Mechanism and application of 3D-printed degradable bioceramic scaffolds for bone repair.

Bioceramics have attracted considerable attention in the field of bone repair because of their excellent osteogenic properties, degradability, and biocompatibility. To resolve issues regarding limited formability, recent studies have introduced 3D printing technology for the fabrication of bioceramic bone repair scaffolds. Nevertheless, the mechanisms by which bioceramics promote bone repair and clinical applications of 3D-printed bioceramic scaffolds remain elusive. This review provides an account of the fabrication methods of 3D-printed degradable bioceramic scaffolds. In addition, the types and characteristics of degradable bioceramics used in clinical and preclinical applications are summarized. We have also highlighted the osteogenic molecular mechanisms in biomaterials with the aim of providing a basis and support for future research on the clinical applications of degradable bioceramic scaffolds. Finally, new developments and potential applications of 3D-printed degradable bioceramic scaffolds are discussed with reference to experimental and theoretical studies.

Poly (trimethylene carbonate)/doxycycline hydrochloride films in the treatment of Achilles tendon defect in rats.

Introduction: In this study, Poly (trimethylene carbonate)/Doxycycline hydrochloride (PTMC/DH) films were introduced to repair the Achilles tendon defects for the first time. Methods: (PTMC/DH) films with different DH content of 10, 20, and 30% (w/w) were prepared by solvent casting. The in vitro and in vivo drug release of the prepared PTMC/DH films was investigated. Results: The results of drug release experiments showed that the PTMC/DH films released effective concentrations of doxycycline for more than 7 and 28 days in vitro and in vivo, respectively. The results of antibacterial activity experiments showed diameters of 25.00 ± 1.00 mm, 29.33 ± 1.15 mm, and 34.67 ± 1.53 mm, respectively, for the inhibition zones produced by the release solutions of PTMC/DH films with 10, 20 and 30% (w/w) DH at 2 h, indicating that the drug-loaded films could inhibit Staphylococcus aureus well. After treatment, the Achilles tendon defects have recovered well, as indicated by the more robust biomechanical properties and the lower fibroblast density of the repaired Achilles tendons. Pathology revealed that the pro-inflammatory cytokine, IL-1ß, and the anti-inflammatory factor, TGF-ß1, peaked in the first three days and gradually decreased as the drug was released more slowly. Discussion: These results demonstrated that the PTMC/DH films have great potential for regenerating Achilles tendon defects.

The Biodegradability and in Vitro Cytological Study on the Composite of PLGA Combined With Magnesium Metal.

The main goal of this study was to develop a novel poly (lactic-co-glycolic acid) (PLGA) composite biodegradable material with magnesium (Mg) metal to overcome the acidic degradation of PLGA and to investigate the cytocompatibility and osteogenesis of the novel material. PLGA composites with 5 and 10 wt% Mg were prepared. The samples were initially cut into 10 mm × 10 mm films, which were used to detect the pH value to evaluate the self-neutralized ability. Murine embryo osteoblast precursor (MC3T3-E1) cells were used for in vitro experiments to evaluate the cytotoxicity, apoptosis, adhesion, and osteogenic differentiation effect of the composite biodegradable material. pH monitoring showed that the average value of PLGA with 10 wt% Mg group was closer to the normal physiological environment than that of other groups. Cell proliferation and adhesion assays indicated no significant difference between the groups, and all the samples showed no toxicity to cells. As for cell apoptosis detection, the rate of early apoptotic cells was proportional to the ratio of Mg. However, the ratios of the experimental groups were lower than those of the control group. Alkaline phosphatase activity staining demonstrated that PLGA with 10 wt% Mg could effectively improve the osteogenic differentiation of MC3T3-E1 cells. In summary, PLGA with 10 wt% Mg possessed effective osteogenic properties and cytocompatibility and therefore could provide a wide range of applications in bone defect repair and scaffold-based tissue engineering in clinical practice.

Accurate Treatment of Condylar Fracture Assisted by Three-Dimensional Prototype and Bioresorbable Plates.

