Dental and maxillofacial tissue defects represented by tooth defect and/or loss, and maxillofacial bone defect are very common in oral and maxillofacial patients. The current treatment methods include autologous or allogeneic tissue transplantation, artificial synthetic material simulation replacement, etc., which cannot achieve physiological dental and maxillofacial tissue structure and function repair. Mesenchymal stem cells (MSCs) have extensive and powerful potential in regenerative medicine application. Stem cell polymer technology based on the principle of mesenchymal condensation and development has the functional characteristics of maintaining cell stemness, remodeling regenerative microenvironment, and restarting histological differentiation. It has been successfully applied to the regeneration and repair of dental pulp, periodontal and bone tissue, which has obtained good efficacy in related clinical trials, and possess a better clinical transformation prospect. Good results have been obtained in relevant clinical trials, and it has a good prospect of clinical transformation. This review highlights the theoretical basis, construction method and research status of stem cell polymerization in dental tissue regeneration, so as to provide new clinical treatment ideas for better realization of the regeneration and repair of dental tissue defects.

Objective: To investigate the clinical characteristics of cemento-osseous dysplasia(COD). Methods: The clinical diagnostic and treatment data of 21 patients with COD were collected. The clinical manifestations (age, gender, location, symptoms and signs), imaging characteristics, intraoperative conditions and prognosis were recorded and analyzed retrospectively. Results: Among the 21 cases, the incidence rate of female were higher than that of male, and 40-49 years old was the predilection age, accounting for 52.4%. 52.4% of the patients had no clinical symptoms. The lesions mostly located in mandible. Cortical bone expansion and missing teeth were common signs, accounting for 57.1%. 38.5% of the lesions caused mandibular canal displacement without lower lip numbness, and 30.8% of the lesions caused root resorption of the adjacent teeth. In radiological imaging, 69.2% of the lesions were mainly transparent and 30.8% were mainly resistant. Surgical treatment was effective for the disease, and new bone formation is found in the lesion area after operation. Conclusion: COD is a rare structural disorder of jaw. The incidence rate in female patients is significantly higher than that of male. It has a predilection for the mandible. Most patients have no clinical symptoms, and some infections can occur. Surgical resection is beneficial for bone regeneration.

Objective: To investigate whether the gene expression changes of the primary cilia and osteoblast in the alveolar bone are associated with occlusal hypofunction. Methods: The unloading model was established in the right mandible on 6-week-old wild type (WT) male mice and the left side was used as a self-control study. Samples were sacrificed 2 weeks after the operation, and the parameters of alveolar bone were scanned and analyzed by micro-CT. The changes in the number and position of osteoblasts and osteoclasts were observed histologically, and real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of osteoblastogenesis and osteoclastogenesis. The changes in the number and location of primary cilia were observed by co-staining, and the expression of cilium-related genes was detected. The Pearson correlation analysis was used to detect the expression of cilium-related genes and osteoblastogenesis, and the colocalization was observed by co-staining.Results: Analysis of the unloading side revealed a significant decrease in bone volume/total volume (BV/TV) (P<0.05). The number of osteoblasts decreased while the number of osteoclasts increased significantly (P<0.01). Both the occurrence rate of primary cilia and expression of cilium-related genes showed a decreasing trend (P<0.05). Furthermore, the expression of osteoblastogenesis and intraflagellar transport genes were significantly correlated (P<0.05). Co-staining results showed that osteoblasts were located on the top of root furcation, and there were primary cilia on the surface.Conclusion: The parameters of alveolar bone on the experimental side were significantly decreased and bone resorption accelerated on the unloading side. Both the number of osteoblasts and primary cilia as well as the expression of related genes decreased significantly and the expression levels of related genes were positively correlated.

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 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.

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.

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.

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 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.

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 explore the application effect of a minimally invasive tooth extraction tool in the treatment of mandibular impacted third molar. Methods: Among the patients with mandibular impacted teeth admitted to our department of stomatology from October 2020 to March 2022, seventy-eight patients were selected and randomly divided into two groups: control group (39 cases) and research group (39 cases) according to the extraction method. The control group took traditional hammer elevator for tooth extraction with high-speed turbines. The research group used the pneumatic tooth elevator with high-speed turbines. The occurrence of surgical indicators (extraction time and socket integrity), the intraoperative evaluation indexes (root fracture, gingival tear, lingual plate fracture, adjacent tooth injury) and the postoperative evaluation indexes (pain level, mouth opening at 72 hours after surgery, facial swelling at 72 hours after surgery) were statistically compared. Results: Theextraction time and the integrity of the extraction socket in the research group were significantly better than those in the control group (P<0.05), and the intraoperative and postoperative evaluation indexes in the research group were significantly better than those in the control group (P<0.05). Conclusion: The advent of pneumatic tooth extraction elevators in the treatment of mandibular impacted third molar combined with minimally invasive high-speed turbine provides new treatment options for managing patients with impacted third molars.

