A historical review of dental schools founded by dentist Situ Bo in modern time / 中华口腔医学杂志

About 8 dental schools were founded by Chinese dentists during modern times (1909-1949) in China. Only one still worked after the founding of the People's Republic of China, which was one of the three dental schools founded by dentist Situ Bo. There were no systematic researches on Situ Bo's participation in dentistry education. This paper analyzes the founder's experience in dentistry and in the two schools he founded at the beginning, focusing on the background and process of the schools' construction, management, teaching, teachers and students training, etc. The results show that the establishment of the first two dental schools have laid important foundation for the establishment and development of Shanghai Dental College by the reserve of trained professional teachers and accumulated valuable experience in running schools. The systematic review of this history will help us better understand the establishment and development of Shanghai Dental College and the efforts in dentistry education made by dentists growed up in modern China, as well as the early development process of stomatology.

Research progress in multi-body system dynamics modeling in stomatology / 中华口腔医学杂志

The stomatognathic system is an organic combination of bone, dentition, joints, masticatory muscles and innervation nerves. It is an organ system for the human body to perform mastication, speech, swallowing and other important functions. Due to the complex anatomical structure of stomatognathic system and ethical limitations, it is difficult to directly measure the movement and force by using the biomechanical experimental methods. Multi-body system dynamics is an important tool to study the kinetics and force of a multi-body system, which consists of several objects with relative motion. We can use the method of multi-body system dynamics simulation in engineering to study the movement, soft tissue deformation and force transfer of this complex stomatognathic system. This paper briefly introduces the history and application methods of multi-body system dynamics and the commonly used modeling methods. The application and research progress of multi-body system dynamics modeling methods in the field of stomatology was emphatically summarized, development prospects of current research and difficulties were put forward.

Clinical analysis of selective tracheostomy necessary for patients undergoing head and neck surgery with free flap reconstruction / 北京大学学报(医学版)

OBJECTIVE@#To discover the factors that may affect the use of selective tracheostomy among patients who have undergone head and neck surgeries with free flap reconstruction, so that the patients will not need tracheostomy nor receive the unnecessary treatment.@*METHODS@#Five hundred and thirty-three patients who had undergone head and neck surgery with free flap reconstruction operated by the same team of surgery at Department of Oral and Maxillofacial Surgery at Peking University School of Stomatology from 2015 to 2016 were reviewed. Three hundred and twenty-one (60.2%) of these patients underwent selective tracheostomy. All the patients' demographic information, operation-related information, prior treatments, comorbidities and complications were recorded and analyzed.@*RESULTS@#The patients with defects of the tongue, mouth floor, oropharynx and bilateral mandible, who underwent neck dissection and with previous radiotherapy and smoking habit were more likely to get selective tracheostomy. Usage of bulky soft tissue flap might also add to the risk of airway obstruction and the need of selective tracheostomy, while other factors were not significantly related to the risk of postoperative airway obstruction and the patients could be kept safe without selective tracheostomy. Most cases without tracheostomy were kept safe except one case, while 8.39% of the patients with tracheostomy suffered from tracheostomy related complications, mainly pneumonia and hemorrhage of the tracheostomy wound, yet none led to serious consequences or even death.@*CONCLUSION@#Selective tracheostomy is not necessary for patients who have undergone head and neck surgeries with free flap reconstruction except that there are defects at the tongue, oropharynx and mandible. Neck dissection, bulky soft tissue flap reconstruction, previous radiotherapy and smoking habit may also add to the risk of postoperative airway obstruction, while a favorable decision would involve a combination of all the above factors to assure the safety of the postoperative airway for the patients undergone head and neck surgeries with free flap reconstruction.