PURPOSE: Although open treatments of condylar fracture have become the conventional treatment option, the accuracy is often not guaranteed. The purpose of this study was to improve the accuracy of fracture reduction assisted by three-dimensional (3D) prototype and bioresorbable plates in the treatment of condylar fractures. METHODS: This was a prospective cohort study. Patients with condylar fractures were treated by surgery from October 2017 to November 2019 at School of Stomatology of China Medical University (Shenyang, China). The patients in the experimental group were treated with 3D-prototype and fixed with absorbable plates. Patients in the control group were treated routinely reduction and fixed with absorbable plates. Primary predictor variables were surgical treatment. Primary outcome was accurate reduction. Secondary outcomes were postoperative efficacy including maximum mouth opening, occlusal status, lateral excursion movements, and patient satisfaction. Other variables of interest included age, sex, type of patients. Continuous variables are reported as mean ± standard deviation. χ2 test and t test were used for analysis. RESULTS: The sample was composed of 48 patients (65 sides) who were treated surgically (25 men, 23 women; mean age, 39.50 year; range, 17 to 65 year) ; 27 patients (38 sides) were treated with the 3D-prototype approach and 21 patients (27 sides) were treated with the traditional approach. All 48 patients completed reduction and fixation of fractures. Preoperative and postoperative CT comparisons showed that 4 patients did not achieve accurate reduction, all in the control group, of which 3 patients had occlusal disorder. All patients in the experimental group achieved accurate reduction, of which 1 patient had occlusal disorder. CONCLUSION: Our results suggest that using 3D prototype for bending the bioresorbable plate is an effective method for accurate treatment of condylar fracture.

Long Noncoding RNA ZEB1-AS1 Downregulates miR-23a, Promotes Tumor Progression, and Predicts the Survival of Oral Squamous Cell Carcinoma Patients.

BACKGROUND: Long non-coding RNAs (lncRNAs) are implicated in cancer-related biological processes such as cell proliferation, cell cycle progression, cell migration, cell invasion, and chemoresistance. However, the effects of the lncRNA ZEB1-AS1 on oral squamous cell carcinoma (OSCC) have not been adequately demonstrated. The aims of our current study were to explore the roles of lncRNA ZEB1-AS1 in OSCC progression to reveal the potential mechanism. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure relative ZEB1-AS1 expression levels in OSCC tissues and adjacent non-cancerous tissues. The biological functions of ZEB1-AS1 in OSCC growth and progression were identified by cell proliferation, wound healing, and in vitro transwell assays as well as in vivo xenograft model. The underlying mechanism was detected with a dual-luciferase reporter (DLR) assay. RESULTS: The up-regulation of ZEB1-AS1 and downregulation of miR-23a-3p (miR-23a) were found in OSCC cancer tissues. A ZEB1-AS1 knockdown remarkably suppressed in vitro cancerous, biological processes of OSCC cell lines such as cell proliferation, invasion, migration, and epithelial-mesenchymal transition (EMT). The tumor growth was also inhibited by silencing ZEB1-AS1 in vivo, and a DLR assay confirmed the association between ZEB1-AS1 and miR-23a. CONCLUSION: The newly identified lncRNA ZEB1-AS1 functions as a tumor promoter in OSCC through regulation of miR-23a. Based on these results, ZEB1-AS1 could be a valid molecular target for treating oral cancer.

BAP18 is involved in upregulation of CCND1/2 transcription to promote cell growth in oral squamous cell carcinoma.

