LncRNA PVT1 induces chondrocyte apoptosis through upregulation of TNF-α in synoviocytes by sponging miR-211-3p.

Temporomandibular joint osteoarthritis (TMJ OA) is an important subtype of temporomandibular disorders (TMD). Articular cartilage destruction is considered a common pathological feature of TMJ OA, which is reported to be mainly induced by chondrocyte apoptosis. Synovial sterile inflammation is an initial factor of TMJ OA-associated articular cartilage destruction. Therefore, determining the mechanism of synovial membrane inflammation-induced articular cartilage destruction in TMJ OA is important for the TMJ OA therapy. In this study, we detected the function of synoviocytes in chondrocyte apoptosis under lipopolysaccharide (LPS)-induced inflammatory conditions and explored the underlying mechanism. We found that synoviocytes in inflammatory conditions facilitated LPS-induced chondrocytes apoptosis by secreting increased Tumor Necrosis Factor α (TNF-α), which was induced by long non-coding RNA plasmacytoma variant translocation 1 (PVT1) upregulation. PVT1 served as a competing endogenous RNA that sponged the microRNA miR-211-3p and prevented the inhibition of TNF-α expression. In conclusion, our in vitro study revealed that PVT1 has a previously unknown role in chondrocyte apoptosis, which may also be a mechanism underlying synoviocyte involvement in TMJ OA.

Role of synovium-derived fibrous cartilage in temporomandibular joint synovial chondromatosis.

BACKGROUND: Synovial chondromatosis (SC) of temporomandibular joint (TMJ) occupies 3% SC cases. In other joints like hip and knee which were composed hyaline cartilage (HC), loose bodies (LBs) were reported to be a HC feature. However, condyle surface and disc in TMJ are fibrous cartilage (FC). Therefore, we proposed a different pathogenesis of TMJSC. METHODS: LBs and synovium were collected from seven TMJSC patients, and histological and immunohistological examinations were performed. RESULTS: Three ways of HC formation were discovered: regular-shaped cartilaginous nodules (CNs) in sublining layer (SL) of vascularized synovium, regional chondrification of SL, and finger-like tissue with a tail attaching to synovium. Detached LBs could fuse and were only positively stained by aggrecan. Without synovium attachment to LBs, fused LBs remained a hyaline extracellular matrix (ECM). However, after synovium attachment, transformation from HC to FC occurred. Two types of FC were observed. First type FC was featured by vertical-distributed type I collagen fibers imbedding few chondrocytes, suggesting mature phase with superior mechanical features. Second type FC was featured by medium-density chondrocytes with type I collagen and aggrecan-positive ECM, suggesting primary phase. The transformation process started in appearance of 2nd type FC deriving from synovium covering LB, and gradually replaced HC from periphery to center. CONCLUSIONS: Three ways of HC formation were closely related. Different with SC in other joints, hyaline ECM in LBs of TMJSC could be replaced by FC deriving from synovium, during which 2nd type FC first replaced HC and then transformed to 1st type FC.

HMGB1-induced angiogenesis in perforated disc cells of human temporomandibular joint.

High mobility group 1 protein (HMGB1), a highly conserved nuclear DNA-binding protein and inflammatory mediator, has been recently found to be involved in angiogenesis. Our previous study has demonstrated the elevation of HMGB1 in the tissue of perforated disc of temporomandibular joint (TMJ). Here, we investigated a novel mediator of HMGB1 in regulating hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) to mediate angiogenesis in perforated disc cells of TMJ. HMGB1 increased the expression of HIF-1α and VEGF in a dose- and time-dependent manner in these cells. Moreover, immunofluorescence assay exhibits that the HIF-1α were activated by HMGB1. In addition, HMGB1 activated extracellular signal-related kinase 1/2 (Erk1/2), Jun N-terminal kinase (JNK), but not P38 in these cells. Furthermore, both U0126 (ErK inhibitor) and SP600125 (JNK inhibitor) significantly suppressed the enhanced production of HIF-1α and VEGF induced by HMGB1. Tube formation of human umbilical vein endothelial cells (HUVECs) was significantly increased by exposure to conditioned medium derived from HMGB1-stimulated perforated disc cells, while attenuated with pre-treatment of inhibitors for VEGF, HIF-1α, Erk and JNK, individually. Therefore, abundance of HMGB1 mediates activation of HIF-1α in disc cells via Erk and JNK pathway and then, initiates VEGF secretion, thereby leading to disc angiogenesis and accelerating degenerative change of the perforated disc.

