The role of magnetic resonance imaging in assessing the extent of tongue squamous cell carcinoma: A prospective cohort study.

PURPOSE: To assess the false-positive and false-negative MRI results in evaluating the extent of tongue squamous cell carcinoma. METHODS: A prospective cohort series of 165 patients was enrolled to assess the false-positive and false-negative MRI results in evaluating the extent of tongue squamous cell carcinoma by comparing intraoperative tumor profile images and postoperative pathological sections. The differences between two-dimensional tumor margins were analyzed using Mimics 15.0 and Geomagic Control 16.0. A paired-samples t-test was used to analyze the agreement among MRI, intraoperative and pathological findings regarding the extent of tongue tumors. Multiple linear regression analysis was used to analyze associated factors. RESULTS: The mean and maximum false-positive values of pathological specimens was 1.95±1.39 mm (95% limit of agreement (LoA) 1.70-2.14) and 3.21 mm, respectively; the false-negative value was 0.44±0.49 mm. The false-positive value of intraoperative specimens was 1.52±0.87 mm (95% LoA 1.36-1.64); the false-negative value was 0.35±0.20 mm. Tumor morphology (ulcer type) (p<0.01) and depth of invasion (DOI) (≤5 mm) (p<0.01) were significantly correlated with the false-positive values of intraoperative and pathology specimens. CONCLUSION: The false-positive values are important when judging the invasion margin of tongue cancer and forming MRI-based operative plans; the false-negative value was almost negligible.

[Experimental study of the gap ossification in the double-barrel technique in rabbit tibia].

PURPOSE: Double-barrel vascularized fibula graft is one of the most common surgical techniques to augment or maintain the height of the neo-mandible. The purpose of this study was to investigate whether the gap completely disappeared and gap ossification ultimately achieved between the double barrels. METHODS: Six rabbits were used in the study. Each animal's tibia was vertically osteotomized at its midpoint, folded onto each other and fixed by mini-titanium plate, thus an animal model of "double barrel" was established. Specimens were obtained at 3 months and 6 months postoperatively, then the gap ossification between the double barrels was evaluated by radiography and histomorphology. Measurements of the gap width between the two tibial struts on X-ray films were performed 3 months after the operation at three sites: distal, middle and proximal site. Measurements were compared with those obtained immediately after operation using SPSS 19.0 software package. RESULTS: Three months after operation, radiography demonstrated that the gap between the double barrels gradually became vague. Histological study showed that irregular new woven bone formed in the gap between the two struts. There was significant difference in mean gap width at the distal and proximal site (P<0.05), but there was no significant difference at the middle site(P=0.552). Radiological and histological study showed cortical bone resorption in the contact area and two thin tubular bones fused into a thicker one 6 months postoperatively. CONCLUSIONS: The double-barrel tibia fixed with titanium microplate can fuse into a large, unique, continuous bone barrel.

A Newly Designed Seed-Loading Device for Verifying the Safety of 125I Implants to the Canine Carotid Artery.

A seed-loading device was designed and modeled using the Monte Carlo method to verify the biological effect of iodine-125 (125I) particles on blood vessels through animal experiments. The dose distribution characteristics of irradiated vessels were established by adjusting the design variables and geometry. The deviation between the actual value and the theoretical value was verified in vitro by the thermoluminescence dosimetry (TLD) method. After verification, the device was used to examine the biological effect of 125I irradiation of canine carotid arteries in two dogs (and one control dog) for 180 days. The hollow cylinder seed-loading device was constructed with an inner diameter of 0.5 cm and a length of 3.3 cm. When six seeds were loaded into a single layer, the source strength ratio of the intermediate layer to the edge layer was 0.7:1. When six layers of seeds were arranged at 0.45-cm intervals, the deviations between the maximum, minimum and mean energy fluence within 2.25 cm of the vessel wall were 2.19% and -4.12%, respectively, and -9% and 4%, respectively, when verified in vitro using TLD. The carotid arteries showed good tolerance to 0.56 kGy (range of 0.51-0.58 kGy) after 180 days of irradiation. In conclusion, this 125I seed-loading device overcomes the random distribution of seeds and lays an accurate radiophysical foundation for subsequent biological experiments. The preliminary results showed that the carotid artery has good tolerance to 0.56 kGy irradiation.

Identification of a Gene Prognostic Signature for Oral Squamous Cell Carcinoma by RNA Sequencing and Bioinformatics.