BACKGROUND: As a reader of histone H3K4me3, BPTF associated protein of 18 kDa (BAP18) is involved in modulation of androgen receptor action in prostate cancer. However, the function of BAP18 on oral squamous cell carcinoma (OSCC) and its molecular mechanism remains to be elusive. METHODS: OSCC-derived cell lines carrying silenced BAP18 were established by Lentiviral infection. Quantitative PCR (qPCR), western blot, and ChIP assay were performed to detect gene transcription regulation and the possible mechanism. Colony formation, cell growth curve and xenograft tumor experiments were performed to examine cell growth and proliferation. FINDINGS: Our study demonstrated that BAP18 was highly expressed in OSCC samples compared with that in benign. BAP18 depletion obviously influenced the expression of a series of genes, including cell cycle-related genes. We thus provided the evidence to demonstrate that BAP18 depletion significantly decreases CCND1 and CCND2 (CCND1/2) transcription. In addition, BAP18 is recruited to the promoter regions of CCND1/2, thereby facilitating the recruitment of the core subunits of MLL1 complex to the same regions, to increase histone H3K4me3 levels. Furthermore, BAP18 depletion delayed G1-S phase transition and inhibited cell growth in OSCC-derived cell lines. INTERPRETATION: This study suggests that BAP18 is involved in modulation of CCND1/2 transcription and promotes OSCC progression. BAP18 could be a potential target for OSCC treatment and diagnosis. FUND: This work was funded by National Natural Science Foundation of China (31871286, 81872015, 31701102, 81702800, 81902889), Foundation for Special Professor of Liaoning Province, and Supported project for young technological innovation-talents in Shenyang (No. RC170541).

Open Reduction Effects of Digitally Treating Zygomaticomaxillary Complex Fractures With Bio-Resorbable Materials.

PURPOSE: The application of bio-resorbable plates in craniomaxillofacial surgery is increasing because of the advantage of avoiding secondary surgery. This study aimed to evaluate the effects of osteosynthesis with prebent bio-resorbable plates for treating zygomaticomaxillary complex (ZMC) fractures. MATERIALS AND METHODS: We implemented a prospective case series composed of patients with ZMC fractures who underwent treatment at the School of Stomatology at China Medical University. Bio-resorbable plates were used for fracture fixation. The fractures were stabilized with bio-resorbable plates prebent on a 3-dimensionally printed skull model with the fractures reduced using virtual simulation. The primary outcome variable was the stability rate of reduced bone segments. Other study variables were mouth opening, occlusion, paresthesia or anesthesia in the infraorbital nerve region (PAIN), and diplopia. Outcome variables were determined by calculating stability rates of reduced bone segments, resolution rates of postoperative restricted mouth opening, malocclusion, PAIN, and diplopia. RESULTS: The sample was composed of 11 patients recruited between November 2016 and September 2018. All surgical procedures were successful, with no severe complications. The stability rate of reduced bone segments from different mechanical buttress regions was 100%. Satisfactory postoperative stability of bio-resorbable plates was obtained in all cases. The resolution rates of postoperative restricted mouth opening and malocclusion were 75 and 100%, respectively. PAIN and diplopia symptoms resolved in 50 and 100% of cases, respectively. CONCLUSIONS: The results suggest that osteosynthesis with bio-resorbable plates prebent on a 3-dimensionally printed skull model, designed by virtual simulation, works well for patients with ZMC fractures. Future studies should focus on the broader applications of these findings in the practice of oral and maxillofacial surgery.

N-Acetylcysteine Attenuates Lipopolysaccharide-Induced Osteolysis by Restoring Bone Remodeling Balance via Reduction of Reactive Oxygen Species Formation During Osteoclastogenesis.

Chronic inflammatory diseases affect bone and teeth health tremendously. Characterized by osteolytic lesion and hyperactive osteoclastogenesis, inflammatory bone diseases are short of effective therapeutics and therefore highlight the importance of understanding pathogenesis and developing ideal medications. Reactive oxygen species (ROS) play a prominent role in the innate immune response of activated macrophages, as well as in the physiological signaling of osteoclasts (OCs) differentiation. N-acetylcysteine (NAC) is a potent ROS scavenger and a potential option for treating diseases characterized by excessive ROS generation. However, whether NAC can protect physiological bone remodeling from in vivo inflammatory conditions is largely undefined. We applied NAC treatment on lipopolysaccharide (LPS)-induced inflammatory osteolysis mice model and found that NAC could attenuate bone erosion and protect mice against LPS-induced osteolysis, due to the suppressive effect on osteoclastogenesis and stimulated effect on osteogenesis. Moreover, in vitro study demonstrated that, in OC precursors (pre-OCs), LPS-stimulated expressions of OC marker genes, such as tartrate-resistant acid phosphatase type 5 (Acp5), cathepsin K (Ctsk), OC stimulatory transmembrane protein (Oc-stamp), dendritic cell-specific transmembrane protein (Dc-stamp), and nuclear factor of activated T cells 1 (NFATc1), were all reduced because of the NAC pretreatment, thereby adversely affecting OC function including F-actin ring formation and bone resorption. Further mechanism study showed that NAC blocked LPS-induced ROS formation in both macrophages and pre-OCs, cutting off the LPS-stimulated autocrine/paracrine mechanism during inflammatory osteolysis. Our findings reveal that NAC attenuates inflammatory osteolysis via the elimination of ROS formation during LPS-stimulated osteoclastogenesis, and provide a potential therapeutic approach to treat inflammatory bone disease.