Clinical Efficacy Evaluation for Treating Trigeminal Neuralgia Using a Personalized Digital Guide Plate-Assisted Temperature-Controlled Radiofrequency.

The aim of this study was to explore the application and efficacy of personalized digital guiding plate-aided radiofrequency in treating trigeminal neuralgia (TN). A total of 117 cases (93 patients) of TN from January 2015 to December 2016 were divided into the study group (n = 53) and the traditional group (n = 64). Patients in the study group were treated by the radiofrequency through a personalized digital guiding plate, whereas those in the traditional group were treated by the traditional method. We found that no significant difference between these 2 groups in age, sex, and divisions affected (V2, V3). However, the values for operation time, recurrence rate, and patient's satisfaction in the plate assisted group were significantly improved compared with those in the traditional group. Therefore, the personalized digital guiding plate-assisted radiofrequency has higher application value than traditional method.

Sex differences underlying orofacial varicella zoster associated pain in rats.

BACKGROUND: Most people are initially infected with varicella zoster virus (VZV) at a young age and this infection results in chickenpox. VZV then becomes latent and reactivates later in life resulting in herpes zoster (HZ) or "shingles". Often VZV infects neurons of the trigeminal ganglia to cause ocular problems, orofacial disease and occasionally a chronic pain condition termed post-herpetic neuralgia (PHN). To date, no model has been developed to study orofacial pain related to varicella zoster. Importantly, the incidence of zoster associated pain and PHN is known to be higher in women, although reasons for this sex difference remain unclear. Prior to this work, no animal model was available to study these sex-differences. Our goal was to develop an orofacial animal model for zoster associated pain which could be utilized to study the mechanisms contributing to this sex difference. METHODS: To develop this model VZV was injected into the whisker pad of rats resulting in IE62 protein expression in the trigeminal ganglia; IE62 is an immediate early gene in the VZV replication program. RESULTS: Similar to PHN patients, rats showed retraction of neurites after VZV infection. Treatment of rats with gabapentin, an agent often used to combat PHN, ameliorated the pain response after whisker pad injection. Aversive behavior was significantly greater for up to 7 weeks in VZV injected rats over control inoculated rats. Sex differences were also seen such that ovariectomized and intact female rats given the lower dose of VZV showed a longer affective response than male rats. The phase of the estrous cycle also affected the aversive response suggesting a role for sex steroids in modulating VZV pain. CONCLUSIONS: These results suggest that this rat model can be utilized to study the mechanisms of 1) orofacial zoster associated pain and 2) the sex differences underlying zoster associated pain.

Up-regulation of proteoglycan 4 in temporomandibular osteoarthritic synovial cells by hyaluronic acid.