Application of iodine staining technique for tumor identification in Micro-CT of mouse model with skull base-infratemporal fossa tumor / 北京大学学报(医学版)

OBJECTIVE@#To establish an animal model with malignant tumor in the skull base-infratemporal region, and to explore the role of iodine staining technique in identifying tumor tissues with Micro-CT data.@*METHODS@#Sedation anesthesia was carried out on 12 BABL/c nude mice using inhaled isoflurane, and then WSU-HN6 cells that cultured and immortalized from human tongue squamous cell carcinoma were injected into the right infratemporal fossa via the submandibular area. The procedure was carried out under ultrasonographic guidance. The nude mice were sacrificed after 3 weeks observation. The head specimens were fixed and scanned by Micro-CT, and repeated scans were performed after staining with 3.75% compound iodine solution. Following decalcification in 20% EDTA for 2-4 weeks, the head specimens were embedded and sectioned. Hematoxylin and eosin staining and Pan-Keratin immunohistochemical staining were carried out. Bright-field microscopy and stereomicroscopy were used to visualize. The Micro-CT data were analyzed using iPlan software (Brainlab).@*RESULTS@#Non-traumatic ultrasonography was used to guide HN-6 cells injection and confirm skull-base tumor formation in all the animals. Ultrasonographic guidance reduced the risk of cervical vessel injury when transferring tumor cells into the skull base space. An obvious asymmetrical appearance was detected via ultrasonography 3 weeks after tumor cell injection. The Micro-CT analysis showed that the bone was obviously damaged on the right side of the skull base, but the soft tissue image was unrecognizable. After four days staining with compound iodine solution, the morphology of the tumor and surrounding soft tissue could be clearly identified. Hematoxylin and eosin staining showed the tumor formation of the right infratemporal fossa region accompanied by bone destruction. Human keratin immunohistochemical staining showed that the tumor tissue originated from human squamous cell carcinoma, and the polynuclear osteoclasts could be seen at the margin of the skull base bone resorption.@*CONCLUSION@#The animal model with malignant tumor in the skull base-infratemporal region could be successfully established via submandibular injection under ultrasound-guidance. Bone changes of the skull were easily observed on Micro-CT, but the tumor counter was not able to be distinguished from surrounding soft tissue. The 3.75% compound iodine staining of the head specimen could help discern the tumor and surrounding soft tissue in more details.

Expression of cartilage oligomeric matrix protein in the synovial chondromatosis of the temporomandibular joint / 北京大学学报(医学版)

OBJECTIVE@#To detect the expression of cartilage oligomeric matrix protein (COMP) in the synovial chondromatosis of the temporomandibular joint (TMJSC), and to discuss the possible interactions between COMP, transforming growth factor (TGF)-β3, TGF-β1 and bone morphogenetic protein-2 (BMP-2) in the development of this neoplastic disease.@*METHODS@#Patients in Peking University School and Hospital of Stomatology from January 2011 to February 2020 were selected, who had complete medical records, TMJSC was verified histologically after operation. The expressions of COMP, TGF-β3, TGF-β1 and BMP-2 in the TMJSC of the temporomandibular joint were detected by immunohistochemistry and quantitative real-time PCR (RT-PCR) at the protein level and mRNA level respectively, compared with the normal synovial tissue of temporomandibular joint. The histological morphology, protein expression and distribution of TMJSC tissues were observed microscopically, and the positive staining proteins were counted and scored. SPSS 22.0 statistical software was used to analyze the expression differences between the related proteins in TMJSC tissue and the normal synovial tissue of temporomandibular joint and to compare their differences. P < 0.05 indicated that the difference was statistically significant.@*RESULTS@#Immunohistochemical results showed that the positive expression of COMP in TMJSC tissues was mostly found in synovial tissues and chondrocytes adjacent to synovial tissues, and the difference was statistically significant, compared with the normal temporomandibular joint synovial tissues. The positive expression of COMP was significantly different between recurrent TMJSC and non-recurrent ones. The positive expressions of TGF-β3, TGF-β1 and BMP-2 were higher than the normal synovial tissue, and were also mostly found in the synovial cells and adjacent chondrocytes, which was further confirmed by Western blot. According to the RT-PCR results, the expressions of COMP, TGF-β3, TGF-β1 and BMP-2 in TMJSC were higher than those in the normal synovial tissue.@*CONCLUSION@#The expression of COMP in TMJSC of temporomandibular joint increased significantly, compared with the normal synovial tissue. There may be interactions between COMP and cytokines related to the proliferation and differentiation, like TGF-β3, TGF-β1 and BMP-2, which may play a potential role in the pathogenesis of TMJSC.