OBJECTIVES: Oral squamous cell carcinoma (OSCC) is the most common oral cancer and has a poor prognosis. We aimed to identify new biomarkers or potential therapeutic targets for OSCC. MATERIALS AND METHODS: Four pairs of tumor and adjacent normal tissues were collected from OSCC patients, and differentially expressed genes (DEGs) were screened via high-throughput RNA sequencing (RNA-seq). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were used to analyze the DEGs. A protein-protein interaction (PPI) network was established with the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database and Cytoscape, and two significant clusters were found. Candidate genes were screened by analyzing head and neck squamous cell carcinoma (HNSCC) data from The Cancer Genome Atlas (TCGA). A DEG-based risk model was established to predict the overall survival (OS) of OSCC patients via Kaplan-Meier analysis and the log-rank test. Furthermore, univariate Cox regression analysis was applied to assess associations between potential biomarkers and the overall survival rate. RESULTS: Of 720 total DEGs, fifty-two DEGs in the two subclusters of the PPI network analysis were selected. A risk model was established, and five candidate genes (SPRR2E, ICOS, CTLA4, HTR1D, and CCR4) were identified as biomarkers of OS in OSCC patients. CONCLUSIONS: We successfully constructed a prognostic signature to predict prognosis and identified five candidate genes associated with the OS of OSCC patients that are potential tumor biomarkers and targets in OSCC.

[Multidisciplinary team model for patients with oral cancer and systemic diseases: an expert consensus].

Large general hospitals currently play an increasingly important role in the diagnosis and treatment for acute critical patients and difficult diseases because of the development of dual referral system and hierarchical diagnosis, as well as the formation of medical treatment alliance. Patients with oral cancers are often associated with systemic diseases, which increases the complexity of the condition. Thus, meeting the demand through the traditional single medical model is difficult. As such, a multidisciplinary team (MDT) model has been proposed and has achieved a good clinical effect. To standardize the application of this model, we organized an event in which relevant experts discussed and formulated a consensus to provide standardized suggestions on the MDT process and the diagnosis and treatment of common systemic diseases as reference for clinical practice.

Prognosis of Pediatric Patients With Mucoepidermoid Carcinoma of the Parotid Gland.

OBJECTIVE: To summarize the prognosis of pediatric patients with mucoepidermoid carcinoma (MEC) of the parotid gland. METHODS: Pediatric patients with MEC of parotid gland who were surgically treated at the Capital Medical University School of Stomatology from 2000 to 2014 were retrospectively analyzed. Clinical characteristics, pathology reports, and operation records were reviewed and analyzed. RESULTS: In total, 33 patients with an average age of 13.2 years were enrolled. The 5-year overall survival and disease-free survival were 95.8% and 84.4%, respectively. The disease-free survival and overall survival rates were lower in the under-10 age group (75.0 versus 87.7% and 83.3% versus 100%), though no statistically significant difference was found (P = 0.279 and P = 0.075). The patients who underwent complete resection all had a good prognosis without any recurrence or death regardless of whether the cut margin was 1.0 cm, 0.5 cm, or only extracapsular. One patient experienced 3 recurrences within 18 months and eventually died of disease. CONCLUSION: Good outcomes were achieved in pediatric patients with MEC of the parotid gland. Radical resection ensured a good prognosis regardless of the extent of resection. Frequent recurrence in a short period was associated with a poor prognosis. TRIAL REGISTRATION: None.

Accuracy of magnetic resonance imaging in evaluating the depth of invasion of tongue cancer. A prospective cohort study.

OBJECTIVES: This study compared the consistency of depth of invasion (DOI) measurements by magnetic resonance imaging (MRI) and intraoperative and postoperative pathological sections due to a lack of large sample studies. MATERIALS AND METHODS: From April 2015 to December 2017, patients with squamous cell carcinoma of the tongue were included in the study. Different invasion depths were measured by MRI and on intraoperative and postoperative pathological sections. The differences between two-dimensional tumor margins were analyzed using Mimics 15.0 and Geomagic Control 16.0. Statistical analyses were performed using IBM SPSS software version 25.0 (IBM Corp., Armonk, NY). RESULTS: This study included 150 patients, the overall difference between MRI and postoperative pathological sections (DMP) and the overall difference between intraoperative and postoperative pathological sections (DIP) based on pathological specimens were 2.32 ±â€¯1.68 mm and 0.68 ±â€¯0.99 mm. The overall difference between MRI and intraoperative pathological sections (DMI) based on intraoperative specimens was 1.64 ±â€¯1.32 mm. The tumor growth pattern and T stage were significantly correlated with measurement differences. The cutoff value of MRI depth that could identify nodal metastasis was 8 mm, and were both 11 mm for OS and DSS. CONCLUSION: Clinicians performing T staging on patients with tongue cancer based on MRI measurements must consider the false-positive mean depth of 2.3 mm as well as the growth pattern and specific infiltration depth. The prognostic MRI depths that enabled the identification of nodal metastasis, OS and DSS were 8 mm, 11 mm and 11 mm, respectively. CLINICAL TRIAL REGISTRATION: Name: A Prospective, Observational, Real-world Study Based on the Register System of Oral and Maxillofacial Malignant Tumors. (ClinicalTrials.gov ID: NCT02395367).