BACKGROUND: Hyaluronic acid (HA) injection is widely used in the treatment of temporomandibular joint (TMJ) osteoarthritis (OA). Proteoglycan 4 (PRG4) is another joint lubricant that protects surface of articular cartilage. But few studies had explored the role of HA in regulation of PRG4 expression in TMJ OA. In this study, the effects of HA on the expression of PRG4 in osteoarthritic TMJ synovial cells were investigated in hypoxia, which was similar to the TMJ physiologically. METHODS: Synovial cells were isolated from the TMJ OA patients and were treated with or without HA under normoxia or hypoxia for indicated time periods. The proliferation of synovial cells was measured using Cell Counting Kit-8 (CCK-8). The gene expression of HAS2, VEGF, and PRG4 was detected by quantitative real-time PCR, and the secretion of PRG4 and VEGF was assayed by enzyme-linked immunosorbent assay (ELISA). Immunofluorescence was used to examine the protein expression of hypoxia-induced factor-1α (HIF-1α). RESULTS: Hyaluronic acid markedly increased the proliferation of osteoarthritic synovial cells in hypoxia. The expression of HAS2 and PRG4 mRNA of osteoarthritic synovial cells under hypoxia was enhanced by HA treatment. However, HA had no effect on reducing the VEGF and HIF-1α expression in synovial cells in hypoxia. CONCLUSIONS: Hyaluronic acid could promote the expression of HAS2 and PRG4, but could not modulate HIF-1α and VEGF expression of TMJ osteoarthritic synovial cells in hypoxia.

Osteoarthritic changes after superior and inferior joint space injection of hyaluronic acid for the treatment of temporomandibular joint osteoarthritis with anterior disc displacement without reduction: a cone-beam computed tomographic evaluation.

PURPOSE: This study compared the effect of superior and inferior joint space injections of hyaluronic acid (HA) and evaluated osteoarthritic changes in patients diagnosed with temporomandibular joint (TMJ) anterior disc displacement without reduction (ADDw/oR) in association with osteoarthritis (OA) by cone-beam computed tomography (CBCT). MATERIALS AND METHODS: One hundred forty-one patients with research diagnostic criteria for ADDw/oR in association with TMJ OA were randomly assigned to 1 of 2 study groups that received superior or inferior joint space injection of HA. CBCT and clinical examination were performed before treatment and at 3 and 9 months after treatment. RESULTS: One hundred twenty-six patients returned for the 3-month evaluations, and 74 returned for the 9-month evaluations. Condylar remodeling and TMJ function showed improvement in most patients after treatment. At 3 months, remodeling scores in the superior and inferior groups were 2.14 ± 3.16 and 4.08 ± 3.82, respectively, and scores were 4.80 ± 3.36 and 7.47 ± 3.90 at 9 months. There were significant differences between the superior and inferior groups at 3 and 9 months after treatment (3-month, P = .002; 9-month, P = .002). The Helkimo index of the inferior group was significantly lower than that of superior group at 3 and 9 months (3-month, P = .008; 9-month, P = .028). There were no significant differences in maximal mouth opening between the 2 groups at 3 and 9 months (3-month, P = .82; 9-month, P = .20). CONCLUSION: Superior and inferior joint space injections of HA are effective methods for the treatment of ADDw/oR in association with TMJ OA. The injection of HA within the inferior joint space appears to result in better condylar reparative remodeling and improvement in jaw function.

Modified condylar distraction osteogenesis via single preauricular incision for treatment of temporomandibular joint ankylosis.

BACKGROUND: Temporomandibular joint (TMJ) ankylosis with facial asymmetry is still controversial to deal with. This study describes a modified condylar distraction osteogenesis protocol via preauricular approach for the treatment of this condition. METHODS: From 2006 to 2013, 18 patients with TMJ ankylosis were enrolled. The Wuhan TMJ Ankylosis treatment protocol includes as follows: (1) preauricular approach is the only surgical access; (2) TMJ arthroplasty is used to recontour the condylar head, and the vertical height of condyle is maintained; (3) distractor placement with distractor port exiting via preauricular incision; (4) distraction after 5 to 7 days of latency period with 0.5 mm twice daily; and (5) distractor removal after 3-month consolidation through preauricular incision. All patients had clinical follow-up and detailed examination. RESULTS: All patients had satisfactory results postoperatively. The mean (range) mouth opening increased from 7.1 (0-18) to 32.1 (28-43) mm during 37 (6-81) months of follow-up period (P < 0.01). Facial asymmetry was corrected in all patients, and all patients had minimal postoperative scar perception of the preauricular incision. CONCLUSIONS: The Wuhan TMJ ankylosis protocol provides a safe and effective treatment alternative in managing TMJ ankylosis, especially in young women who are anxious about perceptive extraoral scar.

