The 5th edition of the Classification of Head and Neck Tumours by the World Health Organization (WHO) was published in March 2022. In the section on oral cavity and mobile tongue tumours, the classification of epithelial tumours in the 5th edition has undergone several modifications compared to the 4th edition published in 2017. Notably, oral potentially malignant disorders (OPMD) and oral epithelial dysplasia (OED) have been addressed separately, and in-depth discussions have been included regarding submucosal fibrosis (SF) and human papillomavirus (HPV)-associated oral epithelial dysplasia (HPVOED). Additionally, the section on squamous cell carcinoma (SCC) now includes carcinoma cuniculatum (CC) and verrucous carcinoma (VC), emphasizing their distinctive clinical and histological characteristics. This review provides a comprehensive overview of the most recent advancements in clinical, histological, and molecular research on epithelial tumours of oral cavity and mobile tongue since 2017.

Deficiency of alveolar bone is a common problem in dental implant clinical practice. Bone augmentation techniques are particularly important in order to ensure that the implant area meets the conditions of implant surgery. One of the key elements of successful bone augmentation surgery is primary wound healing without tension. Tension-release techniques are the key to achieving tension-free wound healing. In this review, we will introduce the tension-release techniques in the bone augmentation for dental implant from three aspects: Tension-release incision, tension-release flap and tension-release suture, in order to provide clinical reference.

Guided bone regeneration (GBR) has been proved to be an efficient technique for alveolar bone augment in more than 40 years' clinical practice. The fundamental components of GBR technology involve ensuring ample blood supply and establishing a stable environment. However, current GBR technology primarily operate under the theoretical framework of "blood supply-core principle" with insufficient emphasis on the significance of stability. Through thorough literature review and a series of clinical trials, we propose a paradigm shift — a dental alveolar bone repair and reconstruction concept centered on "stability-core principle". Under this innovative approach, we have introduced a novel treatment method that utilizes exclusively artificial bone powder for the repair of severe dental alveolar bone defects. This groundbreaking development challenges the conventional international practice that necessitates the use of autogenous bone for bone defect repairs. This article delves into the historical trajectory of GBR technology, highlighting the critical importance of stability. Integrating this insight with existing bone regeneration theories, we provide a detailed exposition on the new technique for dental alveolar bone repair and reconstruction, centered around the core principle of "stability".

Objective: To investigate the effects of Lmo7 gene in the process of proliferation, migration and osteogenic differentiation of MC3T3-E1 cells. Methods: The preosteoblasts MC3T3-E1 cells were cultured in vitro with osteogenic induction. The relative expression of Lmo7 was detected by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting at 0, 3, 7 and 14 d respectively. At the same time, MC3T3-E1 cells were transfected with pLV-shLmo7 and pLV-shControl to construct the stably interfering cell line. Cell proliferation and cell migration were detected by CCK-8 assay, EdU assay, wound healing assay and Transwell migration assay. While alkaline phosphatase (ALP) staining was used to detect the expression activity of ALP, and RT-qPCR was used to detect the expression of osteogenesis-related genes such as Runt-related transcription factor 2 (Runx2), Osterix, alkaline phosphatase (ALP) and osteocalcin (OCN). Results: Lmo7 gene expression level was up-regulated during the osteogenic differentiation of MC3T3-E1 cells in vitro. The stable MC3T3-E1 cell line with Lmo7 interference was successfully constructed, and its proliferation activity was significantly improved, while its migration ability was inhibited. After osteogenic induction, compared with the control group, the ALP staining of the Lmo7 interfering cells was lighter, and the expression levels of osteogenesis-related genes such as Runx2, Osterix, ALP, and OCN were significantly down-regulated (P<0.05). Conclusion: Lmo7 interference promoted the cell proliferation but inhibited the cell migration. Furthermore, the osteogenic differentiation ability of cells was suppressed.

Objective: To establish a design program for orthognathic surgical splints based on artificial intelligence (AI), and to compare the precision between the AI splints and manual digital splints. Methods: This research established an AI algorithm for orthognathic surgical splints and obtained the available automatic design program. The time required for designing surgical splints in the same case was compared. Besides, 40 dentition models of patients with skeletal Class Ⅱ malocclusion (20 for mandibular surgery, and 20 for bimaxillary surgery) were included for comparison. The splints were designed by AI program and manual digital software respectively and scanned for the digital data to compare the difference. Results: The overall deviation between the AI and manual digital splints in guiding the positioning of the models was less than 0.1 mm, indicating that there was no significant difference between them. Comparison of cusp position showed that the mean deviation distance between the AI and manual digital splints was about 0.10-0.14 mm. The application of the AI program can greatly reduce the design time in both the mandibular surgery [(10.7±2.4) s] and the bimaxillary surgery [(21.5±3.9) s]. Conclusion: There is no significant difference in accuracy between AI and manual digital splints, and AI program can improve the design efficiency of orthognathic surgical splints.

The structural and functional heterogeneity of cells in bone tissue is closely related to their spatial location. Spatial transcriptomics can simultaneously obtain location information and transcriptome changes of spatial units within tissues. In recent years, the rapid development of spatial transcriptomics has enabled high-resolution and high-throughput transcriptome analysis of tissues and organs, and has been continuously applied in the study of the skeletal system. This article reviews the progress of spatial transcriptomics and its applications in bone research.

Necrotizing fasciitis (NF) is a rapidly progressive and critical soft tissue infection that presents with extensive necrosis of fascial and subcutaneous tissues, ultimately leading to severe systemic toxic symptoms. Early diagnosis and surgical intervention can greatly reduce mortality and are important for the prognosis of patients. This article discusses the epidemiology, etiology, clinical manifestations, diagnosis, and treatment of NF in the hope that it will be useful to clinicians in the management of necrotizing fasciitis.

