Will Closed Treatment Provide Better Mandibular Motion Than Open Reduction and Internal Fixation in Cases of Unilateral Displaced Subcondylar Fracture? A Systematic Review and Meta-Analysis.

PURPOSE: The aim of the present systematic review was to determine whether closed treatment (CLT) with intermaxillary fixation (IMF) is superior or equivalent to open reduction and internal fixation (ORIF) in the management of unilateral displaced subcondylar fractures regarding the range of mandibular motion. MATERIALS AND METHODS: To address our question, we conducted a systematic review and meta-analysis of the reported data after a comprehensive manual and electronic database search of studies reported up to 2017 in the English language that had compared CLT and ORIF of mandibular condyle fractures in adults. The following outcomes were recorded: maximum interincisal opening (MIO), protrusive movement (PM), lateral excursion toward the fractured side (LEFS), and lateral excursion toward the nonfractured side (LENFS). RESULTS: The search resulted in 8 studies, 4 of which were included in the meta-analysis. The MIO and PM showed no statistically significant differences, with an effect size of -0.823 (P = .112) and -0.633 (P = .079), respectively. However, the LEFS and LENFS were superior after CLT, with an effect size of -0.710 (P = .031) and -0.682 (P = .017), respectively. CONCLUSIONS: The findings from the present review suggest that both ORIF and CLT can provide comparable MIO and PM in subjects with unilateral displaced subcondylar fractures. However, CLT was superior to ORIF for both LEFS and LENFS.

Computer-Guided Arthrocentesis Using Patient-Specific Guides: A Novel Protocol for Treatment of Internal Derangement of the Temporomandibular Joint.

PURPOSE: The aim of the present study was to evaluate the accuracy of 3-dimensionally (3D) printed patient-specific guides (PSGs) to direct the passage of inlet and outlet needles into the superior joint spaces of the temporomandibular joint (TMJ) in preparation for arthrocentesis. PATIENTS AND METHODS: The present study included 10 patients with 14 TMJs with anterior disc displacement with reduction. A 3D PSG was designed for each patient to lead the inlet and outlet needles into the superior joint space of the TMJ. The PSGs were implemented, and their accuracy for guiding the needles into the superior joint space was assessed. RESULTS: Both arthroscopic verification and clinical evaluation revealed that direct access to all the predetermined anatomic locations inside the TMJs had been obtained, except for 1 case, during which the patient had failed to maintain the maximum mouth opening during computed tomography scanning. CONCLUSIONS: The virtual computer-initiated PSGs were beneficial for directing the passage of the needles into the superior joint space.

Regulation of human and pig renal Na(+),K (+)-ATPase activity by tyrosine phosphorylation of their alpha(1)-subunits.

Modulation of the physiologically influential Na(+),K(+)-ATPase is a complex process involving a wide variety of factors. To determine the possible effects of the protein tyrosine phosphatase (PTP) inhibitors dephostatin and Et-3,4-dephostatin on human and pig, renal cells and enzymatic extracts, we treated our samples (15 min-24 h) with those PTP inhibitors (0-100 microM). PTP inhibitors were found to possess a concentration-dependent inhibition of Na(+),K(+)-ATPase activity in both human and pig samples. The inhibition was similarly demonstrated on all cellular, microsomal fraction and purified Na(+),K(+)-ATPase levels. Despite rigorous activity recovery attempts, the PTP inhibitors' effects were sustained on Na(+),K(+)-ATPase activity. Western blotting experiments revealed the expression of both alpha(1)- and beta(1)-subunits in both human and pig tissues. alpha(1)-Subunits possessed higher tyrosine phosphorylation levels with higher concentrations of PTP inhibitors. Meanwhile, serine/threonine residues of both alpha(1)- and beta(1)-subunits demonstrated diminished phosphorylation levels upon dephostatin treatment. Accordingly, we provide evidence that Na(+),K(+)-ATPase can be regulated through tyrosine phosphorylation of primarily their alpha(1)-subunits, using PTP inhibitors.

Effects of estrogen on PMCA 2 and 4 in human fibroblast-like synovial cells and mouse macrophage-like cells.

We investigated the possible roles of estrogen on plasma membrane Ca(2+)-ATPase (PMCA) in human fibroblast-like synovial cells (HFLS) and mouse macrophage-like cells (RAW 264.7). Western blots revealed the expression of PMCA 2 and 4 in both cells. In vitro treatments with 17beta-estradiol for 24 hours resulted in a concentration dependent decrease in PMCA expression. Moreover, Ca(2+)-ATPase specific activity was similarly decreased with estrogen treatments. However, treatments for 1 hour in the presence or absence of cycloheximide demonstrated non-significant effects. These results suggest that estrogen has a modulatory role on Ca(2+) homeostasis through decreasing PMCA expression and abating their activity.

Effect of estrogen on bone resorption and inflammation in the temporomandibular joint cellular elements.

Several epidemiological studies have reported that temporomandibular disorder is more prevalent in women, which suggests the involvement of sex hormones, such as estrogen, in the pathogenesis of this disease. PCR amplification and Western blotting were employed to target the expression of estrogen receptors (ERs) in human fibroblast-like synovial and ATDC5 cells. The effect of estrogen was investigated through the expression of RANKL, osteoprotegerin (OPG), M-CSF/CSF-1 and c-fms. We showed expression of M-CSF/ CSF-1 and c-fms, with time-dependent increase in both after the addition of estrogen. Based on previous studies reporting that M-CSF/CSF-1 regulates the proliferation and differentiation of hemopoietic progenitor cells into mature macrophages, we put forward a new hypothesis based on the increased inflammation and tendency of females to suffer more from temporomandibular disorder (TMD) in the presence of external exacerbating factors. Detection of RANKL and OPG in ATDC5 and expression of both in HFLS was confirmed with complete disappearance of the RANKL band, and marked increase in the expression of OPG after 1 h from the addition of estrogen.

Novel effect of estrogen on RANK and c-fms expression in RAW 264.7 cells.

Temporomandibular disorder (TMD), a progressive disease entity, and osteoarthrosis preferentially affect females, denoting a possible role of estrogen. Using RAW 264.7 cells, the expression of estrogen receptors (ERs) alpha and beta and the consequent effect of estrogen was investigated. We present the novel detection of ER beta expression in RAW 264.7 cells. Furthermore, we innovatively demonstrated the increase in expression of both ER alpha and beta, as well as RANK and c-fms, with estrogen treatment. However, a decrease in expression of c-fms, RANK and ER beta, and nearly no change in the expression of ER alpha were experienced upon further increase in estrogen concentrations. These findings lead us to hypothesize a new mechanism of inflammation in TMD.

Up-regulation of the G3PDH 'housekeeping' gene by estrogen.

Proteomic and genomic studies commonly involve the assessment of mRNA levels using reverse transcription-polymerase chain reaction (PCR) and real-time quantitative PCR. An internal standard RNA is fundamentally analyzed along with the investigated mRNA to document the specificity of the effect(s) on mRNA and to correct for inter-sample variations. In our studies implementing estrogen treatments on different cell lines, we initially used glyceraldehyde-3-phosphate dehydrogenase (G3PDH) as an internal standard. However, the results of PCR amplification demonstrated that 17ß-estradiol enhanced the expression of the G3PDH gene, rendering it impossible to use G3PDH as an unbiased comparative control.