Triple-layered cell sheet for tissue-engineering the synovial membrane of the temporomandibular joint.

OBJECTIVE: Temporomandibular disorder causes the dysfunction of fibroblast-like synoviocytes (FLSs) which are predominant in the lining layer (LL) of synovial membrane (SM) and responsible for the secretion function of the SM of the temporomandibular joint (TMJ). This study aimed to construct a triple-layered cell sheet (CS) for tissue-engineering the SM. METHODS: FLSs were harvested and identified immunocytochemically. A triple-layered CS was fabricated by an original method of combining type I collagen and FLSs. Staining and a transmission electron microscope were used to compare the morphological similarities between the CS and the natural LL. Hyaluronic acid (HA) production and HA synthase 2 (HAS2) gene expression were assessed by ELISA and PCR, respectively. Transplantation of triple-layered CSs into nude mice was performed and examined by staining and immunohistochemical methods. RESULTS: FLSs expressed vimentin, CD44 and heat shock protein 27. The triple-layered CS possessed a structure similar to natural LL. No tight conjunction was observed between adjacent FLSs. The triple-layered CS secreted HA at a quantity about 3 times that of the single-layered CS. The triple-layered structure induced higher expression of HAS2 in FLSs. No difference in HAS2 expression between the triple-layered CS and natural SM was observed. Multiple-layered FLSs and invasion of host fibroblasts and vessels were observed 2 weeks after transplantation. HAS2 and HA were expressed in surface cells and extracellular matrix, respectively. CONCLUSION: FLSs of the TMJ were type B synoviocytes. The triple-layered CS mimicked natural SM morphologically and functionally. The CS survived for 2 weeks in vivo. Therefore, triple-layered CS might be highly competent for tissue-engineered SM.

Fibroblast growth factor 2 involved in the pathogenesis of synovial chondromatosis of temporomandibular joint.

BACKGROUND: Synovial chondromatosis (SC) of temporomandibular joint (TMJ) is a rare proliferative disorder characterized by the formation of cartilaginous or osteocartilaginous nodules in synovium and joint space. Fibroblast growth factor 2 (FGF-2) is frequently applied in chondrogenic differentiation assays. Therefore, we hypothesized that FGF-2 might involved in the pathogenesis of SC. METHODS: SC synovium and loose bodies (LBs) specimens were observed by histological and immunohistochemical methods. Real-time PCR was conducted for comparing genes expressions in SC and normal synovium. SC synoviocytes were stimulated by FGF-2 in the presence or absence of its antagonist long pentraxin-3 (PTX3) for 6 days. Real-time PCR and alkaline phosphatase (ALP) activity were performed to examine the effects exerted by FGF-2 and PTX3. RESULTS: SC synovium, no matter facing the articular cavity or covering LB, was characterized by increased quantity of synoviocytes and blood vessels. FGF-2 was expressed in chondrocytes and fibroblast-like cells of LBs, and the wall of blood vessels. Expressions of chondrogenic genes (Sox9 and Wnt-4), osteogenic genes (Foxc2), FGF-2, and VEGF-A mRNA were significantly higher in SC synovium than that of the control group. The stimulation of FGF-2 on SC synoviocytes increased ALP activity and expressions of chondrogenic genes (Sox9, Col2α1, and Aggrecan), osteogenic genes (Foxc2, osteocalcin, and Col1α1), and VEGF-A, but PTX3 inhibited these effects. CONCLUSION: FGF-2 was responsible for the formation of cartilaginous loose bodies and involved in the pathogenesis of SC.

Superficial temporal artery pseudoaneurysm: report of a rare case secondary to mandibular condylar fracture.