Through summarizing the mechanism of oral and maxillofacial firearm wounds formation and oral and maxillofacial grading treatment in modern traumatology, combined with analysis of medical service data during the war. This article aims to provide a treatment plan for oral and maxillofacial firearm injuries, and to provide suggestions for the staffing and equipment configuration of our military′s medical services.

Objective: To summarize the application of bony fenestration technique in the root area to remove the low-positioned dental root fragments. Methods: Develop inclusion and exclusion criteria, and select 30 cases of low-positioned dental root in our hospital's stomatological department from January to December 2020, which the root was removed through bony fenestration. The time of root extraction was recorded. All the patients were followed up for 3 months to 1 year to compare the preservation of alveolar ridge height and width before and after surgery. Results: All patients successfully removed the root,and the height and width of alveolar ridge were well preserved. Conclusion: The bony fenestration technique is a good method to remove the low-positioned dental root fragments, which is worthy of clinical promotion.

Objective: To investigate the voice characteristics and the effect of speech rehabilitation in children with voice disorder (VD) after cleft palate (CP) plastic surgery. Methods: We selected 40 children who underwent CP repair in our hospital (January 2018 to December 2018), and all of them received speech rehabilitation one month after CP repair. The /a/ sound acoustic characteristic parameters and clinical efficacy were compared before and after speech rehabilitation treatment. Results: After the CP plastic surgery, there was no significant difference in the F₀ value of /a/ sound before and after the speech rehabilitation (t=0.661, P>0.05). After speech rehabilitation, the harmonic-noise ratio(HNR) value was significantly higher than that before treatment, and the normalized noise energy(NNE), amplitude perturbation (Shimmer) and fundamental frequency perturbation (Jitter) values were significantly lower than those before treatment (t=1.690, 3.974, 2.287, 24.558, P<0.05); before speech rehabilitation treatment, the phonetic intelligibility(PI) value of children with severe VD was significantly lower than that of children with mild VD (F=3.452, P<0.05). After treatment, the PI value of children with different postoperative VD severity increased significantly, and there was no difference among the groups (F=1.153, P>0.05). The effective rates of clinical treatment for severe, moderate and mild children were 88.89%, 100.00% and 100.00% respectively. Conclusions: VD often exists after CP palatoplasty, and speech rehabilitation can effectively improve the voice quality of children with CP. VD training after CP surgery should be emphasized in clinical practice.

Objective: To investigate and compare the efficacy between thin anterolateral thigh flap and forearm flap in repairing defect after oral cancer resection with elderly patients. Methods: A total of 54 elderly patients with oral cancer who were treated in our hospital from January 2017 to October 2019 were enrolled. All patients had accepted ablative oral resection. 24 cases were repaired with thin anterolateral thigh flaps, which was the anterolateral thigh group, while the other 30 cases who were repaired with the forearm flap were the forearm group. The comparison of outcomes between groups were prepared in accordance with guidelines from The University of Washington quality of life (UW-QOL) and the 14-item oral health impact profile questionnaires (OHIP-14). Results: There were 23 patients in forearm group and 29 patients in anterolateral thigh group completed the reconstruction. There were no significant differences in the number of survivors, vascular crisis and necrosis, recovery time between the two groups(P>0.05). The incidence of pigmentation of the forearm group was higher than that of the anterolateral thigh group, and the difference was statistically significant (P<0.05). The incidence of scar hyperplasia was significantly higher in the forearm group than that in the anterolateral thigh group, and the difference was statistically significant (P<0.05). There were no significant differences between the two groups in the UW-QOL scale and the OHIP-14 scale(P>0.05). Conclusion: On repairing defect in elderly patients after oral cancer resection, using thin anterolateral thigh flap showed no significant difference in the recovery of the defect area and the postoperative scale score, compared with using forearm flap, but can reduce the relative concurrency of the flap donor area.

Temporomandibular joint osteoarthritis (TMJOA) is a common clinical disease. However, the pathogenesis of TMJOA is still unclear, and there is a lack of effective treatment, bringing great distress to patients. Therefore, it is of great significance to explore the pathogenesis of temporomandibular arthritis and to find effective therapy. Recent studies have shown that noncoding RNA (ncRNA) is involved in regulating the development of TMJOA and has great potential in the diagnosis and treatment of TMJOA. Thus, ncRNA is expected to become new diagnostic marker and therapeutic target. We will review the research progress of noncoding RNA in temporomandibular arthritis.

Objective: Through reporting the clinical features, the differential diagnosis and prognosis of a case of melanotic schwannoma (MS) of the head and neck to improve understanding and treatment of this diseases. Methods: A case of head and neck MS in the Department of Stomatology, Xuzhou Municipal Central Hospital, was admitted in May 2019. The clinical manifestations, imaging findings, and pathological data were summarized, and relevant domestic and foreign literatures were analyzed. Results: The patient complained of a mass in the right neck for the past ten days. The CTA of the neck showed that the blood vessels and soft tissues around the lesion were compressed and pushed forward, and the lesion may be neurogenic origin. It was removed by surgery. Immunohistochemistry examination: HMB45(+), KI67(10%, +), CD34 (+), S100(+). Pathological diagnosis: This lesion (right neck) was consistent with MS. Conclusion: MS is derived from neural crest cells with bidirectional differentiation potential. Considering its potential malignancy, the patient needs long-term follow-up after surgery.