A New Method To Reposition the Displaced Articular Disc For a Patient With Comminuted Condylar Fracture.

BACKGROUND: Repositioning the displaced articular disc is the key procedure that prevents ankylosis of the temporomandibular mandibular joint (TMJ) in the treatment of patients with comminuted condylar fractures. The conventional procedure performed clinically is to use two anchors and sutures to reposition the displaced articular disc. Therefore, this paper introduces a new and economical method to reposition the articular disc without metallic implantation materials. CLINICAL PRESENTATION: A 60-year-old male patient who had fainted suddenly 3 days before came to our hospital to complain of pain of the bilateral TMJ areas and limited mouth opening. Clinical examination revealed severe restriction of mouth opening and the disappearance of bilateral condylar movements. Preoperational 3-dimensional computed tomography (3-DCT) indicated bilateral intracapsular comminuted fractures of the mandibular condyles. The patient was operated in a bilateral preauricular approach for repositioning of the bilateral articular discs and removal of the fracture fragments. Instead of repositioning the displaced disc with anchors, we designed a method to use sutures to stabilize the TMJ disc and to assess the disc's position using a magnetic resonance imaging (MRI) scan when following up. There were no severe complications during the operation. Results of an MRI scan 1 month after operation showed that post-operation articular discs kept their normal position, the mouth opening and the lateral and protrusive movements of the mandible recovered when followed up for 3 months. CONCLUSION: The method of using sutures to reposition and stabilize the articular disc for a patient with comminuted fractures is effective. There is great significance not only for patients with comminuted condylar fractures but for treatment of TMJ dysfunction especially for patients with high psychological pressure who persist in requiring the removal of metallic anchors although there are no clinical symptoms.

Evaluation of the Effect of Bioresorbable Plates and Screws in the Treatment of Condylar Fractures, Assisted by Digital Preoperative Planning.

PURPOSE: Although bioresorbable materials have begun to be applied in the clinic, they are used primarily in children with fractures; thus, there are few reports of their application for treatment of condylar fractures. This study evaluated the effect of the application of bioresorbable plates and screws for patients with condylar fractures, assisted by digital preoperative planning. MATERIALS AND METHODS: This was a prospective interventional study. The sample was composed of 46 patients treated at the School of Stomatology of the China Medical University (Shenyang, China) from October 2016 through May 2018 for condylar fractures alone or in combination with other facial fractures. All patients underwent confirmatory preoperative computed tomography (CT) to obtain Digital Imaging and Communications in Medicine (DICOM) format data for preoperative designing. By digital designing, the authors confirmed operative plans for each patient. All 46 patients underwent bioresorbable osteosynthesis and underwent repeat CT on postoperative day 3. Postoperative clinical assessments included postoperative positions of the fracture segments, maximal mouth opening, lateral excursion movements, occlusal status, and patient satisfaction. These variables were used to assess postoperative efficacy. RESULTS: The sample was composed of 46 patients who had open reduction with internal fixation on 52 sides. At the 3-month follow-up visit, the proportions of patients who were satisfied with the results and who achieved stable occlusion, appropriate maximal mouth opening, and flexible lateral excursion movement were 97, 100, 66, and 95%, respectively. One patient sustained postoperative displacement of a condylar fracture fragment, as confirmed by repeated CT. He was lost to follow-up at 3 months postoperatively. CONCLUSION: The results of this study suggest that open reduction treatment of condylar fractures implanted with bioresorbable materials in combination with digital preoperative designing is an effective method for managing patients in clinical practice.