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 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.

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: 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 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: 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.

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 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 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.

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.

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.

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.

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.

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).

As a marker of mesenchymal cells, the transcription factor paired related homeobox 1 (Prrx1) not only participates in the bone development process during the embryonic period, but also plays a role in the adjustment of the body's bone homeostasis and the repair process after injury in adulthood. Prrx1⁺ cells are a subpopulation of the body's mesenchymal cells, which are believed to be involved in the development and formation of long bones and skulls as osteogenic precursor cells. This article reviews the role and influence of Prrx1 and Prrx1⁺ cells in bone development and bone remodeling.

Objective: To construct a prognostic nomogram model combined with the clinical features of patients with head and neck squamous cell carcinoma (HNSCC) and to predict the disease-specific analysis, based on Surveillance, Epidemiology, and End Results (SEER)—an authoritative cancer statistical database.Methods: All patients diagnosed with HNSCC from 2004 to 2016 were selected from SEER registry database, including age, gender, race, marital status, primary tumor site, tumor stage (TNM), surgical situation, etc. The population epidemiological characteristics, prognostic factors, and treatment-related outcomes were calculated after adjustment for different variables. Cox proportional-hazards model was applied to achieve univariate and multivariate analysis. Finally, the performance evaluation model was used to determine the prediction model.Results: A total of 1 026 cases' available information was found in SEER database. Multivariate survival analysis of Cox proportional-hazards model showed that the risk of death in female patients was higher than that in male patients (P<0.001); patients aged over 60 years had higher risk of death than that in patients aged younger than 60 years (P<0.001); for the primary tumor site, taking tongue as a reference, the death risk of buccal mucosa, maxillary sinus, the floor of mouth was lower (P<0.05) and that in other locations (gingiva, palate, oropharynx, nasopharynx, larynx) was higher (P<0.05); in TNM stage, the risks of stageⅡ (P<0.001), stageⅢ (P<0.001) and stageⅣ (P<0.001) were relatively higher compared with stageⅠ patients; similarly, in terms of radiochemotherapy and immunotherapy, patients who did not receive radiochemotherapy or immunotherapy had an increased risk of death compared with patients who received radiochemotherapy or immunotherapy (P<0.001).Conclusion: Gender, HPV infection, TNM stage, radiotherapy and chemotherapy are the important factors for the survival of patients suffered from HNSCC. Patients with high risk factors should be paid more attention to after diagnosis, which is helpful for doctors to make clinical decisions in actual therapies.

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.

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.

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.

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 reconstruct the structure of mouse tooth germ in the early stage of development, and to compare the morphological differences between the rudimentary bud 2 (R2) in the diastema region and the first molar (M1) in the molar region. Methods: After being fixed, the head specimens of E12.5 and E13.5 mouse embryos were embedded in paraffin, serially sectioned in the frontal plane, and stained with hematoxylin and eosin (HE). All images were processed with Photoshop CC 2018 software and Fiji software, then imported into Mimics Research 19.0 software for three-dimensional reconstruction and analysis. Results: It was observed in the reconstructed three-dimensional model that the epithelium of the tooth germ in the diastema forms a bud shape, but there was no obvious condensation of mesenchyme cells below it. After assigning virtual CT values to the R2 and M1, semi-quantitative measurements of the reconstructed images revealed that the mesenchymal cells coalescing around the bud-like epithelium of R2 were less dense and had a smaller condensation area. This phenomenon may be related to less cell proliferation in the diastema region. Conclusion: Three-dimensional reconstructions based on histological sections revealed a loss of the ability to form the condensational mesenchymal cell cluster in the diastema region of mice during early tooth development.

Objective: To explore the anatomical characteristics of mandibular lingual foramen (MLF) in different age groups by cone beam computed tomography (CBCT), so as to provide reference for clinical operation to avoid risk.Methods: CBCTimages of 280 patients' mandible were selected, including underage group (6-17 years old), young group (18-39 years old), middle-aged group (40-59 years old) and elderly group (over 60 years old), 70 cases in each group. The number, diameter, distribution of the lingual foramen, the distance from the lingual alveolar crest and the shape of the mandibular lingual canal were observed, and the anatomical characteristics between different age groups were compared.Results: The high incidence areas of the mandibular lingual foramen were the medial region of the body of mandible and the premolar area. The superior foramen of mental spine in the median area has the highest detection rate and larger diameter. The detection rate of the MLF in the underage group were lower than those in the other three groups. The diameter of lingual foramen in young group was significantly different from that in underage group and elderly group (P<0.01). The diameter of lingual foramen in middle-aged group was significantly different from that in underage group and elderly group (P<0.01), and the clarity of mandibular lingual canal (MLC) wall was positively correlated with age (r=0.141).Conclusion: The detection rate of MLF is high, so it is recommended to take CBCT examination before relevant surgery, so as to be familiar with the anatomical structure and avoid serious postoperative complications.