[Primary acinic cell carcinoma in mandible: a case report].

Acinic cell carcinoma is a relatively rare salivary gland tumor predominantly occurring in the major glands. Therefore, acinic cell carcinoma rarely occurs in the mandible. In this study, a case of primary acinic cell carcinoma of the mandible was reported, and relevant literature was reviewed. The etiology, clinical symptom, image and histological features, diagnosis, treatment, and prognosis of acinic cell carcinoma in the mandible were discussed.

Surgery combined with postoperative 125 I seed brachytherapy for the treatment of mucoepidermoid carcinoma of the parotid gland in pediatric patients.

BACKGROUND: This retrospective study was undertaken to analyze the effectiveness and safety of surgery combined with postoperative 125 I seed brachytherapy in the treatment of mucoepidermoid carcinoma (MEC) of the parotid gland with risk factors in pediatric patients. PROCEDURE: From September 2002 to January 2012, 24 patients, ages 5-16 years (mean, 13.2 years; median, 12.3 years), with MEC of the parotid gland were included. Patients with high risk factors received 125 I seed brachytherapy (median actuarial D90, 97 Gy) within 4 weeks following surgery. Radioactivity was 18.5-33.3 MBq per seed and the prescription dose was 60-120 Gy. Overall and disease-free survival rates, local control rate, and distant metastasis were recorded. Radiation-associated late side effects, including dermatitis, hearing loss, thyroid nodules, and secondary malignancy, were also evaluated. RESULTS: During the follow-up period of 5-13.4 years (median, 7.2 years), the overall and disease-free survival rates were all 100%. No patients developed local recurrence, regional/distant metastasis, and no severe radiation-associated complications including the second malignancy were noted. CONCLUSION: Surgery combined with postoperative 125 I seed brachytherapy is effective and safe in the treatment of MEC of the parotid gland in pediatric patients, with no evidence of severe late radiation-related complications. More patients and longer follow-up data are still needed to prove the efficacy of 125 I brachytherapy.

Serum SCCA, Cyfra 21-1, EGFR and Cyclin D1 levels in patients with oral squamous cell carcinoma.

OBJECTIVES: To determine the concentrations of SCCA, Cyfra 21-1, EGFR and Cyclin D1 in serum of patients with oral squamous cell carcinoma, and investigate their diagnostic value and their relationship with clinical stage, histological differentiation and lymph node metastasis. METHODS: Seventy hospitalized patients with oral squamous cell carcinoma and 72 healthy individuals were included in the study. Venous blood was collected from all study participants, in the oral carcinoma patients before tumor resection. One week after surgery, venous blood was collected again from 20 patients. Serum marker levels were determined by enzymelinked immunosorbent assay (ELISA). RESULTS: The serum SCCA, EGFR and Cyclin D1 concentrations were significantly higher in patients with oral squamous cell carcinoma than in healthy controls, while there was no significant difference in Cyfra 21-1 levels between patients and controls. The serum SCCA concentration decreased after surgery, but there was no significant difference in the serum Cyfra 21-1, EGFR and Cyclin D1 concentrations before and after surgery. Serum SCCA, Cyfra 21-1, EGFR and Cyclin D1 concentrations were not correlated with clinical stage, histological differentiation and lymph node metastasis. When SCCA, EGFR and Cyclin D1 were measured separately, EGFR had the highest diagnostic sensitivity and accuracy and Cyclin D1 had the highest specificity; when any two of the markers were tested in combination, the combined detection of EGFR and Cyclin D1 had the highest sensitivity, specificity and accuracy. CONCLUSIONS: SCCA, EGFR and Cyclin D1 may prove to be useful tumor markers in oral squamous cell carcinoma. The combined determination of EGFR and Cyclin D1 may be of value in the diagnosis of oral squamous cell carcinoma. Serum SCCA may be used as an adjunct in monitoring treatment response.