Long non-coding RNA TUG1 promotes progression of oral squamous cell carcinoma through upregulating FMNL2 by sponging miR-219.

Oral squamous cell carcinoma (OSCC) is a prevalent oral disease with a high morbidity and mortality rate. Several long non-coding RNAs (lncRNAs) were identified as important regulators of carcinogenesis. However, the pathogenic implications of TUG1 in OSCC are still unclear. In the present study, the expression of TUG1 was increased in OSCC cells. Knockdown of TUG1 inhibited cell proliferation, migration, and invasion, and induced cell cycle arrest at G0/G1 phase, whereas overexpression of TUG1 exerted the opposite effect on OSCC cells. A reciprocal repressive interaction between TUG1 and miR-219 was found, and miR-219 inhibition abolished the tumor-suppressive effect of TUG1 knockdown on cell growth and motility. Furthermore, bioinformatics analysis and luciferase reporter assay showed that FMNL2 was a direct target of miR-219. Restoration of FMNL2 abrogated the miR-219-induced inhibition of cell proliferation, cell cycle progression, migration, and invasion. Besides, overexpression of TUG1 promoted tumor growth and metastasis in vivo. Clinically, the expression of TUG1 and FMNL2 were increased, but miR-219 was decreased in primary tumors compared to non-tumor tissues. Both the upregulated TUG1, and FMNL2 and the downregulated miR-219 was associated with advanced stage of OSCC and poor overall survival. Notably, multivariate analyses confirmed that FMNL2 was an independent risk factor for OSCC. In conclusion, our data revealed that TUG1 confers oncogenic function in OSCC and TUG1/miR-219/FMNL2 axis may be a novel therapeutic strategy in this disease.

RNF8 identified as a co-activator of estrogen receptor α promotes cell growth in breast cancer.

The ring finger protein 8 (RNF8), a key component of protein complex crucial for DNA-damage response, consists of a forkhead-associated (FHA) domain and a really interesting new gene (RING) domain that enables it to function as an E3 ubiquitin ligase. However, the biological functions of RNF8 in estrogen receptor α (ERα)-positive breast cancer and underlying mechanisms have not been fully defined. Here, we have explored RNF8 as an associated partner of ERα in breast cancer cells, and co-activates ERα-mediated transactivation. Accordingly, RNF8 depletion inhibits the expression of endogenous ERα target genes. Interestingly, our results have demonstrated that RNF8 increases ERα stability at least partially if not all via triggering ERα monoubiquitination. RNF8 functionally promotes breast cancer cell proliferation. RNF8 is highly expressed in clinical breast cancer samples and the expression of RNF8 positively correlates with that of ERα. Up-regulation of ERα-induced transactivation by RNF8 might contribute to the promotion of breast cancer progression by allowing enhancement of ERα target gene expression. Our study describes RNF8 as a co-activator of ERα increases ERα stability via post-transcriptional pathway, and provides a new insight into mechanisms for RNF8 to promote cell growth of ERα-positive breast cancer.

MicroRNA-22 Promoted Osteogenic Differentiation of Human Periodontal Ligament Stem Cells by Targeting HDAC6.

Stem cells transplantation is a promising therapy strategy for accelerating periodontal regeneration and reconstruction. Genetic modification could induce stem cells directional differentiation to facilitate recovery of physiological functions. In this study, we investigated the role and mechanism of miR-22 on human periodontal ligament stem cells (PDLSCs). First, a cellular model of osteogenic differentiation was first established by osteogenic inductive cocktail. Real-time PCR determined that expression of miR-22 was significantly increased during PDLSCs osteogenic differentiation. Alizirin red staining showed that overexpression of miR-22 in PDLSCs induced better mineralized nodule formation. Real-time PCR and Western blot further confirmed up-regulation of osteogenic genes Runx2 and OPN in miR-22-overexpressing PDLSCs. Conversely, inhibition of miR-22 delayed the process of PDLSCs osteogenic differentiation. Furthermore, Histone deacetylase 6 (HDAC6) was identified as a target gene of miR-22. Overexpression of miR-22 not only reduced the luciferase activity of the reporter containing the 3' untranslated region of HDAC6 mRNA, but also suppressed the endogenous protein expression of HDAC6. Rescue experiment showed that the promotion role of miR-22 in osteogenic differentiation could be relieved by overexpression of HDAC6. Meanwhile, overexpression of HDAC6 alone could also delay the osteogenic differentiation process. The results demonstrated that miR-22 promoted PDLSCs osteogenic differentiation by inhibiting HDAC6 expression, suggesting that miR-22 might be developed as a target of genetic modified stem cells therapy for periodontal diseases. J. Cell. Biochem. 118: 1653-1658, 2017. © 2017 Wiley Periodicals, Inc.