A rare case of superficial temporal artery pseudoaneurysm secondary to mandibular condylar fracture is presented. A 21-year-old man referred to the Department of Oral and Maxillofacial Surgery with limited mouth opening and left preauricular swelling for more than 40 days after a traffic accident injury. He had received mandibulomaxillary fixation in the emergency department. Computed tomography showed left mandibular condylar fracture, and digital subtraction angiography confirmed left superficial temporal artery pseudoaneurysm. Endovascular embolization of the left external carotid artery was performed, followed by excision of the traumatic pseudoaneurysm and open reduction internal fixation of the left condylar fracture. Six months after treatment, the patient can open his mouth to approximately 35 mm and showed no swelling in the left preauricular region.

Surgical treatment of sagittal fracture of mandibular condyle using long-screw osteosynthesis.

PURPOSE: The retrospective study evaluated long-screw (bicortical screw) osteosynthesis used in the surgical treatment of sagittal fracture of the mandibular condyle and compared it with titanium plates and removal of the condylar fragment. PATIENTS AND METHODS: Ninety-five patients with sagittal fracture of the mandibular condyle received open surgical treatment from 1997 to 2008. Among these patients, the condylar fragments were fixed with long screws in 56 cases (group A), were fixed with titanium plates in 12 cases (group B), and were completely removed in 24 cases (group C). Follow-up was carried out clinically and radiologically. The clinical features included limitation of mandibular mobility, occlusion disturbance, lateral deviation on mouth opening, joint pain, clicking, facial asymmetry, and patient's subjective evaluation. The radiologic parameters consisted of degree of bony resorption, bony change, change of osteosynthesis material, and shortening of mandibular ramus height. RESULTS: Anatomic reduction and functional restoration were obtained and no severe complication was detected in group A. However, 3 of 14 patients had severe osteoarthrosis and 2 of 14 patients had ankylosis in group B. In group C 3 of 24 patients had mandibular retrusion, 4 of 24 patients had front teeth open bite, 4 of 24 patients had severe osteoarthrosis, and 1 of 24 patients had ankylosis. CONCLUSION: The long-screw fixation group had a more favorable prognosis than the titanium plate group and the group in which removal of the condylar fragment was performed. The long-screw fixation technique might be suitable for use in the surgical treatment of sagittal fractures of the mandibular condyle.

A randomized controlled trial of superior and inferior temporomandibular joint space injection with hyaluronic acid in treatment of anterior disc displacement without reduction.

PURPOSE: To compare the outcome of inferior and superior joint space injection of sodium hyaluronate in patients with disc displacement without reduction of the temporomandibular joint (TMJ). MATERIALS AND METHODS: One hundred twenty patients with disc displacement without reduction of TMJ were randomized into 2 experimental groups. One group of patients received superior joint space injections of sodium hyaluronate and the other group was treated with inferior joint space injections. Patient's TMJ status and clinical symptoms were evaluated at the 3 and 6 month follow-up appointments. The clinical parameters recorded were maximal mouth opening (MMO), pain intensity on a visual analog scale (VAS), and modified Helkimo's clinical dysfunction index and analyzed with ANCOVA. RESULTS: Fifty of the superior and 54 of the inferior joint space injection therapy group returned for the 3 and 6 month evaluations; 86.67% of the patients were retained in the follow-up. MMO, VAS, and Helkimo's index of both groups improved at the 3 and 6 month follow-ups. The results of MMO changes and TMJ function were almost the same in both groups at 3 month follow-up. However, there was a significant reduction in TMJ pain in the inferior joint injection group at 3 month follow-up compared with the superior joint injection group (P< .001). There were also significant differences between the inferior joint injection group and superior joint injection group in MMO (P< .005), VAS (P< .001), and Helkimo's index (P< .001) at 6 month follow-up. CONCLUSION: This study showed that inferior joint space injection with sodium hyaluronate is a valid method of treating disc displacement without reduction of TMJ and a long-term study will be needed to assess the effect of inferior joint injection on the morphologic changes of the TMJ.

