OBJECTIVES: This retrospective study aimed to investigate factors influencing positional changes of the condyle and temporomandibular joint (TMJ) following mandibular defect reconstruction with bone flaps, and to evaluate the biomechanical impacts of flap reconstruction on condylar positioning, thereby providing evidence for optimizing surgical protocols and TMJ functional rehabilitation. METHODS: A retrospective study was conducted on 90 patients undergoing mandibular segmental resection with immediate bone flap reconstruction at Guizhou Medical University Affiliated Stomatological Hospital (June 2019 to May 2024). After strict screening, 50 cases with complete data were analyzed. Clinical parameters (defect size, location, reconstruction method) and craniofacial CT scans at four timepoints [preoperative (T0), 7-10 days (T1), 3 months (T2), and 6 months (T3) postoperatively] were collected. Mimics 20 software facilitated 3D reconstruction for measuring TMJ anterior/posterior/superior joint spaces (Kamelchuk method) and calculating condylar position via the Pullinger index [Ln (posterior/anterior space)]. Vitral and Krisjane methods quantified mandibular linear parameters (ramus length, condylar pole distances to the sagittal plane, angulation) and glenoid fossa morphology. Statistical analyses were performed using SPSS 21.0. RESULTS: Mandibular defect size and location were significant factors influencing postoperative condylar position changes (P<0.05). Compared to preoperative measurements, postoperative condylar anterior, posterior, and superior joint spaces were significantly increased (P<0.001). The most pronounced anterior condylar displacement occurred within 7-10 days postoperatively (P<0.05). In patients with condyle resection, postoperative joint space and angle changes were significant; in patients with condyle preservation, only superior and anterior joint space changes were statistically significant (P<0.05). Additionally, from T1 to T2, the changes in condylar medial-lateral distance, superior joint space, and anterior joint space were negatively correlated with the preoperative condylar position. Compared with preoperative,in the T0-T1 period, condylar medial-lateral distance, posterior joint space, and articular tubercle angle changes were significantly negatively correlated with time (P<0.05). Notably, the angle between the condylar long axis and the coronal axis showed a sustained negative trend from T1 to T3 (P<0.05). CONCLUSIONS Condylar position changes after mandibular defect repair with bone flap reconstruction are associated with the size and location of the defect. Additionally, adaptive remodeling of the temporomandibular joint (TMJ) joint space occurs postoperatively. The phenomenon of anterior displacement of the condyle in the early postoperative period (7-10 days) shows a trend of reduction with prolonged follow-up time, and further sample size research is needed.
Humans ; Retrospective Studies ; Temporomandibular Joint/surgery* ; Mandibular Condyle/surgery* ; Male ; Female ; Adult ; Middle Aged ; Mandibular Reconstruction/methods* ; Mandible/surgery* ; Surgical Flaps ; Tomography, X-Ray Computed ; Young Adult ; Biomechanical Phenomena ; Aged ; Adolescent ; Imaging, Three-Dimensional

Objective:To explore the effects of parathyroid hormone(PTH)on the osteogenic differentiation of osteoblasts by reg-ulating macrophage polarization in inflammatory microenvironment.Methods:Macrophages were pretreated with lipopolysaccharide(LPS)for 2 h to establish an inflammatory microenvironment model,and then treated with PTH for 24 h.Macrophages and osteo-blasts were co-cultured in Transwell cells.Alkaline phosphatase staining,alizarin red staining,RT-qPCR and Western blot were applied to detect osteogenic differentiation.The expression of SOCS1/JAK2/STAT3 protein in macrophages was detected by West-ern blot.The change of STAT3 expression was detected after adding AG490.The expression of miR-155-5p,SOCS1,IL-1β,IL-6 and i-NOS was detected by ELISA and RT-qPCR.Results:LPS induced M1-type polarization of macrophages and inhibited the osteogenic differentiation of osteoblasts.PTH inhibited the polarization of M1-type macrophages and promoted the osteogenic differ-entiation of osteoblasts in inflammatory microenvironment(P＜0.05).PTH down-regulated the expression of miR-155-5p,IL-1β,IL-6,i-NOS,p-JAK2/JAK2 and p-STAT3/STAT3 in macrophages under inflammatory microenvironment(P＜0.05),and up-reg-ulated SOCS1(P＜0.05).AG490 further inhibited p-STAT3/STAT3 expression.Conclusion:PTH inhibits the polarization of M1-type macrophages and promotes osteogenic differentiation of osteoblasts by down-regulating miR-155-5p and then targeting SOCS1/JAK2/STAT3 signaling pathway in inflammatory microenvironment.