Superficial parotidectomy versus partial superficial parotidectomy in treating benign parotid tumors.

The aim of the present study was to compare the outcomes of superficial parotidectomy (SP) and partial superficial parotidectomy (PSP) in treating benign parotid tumors. Individuals who had undergone SP or PSP between 2005 and 2008 were enrolled, the medical records were reviewed, and a questionnaire was created and mailed to the patients. For the statistical analysis, χ2 and non-parametric Mann-Whitney tests were used to analyze the variables. In total, 320 patients were included in the present study. Within the PSP group, immediate facial nerve weakness occurred in six patients (7.6%), and Frey's syndrome occurred in five (6.3%). Despite this, facial nerve function recovered fully during the follow-up, and recurrence was not identified. Within the SP group, Frey's syndrome occurred in 38 patients (15.8%), immediate facial nerve weakness in 55 patients (22.8%) and permanent facial nerve dysfunction in two patients (0.8%). However, no recurrence was evident. In total, 216 (67.5%) patients returned the questionnaire. Those with PSP demonstrated improved scores in the domains of appearance, facial contours, facial nerve function and Frey's syndrome. Compared with SP, PSP not only decreased the incidence of Frey's syndrome and transient facial nerve weakness, but also improved quality of life outcomes and guaranteed a low recurrence rate.

Expedient construction of the [5-6-7] tricyclic core of calyciphylline a-type alkaloids.

An efficient synthetic route toward the highly congested [5-6-7] tricyclic core of calyciphylline A-type alkaloids has been developed. This approach features a highly efficient intramolecular Diels-Alder cycloaddition to establish the aza-five-membered C ring as well as the C1 all-carbon quaternary center, and a subsequent cyclopropanation together with a ring-expansion reaction of the resulted adduct to construct the seven-membered D ring.

One-pot novel regioselective cycloisomerization synthesis of 2-substituted or 3-substituted 4H-furo[3,2-c]chromene through the intermediate cyclopropenes of 3-diazochroman-4-one and phenylacetylene.

A new class of cyclopropenes containing a chroman-4-one motif were synthesized using 3-diazochroman-4-one and phenylacetylene with rhodium(II) catalyst and followed by cycloisomerization to give 2-substituted or 3-substituted 4H-furo[3,2-c]chromene, respectively. Using BF3·Et2O as catalyst, 2-substituted 4H-furo[3,2-c]chromene was exclusively obtained in 70% yield. Using Cu(OTf)2 as catalyst, 3-substituted 4H-furo[3,2-c]chromene was obtained in 95% yield with 98:2 regioselectivity. A one-pot cascade addition-cycloisomerization process was also developed with no need to isolate cyclopropenes of chroman-4-one intermediates.

Functional tongue reconstruction with the anterolateral thigh flap.

BACKGROUND: A retrospective study was conducted to evaluate the advantages of anterolateral thigh (ALT) flap in tongue reconstruction. METHOD: From September 2008 to February 2012, patients receiving ALT flap tongue reconstruction were included in the study. Patients undergoing ALT flap were compared with those undergoing similar surgery with radial forearm flap (RFF). The medical records of the included patients were reviewed, and a questionnaire was used to assess acceptability of the surgery. RESULTS: All flaps (both ALT and RFF) were successful In the ALT group, most patients were satisfied with the appearance of the reconstructed tongue and the intelligibility of their speech, and there were fewer complications with this technique compared with the RFF. CONCLUSION: The ALT flap is an ideal method for tongue reconstruction. The thickness and volume of the ALT flap can be adjusted based on the individual extent of the defect, and it can not only provide bulk but also ensure mobility, and it has other advantages also, including a long pedicle and low donor site morbidity.