Objective: To prospectively analyze the application value of 3D visualization and 3D printing technology based on CBCT in the extraction of complex impacted teeth. Methods: From April 2020 to August 2020, 60 patients with complicated impacted teeth extraction in our hospital were selected as the research objects and divided into two groups (group A and group B) by random envelope method, with 30 patients in each group. In group A, CBCT image data were processed by 3D visualization, preoperative evaluation and operation plan were carried out by three-dimensional visualization model. As for group B, 3D solid model was used for preoperative evaluation and formulation of surgical plan, and the therapeutic effect and follow-up results of the two groups were compared and analyzed. Results: The operation time of group B was shorter than that of group A (P<0.05); the excellent and good rate of treatment was higher than that of group A (P<0.05); the incidence of complications was lower than that of group A(P<0.05), and patient satisfaction was better than that of group A(P<0.05). Conclusion: The 3D printing technology based on CBCT has a good application effect in the extraction of complex impacted teeth. It can visually display the spatial relationship of impacted teeth, simulate the surgical process in real life, and provide help to make preoperative evaluation and surgical plan formulation, so as to achieve accurate, safe and efficient surgery, and it is worthy of popularization and application.

Objective: To investigate the regularity of primary cilia distribution in growth plate during long bone development. Methods: Immunofluorescence staining was applied to label primary cilia in femur sections of 1-, 4- week-old mice to study the distribution of primary cilia in cartilage growth plates. Growth plate chondrocytes were cultured, and changes of primary cilia were observed during the process of hypertrophic differentiation induction; the proportion of ciliated chondrocytes was increased through serum-free starvation, and then hypertrophic differentiation induction were performed; the expression of hypertrophic chondrocyte markers was detected by real-time quantitative polymerase chain reaction (RT-qPCR) and immunofluorescence staining. Results: Ciliated chondrocytes of 1-, 4- week-old mice were mainly distributed in the resting layer, the proliferating layer and the anterior hypertrophy layer, and primary ciliated cells were significantly reduced in the hypertrophy layer. It was found that the proportion of ciliated cells decreased after hypertrophic differentiation induction in vitro. After raising the proportion of ciliated cells, chondrocyte fertilization was induced, and the expression of COL10 and Prg4, the marker gene of hypertrophic chondrocytes, was significantly reduced. Conclusion: The primary cilia mainly existed in the resting zone, proliferation zone and the prehypertrophy zone of the growth plate. The chondrocytes in hypertrophy zone have less primary cilia. Increasing the proportion of ciliated cells by serum-free starvation can reduce the expression of the marker genes of hypertrophic chondrocytes.

Objective: To analyze the risk factors of postoperative infection in patients with oral squamous cell carcinoma (OSCC) after radical resection, to establish an infection risk prediction model, and to verify the model externally to explore its predictive value. Methods: A total of 568 patients with OSCC after radical resection in the Department of Oral and Maxillofacial Surgery of Xi'an Jiaotong University Stomatological Hospital from January 2017 to December 2022 were retrospectively collected. They were randomly divided into the modeling group (386 cases) and the validation group (182 cases), and their clinical data were collected. The multiple factor Logistic regression model was used to analyze the influencing factors of infection in patients, and R software was used to build a line graph prediction model for internal and external verification. Results: Multivariate Logistic regression analysis showed that age ≥60 years, American Society of Anesthesiologists (ASA) grade ≥Ⅱ, diabetes mellitus, tracheotomy, and operation time >260 min were independent risk factors of infection after radical resection in OSCC patients (P<0.05). The results of the Hosmer-Lemeshow test were χ²=8.529, P=0.384, which suggested that the model had good discrimination and accuracy. The area under the curve (AUC) of receiver operating characteristic (ROC) were 0.805 and 0.794 in the modeling group and the validation group respectively. The calibration curve showed that the model has good discrimination and accuracy. Conclusion: The nomogram constructed by age, ASA grade, diabetes mellitus, tracheotomy and time length of surgery can accurately predict the risk of infection in patients with OSCC after radical resection, with high clinical application value.

Objective: To study the effect of the depth of invasion (DOI) on predicting lymph node metastasis and evaluating prognosis in patients with early oral squamous cell carcinoma (OSCC). Methods: Patients with early OSCC from January 2015 to December 2017 were enrolled and evaluated for pathological DOI and lymph node metastasis. The DOI cutoff value of lymph node metastasis in OSCC was predicted by the area under curve (AUC) of the receiver operating characteristic (ROC) curve. Moreover, the difference of lymph node metastasis rate and survival curve among different DOI groups was compared.Results: Ninety four early OSCC patients were included, with the median follow-up age of 66 and median follow-up time of 35.5 months. Pathological metastasis-positive node were observed in 18 patients with the average DOI of 6.09 mm; the average DOI of others was 3.61 mm (P<0.05 ). The area under the ROC curve was 0.86, and the optimal DOI cutoff value was 4.41 mm (sensitivity 78%; specificity 84%). When DOI>4.41 mm, lymph node metastasis rate was higher, that is 14.89% vs 4.25% (P<0.05) and the median survival was shorter (41.4 months vs 52.6 months; HR: 1.80, 95%CI: 0.88~3.69, P=0.10 ). Conclusion: DOI in early OSCC showed positive correlation with the lymph node metastasis rate. However, the prognosis of these patients was not apparently worse, indicating the index may not be an independent predictor for both lymph node metastasis and prognosis in early OSCC patients.