Accuracy analysis of robotic assistant needle placement for trigeminal gasserian ganglion / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the accuracy and feasibility of a custom robot system guided by optical navigation for needle puncture on trigeminal gasserian ganglion.@*METHODS@#A synthetic human skull model was used, with plasticine placed around the skull base to imitate the human soft tissue. Cone beam CT (CBCT) scanning was performed before the operation. With image data transferred to the graphical user interface of the computer workstation, the oval foramen was selected as the target and the "skin entry point" was also determined by the surgeon on the surgical planning software. Thus the needle trajectory was eventually planned. The skull model was fixed firmly to the trial table with a head clamp and relative size of the trial table was the same as a standard operating table. Following point-based registration, the data were sent to the robot control unit. Only after the surgeon's confirmation, the needle was automatically inserted into the intended target by the robot guided by optical navigation. When the procedure was completed, the instantaneous data of the needle tip orientation acquired by navigation system was sent back to the computer workstation for accuracy verification by calculating the geometric distance between the needle tip and the planning target after matrix transformation. Subsequently, after the needle had been released, CBCT scanning was also acquired to make image fusion of the preoperative skull and the postoperative skull. The data of the needle tip orientation was acquired on the postoperative image and the accuracy was re-verified by calculating the geometric distance between the needle tip and the planning target after matrix transformation. IBM SPSS Statistics 20 was used for statistical analysis and the paired t-test was used to compare the differences in the accuracy measured by the intraoperative navigation and postoperative image fusion.@*RESULTS@#All 20 interventions were successfully located in oval foramen at the first needle insertion. The mean deviation of the needle tip was (0.56±0.07) mm (measured by the navigation system) and (1.49±0.14) mm (measured by the image fusion), respectively (P<0.001).@*CONCLUSION@#The experimental results show the robot system is efficient and reliable. The navigation accuracy is one of the most significant factors in robotic procedures.

Diagnostic test for detection of cervical lymph node metastasis from oral squamous cell carcinoma via infrared thermal imaging / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the diagnostic performance of a non-invasive, non-radiating, economical and convenient infrared thermal imaging in the detection of oral squamous cell carcinoma (OSCC) cervical lymph node metastasis, and evaluate its applicability via parallel test and series test.@*METHODS@#This study was a prospective clinical study which passed the ethical review by the Biomedical Ethics Committee, Hospital of Stomatology, Peking University, and had been submitted for clinical trial registration. Totally 74 OSCC patients who were to undergo a neck dissection were included in this study. The inclusion criteria were patients who: (1) were pathologically diagnosed as malignant tumors and planned to undergo surgical treatment including neck dissection; (2) agreed to participate in this study. The exclusion criteria were those who: (1) had undergone surgeries at head and neck previously; (2) with a history of systemic tumor adjuvant therapies such as radiotherapy or chemotherapy etc; (3) were unwilling or unable to cooperate. Basal information as well as clinical examination results were collected, such as physical examination and contradictive enhanced CT. Besides, infrared thermal imaging was done ahead of surgery. Analysis of the diagnostic power of infrared thermal imaging followed the principles of diagnostic test. The positive signs of infrared thermal imaging were: (1) asymmetric thermographic pattern including vascular pattern in ROI; (2) thickening image of unilateral facial artery/vein, submental artery/vein or external carotid artery; (3) surface temperature of ROI raised over 1 °C compared with the opposite side; (4) changes of neck profile with abnormal temperature pattern. The gold standard of this diagnostic test was pathology diagnosis of cervical lymph nodes.@*RESULTS@#The sensitivity of infrared thermal imaging was 75.0%, while the specificity was 69.0%, accuracy was 71.6%, positive predictive value was 64.9% and negative predictive value was 78.4%. The sensitivity of parallel test which stood for the combination of infrared thermal imaging and conventional clinical examinations was 87.9% while the specificity of series test was 97.6%.@*CONCLUSION@#Infrared thermal imaging is a promising non-invasive, non-radiating and economical tool in the detection of cervical lymph node metastasis from OSCC when combined with conventional pre-operative examination.