Objective:To explore the effects of parathyroid hormone(PTH)on the osteogenic differentiation of osteoblasts by reg-ulating macrophage polarization in inflammatory microenvironment.Methods:Macrophages were pretreated with lipopolysaccharide(LPS)for 2 h to establish an inflammatory microenvironment model,and then treated with PTH for 24 h.Macrophages and osteo-blasts were co-cultured in Transwell cells.Alkaline phosphatase staining,alizarin red staining,RT-qPCR and Western blot were applied to detect osteogenic differentiation.The expression of SOCS1/JAK2/STAT3 protein in macrophages was detected by West-ern blot.The change of STAT3 expression was detected after adding AG490.The expression of miR-155-5p,SOCS1,IL-1β,IL-6 and i-NOS was detected by ELISA and RT-qPCR.Results:LPS induced M1-type polarization of macrophages and inhibited the osteogenic differentiation of osteoblasts.PTH inhibited the polarization of M1-type macrophages and promoted the osteogenic differ-entiation of osteoblasts in inflammatory microenvironment(P＜0.05).PTH down-regulated the expression of miR-155-5p,IL-1β,IL-6,i-NOS,p-JAK2/JAK2 and p-STAT3/STAT3 in macrophages under inflammatory microenvironment(P＜0.05),and up-reg-ulated SOCS1(P＜0.05).AG490 further inhibited p-STAT3/STAT3 expression.Conclusion:PTH inhibits the polarization of M1-type macrophages and promotes osteogenic differentiation of osteoblasts by down-regulating miR-155-5p and then targeting SOCS1/JAK2/STAT3 signaling pathway in inflammatory microenvironment.

BACKGROUND:Bone defects are caused by many factors,such as inflammation,tumor,trauma or bone diseases.Erythropoietin can promote the differentiation of mesenchymal stem cells into osteoblasts and osteoclasts and act on vascular endothelial cells to induce angiogenesis and accelerate the repair of bone and cartilage defects.Erythropoietin is a growth factor with potential application in bone tissue engineering construction. OBJECTIVE:To expound the application and potential mechanism of erythropoietin in bone tissue engineering. METHODS:The first author searched the related articles published in CNKI,WanFang,VIP,and PubMed databases from 2004 to 2022 by computer.Search terms were"erythropoietin,bone defect,bone regeneration,angiogenesis,osteogenesis,osteoblast,osteoclast,bone tissue engineering"in Chinese and English.Finally,64 articles were included for review. RESULTS AND CONCLUSION:(1)Erythropoietin can directly act on osteoblasts and osteoclasts in the bone marrow microenvironment by promoting the differentiation of mesenchymal stem cells into osteoblasts,osteoclasts,adipocytes,nerve cells and stromal cells.The activation of Wnt/β-catenin,hypoxia-inducible factor 1α/vascular endothelial growth factor,p38 MAPK and EphrinB2/EphB4 signaling pathways mediates the osteogenic differentiation of mesenchymal stem cells.(2)Erythropoietin can not only regulate the production of erythrocytes to alter the oxygen-carrying capacity of blood but also stimulate vascular endothelial cells to promote angiogenesis.The new blood vessels can carry oxygen,nutrients,growth factors,and bone progenitor cells necessary for osteogenesis to the osteogenic site,thereby promoting bone formation and fracture healing.(3)Currently,erythropoietin is being used as a growth factor with osteogenic and angiogenic effects in various types of scaffold materials such as chitosan,polycaprolactone,bioceramics,and nanofibers through various drug delivery methods.Erythropoietin,along with other growth factors such as bone morphogenetic protein-2 and bone morphogenetic protein-9,has been applied to the surface of scaffold materials to participate in the repair of bone defects.Erythropoietin has demonstrated excellent practicality in the construction of new tissue-engineered bone and has potential clinical application value.