Objective: To explore the clinical effect of Piezocision guided by three dimensions (3D) printing guide plate to assist skeletal Class Ⅱ malocclusion correction. Methods: Twenty-four patients with skeletal Class Ⅱ malocclusion were selected from our hospital. The treatment plan involved the extraction of the bilateral maxillary first premolars and anterior retraction by mini-implant anchorage in upper arch. The patients were randomly divided into two groups: The control group underwent conventional orthodontic treatment, while the research group underwent Piezocision guided by 3D printing guides at the beginning of the space-closing phase of the orthodontic treatment. The loading method was the same as that of the control group after the operation. The indexes related to the changes of hard and soft tissues and the treatment effects of the two groups were recorded for analysis and comparison. Results: In the research group, the change value of U1-SN was (-1.49±2.18)°，U1-NA was (-5.63±3.39)°，NA-Apo was -4.10 (-4.60, -2.00)°，U1-Apo was (-3.10±0.95) mm. There was significant difference comparing with the control group. The average speed of movement of the teeth in the research group during the process of space closure was (0.90±0.21) mm per month, which was significantly faster than that of the control group [(0.54±0.15) mm per month]. None of the roots were damaged after operation, and there was no significant difference in the degree of root resorption and the depth of periodontal probing between the research group and the control group after the treatment. Conclusion: In skeletal ClassⅡmalocclusion correction, 3D printing-guided Piezocision can effectively realize the overall movement of the maxillary anterior teeth, shorten the treatment time, and have fewer surgical complications, which can be viewed as an effective adjuvant treatment of patients with skeletal ClassⅡmalocclusion undergoing orthodontic treatment.

Objective: To report a case of ameloblastoma of mandible in our hospital using Masquelet's induced membrane technique (MIMT) to reconstruct mandibular segment defect in February 2021. Methods: According to the principle of MIMT, partial resection and implantation of bone cement were given in the first stage; with the help of digital surgery, three dimension printing model and pre-fabricated titanium mesh were used to transplant the iliac bone in the second stage; the plate and titanium mesh were removed in the third stage. Results: According to the post-operation CT images and intraoperative findings, the bone regeneration shows a good result with MIMT. Conclusion: MIMT can be further studied in the reconstruction of mandibular segmental defect.

Objective: To observe the effect of resveratrol on the chemoresistance of oral squamous cell carcinoma (OSCC) cells induced by cisplatin (DDP), and to explore the related mechanism. Methods: CAL-27/DDP cells in logarithmic phase were taken and randomly divided into control group (conventionally cultured), resveratrol group (added resveratrol 200 μmol/L), agonist group [added tumor necrosis factor-α (TNF-α) 10 ng/mL], resveratrol combined with agonist group (added resveratrol 200 μmol/L, TNF-α 10 ng/mL). All groups were cultured for 48 h for subsequent experiments. The inhibition rate of cell proliferation was detected by MTT method. Double staining was used to detect the apoptosis rate. Intracellular DDP accumulation and retention were examined. Western blotting was used to detect the protein expressions of P-glycoprotein (P-gp), topoisomorases Ⅱ (Topo Ⅱ), nuclear factor-κB (NF-κB) p65, phosphorylated NF-κB (p-NF-κB) p65, inhibition of NF-κBα (IκBα) and phosphorylated IκBα(p-IκBα). Results: Compared with the control group, the proliferation inhibition rate, apoptosis rate, drug accumulation, drug retention, and TopoⅡprotein expression were increased, and the expression of P-gp protein, as well as the ratios of p-NF-κB p65/NF-κB p65, p-IκBα/IκBα protein expression were decreased in the resveratrol group (P<0.05). Also compared with the control group, the proliferation inhibition rate, apoptosis rate, drug accumulation, drug retention, and Topo Ⅱ protein expression were decreased, P-gp protein expression, p-NF-κB p65/NF-κB p65, p-IκBα/IκBα protein expression ratios were increased in the agonist group (P<0.05). Compared with the resveratrol group, the proliferation inhibition rate, apoptosis rate, drug accumulation, drug retention, and TopoⅡprotein expression were decreased, while the expression of P-gp protein, and the ratios of p-NF-κB p65/NF-κB p65, p-IκBα/IκBα protein expression were increased in the resveratrol combined agonist group (P<0.05). Compared with the agonist group, the proliferation inhibition rate, apoptosis rate, drug accumulation, drug retention and TopoⅡprotein expression were increased, while the expression of P-gp protein and the ratios of p-NF-κB p65/NF-κB p65, p-IκBα/IκBα protein expression were decreased in the resveratrol combined with agonist group. Conclusion: Resveratrol can reduce the chemotherapy of cisplatin-induced OSCC cells, and its mechanism may be related to the inhibition of NF-κB pathway.

Objective: To investigate the effect of local injection of desferrioxamine (DFO) on the bone remodeling of alveolar bone through the regulation of osteoclasts by hypoxia inducible factor-1α (HIF-1α). Methods: DFO was injected locally into the alveolar bone of C57 mice; changes in alveolar bone volume were observed by micro-CT and histological staining; osteoclastogenesis was observed by immunofluorescence and tartrate-resistant acid phosphase (TRAP) staining; the effects of DFO on the differentiation of Raw264.7 to osteoclasts via HIF-1α were observed in vitro by TRAP staining and immunofluorescence. Results: Micro-CT and histological staining showed that local bone density decreased and bone volume decreased after local injection of DFO; histological staining revealed that the number of local osteoclasts increased and HIF-1α expression increased in the DFO injection group compared with the control group; in vitro cell culture revealed that DFO promoted the expression of HIF-1α in Raw264.7 cells and its differentiation to osteoclasts. Conclusion: Local injection of DFO can promote bone remodeling of alveolar bone and differentiation of Raw264.7 into osteoclasts.