Application of digital mandibular movement record and masticatory muscle electromyography in the evaluation of stomatognathic function in patients with mandibular tumor / 北京大学学报(医学版)

OBJECTIVE@#To study the clinical characteristics of mandibular movement and masticatory muscle function in preoperative and postoperative patients with unilateral mandibular tumors in the region of mandibular body and ramus by combining digital mandibular movement records with electromyography, and to preliminarily explore the relationship and mechanism between movement and masticatory muscle function.@*METHODS@#Six preoperative patients with tumor in unilateral body and ramus of mandible were included, and three postoperative patients with unilateral segmental resection and reconstruction of mandibular bone were included. The mandibular movement recording system and surface electromyography system were used to collect the movement trajectory of the patients' mandibular marginal movement and chewing movement, and the surface electromyography of bilateral masseter and temporalis was recorded concurrently. The surface electromyography of bilateral masseter and temporalis was collected when the patients were at relaxation and at maximal voluntary clenching (MVC). The motion trajectory was observed on the digital virtual model, and the motion amplitude and direction of mandibular marginal movements were analyzed. The characteristics of masticatory electromyogram (EMG) activity in affected and unaffected sides at relaxation, MVC and bilateral mastication were analyzed, and the asymmetry indexes and activity indexes were calculated.@*RESULTS@#The preoperative mean maximum opening of the patients was (35.20±6.87) mm. Three patients had mild mouth opening limitation, and all the patients' mouth opening trajectory was skewed to the affected side. During lateral movements, the mean range of motion of the affected side [(10.34±1.27) mm] and that of the healthy side [(6.94±2.41) mm] were significantly different. The maximum opening of the postoperative patients was (30.65±17.32) mm, and the mandibular marginal movement characteristics were consistent with those of the patients before surgery. During MVC in the preoperative patients, the median EMG activities of the masseter muscle [44.20 (5.70, 197.90) μV] and the temporalis muscle [42.15 (22.90, 155.00) μV] on the affected side were slightly lower than those of the masseter [45.60 (7.50, 235.40) μV] and the temporalis muscle [63.30 (44.10, 126.70) μV] on the healthy side. In the postoperative patients, individualized changes occurred. Some patients suffered from weakened electromyographic activity on the affected side, while some other ones showed hyperelectromyographic activity on the affected side.@*CONCLUSION@#Both benign and malignant tumors as well as their surgery can cause abnormal mandibular movements and change of electromyographic activity of bilateral masseter and temporalis muscles.

Multimodal image fusion technology for diagnosis and treatment of the skull base-infratemporal tumors / 北京大学学报(医学版)

OBJECTIVE@#To explore the value of incorporated multimodal image fusion technology with computer-aided design of the skull base-infratemporal tumor treatment.@*METHODS@#A retrospective study was carried out to enroll seventeen patients with skull base-infratemporal tumors treated at Peking University Hospital of Stomatology from February 2011 to September 2018. Plain CT, enhanced CT and MRI data were imported into the iPlan 3.0 software (BrainLab navigation system), and the image fusion was performed for each patient preoperatively. Then the three-dimensional images of the tumor, vital vessels and craniofacial bones were reconstructed to prepare virtual operation design. We evaluated the application of multimodal image fusion technology that had been incorporated with computer-aided planning during the navigation-guided biopsy or surgery, through the analysis of the biopsy and operation data and regular follow-up postoperatively.@*RESULTS@#The mean age of 17 patients (7 males and 10 females) was 46 years. Primary tumors occurred in 11 cases, and recurrent tumors in 6 cases. The size of the 17 tumors ranged from 2.9 cm to 9 cm, and the mean size was 4.35 cm. There were 7 cases with skull base bone destruction and/or intracranial extension, and 10 cases with tumors adjacent to the skull base. High-quality multimodal fused images were obtained in all the 17 cases. The spatial-position relationships of the tumors, adjacent craniomaxillofacial bones and vital vessels labeled with different colors were displayed well on the generated fusion images. The multimodal image fusion technology that incorporated with computer-aided three-dimensional reconstruction and then applied in navigation-guided biopsy or surgery showed that, preoperative analysis and virtual operation design functioned with good results, especially in cases with small tumor size, recurrence or illdefined borders in the skull base-infratemporal region. Operation was carried out in 16 cases after preoperative diagnosis and assessment, and 1 case was performed by navigation-guided biopsy only. The proportions of navigation-guided surgery and biopsy were 70.6% (12/17) and 17.6% (3/17) individually. The positive rate of pathologic diagnosis using navigation-guided biopsy was 100% (3/3). All the navigation-guided biopsies or operations were carried out successfully. Complications included 1 case of cerebrospinal fluid leak from a recurred meningioma patient postoperatively, and 1 case of facial paralysis resulting from parotid-gland deep lobe tumor. Most (14/15) tumors got complete removal with safe boundary through intra-operative navigation verification and post-operative imaging confirmation, except for one case of subtotal resection to avoid the injury of cavernous sinus. The pathological results of the tumors could be classified to mesenchymal (10), adenogenous (3), neurogenic (3) or epithelial (1) resources. The follow-up time ranged from 3 to 94 months, with the median follow-up time of 9 months.@*CONCLUSION@#Taking full advantages of individualized multimodal images, could help analyze the three-dimensional spatial position relationship of tumors, vital vessels and craniofacial bones properly, and then complete the virtual operation design well. The incorporated multimodal image fusion technology with navigation technology may improve the accuracy and safety of core needle biopsy and surgical treatment of skull base-infratemporal tumors.