[Establishment of an animal model of widening distraction of tubular bone with dental implant distractor].

OBJECTIVE: To establish an animal model of widening distraction of tubular bone with dental implant distractor (DID) and investigate radiographical and histomorphological changes of long tubular bone following widening distraction with dental implant. METHODS: Twelve Chinese mountain goats were used. Two sets of DID were installed in each goat's tibiae. After an 8-day latency period, nine tibiae were distracted at a rate of 0.35 mm each time and 2 times per day using DID devices. Radiography and histomorphology were used to evaluate the new generated bone in different period after distraction. The other three animals served as sham control. RESULTS: After 10 - 14 days' distraction, the average width of the tibiae increased by 7.83 mm. Digital subtraction angiography (DSA) showed that there was a similarity between goat's tibiae and human's fibula in the blood supply. From the end of distraction to 3-month after the consolidation period, radiography demonstrated that the distraction gaps gradually became vague and filled with newly formed bone. The histomorphological study showed different results of bone formation in both distracted gaps. The osseointegration between bone and implant only occurred at screw-shaped part, while the moving part in tibiae was encapsulated by fibrous tissue. CONCLUSIONS: There are lots of similarities between goat's tibiae and human's fibula in anatomy and blood supply. The model of widening distraction osteogenesis of the goat's tibiae is ideal for studying human's fibula.

[Experimental study of tissue-engineered biological small intestinal submucosa, membrane employed in dental implant traction].

OBJECTIVE: To construct the tissue-engineered biological small intestinal submucosa(SIS) membrane and evaluate the feasibility of its use as a surrogate of periosteum and its possible role in dental implant distraction (DID). METHODS: The tissue-engineered biological SIS membrane was constructed through the co-culturing of boat bone marrow stromal cells (BMSC) and small intestinal submucosa. The cellular compatibility was evaluated with the phase contrast microscope, SEM, alkaline phosphatase(ALP) activity and histology, and its effect of osteogenesis promotion was detected by Micro-CT and histology after implanted in the exposed side of DID operation. RESULTS: The phase contrast microscope, SEM, ALP activity and histology confirmed that the BMSC could adhere to SIS and proliferate on it normally, the cellular activity and function were not affected by SIS. Three months after the tissue-engineered biological SIS membrane was implanted into the exposed side, some discontinuous new bone in the "biological SIS membrane" group was detected by the Micro-CT under a higher window level. The histology revealed that there was a quantity of new bone in the distracted region and the majority was woven bone. The quantity and quality of the new bone in the "biological SIS membrane" implanted group were similar to the unexposed side, but the bone nonunion was detected in the un-implanted group and the interspace was fixed by fibrous connective tissue. CONCLUSIONS: The tissue-engineered biological SIS membrane can provide both daughter cells, guide bone regeneration in DID and promote the osteogenesis. But the outcome of the biological SIS membrane, especially the function of the osteoblast cultured in the SIS in new bone formation, still needs further study.

Serum hyaluronan levels in oral cancer patients.

BACKGROUND: Hyaluronan (HA) is most likely associated with tumor invasion and metastasis. Studies have shown that HA levels are often increased in serum of patients with various malignant tumors. The purpose of this study was to determine the levels of serum hyaluronan in patients with oral cancer and evaluate the value of serum HA in adjuvant diagnosis, staging and monitoring treatment response in these patients. METHODS: Eighty-four hospitalized patients with oral cancer, 65 patients with benign tumors in the oral and maxillofacial region and 67 healthy individuals were included in this investigation. Venous blood was collected from these patients and the healthy individuals before therapy. One week after therapy, venous blood was collected once again in 43 patients with oral cancer. Serum samples were obtained and serum HA levels examined. RESULTS: The serum HA concentration was significantly higher in oral cancer patients than in patients with benign tumors and in healthy controls (P<0.05). The serum HA level in patients with stages III and IV disease was higher than in patients with stages I and II disease, but there was no significant difference in the HA level between stages I and II nor between stages III and IV (P>0.05). After a complete treatment the HA levels in patients with oral cancer became lower than before treatment, but the difference was not significant (P>0.05). CONCLUSIONS: The results of this study suggest that the determination of HA levels may provide additional information in diagnosis of oral cancer, but its usefulness as an adjunct in clinical staging and in monitoring treatment response was limited.

[Fibular flap combined with lateral crural flap for reconstruction of oral and maxillofacial defect].