Objective: To investigate the application and security of anticoagulants during the perioperative period of tooth extraction in patients after heart valve replacement. Methods: A case-control study was carried out on patients with molar teeth extraction from the Department of Stomatology, Nanjing First Hospital from January 2019 to December 2021. The patients in the research group (n=66) took warfarin anticoagulation after heart valve replacement; the control group consisted of 150 patients didn't take anticoagulant. Perioperative medication and hemostasis were performed to compare bleeding and wound healing after tooth extraction. Results: There was no significant difference between the two groups in the bleeding rate after operation and the healing of tooth extraction wounds 7 days after operation (P>0.05). Conclusion: The replacement therapy with low molecular weight heparin can not only ensure the safety of the perioperative period, but also prevent the complications caused by withdrawal of the drug.

Objective: To investigate the function of Alpl gene during orthodontic tooth movement. Methods: Firstly, agarose gel electrophoresis was used for screening heterozygote (Alpl semi-knockout group) and wildtype (wildtype group) mice, 12 mice in each group. Then orthodontic tooth movement model was established and the changes of body weight of the two groups were observed. Furthermore, maxillary samples from the two groups were collected after 7 days of orthodontic force. Micro-CT 3D reconstruction was applied to detect the distance of tooth movement in wildtype group and Alpl semi-knockout group. After demineralization, the collected maxillary samples were embedded and cut into slices. HE staining was applied to observe the histological changes in periodontal tissue. Finally, immunofluorescent staining was used to compare the expression of alkaline phosphatase(ALP) in periodontal tissue. Results: Agarose gel electrophoresis results showed that Alpl heterozygous mice were successfully generated. And the orthodontic tooth movement model was established. In addition, the body weight of the two groups both decreased significantly in the first four days and then increased. There was no significant difference in body weight within the two groups. Micro-CT 3D reconstruction result displayed that Alpl heterozygous mice gene showed less tooth movement compared with wildtype mice. Furthermore, HE staining showed that the periodontal membrane was compressed on the pressure side and widened on the tension side in both groups. However, more osteoclastic lacunaes can be seen on the pressure side in wildtype group than that in Alpl semi-konckout group. Finally, immunofluorescence staining demonstrated that periodontal tissue of wildtype mice showed extensive expression of ALP, while the expression of ALP significantly dropped in Alpl semi-knockout group. Conclusions: The deficiency of Alpl gene inhibits orthodontic tooth movement.

Objective: To construction a mandible deviated occlusion(MDO) rat model and investigate the changes in the micro-CT images and histology of condyles. Methods: Twelve 6-week-old female SD rats were randomly divided into control group and MDO group (n=6 in each group). The method of MDO model: The left maxillary central incisors and the bilateral mandibular central incisors were bonded with the metal tubed aberrant prosthesis. The maxillary metal tube was designed to have a lingual inclined guide plate in order to achieve normally derived over-jet and over-bite relationship. The mandibular metal tube was designed to have an inclined plate, 45 degrees in mesial-distal direction to guide the mandible to deviate to right side when rat biting. The control group did not do any treatment. The rats in the two groups were fed for 12 weeks, and bilateral mandibular condyles were collected for micro-CT scanning and then taken for histological staining. The data of bilateral condyles in the control group were combined to get the average value. The data from the MDO group were divided into the MDO-left group and the MDO-right group. Results: Micro-CT images showed that the condyles in control group had smooth and intact articular surface. The density of the subchondral bone was normally impact. In contrast, the length and width of the condyles in MDO group were increased in varying degree and trabecular bone loss was obviously absorbed. Three left condyles out of the total twelve condyles in MDO group showed lacunae on the articular surface. Histological staining showed that the condyle chondrocytes in control group had well organized zonal cartilage. While in the MDO-left group, lacunaes of left condyles were filled with cartilage tissue or fibrous tissue. Histomorphometry analysis showed that the cartilage in middle third of the condyle in both MDO-left and MDO-right groups was thicker than that in control group (P<0.05). Unmineralized cartilage in posterior third of MDO-left group was thicker than that in control group (P<0.05). Conclusion: MDO could lead to asymmetrically aberrant remodeling of bone and cartilage in the mandibular condyles, and formation of cartilage projections in the articular surface which displayed on micro-CT images as lacuna of the condylar articular surface.

Objective: To investigate the auxiliary diagnostic value and clinical significance of peripheral blood neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and lymphocyte to monocyte ratio (LMR) in oral squamous cell carcinoma(OSCC). Methods: Clinical data and fasting blood routine of 108 OSCC patients, 95 oral precancerous lesions patients, and 100 normal patients were collected. Neutrophils(NEUT), lymphocytes(LYMPH), monocytes (MONO), platelets (PLT) were collected, NLR, PLR, LMR were analyzed statistically and the relationship with lymph node metastasis were investigated. Results: OSCC, oral precancerous lesions, and normal patients had significant difference in gender comparison. OSCC occurred more frequently in men(P=0.003), and there was no significant gender difference in patients with precancerous lesions(P>0.05); age, NEUT, LYMPH, MONO, PLT, NLR, PLR, LMR have no statistically significant difference among the three groups(P>0.05). NLR, PLR and LMR in patients with OSCC showed no significant difference in connection with lymph node metastasis(P>0.05). Conclusion: NLR, PLR, LMR demonstrate no auxiliary diagnostic value in lymph node metastasis，and has limited role in the differential diagnosis of the diseases. Clinicians should pay attention to other diagnostic methods so as to achieve early diagnosis and treatment of oral cancer.