Expression of hypoxia-inducible factor 1α is associated with lymph node metastasis in oral squamous cell carcinoma / 北京大学学报(医学版)

OBJECTIVE@#To explore the association between hypoxia-inducible factor 1α (HIF-1α) expression and lymph node metastasis in oral squamous cell carcinoma (OSCC).@*METHODS@#Tumor specimens from 125 patients with histologically-proven, surgically-treated OSCC were examined by immunohistochemical staining for expression of HIF-1α. The patients were divided into two groups by the expression of HIF-1α, high expression of HIF -1α group (H-group) and low expression of HIF-1α group (L-group). The main assessment parameters were lymph node metastasis rate and disease-specific survival (DSS). The lymph node metastasis rate and clinicopathologic features were compared using Mann-Whitney test. The Kaplan-Meier curve was generated for each group and compared using the log-rank test. Cox proportional hazard models were utilized for multivariate analyses of HIF-1α expression and other baseline factors with DSS. All calculations and analyses were performed using the SPSS 17.0 software package.@*RESULTS@#The protein expression levels of HIF-1α were up-regulated in OSCC and two patients were unable to evaluate. There were 48 patients in L-group and 75 patients in H-group. Lymph node metastasis rate was 37.5% (18/48) for L-group and 58.7% (44/75) for H-group (P=0.027). Expression of HIF-1α was significantly correlated with lymph node metastasis. The patients of L-group had a significantly better DSS than the patients of H-group (70.8% vs. 46.7%, P=0.005), while the patients of L-group had a significantly better disease-free survival (DFS) than the patients of H-group (60.4% vs. 36.0%, P=0.009) by Kaplan-Meier method. A multivariate survival analysis also showed that HIF-1α expression (HR=2.164, 95%CI: 1.150-4.074, P=0.017) and T-stage (HR=1.387, 95%CI: 1.066-1.804, P=0.015) both were the independent factors associated with prognosis.@*CONCLUSION@#HIF-1α expression is significantly correlated with lymph node metastasis in OSCC. HIF-1α expression is an independent predictive factor for prognosis of OSCC patients, and may serve as a potential biomarker for molecular diagnosis and targeted therapy in future.

Surgical reconstruction of maxillary defects using computer-assisted techniques / 北京大学学报(医学版)