[3D printing navigation template-guided percutaneous radiofrequency thermocoagulation for V2 trigeminal neuralgia treatment].

OBJECTIVE: This paper aimed to evaluate the effectiveness of the 3D printing puncture navigation template-guided percutaneous radiofrequency thermocoagulation for V2 trigeminal neuralgia treatment. METHODS: A total of 52 patients with V2 trigeminal neuralgia were treated with radiofrequency thermocoagulation. A total of 32 patients were treated under the guidance of the 3D printing puncture navigation template (guide plate group), while 20 patients underwent puncture via pterygopalatine fossa routinely (routine treatment group). The puncture time, operation time, puncture success rate, and immediate postoperative pain were recorded. The degree of immediate postoperative pain was indicated by visual analogue scale (VAS). Barrow Neurological Institute (BNI) classification criteria were used to evaluate the efficacy, and the postoperative complications were observed. All patients were followed up for 1 year. RESULTS: The two groups showed significant decrease in VAS after the operation (P<0.05). The puncture and operation times of the guide plate group were significantly lower than those of the routine treatment group (P<0.05). The difference in terms of the clinical effects and recurrence rate between the two groups was insignificant (P>0.05). CONCLUSIONS: 3D printing puncture navigation template-guided radiofrequency thermocoagulation may increase the operation success rate and reduce complication incidence. Therefore, this technique possesses clinical promotional value.

Acupuncture therapy in the management of the clinical outcomes for temporomandibular disorders: A PRISMA-compliant meta-analysis.

PURPOSE: The purpose of this study was to evaluate conventional acupuncture therapy in the management of clinical outcomes for temporomandibular disorders (TMD) in adults. METHODS: The electronic databases PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and Clinical Trails.gov were searched for reports published until March 31, 2016. RESULTS: Nine eligible studies from 8 publications involving 231 patients were included in the meta-analysis. A comparison of the main outcome of visual analog scale (VAS) values of pain between the acupuncture group and control group showed a significant decrease (MD = -0.98, 95% CI [-1.62, -0.34], I=54%, P = 0.003) in the VAS following acupuncture treatment. However, subgroup analysis according to the type of sham control group indicated that there were significant differences in the results when sham acupuncture was used as the control group (MD = -1.54, 95% CI [-2.63, -0.45], I=58%, P = 0.006) as well as when sham laser treatment was used as the control group (MD = -1.29, 95% CI [-2.32, -0.27], I = 0%, P = 0.01). However, there was no significant difference when the splint treatment group was used as the control group (MD = -0.09, 95% CI [-0.69, 0.50], I = 0%, P = 0.76). Subgroup analyses of VAS for pain by the classification of diseases indicated that the myogenous TMD subgroup demonstrated a significant difference (MD = -1.49, 95% CI [-2.45, -0.53], I = 47%, P = 0.002), and TMD showed no statistically significant difference (MD = -0.42, 95% CI [-1.14, 0.30], I = 46%, P = 0.25). Subgroup analysis according to whether the subgroup penetrated the skin showed that nonpenetrating sham acupuncture as the control group showed a significant difference (MD = -1.56, 95% CI [-2.70, -0.41], I = 58%, P = 0.008) compared with the conventional acupuncture as the treatment modality, while penetrating sham acupuncture as the control group showed no significant difference (MD = -1.29, 95% CI [-3.40, 0.82], I = not applicable, P = 0.23). No publication bias was observed considering the symmetry of the funnel plots. CONCLUSIONS: Our results indicate that conventional acupuncture therapy is effective in reducing the degree of pain in patients with TMD, especially those with myofascial pain symptoms.

Lateral thalamic control of nociceptive response after whisker pad injection of varicella zoster virus.