Dentigerous cyst is a common odontogenic cyst of the jaw, caused by the accumulation of cystic fluid between the tooth crown and the reduced enamel epithelium. Dentigerous cysts tend to occur in teenagers, more often in males than females, especially in mixed dentition, and most commonly involving mandibular premolars, mandibular third molars and maxillary canines. In recent years, some traditional treatments of children jaw cysts have been replaced by conservative treatments, such as open tamponade, vacuum sealing drainage, marsupialization, supplemented by obturator, pocket suture, orthodontic treatment, etc. However, few cases of natural fenestration have been reported. In this paper, we report a case of children dentigerous cyst with natural fenestration, which provides ideas for the treatment of dentigerous cysts in adolescents.

Objective: To investigate the expression and clinical significance of E2F transcription factor 1 (E2F1) in oral squamous cell carcinoma (OSCC), and to analyze its function in apoptosis and cell cycle. Methods: The correlation between E2F1 expression and clinicopathology in OSCC was analyzed based on R language and The Cancer Genome Atlas (TCGA) database. The main biological processes involved in E2F1 were identified by gene set enrichment analysis (GSEA). Western blotting and real-time quantitative polymerase chain reaction (RT-qPCR) were used to detect E2F1 expression in OSCC patients' tissue. After increasing and knocking down the expression of E2F1 in SCC15 cell lines by cell transfection, the effect of changes in E2F1 expression on apoptosis and cycle of SCC15 cells was analyzed by flow cytometry. Results: E2F1 was highly expressed in the OSCC-related TCGA dataset and correlated with T-stage (T2 or T4 vs T1), histological grade (G2 or G3 vs G1), clinical stage (Ⅲ vs I), age (middle vs young), and gender (male vs female) (P<0.05), which were mainly enriched in the genome of cell cycle or nucleotide excision repair [P<0.05 and false discovery rate (FDR) <0.25]. Both mRNA and protein expression of E2F1 were upregulated in the tissues of 37 OSCC patients (P<0.001). The expression of upregulated E2F1 decreased the rate of apoptosis in SCC15 cells (P<0.05), and also decreased the rate of G1 phase (P<0.01) and increased the rate of S phase (P<0.001) in the cell cycle. Conclusion: E2F1 is highly expressed in OSCC and can inhibit apoptosis and promote G1/S phase transition in the cell cycle.

Objective: To evaluate the clinical effect of guided bone regeneration technique (GBR) with resorbable collagen membrane and particulate xenograft in horizontal bone augmentation in the posterior mandible. Methods: A total of 33 patients who had missed a single mandibular posterior tooth and received implant placement combined with GBR procedure were included. Patients were divided into two groups: the premolar group (n=16) and the first molar group (n=17). CBCT datasets of patients before surgery, immediate post-surgery and 6-8 months after surgery were three-dimensionally reconstructed and superimposed. After that, alterations of bone graft contour at 0, 3, 6 mm below the implant platform during the healing stage were measured to evaluate the effect of horizontal bone augmentation. Results: There were no statistically significant differences about the amount of bone grafting, bone resorption, new bone formation between the premolar group and the first molar group at different vertical levels（P>0.05）. In each group, the amount of bone grafting and resorption at 0 mm and 3 mm below the implant platform were higher than that at 6 mm (P<0.05), and there was no statistical difference in the amount of new bone formation at different vertical levels (P>0.05). Conclusion: When GBR was performed in the posterior mandible using resorbable collagen membrane and particulate xenograft, greater horizontal reduction was observed near the coronal alveolar ridge during the healing stage. In addition, for two- or three-wall bone defects, the GBR procedure in posterior mandible can achieve a horizontal bone augmentation of about 2.0-2.5 mm.

Objective: To compare the influence between retromandibular transmasseteric anterior parotid approach (RMTMAP) and retromandibular transparotid approach (RMTP) on the facial nerve damage and salivary fistula in the treatment of condylar fractures. Methods: A comprehensive literature search of randomized controlled trials on surgical approaches for condylar fractures was undertaken in various Chinese and English databases (the Cochrane Library, PubMed, Embase, CNKI, CBM, VIP, Wanfang and Chinese Clinical Trial Registry). The search period is from the establishment of the database until now (November 2021), and manual search is carried out to avoid omissions. A total of 7 studies restricted in randomized controlled trials were included, and the quality of these studies was moderate to high. RevMan 5.3 software was used to perform meta analysis. Results: A total of 7 studies were included in this study, and the results showed that patients in both groups could achieve satisfactory results after surgery. The incidence of postoperative facial nerve injury in RMTMAP group was lower than that in RMTP group [relative risk (RR)=0.49, 95%CI=0.25-0.97]. P=0.04], and the incidence of postoperative salivary fistula was lower in the RMTMAP group (RR=0.35, 95%CI=0.15-0.85, P=0.02). The difference between the two groups was statistically significant. Conclusion: A lower incidence of postoperative facial nerve injury and salivary fistula was observed in RMTMAP group than that in RMTP group. Therefore, RMTMAP deserves clinical application.