The maxilla is the most important bony support of the mid-face skeleton and is critical for both esthetics and function.Maxillary defects,resulting from tumor resection,can cause severe functional and cosmetic deformities.Furthermore,maxillary reconstruction presents a great challenge for oral and maxillofacial surgeons.Nowadays,vascularized composite bone flap transfer has been widely used for functional maxillary reconstruction.In the last decade,we have performed a comprehensive research on functional maxillary reconstruction with free fibula flap and reported excellent functional and acceptable esthetic results.However,this experience based clinical procedure still remainssome problems in accuracy and efficiency.In recent years,computer assisted techniques are now widely used in oral and maxillofacial surgery.We have performed a series of study on maxillary reconstruction with computer assisted techniques.The computer assisted techniques used for maxillary reconstruction mainly include:(1) Three dimensional (3 D) reconstruction and tumor mapping:providing a 3 D view of maxillary tumor and adjacent structures and helping to make the diagnosis of maxillary tumor accurate and objective;(2) Virtual planning:simulating tumor resection and maxillectomy as well as fibula reconstruction on the computer,so that to make an ideal surgical plan;(3) 3D printing:producing a 3D stereo model for prebending individualized titanium mesh and also providing template or cutting guide for the surgery;(4) Surgical navigation:the bridge between virtual plan and real surgery,confirming the virtual plan during the surgery and guarantee the accuracy;(5) Computer assisted analyzing and evaluating:making a quantitative and objective of the final result and evaluating the outcome.We also performed a series of studies to evaluate the application of computer assisted techniques used for maxillary reconstruction,including:(1)3D tumor mapping technique for accurate diagnosis and treatment of maxillary tumor;(2) Maxillary reconstruction with free fibula flap used computer assisted techniques;(3) Computer assisted orbital floor reconstruction after maxillectomy.The results suggested that computer assisted techniques could significantly improve the clinical outcome of maxillary reconstruction.

Application of computer-aided design and navigation technology in skull base and infratemporal fossa tumor surgery / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the application of computer-aided design and navigation technology in skull base and infratemporal fossa tumor surgery and to analyze its advantages and disadvantages.</p><p><b>METHODS</b>Twenty-nine cases with tumor of skull base and infratemporal fossa were treated with computer-aided design and navigation surgery. The Parameters of age, gender, primary or recurrent tumor, tumor nature and surgical approach were recorded.</p><p><b>RESULTS</b>En bloc resection was performed in 20 cases and subtotal resection in 9 cases. The margin status was negative margin in 8 cases, near-tumor margin in 17 cases and positive resection margin in 4 cases. Postoperative complication rate was 14% (4/29). During the follow-up period, 2 benign cases recurred.In the malignant group, there were 7 cases of recurrence, 2 cases of metastasis and 3 deaths. The 5-year overall survival and progression-free survival rate were 69% and 40% respectively.</p><p><b>CONCLUSIONS</b>Navigation technology can enhance the confidence of the surgeons and operation safety in handling malignant tumors in skull base and infratemporal fossa.</p>

Retrospective study of 93 patients with jaw osteoradionecrosis / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the clinical feature, treatment, and prognosis of hospitalized patients with jaw osteoradionecrosis.</p><p><b>METHODS</b>A total of 93 cases with jaw osteoradionecrosis treated between 2000 and 2010 was reviewed. Of the 93 cases, 79 cases were with mandible lesions, 13 cases with maxillary lesions, and 1 case with both mandible and maxillary lesions. Sixty-six cases received one course of radiotherapy, with the radiation doses of 34 - 90 Gy (mean 64.6 Gy). Twenty-two cases experienced tooth extraction or other operative procedures before exhibition of the clinical symptoms for osteoradionecrosis. The interval time between radiotherapy and the onset of osteoradionecrosis varied from 2 weeks to 32 years (mean 54 months).</p><p><b>RESULTS</b>Of 93 cases, 56 patients underwent radical resection of the pathologic bone and reconstruction with free tissue flaps, in whom 7 cases received the second surgery due to microvascular thrombosis in flap vessels, and flaps were survival by new vascular anastomosis in 3 cases, the failed flaps were removed and replaced successfully by non vascularized bone grafts in 2 cases, and the failed flaps removed and the defects were repaired with adjacent skin in other 2 cases. In the 56 cases, only one case was with disease recurrence and 53 cases with significant improvement in chewing and swallowing functions. Only 2 of 93 cases underwent resection of the pathologic bone and reconstruction with titanium plates, and thereafter they encountered titanium exposure. Scaling of osteoradionecrosis lesions was applied to 20 of 93 patients and 9 cases of them were with disease recurrence. Fifteen cases had resection of the effected mandible without reconstruction. Disease relapse was encountered in 2 of them, others had poor chewing and swallowing.</p><p><b>CONCLUSIONS</b>The mandible is more susceptible to osteoradionecrosis than maxilla. Radical resection with reconstruction by free tissue flap is recommended for the treatment of jaw osteoradionecrosis, and scaling and reconstruction only with titanium plate should be avoided because of high risks of titanium exposure and disease relapse.</p>