Pain is a common complication of herpes zoster (HZ) infection which results from reactivation of a latent varicella zoster virus (VZV). A third of HZ patients' progress to a chronic pain state known as post herpetic neuralgia (PHN), and about a quarter of these patients' have orofacial pain. The mechanisms controlling the pain responses are not understood. Studies suggest central pathways involving the thalamus could control pain related to HZ, and studies in our lab suggest (VGAT) in the lateral thalamus influences orofacial pain. We hypothesized that thalamic VGAT functions, in part, to reduce pain, particularly orofacial pain, associated with VZV. To address this hypothesis VZV was injected into the whisker pad. Affective and motivational aspects of pain were measured using the Place Escape/Avoidance Paradigm. Thalamic neuronal activity was modulated after injecting an adeno-associated virus (AAV) expressing an engineered acetylcholine Gi-protein-coupled receptor. This receptor inhibits neuronal firing when bound by clozapine-n-oxide (CNO). VGAT expression was attenuated in the thalamus by injecting an AAV construct that expressed a VGAT silencing shRNA. VZV-induced nociception was significantly decreased after administering CNO in male rats. Nociception significantly increased concomitant with increased thalamic c-fos expression after attenuating thalamic VGAT expression. These data establish that the lateral thalamus (posterior, ventral posteromedial, ventral posterolateral and/or reticular thalamic nucleus) controls VZV-induced nociception in the orofacial region, and that GABA in this region appears to reduce the response to VZV-induced nociception possibly by gating facial pain input.

Efficacy of splint therapy for the management of temporomandibular disorders: a meta-analysis.

Temporomandibular disorders (TMD) are a group of clinical problems affecting temporomandibular joint (TMJ), myofascial muscles and other related structures. Splint therapy is the most commonly used approach to treatment of TMD, but its effectiveness is remains unclear. We therefore conducted a meta-analysis to evaluate the effectiveness of splint therapy for TMD in adults. The electronic databases PubMed, EMBASE, Cochrane Library, and ClinicalTrials.gov were searched for reports published up to March 31, 2016. Thirteen eligible studies involving 538 patients were identified. The results indicated that splint therapy increased maximal mouth opening (MMO) for patients with a MMO <45mm and reduced pain intensity measured using the visual analogue scale (VAS) for patients with TMD without specific description (TMDSD). Splint therapy also reduced the frequency of painful episodes for patients with TMJ clicking. No publication bias was observed, as determined with Egger's test for all outcomes. On the basis of this evidence, we recommend the use of splints for the treatment and control of TMD in adults.

Association between polymorphism of MMP-1 promoter and the susceptibility to anterior disc displacement and temporomandibular joint osteoarthritis.

OBJECTIVE: To investigate the correlation of the polymorphism of MMP-1 promoter (-1607 1G/2G) with the susceptibility to anterior disc displacement (ADD) and temporomandibular joint osteoarthritis (TMJ OA). METHODS: A total of 185 healthy individuals (group A), 141 unilateral ADDWR patients (group B), and 321 unilateral ADDWOR patients (group C) were included in the investigation. Group C included 115 patients without TMJ OA (named group C-1) and 206 with TMJ OA (named group C-2). The genotyping of this single nucleotide polymorphism was evaluated by high resolution melting assay. Pairwise comparison between the distributions of genotypes and alleles in these groups was conducted with a multivariate logistic regression model adjusted on the basis of possible covariates. RESULTS: A significant difference in the 2G2G genotype frequency was found among the different groups on the basis of three sets of comparisons (P(C-A)<0.0005; P(C1-B)=0.049; P(C2-B)=0.018). The susceptibility of 2G2G genotype carriers to ADDWOR with or without TMJ OA was considerably higher than that of other genotypes carriers (OR(C-A)=2.455; OR(C1-B)=1.849; OR(C2-B)=1.912). A significant difference in 1G2G genotype frequency was also observed on the basis of two sets of comparisons (P(C-A)<0.0005; P(C2-B)=0.041). The susceptibility of 1G2G genotype carriers to ADDWOR with or without TMJ OA was also considerably higher than that of other genotype carriers (OR(C-A)=2.641; OR(C2-B)=1.896). CONCLUSION: The -1607 1G/2G polymorphism of MMP-1 promoter may be related to the susceptibility to ADDWOR with or without TMJ OA.