OBJECTIVE: To investigate the therapeutic effect of fibular flap combined with lateral crural flap for reconstruction of oral and maxillofacial defect. METHODS: Based on the peroneal vascular system, fibular flap combined with lateral crural flap were used for reconstruction of oral and maxillofacial defect. The fibular flap was used for bone defect, and the lateral crural flap was for the reconstruction of soft tissue defect of the oral cavity and pharynx. RESULTS: During the period of Mar. 2005 to Mar. 2007, 26 cases were treated, including 25 cases of defects after tumor resection and 1 case of bilateral maxillary defect. The flaps were harvested without any injury to the peroneal vascular system and perforator. All the flaps were survived. One case of arterial insufficiency and one case of venous thrombosis occurred 12 hours and 24 hours after operation, but the flaps were salvaged after urgent re-operation. All the patients were followed up for 6 months to 2 years. The patients acquired satisfactory appearance with normal social life. CONCLUSIONS: For complicated oral and maxillofacial reconstruction, fibular flap combined with lateral crural flap can achieve good reconstruction results and could be selected as the first line treatment.

[The histomorphological changes of tubular bone following widening distraction osteogenesis].

OBJECTIVE: The purpose of this experimental study was to investigate the histomorphological changes of tubular bone following widening distraction osteogenesis. METHODS: Twelve Chinese mountain goats were subjected to the study. After the procedure of vertical and horizontal osteotomy, two widening distraction osteogenesis devices were put in each goat's left tibiae. After an 8-day latency period, nine tibiae were widening distracted; another three tibiae served as sham control group. Every three animals from the experimental group were sacrificed in different consolidated periods including 1-month, 2-month, and 3-month. Radiography, tetracycline double labeling, histomorphology, as well as biomechanics were used to evaluate the quality and quantity of new generated bone in different consolidated period after distraction osteogenesis. RESULTS: After a distraction period, the average width of the tibiae is increased 7.83mm. From the end of distraction to 3-month after the consolidation period, radiography demonstrated that the distraction gaps gradually became vague. Tetracycline double labeling showed that the double labeling brands were rarely seen in normal cortex bone, but strongly increased in the distracted callus. Mineralization rates (MR) has a significant difference (P < 0.05) within distracted callus region compared with control cortex bone. Histomorphological study shows that there was a different result in two sides of vertical distracted gaps. The non-exposure side had a good bone formation, while a non-union of bone occurred at the exposure side. Three months after consolidation period, part of the gap in exposure side was filled with dense connection tissue, whereas the distracted callus had been remodeled and become lamellar bone in non-exposure side. The control group showed normal fracture healing procedure. CONCLUSIONS: There was a different outcome in two sides distraction gaps of tubular bone following widening distraction osteogenesis. A viable and well-perfused soft-tissue envelope in the area of distraction osteogenesis is important for creation of sufficient amount of new bone during distraction osteogenesis.

[Reconstruction of mandibular defect by using Titanium mandibular prosthesis: a preliminary experimental study].

PURPOSE: The aim of this experiment was to investigate the possibility of application of mandibular reconstruction with titanium mandibular prosthesis. METHODS: Two healthy adult goats were used in this study. Spiral CT of the mandibular region was performed. The data collected was related to the computer. Then a 5 cm mandibular body defect and a mandibular angle defect were designed accordingly. Titanium mandibular prostheses were manufactured according to the size of the above defect. Surgical operation was performed and the prosthesis were implanted into the aimed defects and internal fixation was used. Autogenic bone graft was introduced into the holes of the angle prosthesis. Radiographic examination was used to evaluate the healing of prostheses every month after operation. Three months later, the animal was sacrificed and the mandible specimens were sectioned for histological and biomechanical evaluation. RESULTS: One of the body prosthesis was found to be exposed two weeks after operation. Four weeks later, fixation failed and the anterior part of the prosthesis separated from the mandible attached. The other body prosthesis also suffered from exposure,but the connection between the prosthesis and the mandible was still stable. Histological examination revealed that there was presence of osseointegration in the angle prosthesis as well as area that was not exposed in the body prosthesis model. Reattachment of the muscles to the bone graft area was found. CONCLUSIONS: CAD/CAM generated Titanium mandibular prosthesis is applicable in human model. The vitality of this experiment revealed that a tight closure plays an important role in the healing by osseointegration. If there was any exposure, the osseointegration will be failed. Reattachment of the muscle to the prosthesis can be achieved by "muscle-bone-prosthesis"model.