Application of computer navigation system in the treatment of post-traumatic reconstruction / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the value of computer aided navigation system (CANS) in the treatment of post traumatic maxillofacial deformation.</p><p><b>METHODS</b>Fifty-four patients (M = 37, F = 17) were included in the study, including 31 cases of zygomatic fracture, 7 cases of pure orbital fracture, 11 cases of temporal mandibular joint ankylosis, 1 case of foreign body and 4 cases of defect reconstruction with custom implant. Data acquisition was done through CT scan, and DICOM data was transferred into workstation. Computer assisted design, including osteotomy, reposition, fibula flap design, orbital implant construction was performed using Surgicase CMF and Brain Lab Iplan system. The virtual design was transferred to Brain Lab navigation system, and the osteotomy, reduction, location of bone graft and custom implant were guided by navigation. Postoperative CT scan was required 48 - 72 hours after surgery. Preoperative and postoperative CT images were superimposed automatically in BrainLab Iplan system, and compared both in 3D objects and 2D slices.</p><p><b>RESULTS</b>All the cases achieved good results without serious complication. The error of important corresponding points in zygomatic fracture reduction, orbital reconstruction and defect reconstruction was 0.2 - 3.5 mm, 0.8 - 2.0 mm and 0.2 - 2.2 mm respectively.</p><p><b>CONCLUSIONS</b>Computer assisted design is of considerable value for the systematic and accurate planning for complicated post traumatic deformation. Virtual plan could be carried out accurately with the assistance of CANS.</p>

Comparison of lateral arm flap and radial forearm flap in reconstruction after oral cancer ablation / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To compare the clinical application of lateral arm flap and radial forearm flap in reconstruction after oral cancer ablation.</p><p><b>METHODS</b>The clinical data of 21 cases with lateral arm flap and 104 cases with radial forearm flap between 2007 and 2009 were reviewed. The flap harvest time, flap survival rate, donor site morbidity and postoperative oral function were compared and analyzed.</p><p><b>RESULTS</b>The average flap harvest time of lateral arm flap and radial forearm flap were (46.4±7.6) min and (41.5±7.5) min (x±s) respectively. The flap survival rates of the two flaps were 90.5% (19/21) and 95.2% (99/104) respectively. There was no significant difference between the two flaps in the average flap harvest time and survival rate (P>0.05). The donor site of lateral arm flap could be primarily closed and radial nerve injury occurred in 2 patients. Skin graft was necessary for the donor site closure of radial forearm flap and conspicuous unattractive scar could be seen. All patients could have oral diet and no difficulty in speech intelligibility.</p><p><b>CONCLUSION</b>The lateral arm flap is relatively safe and reliable alterative to the radial forearm flap for the defects reconstruction after oral cancer ablation.</p>

Reliability of superficial temporal artery and vein as the recipient vessels in free flap transfers in head and neck region / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To examine the reliability of superficial temporal artery and vein as the recipient vessels in free flap transfers in head and neck region.</p><p><b>METHODS</b>From May 2001 to June 2008, 25 cases of head and neck reconstructions were performed by using the vessels in the temporal region as recipient vessels.</p><p><b>RESULTS</b>Among the 25 recipient veins, 23 were superficial temporal veins, and 2 were deep temporal veins. The recipient arteries of all 25 free flaps were superficial temporal arteries. All the free flaps survived completely, without postoperative vessel thrombosis.</p><p><b>CONCLUSIONS</b>The superficial temporal artery and vein can be used as reliable recipient vessels in free flap transfers in head and neck region.</p>