Objective: This study aimed to evaluate the role of long intergenic non-coding RNA-EPS (lincRNA-EPS) in enamel development using lincRNA-EPS knockout(KO) mice model. Methods: The genotypes of lincRNA-EPS KO mice were identified by polymerase chain reaction(PCR). The mandibular molars of 8-week-old KO mice and wildtype (WT) mice was analyzed by micro-CT. The morphology and microstructure of enamel were detected by scanning electron microscope (SEM). The degree of enamel mineralization was explored by X-ray and energy dispersive X-ray spectroscopy (EDX). Integrated mandibular first molar germs of 0.5 day post-natal mice were isolated and used for real-time quantitative polymerase chain reaction(RT-qPCR) to detect the relative mRNA expression of AMELX, ENAM, AMBN, AMTN. Results: Micro-CT imaging showed that compared with WT mice, lingual side of mandibular molar exhibited large enamel defects in lincRNA-EPS KO mice, and lingual cusps were worn into pits. SEM analysis showed that the enamel from lincRNA-EPS KO mice displayed structural disorganization. Moreover, there were gaps between the hydroxyapatite crystals in the rods. Compared with WT mice, the relative mRNA expression of enamel matrix protein significantly decreased in KO mice(P<0.05). Conclusion: Deficiency of lincRNA-EPS may lead to alternation of the gene expression of enamel matrix protein, which resulted in defects in the structure of enamel in KO mice. Our findings support an essential role of lincRNA-EPS in the process of amelogenesis.

Submandibular and submental areas were not common sites of occurrence of epidermoid cysts. Though the lesions varied in size, giant case was rare. A case of submental-submaxillary giant epidermoid cyst was reported in this paper, and the diagnosis, treatment and causes were discussed by reviewing relevant literatures.

Objective: To analyze the incidence and influencing factors of vascular pedicle ossification after the repair of maxillofacial defects by free flap. Methods: Search PubMed, Web of Science and CNKI databases for keywords "pedicle ossification", "free flap" and "maxillofacial". The literatures on heterotopic ossification of free flap vascular pedicle from January 1, 2000 to December 1, 2021 were obtained. RevMan 5.4 software was used for meta analysis. Results: Five literatures were included, consisting of 829 cases in total. The incidence of heterotopic ossification of vascular pedicle visible on imaging examinations was about 11%, and the incidence of ossification with clinical symptoms was about 2%. The combined odds ratio showed that the occurrence of heterotopic ossification of vascular pedicle was significantly correlated with flap type (OR=14.01, 95%CI=3.58-54.85, P<0.001), but not with gender (OR=1.63, 95%CI=1.00-2.67, P=0.05), site of reconstruction（OR=0.90, 95%CI=0.46-1.74, P>0.05), or whether radiotherapy had been performed（OR=0.79, 95%CI=0.52-1.22, P>0.05). Conclusion: After the repair of maxillofacial defects by free flap, the incidence of heterotopic ossification of vascular pedicle visible on imaging examinations was about 11%, and the incidence of ossification with clinical symptoms was about 2%, which was mainly related to the type of free flap and mostly occurred in free fibular flap.

Objective: To study the classification and localization extraction of high-impacted supernumerary teeth in maxillary esthetic area based on cone beam computed tomography (CBCT). Methods: A total of 320 cases of high-impacted supernumerary teeth in maxillary esthetic area were examined by CBCT. According to their relationship with adjacent central incisors, they were classified as high-impacted labial, high-impacted palatal, high-impacted vertical, and high-impacted horizontal teeth.The thicknesses of the alveolar bone of different types of supernumerary from crowns to labial sides, palatal sides, and nasal floors were measured and statistically compared. Based on the typing and measuring results, extraction approaches were determined, which included labial approach, palatal approach, and nasal floor approach. Also, the location and the amount of bone resection were determined. Results: Among the 320 patients, the thickness of the alveolar bone varied at different types. On the extraction approaches, 101 had labial approach, 29 had nasal floor approach, and 190 had palatal approach. No complications such as permanent tooth loosening, necrosis, or wound cavity infection were observed. Conclusion: CBCTis effective in identifying and categorizing different types of high-impacted supernumerary teeth. There are differences in bone thickness between different types of supernumerary teeth on the labial sides, palatal sides, and nasal floors. These findings are beneficial to determining the extraction approach and the position of bone resection, which can reduce damage of adjacent teeth and amount of bone resection.

Objective: To explore the potential of BB-94, a matrix metalloproteinase-9 (MMP-9) inhibitor, in alleviating malignant biological behavior of human oral squamous cell carcinoma (OSCC) cell line CAL27 and its possible mechanism. Methods: CAL27 cells in logarithmic growth phase were cultured in BB-94 culture medium with different concentrations (0, 0.125, 0.25, 0.5, 1.0 μg/mL) for 48 hours; the activity of MMP-9 in cell culture supernatant was analyzed by gelatin zymogram; the cell survival rate was detected by cell counting kit-8 (CCK-8) method; the apoptosis, migration, and invasion of CAL27 cells were detected by flow cytometry, wound healing test and Transwell test; real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the mRNA expression levels of phosphatidylinositol 3-kinase (PI3K) and protein kinase B (Akt); the expressions of PI3K, phosphorylated protein kinase B (p-Akt), MMP-9, vimentin (Vim), N-cadherin (N-cad) and E-cadherin (E-cad) proteins were detected by Western blotting. Results: The relative activity of MMP-9, the survival rate of CAL27 cells, the wound healing rate, the number of cell invasion, the relative expression level of PI3K and Akt mRNA and the relative expression level of PI3K, p-Akt, Vim, N-cad and MMP-9 protein decreased with the increase in the concentration of BB-94 (P<0.05). The apoptosis rate of CAL27 cells and the relative expression level of E-cad protein increased as the concentration of BB-94 went up (P<0.05). Conclusion: These results indicate that MMP-9 inhibitor could inhibit the malignant biological behavior of human OSCC cell line CAL27, and its mechanism may be related to preventing the activation of PI3K/Akt signaling pathway and the progress of epithelial mesenchymal transition (EMT).

