Efficacy of bone grafts in jaw cystic lesions:A systematic review

BACKGROUND Bone grafts have been applied for many years in orthopedic surgery to assist with bone repair for defects or bone discontinuity caused by trauma and tumors as well as periodontal defects.Jaw cysts are another common benign disease of the maxillofacial region which may lead to pathological bone fracture,loss of teeth,and infection.However,whether bone grafts are beneficial for bone regeneration in jaw cystic lesions and when bone grafts should be used remains unclear.AIM To study the efficacy of bone grafts compared to spontaneous healing in the treatment of jaw cystic lesions.METHODS A literature search was performed in Medline,Cochrane Library and Embase to identify related articles published in English in the last ten years.The following key words and Me SH terms were used:“jaw cyst”,“cystic lesion”,“odontogenic cyst”,“periapical cyst”,“dentigerous cyst”,“follicular cyst”,“keratocyst”,“treatment”,“surgery”,“bone graft”,“enucleation”,“cystectomy”,and“bone regeneration”.Case reports,clinical trials,clinical studies,observational studies and randomized controlled trials were included.Study quality was evaluated.RESULTS Ten studies(n=10)met the inclusion criteria.Five studies reported spontaneous bone healing after enucleation,three studies investigated the efficacy of various bone grafts,and two randomized comparative studies focused on the comparison between spontaneous healing and bone grafting.Over 90%of bone regeneration occurred within 6 mo after bone grafting.The bone regeneration rate after cystectomy showed great variation,ranging from 50%to 100%after 6 mo,but reaching over 90%after 12 mo.CONCLUSION While the long-term superiority of bone grafting compared with spontaneous healing after cystectomy is unclear,bone grafts accelerate the process of healing and significantly increase bone quality.

Trismus originating from rare fungal myositis in pterygoid muscles:A case report

BACKGROUND Trismus is a common problem with various causes.Any abnormal conditions of relevant anatomic structures that disturb the free movement of the jaw might provoke trismus.Trismus has a detrimental effect on the quality of life.The outcome of this abnormality is critically dependent on timely diagnosis and treatment,and it is difficult to identify the true origin in some cases.We present a rare case of trismus due to fungal myositis in the pterygoid muscle,excluding any other possible pathogenesis.CASE SUMMARY The patient presented with a 2-mo history of restricted mouth opening.Computed tomography showed obvious enlargement of the left pterygoid muscles.Furthermore,the patient had trismus without obvious predisposing causes.The primary diagnosis was pterygoid myosarcoma.Consequently,lesionectomy of the left pterygoid muscle was performed.Intraoperative frozen biopsy implied the possibility of an uncommon infection.Postoperative pathologic examination confirmed myositis and necrosis in the pterygoid muscle.Fungi were detected in both muscle tissue and surrounding necrotic tissue.The patient recovered well with antifungal therapy and mouth opening exercises.The rarity of fungal myositis may be responsible for the misdiagnosis.Although the origin of pathogenic fungi is still unknown,we believe that both hematogenous spread and local invasion could be the most likely sources.To the best of our knowledge,this is the
rst case in the literature that reported fungal myositis in pterygoid muscles as the only reason that results in trismus.CONCLUSION Surgeons should remain vigilant to the possibility of trismus originating from fungal myositis.

Development and validation of novel nomograms to predict survival of patients with tongue squamous cell carcinoma

BACKGROUND There is no unified standard to predict postoperative survival in patients with tongue squamous cell carcinoma(TSCC),hence the urgency to develop a model to accurately predict the prognosis of these patients.AIM To develop and validate nomograms for predicting overall survival(OS)and cancer-specific survival(CSS)of patients with TSCC.METHODS A cohort of 3454 patients with TSCC from the Surveillance,Epidemiology,and End Results(SEER)database was used to develop nomograms;another independent cohort of 203 patients with TSCC from the Department of Oral and Maxillofacial Surgery,First Affiliated Hospital of Zhejiang University School of Medicine,was used for external validation.Univariate and multivariate analyses were performed to identify useful variables for the development of nomograms.The calibration curve,area under the receiver operating characteristic curve(AUC)analysis,concordance index(C-index),net reclassification index(NRI),and decision curve analysis(DCA)were used to assess the calibration,discrimination ability,and clinical utility of the nomograms.RESULTS Eight variables were selected and used to develop nomograms for patients with TSCC.The Cindex(0.741 and 0.757 for OS and CSS in the training cohort and 0.800 and 0.830 in the validation cohort,respectively)and AUC indicated that the discrimination abilities of these nomograms were acceptable.The calibration curves of OS and CSS indicated that the predicted and actual values were consistent in both the training and validation cohorts.The NRI values(training cohort:0.493 and 0.482 for 3-and 5-year OS and 0.424 and 0.402 for 3-and 5-year CSS;validation cohort:0.635 and 0.750 for 3-and 5-year OS and 0.354 and 0.608 for 3-and 5-year CSS,respectively)and DCA results indicated that the nomograms were significantly better than the tumor-node-metastasis staging system in predicting the prognosis of patients with TSCC.CONCLUSION Our nomograms can accurately predict patient prognoses and assist clinicians in improving decision-making concerning patients with TSCC in clinical practice.

Effects of nanofibers on mesenchymal stem cells:environmental factors affecting cell adhesion and osteogenic differentiation and their mechanisms

Nanofibers can mimic natural tissue structure by creating a more suitable environment for cells to grow,prompting a wide application of nanofiber materials.In this review,we include relevant studies and characterize the effect of nanofibers on mesenchymal stem cells,as well as factors that affect cell adhesion and osteogenic differentiation.We hypothesize that the process of bone regeneration in vitro is similar to bone formation and healing in vivo,and the closer nanofibers or nanofibrous scaffolds are to natural bone tissue,the better the bone regeneration process will be.In general,cells cultured on nanofibers have a similar gene expression pattern and osteogenic behavior as cells induced by osteogenic supplements in vitro.Genes involved in cell adhesion(focal adhesion kinase(FAK)),cytoskeletal organization,and osteogenic pathways(transforming growth factor-β(TGF-β)/bone morphogenic protein(BMP),mitogen-activated protein kinase(MAPK),and Wnt)are upregulated successively.Cell adhesion and osteogenesis may be influenced by several factors.Nanofibers possess certain physical properties including favorable hydrophilicity,porosity,and swelling properties that promote cell adhesion and growth.Moreover,nanofiber stiffness plays a vital role in cell fate,as cell recruitment for osteogenesis tends to be better on stiffer scaffolds,with associated signaling pathways of integrin and Yes-associated protein(YAP)/transcriptional co-activator with PDZ-binding motif(TAZ).Also,hierarchically aligned nanofibers,as well as their combination with functional additives(growth factors,HA particles,etc.),contribute to osteogenesis and bone regeneration.In summary,previous studies have indicated that upon sensing the stiffness of the nanofibrous environment as well as its other characteristics,stem cells change their shape and tension accordingly,regulating downstream pathways followed by adhesion to nanofibers to contribute to osteogenesis.However,additional experiments are needed to identify major signaling pathways in the bone regeneration process,and also to fully investigate its supportive role in fabricating or designing the optimum tissue-mimicking nanofibrous scaffolds.