[Study on accuracy of virtual surgical planning in free fibula mandibular reconstruction by using SurgiCase software].

OBJECTIVE: To evaluate the directional significance of SurgiCase software in free fibula mandibular reconstruction. METHODS: Between September 2010 and March 2012, 10 patients with mandibular defect underwent free fibula mandibular reconstruction. There were 7 males and 3 females, with an age range of 19-43 years (mean, 27 years). The extent of lesions was 7 cm x 5 cm to 16 cm x 8 cm. In each case, three-dimensional spiral CT scan of the maxilla, mandible, and fibula was obtained before surgery. The CT data were imported into the SurgiCase software and the virtual surgery planning was performed. After that, the mandibular rapid prototyping was made according to customized design. The reconstruction surgery was then carried out using these preoperative data. During actual surgery, the extent of mandibular defect was from 6 cm x 3 cm to 16 cm x 5 cm; the length of fibula which was used to reconstruct mandible was 6-17 cm; and the area of flap was from 6 cm x 5 cm to 16 cm x 6 cm. RESULTS: Preoperative data could not be applied because the intraoperative size of tumor was larger than preoperative design in 1 case of mandibular ameloblastoma, and the fibula was shaped according to the actual osteotomy location; operations were performed successfully according to preoperative design in the other 9 patients. The operation time was 5-7 hours (mean, 6 hours). Primary healing of incision was obtained, without early complications. Ten patients were followed up 1 year. At last follow-up, 8 patients were satisfactory with the appearance and 2 patients complained with unsatisfied wide facial pattern. The panoramic radiograghs showed good bone healing. The range of mouth opening was 2.5-3.5 cm. CONCLUSION: SurgiCase software can provide precise data for free fibula mandibular reconstruction during surgery. It can be applied widely in clinic.

Three-dimensional finite element analysis of the craniomaxillary complex during maxillary protraction with bone anchorage vs conventional dental anchorage.

INTRODUCTION: The aim of this study was to explore the biomechanical effects on the craniomaxillary complex of bone anchorage and dental anchorage during maxillary protraction. METHODS: We established 2 finite element models. One simulated maxillary protraction with dental anchorage in the maxillary first molars and the other with bone anchorage in the infrazygomatic buttresses of the maxilla. The magnitude of the applied forces was 500 g per side, and the force directions were 0°, 10°, 20°, and 30° forward and downward relative to the occlusal plane. RESULTS: The finite element model of the craniomaxillary complex could displace in an almost translatory manner when the force direction was about 20° in the bone anchorage model and about 30° in the dental anchorage model. The nodes representing the sutures at the back of the maxilla showed greater stress in the bone anchorage model than in the dental anchorage model in the same force direction. It is the opposite at the front of the maxilla. CONCLUSIONS: We should determine the direction of applied force according to the anchorage location and skeletal characteristics of patients before maxillary protraction. The dramatic effects of maxillary protraction with bone anchorage can be based on the advantages of bone anchorage, not on the changes in the region of the applied force.

[Surgical management of complicated orbital fractures: experiences with 89 orbital corrections and reconstructions].

OBJECTIVE: To summarize the experiences in the treatment of complicated orbital fractures. METHODS: A total of 89 patients with complicated orbital fractures treated in Department of Oral and Maxillofacial Surgery, China Medical University from January 2005 to January 2010 were retrospectively reviewed. The classification of these cases included naso-orbital-ethmoid fracture, frontal orbital fracture and orbitozygomatic fracture. All patients were followed up for 6 - 36 months. RESULTS: The orbital frame was repaired or reconstructed in these patients. The function of lacrimal pathways was improved. All the patients and the physicians were satisfied with the surgical effects. However, recurrence of deformity after endophthalmas correction was found in several cases. CONCLUSIONS: The experiences, comprehensive management of complicated orbital fractures by team approaches, concluded from this study could be expanded. There are still challenges in the treatment of complicated orbital fractures, such as severe endophthalmas deformity, recurrence of endophthalmas deformity and malunion of complicated orbital fracture.