Objective: To investigate the effect of 4-octyl itaconate (4-OI) on lipopolysaccharide (LPS)-induced calvarial osteolysis in mice. Methods: CCK-8 assay was used to evaluate the effect of different concentrations of 4-OI on the cell viability of RAW 264.7 macrophages and murine primary bone marrow-derived macrophages (BMMs). Real-time quantitative polymerase chain reaction (RT-qPCR), immunofluorescence staining, and intracellular reactive oxygen species (ROS) detection kit (DCFH-DA) were used to explore the effect of 4-OI at different concentrations (12.5 µmmol/L and 50 µmmol/L) on the inflammatory response of macrophages. Tartrate-resistant acid phosphatase (TRAP) staining was used to explore the effect of 4-OI on osteoclast differentiation. The murine LPS-induced mouse calvarial osteolysis model was established, and the therapeutic effect of 4-OI on inflammatory osteolysis was evaluated by micro-CT and histological staining. Results: The results of CCK-8 showed that 4-OI below a concentration of 50 µmmol/L had no obvious cytotoxicity to RAW 264.7 macrophages and murine BMMs. RT-qPCR and immunofluorescence results showed that 4-OI was concentration-dependent, and inhibited the expression of pro-inflammatory cytokines. TRAP staining showed that 4-OI effectively inhibited the osteoclast differentiation induced by receptor activator of nuclear factor κB ligand (RANKL). Micro-CT and histological staining demonstrated that 4-OI effectively alleviated the inflammatory response and bone resorption around the osteolysis site. Conclusion: 4-OI can effectively inhibit inflammatory osteolysis, and it has great potential application in the treatment of osteolysis related diseases in oral and maxillofacial region.

Neurolemmoma, also known as schwannoma, is a benign tumor originated from schwann cells in the nerve sheath. Schwannomas in the head and neck account for 25%~45% of all schwannomas, while schwannomas in the submaxillary region are rare. A case of submandibular neurilemmoma was reported. The etiology, incidence rate, clinical manifestations, diagnosis, and treatment of the disease were discussed in combination with the relevant literature.

Objective: To summarize the clinical outcomes of vacuum sealing drainage(VSD) combined with closed drainage under thoracoscopy in the management of multi-space infection of maxillofacial and neck complicated with descending necrotizing mediastinitis (DNM) and to provide clinical references. Methods: A total of 3 cases of multi-space infection of maxillofacial with DNM who were treated between January 2016 to December 2017 in Department of Otolaryngology and Department of Stomatology were included for the retrospective analysis. Results: Among 3 patients, 2 males, 1 female, aged from 41 to 53, diagnosis of all patients were confirmed by neck and chest CT scan. They were treated by VSD combined with closed drainage under thoracoscopy. Under general anesthesia, the device of VSD was discharged after a week, and the closed thoracic drainage tube was placed and lasted for about 36 days. The mean in-hospital day was 48 days (44-57 days), with a 33-50 months follow up. There was no recurrence of infection. Conclusion: VSD combined with closed drainage under thoracoscopy treating multi-space infection of maxillofacial with DNM has the advantage of reliable drainage, small surgical trauma and meets patients′satisfaction. It has certain clinical application value.

Lipomas are commonly found in the proximal part of the trunk or limbs and also found in the oral cavity. Lipoma has been divided into three types based on the origin of the location: superficial lipoma, deep lipoma, and parosteal lipoma (PL). PL is a rare entity and is seldom seen in the oral cavity. This article presents a case of PL in mandibular buccal vestibul and discusses clinical manifestation, diagnosis, and treatment of oral parosteal lipoma.

Transverse facial cleft is a clinical type of craniofacial cleft malformation, which constitutes a rare congenital facial cleft deformity compared to cleft lip and palate. The pathogenesis of transverse facial cleft arises from incomplete fusion of maxillary process and mandibular process during embryo, resulting in a transverse facial cleft extending from the oral commissure to the buccal region. In addition to the oral and buccal malformations, developmental malformations of the first branchial arch may also co-occur, such as unilateral facial hypoplasia, preauricular fistula, appendage and other deformity. The precise pathogenesis remains unclear, potentially stemming from genetic, nutritional, or environmental factors. We present a clinical case of congenital atypical transverse facial cleft of the right face with buccal fistula and odontogenic keratocyst of mandible, thereby contributing to the clinical understanding of this condition.

Objective: To explore the application effect of light sedation technique in impacted tooth extraction in patients with anxiety. Methods: Intravenous infusion of propofol was administered to 20 patients with mandibular impacted teeth anxiety, and the impacted teeth were removed when the bispectral index (BIS) reached 80-85. The patients' heart rate (HR), mean arterial pressure (MAP), respiratory rate and blood oxygen saturation were monitored during operation, and the patients were instructed to record the visual analogue scale (VAS) after operation, and were asked about anterograde amnesia. SPSS 20.0 software package was used for data statistics, paired t test was used to compare the differences between intraoperative physiological indexes and the time of admission, and descriptive analysis was used to analyze the intraoperative pain of the patients. Results: All patients successfully completed the operation, and there were no obvious adverse reactions during the operation.There were no abnormalities in HR, MAP, respiratory rate and blood oxygen saturation. The postoperative VAS scores of the patients were 1-3, and the patients' anterograde amnesia of the start of surgery, mucosal incision and dental drill sound were recorded, which means that the anxiety was relieved. Conclusion: For the removal of mandibular impacted teeth in patients with dental anxiety, propofol intravenous light sedation technology (BIS=80-85) can achieve satisfactory results, reduce patients' anxiety and improve comfort.