Objective: To investigate the effect of parathyroid hormone (PTH) on the bone healing of mandibular ramus osteotomy. Methods: The mandibular ramus osteotomy model was established in sixty rabbits and these rabbits were randomly divided into experimental group A, experimental group B and control group. In the experimental group A and experimental group B, the rabbits were given PTH (20 and 40 μg/kg respectively) every other day after operation. In the control group, 1 ml saline was given. The animals were sacrificed at 1 week, 2 weeks, 3 weeks and 4 weeks postoperatively. The new bone formation was observed by histology and cone bone CT. The expression of osteoprotegerin and receptor activator of nuclear factor kappa-B (RANKL) in the new bone was detected by real-time quantitative PCR. Results: The experimental groups has better osteogenesis and the bone mineral density than the control group in osteotomy area. The experimental group B showed the best osteogenesis.Osteoprotegerin mRNA expression in experimental group A (1.127±0.035, 1.742±0.049, 1.049±0.062, 1.063±0.036) was significantly higher than that in the control group in each period (0.965±0.082, 1.254±0.071, 0.793±0.061, 0.684±0.055) (P=0.010, P=0.000, P=0.001, P=0.020), while group B (1.416±0.205, 2.648±0.168, 1.652±0.091, 1.712±0.070) was significantly higher than group A (P=0.000, P=0.010, P=0.023, P=0.003). RANKL mRNA expression in control group (1.666±0.086, 1.058±0.105, 0.885±0.124, 0.972±0.136) was significantly higher than that of the group A (0.788±0.036, 0.585±0.017, 0.692±0.017, 0.527±0.051) (P=0.001, P=0.006, P=0.003, P=0.028) in each period, while group A was significantly higher than group B(0.247±0.022, 0.240±0.034, 0.134±0.011, 0.103±0.050) (P=0.000, P=0.001, P=0.002, P=0.012). Conclusions PTH can upregulate the expression of osteoprotegerin and reduce expression of RANKL, thus promoting new bone formation. Intermittent administration of high dose of parathyroid hormone can further promote the healing process after mandibular ramus osteotomy.

Objective To understand the current status of receiving no methadone maintenance treatment (MMT) and influencing factors in HIV infected injecting drug users (IDUs) in Dehong Dai and Jingpo autonomous prefectures,Yunnan province.Methods Data of survival of IDUs with AIDS in Dehong were collected from "Chinese National Comprehensive HIV/AIDS and Care Information System" in December,2014.Results There were 987 IDUs who should receive MMT,the majority of them were males (94.6％,934/987),aged 35-44 years (53.0％,523/987) and farmers (77.2％,762/987).Among the 987 IDUs,60.2％ (592/987) received no MMT.Multivariate logistic regression analysis showed that being female (OR=2.66,95％CI:1.21-5.87),in Jingpo ethnic group (OR=3.05,95％CI:1.97-4.71) were the major risk factors for receiving no MMT;not being farmers (OR=0.46,95％CI:0.31-0.70),in Dai ethnic group (OR=0.53,95％CI:0.36-0.79),diagnosed HIV infection history ≥ 10 years (OR=0.60,95％CI:0.45-0.81) were the major protective factors for receiving no MMT.The reasons for receiving no MMT included long distance journey (289,48.8％),fear of exposure (124,20.9％),poor daily medication compliance (59,10.0％),fear of side effects (47,7.9％),others (73,12.3％).Conclusions The proportion of receiving no MMT in IDUs with AIDS in Dehong was high.Being female and farmer,in Jingpo ethnic group,low educational level,short diagnosed HIV infection history were influencing factors for receiving no MMT.The effective intervention measures should be taken to further improve MMT coverage according to the different characteristics of the patients.

OBJECTIVEThis research aimed to investigate the expression of osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) in mandibular distraction osteogenesis (DO) regulated by parathyroid hormone (PTH) and to explore the mechanism by which PTH promotes DO.

METHODSA rabbit mandibular DO model was established. The rabbits were randomly divided into experimental group and control group. The former were subcutaneously injected with different doses of PTH on alternate days, the latter was injected with normal saline every other day. Serum OPG levels were detected through enzyme-linked immunosorbent assay. The OPG and RANKL expression levels in the DO-induced formation of a new bone tissue were examined through immunohistochemistry staining.

