to accurately predict the prognosis of these patients. AIM: To develop and validate nomograms for predicting overall survival (OS) and cancer-specific survival (CSS) of patients with TSCC. METHODS: A cohort of 3454 patients with TSCC from the Surveillance, Epidemiology, and End Results (SEER) database was used to develop nomograms; another independent cohort of 203 patients with TSCC from the Department of Oral and Maxillofacial Surgery, First Affiliated Hospital of Zhejiang University School of Medicine, was used for external validation. Univariate and multivariate analyses were performed to identify useful variables for the development of nomograms. The calibration curve, area under the receiver operating characteristic curve (AUC) analysis, concordance index (C-index), net reclassification index (NRI), and decision curve analysis (DCA) were used to assess the calibration, discrimination ability, and clinical utility of the nomograms. RESULTS: Eight variables were selected and used to develop nomograms for patients with TSCC. The C-index (0.741 and 0.757 for OS and CSS in the training cohort and 0.800 and 0.830 in the validation cohort, respectively) and AUC indicated that the discrimination abilities of these nomograms were acceptable. The calibration curves of OS and CSS indicated that the predicted and actual values were consistent in both the training and validation cohorts. The NRI values (training cohort: 0.493 and 0.482 for 3- and 5-year OS and 0.424 and 0.402 for 3- and 5-year CSS; validation cohort: 0.635 and 0.750 for 3- and 5-year OS and 0.354 and 0.608 for 3- and 5-year CSS, respectively) and DCA results indicated that the nomograms were significantly better than the tumor-node-metastasis staging system in predicting the prognosis of patients with TSCC. CONCLUSION: Our nomograms can accurately predict patient prognoses and assist clinicians in improving decision-making concerning patients with TSCC in clinical practice.

Trismus originating from rare fungal myositis in pterygoid muscles: A case report.

BACKGROUND: Trismus is a common problem with various causes. Any abnormal conditions of relevant anatomic structures that disturb the free movement of the jaw might provoke trismus. Trismus has a detrimental effect on the quality of life. The outcome of this abnormality is critically dependent on timely diagnosis and treatment, and it is difficult to identify the true origin in some cases. We present a rare case of trismus due to fungal myositis in the pterygoid muscle, excluding any other possible pathogenesis. CASE SUMMARY: The patient presented with a 2-mo history of restricted mouth opening. Computed tomography showed obvious enlargement of the left pterygoid muscles. Furthermore, the patient had trismus without obvious predisposing causes. The primary diagnosis was pterygoid myosarcoma. Consequently, lesionectomy of the left pterygoid muscle was performed. Intraoperative frozen biopsy implied the possibility of an uncommon infection. Postoperative pathologic examination confirmed myositis and necrosis in the pterygoid muscle. Fungi were detected in both muscle tissue and surrounding necrotic tissue. The patient recovered well with antifungal therapy and mouth opening exercises. The rarity of fungal myositis may be responsible for the misdiagnosis. Although the origin of pathogenic fungi is still unknown, we believe that both hematogenous spread and local invasion could be the most likely sources. To the best of our knowledge, this is the first case in the literature that reported fungal myositis in pterygoid muscles as the only reason that results in trismus. CONCLUSION: Surgeons should remain vigilant to the possibility of trismus originating from fungal myositis.

Effects of nanofibers on mesenchymal stem cells: environmental factors affecting cell adhesion and osteogenic differentiation and their mechanisms.

Nanofibers can mimic natural tissue structure by creating a more suitable environment for cells to grow, prompting a wide application of nanofiber materials. In this review, we include relevant studies and characterize the effect of nanofibers on mesenchymal stem cells, as well as factors that affect cell adhesion and osteogenic differentiation. We hypothesize that the process of bone regeneration in vitro is similar to bone formation and healing in vivo, and the closer nanofibers or nanofibrous scaffolds are to natural bone tissue, the better the bone regeneration process will be. In general, cells cultured on nanofibers have a similar gene expression pattern and osteogenic behavior as cells induced by osteogenic supplements in vitro. Genes involved in cell adhesion (focal adhesion kinase (FAK)), cytoskeletal organization, and osteogenic pathways (transforming growth factor-ß (TGF-ß)/bone morphogenic protein (BMP), mitogen-activated protein kinase (MAPK), and Wnt) are upregulated successively. Cell adhesion and osteogenesis may be influenced by several factors. Nanofibers possess certain physical properties including favorable hydrophilicity, porosity, and swelling properties that promote cell adhesion and growth. Moreover, nanofiber stiffness plays a vital role in cell fate, as cell recruitment for osteogenesis tends to be better on stiffer scaffolds, with associated signaling pathways of integrin and Yes-associated protein (YAP)/transcriptional co-activator with PDZ-binding motif (TAZ). Also, hierarchically aligned nanofibers, as well as their combination with functional additives (growth factors, HA particles, etc.), contribute to osteogenesis and bone regeneration. In summary, previous studies have indicated that upon sensing the stiffness of the nanofibrous environment as well as its other characteristics, stem cells change their shape and tension accordingly, regulating downstream pathways followed by adhesion to nanofibers to contribute to osteogenesis. However, additional experiments are needed to identify major signaling pathways in the bone regeneration process, and also to fully investigate its supportive role in fabricating or designing the optimum tissue-mimicking nanofibrous scaffolds.