[SCREW-BASED INTERMAXILLARY TRACTION COMBINED WITH OCCLUSAL SPLINT FOR TREATMENT OF PEDIATRIC MANDIBULAR CONDYLAR FRACTURE].

OBJECTIVE: To evaluate the effectiveness of the screw-based intermaxillary traction combined with occlusal splint in the treatment of pediatric mandibular condylar fracture. METHODS: Between June 2005 and December 2013, 35 pediatric patients with 49 mandibular condylar fractures were treated, and the clinical data were retrospectively reviewed. There were 25 boys and 10 girls, aged 3-13 years (mean, 7.3 years). The injury causes included falling (18 cases), traffic accident (14 cases), and violence (3 cases). The time between injury and treatment was 2-30 days (mean, 6.8 days). Restricted mouth opening was observed, and the maximal mouth opening was (22.74 +/- 7.22) mm except 3 patients who were too young to measure. Condylar fractures were located at the left (12 cases), at the right (9 cases), at bilateral (14 cases) based on the sites; and fractures were classified as intracapsular (35 fractures), neck (10 fractures), and subcondylar (4 fractures) based on the fracture line. Four self-drilling titanium screws were inserted into the alveolar bone of both maxilla and mandible. After screw inserting, an occlusal splint with a fulcrum was used on the affected side and elastic band was put to perform anterior intermaxillary traction. After 1 month, the screws and splint were removed. Follow-up examinations were carried out on schedule. RESULTS: All the patients were followed up from 6 months to 8 years and 10 months (median, 71 months). No screw-related complication occurred in the others except one case of screw loosening. The postoperative maximal mouth opening was (38.82 +/- 2.02) nim. Mild joint noise was found in 4 cases and opening deviation occurred in 6 cases. Radiographic results demonstrated complete condyle remodeling was achieved in 24 cases (32 fractures), and moderate remodeling in 11 cases (17 fractures) at last follow-up. CONCLUSION: The screw-based intermaxillary traction combined with occlusal splint might be an effective method for pediatric mandibular condylar fracture. The screw-related complications may be avoided by careful preoperative investigations.

Sexual dimorphism of the mandible in a contemporary Chinese Han population.

A present limitation of forensic anthropology practice in China is the lack of population-specific criteria on contemporary human skeletons. In this study, a sample of 203 maxillofacial Cone beam computed tomography (CBCT) images, including 96 male and 107 female cases (20-65 years old), was analyzed to explore mandible sexual dimorphism in a population of contemporary adult Han Chinese to investigate the potential use of the mandible as sex indicator. A three-dimensional image from mandible CBCT scans was reconstructed using the SimPlant Pro 11.40 software. Nine linear and two angular parameters were measured. Discriminant function analysis (DFA) and logistic regression analysis (LRA) were used to develop the mathematics models for sex determination. All of the linear measurements studied and one angular measurement were found to be sexually dimorphic, with the maximum mandibular length and bi-condylar breadth being the most dimorphic by univariate DFA and LRA respectively. The cross-validated sex allocation accuracies on multivariate were ranged from 84.2% (direct DFA), 83.5% (direct LRA), 83.3% (stepwise DFA) to 80.5% (stepwise LRA). In general, multivariate DFA yielded a higher accuracy and LRA obtained a lower sex bias, and therefore both DFA and LRA had their own advantages for sex determination by the mandible in this sample. These results suggest that the mandible expresses sexual dimorphism in the contemporary adult Han Chinese population, indicating an excellent sexual discriminatory ability. Cone beam computed tomography scanning can be used as alternative source for contemporary osteometric techniques.