RESULTSThe serum OPG levels gradually increased during distraction. At the end of the stretch, the OPG expression in the experimental group was significantly stronger than that in the control group. As the fixed period was extended, the OPG expression in the new bone gradually decreased, but the RANKL expression increased.

CONCLUSIONIntermittent subcutaneous PTH injection can upregulate the OPG expression and accelerate bone metabolism. Thus, this procedure promotes the early generation of a new bone in the mandible through DO.

Animals ; Enzyme-Linked Immunosorbent Assay ; Mandible ; NF-kappa B ; metabolism ; Osteogenesis, Distraction ; methods ; Osteoprotegerin ; metabolism ; Parathyroid Hormone ; metabolism ; RANK Ligand ; metabolism ; RNA, Messenger ; Rabbits ; Random Allocation

Parathyroid hormone(PTH) is synthesized and secreted by chief cell of Gley's glands which possesses dual functions of catabolism and anabolism.It regulates the proliferation and differentiation of multiple cell lines including osteoblast,osteoclast and skeletal lining cells.Furthermore,PTH activates various signaling pathways which control calcium,phosphorous' metabolism and bone conversion,accelerating the bone regeneration and reconstruction.However,the study of PTH in craniomaxillofacial bone regeneration is relatively less and whether the role of parathyroid glands and the mechanism of ossification are consistent with the long bone or not needs further investigation.This review focuses on the progress of PTH in craniomaxillofacial bone regeneration in recent years.

Objective To analyze the clinical features, diagnosis, treatment and prognosis of neurosyphilis. Methods Clinical data on and laboratory findings in 18 cases with neurosyphilis collected in the Affiliated Provincial Hospital, Anhui Medical University from 2006 to 2008 were retrospectively studied.Results Among the 18 patients, 3 sufferred from asymptomatic neurosyphilis, 1 from meningeal syphilis, 7 from meningovascular syphilis, 5 from paralytic dementia, and 2 from intracranial space-occupation. Toluidine red unheated serum reagin test (TRUST) and Treponema pallidum particle agglutination test (TPPA) of sera were positive in all the patients; cerebrospinal fluid (CSF) TRUST was positive in 16 patients, and CSF TPPA in all patients. An increase was observed in CSF leukocyte count in 7 patients and in CSF protein in 13 patients.The findings on cerebral magnetic resonance imaging (MRI) mainly included demyelination, brain atrophy,cerebral infarction, etc. All the patients, except 2 with a TRUST titer of 1:4, experienced a 4-fold decrease in TRUST titer within a 3-month follow up. Clinical symptoms of neurosyphilis improved in all patients except 1 with paralytic dementia. Conclusions The diversity of clinical manifestations usually leads to the misdiagnosis of neurosyphilis, which should be diagnosed based on comprehensive analysis of clinical characteristics as well as laboratory and imaging findings. Early diagnosis and treatment are beneficial to its prognosis.

OBJECTIVETo study the biomechanical properties of the new bone generated by mandibular distraction osteogenesis (DO).

METHODSA total of 11 healthy adult goats were randomly divided into 2 groups, the experimental group (n=9) and the control group (n=2). For the goats in the experimental group, the bilateral mandibles were gradually lengthened for 10 mm with distraction appliances. Three goats were sacrificed respectively at 2, 4 and 8 weeks after completion of distraction. Compressive, three-point bending and shearing tests were conducted on the standard regenerated bone samples and the whole unilateral mandibular specimens. For the goats in the cont rol group, no operation was made and the whole unilateral mandible was taken as the test specimen.

RESULTSThe compressive strength and bending stiffness of the new bone reached the normal level at 4 and 8 weeks after completion of distraction, respectively. But the shearing strength remained significantly weaker than that of the controls at 8 weeks after distraction.

CONCLUSIONSThe distraction appliance can be removed and the lengthened mandible should be exposed to adaptive functional exercise at 8 weeks after completion of distraction.

Animals ; Biomechanical Phenomena ; Bone Regeneration ; physiology ; Goats ; Male ; Mandibular Advancement ; Models, Animal ; Osteogenesis, Distraction ; Probability ; Random Allocation ; Reference Values ; Tensile Strength