Primary small cell carcinoma with neuroendocrine properties of the mandible: A case report and literature review.

Small-cell carcinomas at extrapulmonary primary sites are rare but they have been documented to arise at various locations. We report a case of small-cell carcinoma arising in the mandible, which has so far not been reported in the literature. A 37-year-old male patient underwent partial resection of the left mandible and adjuvant chemotherapy. Immunohistochemistry confirmed the diagnosis of small-cell carcinoma with neuroendocrine properties. The patient has been free of disease for 18 months after receiving treatment and was alive at the time of writing. We recommend surgical resection followed by chemotherapy for managing small-cell carcinomas in the mandibular region.

[Tissue engineered bone reconstruction with modified PLGA/Type-I collagen compound scaffold].

OBJECTIVE: To fabricate bone grafts by bone marrow stromal cell combined with modified PLGA/Type-I collagen compound scaffold using tissue engineering method. METHODS: The modified PLGA/Type-I collagen compound scaffold was fabricated. The rabbit primary cultured osteoblasts were identified and seeded onto the modified compound scaffold for one week in vitro. The adhesion and growth of cells were observed with scanning electron microscope. The complex of cells and scaffold was implanted into the subcutaneous region of rabbits and new bone formation was evaluated. RESULTS: The rabbit bone marrow stromal cells were induced and differentiated into osteoblasts. The adhesion and growth of osteoblasts in cluster were observed on the surface of scaffolds. New bone formation was observed at one month postoperatively and active osteoblasts were found on the surface of the newly formed bone in vivo. CONCLUSION: The complex of PLGA and type-I collagen is an appropriate biodegradable scaffold and can be applied in bone tissue engineering.

[Experimental study on allogeneic mandible transplantation combined with basic fibroblast growth factor]

OBJECTIVE: To study the effect of basic fibroblast growth factor(b-FGF) on revascularization and bone remodeling of allogeneic mandible transplantation in repair of mandible defects in rabbits. METHODS: The mandible defects of 20 adult rabbits were created in both sides. The defects on the left side were implanted with allogeneic bone and local administration of b-FGF; the defects on the right side were only repaired with allogeneic bone as control group. At 1, 3 months after operation, the revascularization and bone remodeling were observed by ink-gelation vascular perfusion-transparency and histological examination. RESULTS: The allogeneic bone and b-FGF group had more marked vascularization and more quick and complete bone formation than control group. CONCLUSION: b-FGF can improve revascularization and bone formation after allogeneic mandible transplantation; allogeneic bone combined with b-FGF is a promising bone substitute in clinical uses.

Use of the versatile sternocleidomastoid flap in oral and maxillofacial surgery: our experience.

Our aim was to evaluate the reliability of sternocleidomastoid (SCM) flaps in the reconstruction of defects after oral and maxillofacial resections, and summarise the ways in which morbidity can be reduced. We retrospectively enrolled 65 patients who had malignant tumours resected, and assessed the postoperative viability of the SCM flap. All complications were recorded during a follow up period of 1-64 months. We also investigated the relation between recurrence in regional lymph nodes and their preoperative histological state. The conventional SCM flap, the split SCM flap with only the sternal head, and the SCM flap with a half-thickness clavicular graft, were used to repair different defects. No flaps necrosed completely, and in only 5 cases was there partial loss of the skin paddle. The skin paddle avulsed in 2 cases 2 patients developed wound infections. Only 9 patients developed complications (14%, 9/65). Use of the split SCM flap overcomes the problem of bulk. The combination of the SCM flap and clavicular bone enables early dental implantation. The SCM flap is convenient, reliable, and technically easy for the reconstruction of intraoral or mandibular tissue loss. Preservation of the branch of the superior thyroid artery and precise surgical technique contribute to a higher success rate.