Transcrestal approach for sinus floor elevation is one of the effective surgical methods to solve the problem of inadequate bone quantity in the posterior maxilla. The technical difficulty is how to prepare the maxillary sinus floor. This paper reviews the related literature on the advantages and disadvantages of different surgical methods of preparing the sinus cortical floor in transcrestal sinus floor elevation to provide a reference for clinicians.

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.

Objective: To explore the indications, surgical methods, and curative effects of transoral resection of accessory parotid gland benign tumors, and to improve the level of diagnosis and treatment. Methods: The clinical features, imaging manifestations and treatment course of 5 patients diagnosed with accessory parotid gland tumor visited in the department of Oral and Maxillofacial-Head and Neck Oncology, Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine were retrospectively analyzed. Results: All the 5 cases underwent complete resection of the accessory parotid gland mass through transoral approach. Two weeks, 3 months and 6 months follow-up indicated that the patient's intraoral wound healed well, and there were no symptoms of parotid duct injury or facial nerve injury. Conclusion: The transoral approach is more suitable for benign tumors with wide range of motion, clear boundary, and no adhesion to the surrounding tissue. The treatment effect is satisfactory and facial incision scar can be avoided. This operating method has good cosmetic effect and high patient satisfaction.

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 evaluate the clinical effects of a new mineralized collagen (MC) bone filling material combined with concentrated growth factor (CGF) in repairing bone defects of jaw cysts. Methods: The sample population consisted of 120 patients after jaw cysts surgery. They were divided into CGF group (group A, 40 patients), MC group (group B, 40 patients) and MC+CGF group (group C, 40 patients) respectively using the random number method. The osteogenic results, pain and swelling degree at 3, 6 and 12 months after surgery were collected and compared. Results: The CT values of the bone defect area in group A were (220.07±29.25), (358.77±48.42), (473.07±55.63) HU at 3, 6, and 12 months postoperatively, and (281.00±36.14), (464.66±51.30), (569.10±71.21) HU in group B; and (344.14±39.31), (528.79±63.98), (603.62±95.04) HU in group C, respectively. Statistical differences between each two groups were found (P<0.05). The visual analogue scale (VAS) scores of pain level in these groups at 2 d postoperatively were 64.13±11.46, 65.31±9.89 and 51.68±14.24, with statistical significance (P<0.05) between them. The degree of postoperative swelling was less in group C than those in groups A and B measured by crude line measurement, and the differences were statistically significant (P<0.05). Conclusion: The current retrospective analysis indicates that applicaton of MC combined with CGF can reduce the degree of postoperative pain, swelling and effectively promote bone regeneration in bone cavity of jaw cysts.

Objective: To investigate the potential application value of salivary alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) in early diagnosis of oropharyngeal carcinoma.Methods: A total of 77 patients with oropharyngeal cancer (cancer group), 61 patients with benign oral tumors (benign group) and 51 healthy volunteers (control group) from January 2018 to January 2022 were selected. The levels of ALP and LDH in saliva were detected between each group, and the clinical data and pathological information were collected. The relationship between salivary ALP, LDH level and the incidence rate of oropharyngeal carcinoma, clinicopathological features of oropharyngeal carcinoma were statistically compared.Results: The expression levels of salivary ALP and LDH in oropharyngeal carcinoma group were higher than those of benign group and control group (P<0.001). The levels of salivary ALP and LDH in patients with low or moderate differentiation, TNM stageⅡand cervical lymph node metastasis were higher than those of patients with high differentiation, TNM stageⅠ and no cervical lymph node metastasis cases (P<0.001). Smoking, high-risk human papilloma virus infection, oral ulcer, high levels of salivary ALP and LDH were risk factors for the incidence of oropharyngeal cancer (P<0.01). The area under the curve of salivary ALP and LDH in the diagnosis of oropharyngeal carcinoma was 0.918, which were greater than the individual diagnosis result of 0.649, 0.769 (z=5.626、3.787, P<0.05).Conclusion: The levels of salivary ALP and LDH in patients with oropharyngeal carcinoma are significantly increased, which are related to the occurrence of oropharyngeal carcinoma and tumor behavior. Salivary ALP and LDH level can be used as a marker for early diagnosis of oropharyngeal carcinoma.