Analysis of iatrogenic factors related to delay in diagnosis of oral squamous cell carcinoma / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the clinical iatrogenic factors related to delay in diagnosis of oral squamous cell carcinoma.</p><p><b>METHODS</b>A total of 102 consecutive patients with squamous cell carcinoma of the oral cavity, treated in Department of Oral and Maxillofacial Surgery, Peking University Hospital of Stomatology were included in the study. For iatrogenic (professional) delay, stepwise multiple logistic regression and monofactor analysis, chi-square, test with 95% confidence interval (CI), were applied to analyze the correlation between the professional delay in diagnosis and the possible related clinical factors.</p><p><b>RESULTS</b>Whether adopting biopsy at the first clinical management, length of time from the first clinical visit to adopting biopsy, number of clinical departments visited and whether taking any treatment before definitive diagnosis had significant influence on the delay.</p><p><b>CONCLUSIONS</b>Taking biopsy at the first clinical visit, shortening the time from the first visit to biopsy and less undirected treatment can reduce the iatrogenic delay.</p>

A pilot study on hypoxia of squamous cell carcinoma in oral cavity / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To examine the extent of hypoxia in oral squamous cell carcinoma and investigate the factors related to the hypoxia.</p><p><b>METHODS</b>An animal model of oral squamous cell carcinoma was established and single photon emission computed tomography (SPECT) with 99mTc-HL91 used to detect the hypoxia extent of the oral squamous cell carcinoma. The expression of hypoxia inducible factor 1 alpha (HIF-1alpha) was examined by immunohistochemical staining in 42 cases of formalin-fixed paraffin-embed squamous cell carcinoma.</p><p><b>RESULTS</b>The uptake of 99mTc-HL91 in the tumor tissue was higher than that in normal tissue and had linear relation with the tumor size (P < 0.05). There was no HIF-1alpha expression in the normal oral mucosa. The expression of HIF-1alpha was high in oral mucosa carcinoma and closely related to the differentiation degree of tumor and metastasis of lymph node (P < 0.05).</p><p><b>CONCLUSIONS</b>Tumor tissue had broad hypoxic region. HIF-1alpha highly expressed in oral squamous cell carcinoma and may play an important role in carcinogenesis and aggression.</p>

Establishment of cervical lymph node metastasis model of squamous cell carcinoma in the oral cavity in mice / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Oral squamous cell carcinoma (OSCC) is the most prevalent malignant tumor in the head and neck region, comprising more than 90% of all oral malignancies. A feasible approach for an animal model to study OSCC lymph node metastasis was established and biological behaviors of three oral squamous cell carcinoma cell lines were compared.</p><p><b>METHODS</b>After implanting three kinds of cell lines (GDC185, Tca8113, Tca83) into three different anatomical sites in nude mice, namely the tongue, floor of the mouth, and axillary fossa, we observed the tumorigenicity and the metastatic capacity, which was confirmed by histopathology under a surgical microscope.</p><p><b>RESULTS</b>The animal model injected with GDC185 cells into the floor of the mouth had the highest rate of neck lymph node metastasis (55.6%) and the cell lines had significantly different biological behaviors.</p><p><b>CONCLUSIONS</b>Nude mice injected with GDC185 cells into the floor of the mouth could be used as a feasible animal model to study neck metastasis of oral squamous cell carcinoma.</p>

Evaluation of patients' temporomandibular joint function after mandible reconstruction with free fibula flap / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the temporomandibular joint (TMJ) function after mandible reconstruction with free fibula flap and with different condyle treatment.</p><p><b>METHODS</b>Forty-one cases of mandible and condyle defects following benign tumor resection were reconstructed with fibula free flap, with the condyle being reconstructed by three methods: placement of the distal end of the fibula flap into the glenoid fossa, the fibula serving as the condyle (24 cases); attachment of the resected condyle as a nonvascularized transplant to the end of the fibula flap (5 cases); condyle preservation plus vascularized fibular reconstruction (12 cases). The postoperative TMJ function was evaluated by Fricton function index.</p><p><b>RESULTS</b>No TMJ ankylosis occurred in all patients. There were no significant differences in aesthetics, deglutition and speech function among the three groups; but there were significant differences in TMJ function index (DI, CMI) among different condyle treatments. Condylar preservation showed better TMJ function than fibula used as a substitute for condyle.</p><p><b>CONCLUSIONS</b>Preservation of condyle during free fibula mandibular reconstruction can improve patients' TMJ function. The location and shape of fibular condyle were important factors that could influence the outcome the condyle reconstruction.</p>