Gui-qing Liao

Does the Surgery-First Approach Produce Better Outcomes in Orthognathic Surgery? A Systematic Review and Meta-Analysis

PURPOSEnThe surgery-first approach (SFA) in orthognathic surgery, performed without presurgical orthodontic treatment, has gained attention, but the results remain controversial. The purpose of this study was to assess the current evidence on stability, efficacy, and surgical results of SFA versus conventional 3-stage method (CTM) orthognathic surgery.nnnMATERIALS AND METHODSnA comprehensive search in PubMed and Web of Science was conducted. A systematic review and cumulative meta-analysis of all comparative studies were performed to assess the 2 strategies (SFA and CTM) using a random- or a fixed-effects model. Outcomes included treatment duration, postoperative stability, surgical movement, and postoperative occlusion.nnnRESULTSnTen nonrandomized controlled studies including 513 patients were identified. Compared with CTM, patients in the SFA group benefited from shorter total treatment duration (weighted mean difference [WMD], -5.25; 95% confidence interval [CI], -8.21 to -2.29; Pxa0=xa0.0005), similar postoperative stability of the mandible (WMD, 0.35xa0mm; 95% CI, -0.24 to 0.94; Pxa0=xa0.55) and maxilla (WMD, 0.13xa0mm; 95% CI, -0.35 to 0.60; Pxa0=xa0.60), similar surgical movements, and other surgical results.nnnCONCLUSIONSnSFA offers an efficient alternative to CTM with shorter total treatment duration, similar postoperative stability, and other surgical results but longer postoperative orthodontic time.

Is Pilocarpine Effective in Preventing Radiation-Induced Xerostomia? A Systematic Review and Meta-analysis

PURPOSEnTo evaluate the efficacy of concomitant administration of pilocarpine on radiation-induced xerostomia in patients with head and neck cancers.nnnMETHODS AND MATERIALSnThe PubMed, Web of Science, Cochrane Library, and ClinicalTrials were searched to identify randomized, controlled trials studying the effect of concomitant administration of pilocarpine for radiation-induced xerostomia. Included trials were systematically reviewed, and quantifiable outcomes were pooled for meta-analysis. Outcomes of interest included salivary flow, clinician-rated xerostomia grade, patient-reported xerostomia scoring, quality of life, and adverse effects.nnnRESULTSnSix prospective, randomized, controlled trials in 8 articles were included in this systematic review. The total number of patients was 369 in the pilocarpine group and 367 in the control group. Concomitant administration of pilocarpine during radiation could increase the unstimulated salivary flow rate in a period of 3 to 6 months after treatment, and also reduce the clinician-rated xerostomia grade. Patient-reported xerostomia was not significantly impacted by pilocarpine in the initial 3 months but was superior at 6 months. No significant difference of stimulated salivary flow rate could be confirmed between the 2 arms. Adverse effects of pilocarpine were mild and tolerable.nnnCONCLUSIONSnThe concomitant administration of pilocarpine during radiation increases unstimulated salivary flow rate and reduces clinician-rated xerostomia grade after radiation. It also relieves patients xerostomia at 6 months and possibly at 12 months. However, pilocarpine has no effect on stimulated salivary flow rate.

Radioprotective Effect of Lidocaine on Neurotransmitter Agonist-Induced Secretion in Irradiated Salivary Glands

Background Previously we verified the radioprotective effect of lidocaine on the function and ultrastructure of salivary glands in rabbits. However, the underlying mechanism of lidocaines radioprotective effect is unknown. We hypothesized that lidocaine, as a membrane stabilization agent, has a protective effect on intracellular neuroreceptor-mediated signaling and hence can help preserve the secretory function of salivary glands during radiotherapy. Methods and Materials Rabbits were irradiated with or without pretreatment with lidocaine before receiving fractionated radiation to a total dose of 35 Gy. Sialoscintigraphy and saliva total protein assay were performed before radiation and 1 week after the last radiation fraction. Isolated salivary gland acini were stimulated with either carbachol or adrenaline. Ca2+ influx in response to the stimulation with these agonists was measured using laser scanning confocal microscopy. Results The uptake of activity and the excretion fraction of the parotid glands were significantly reduced after radiation, but lidocaine had a protective effect. Saliva total protein concentration was not altered after radiation. For isolated acini, Ca2+ influx in response to stimulation with carbachol, but not adrenaline, was impaired after irradiation; lidocaine pretreatment attenuated this effect. Conclusions Lidocaine has a radioprotective effect on the capacity of muscarinic agonist-induced water secretion in irradiated salivary glands.

Zoledronate suppressed angiogenesis and osteogenesis by inhibiting osteoclasts formation and secretion of PDGF-BB

Purpose Bisphosphonates related osteonecrosis of jaw (BRONJ) is a severe complication of systemic BPs administration, the mechanism of which is still unclarified. Recently, platelet-derived growth factor-BB (PDGF-BB) secreted by preosteoclasts was reported to promote angiogenesis and osteogenesis. This study aimed to clarify whether bisphosphonates suppressed preosteoclasts releasing PDGF-BB, and whether the suppression harmed coupling of angiogenesis and osteogenesis, which could contribute to BRONJ manifestation. Methods and results Zoledronate significantly inhibited osteoclast formation by tartrate-resistant acid phosphatase (TRAP) staining and PDGF-BB secretion tested by ELISA. In line with decreasing secretion of PDGF-BB by preosteoclasts exposed to zoledronate, conditioned medium (CM) from the cells significantly induced less migration of endothelial progenitor cells (EPCs) and mesenchymal stem cells (MSCs) compared to CM from unexposed preosteoclasts. Meanwhile, angiogenic function of EPCs and osteoblastic differentiation of MSCs also declined when culturing with CM from preosteoclasts treated by zoledronate (PZ-CM), evidenced by tube formation assay of EPCs and alkaline phosphatase activity of MSCs. Western blot assay showed that the expression of VEGF in EPCs and OCN, RUNX2 in MSCs declined when culturing with PZ-CM compared to CM from preostoeclasts without exposure of zoledronate. Conclusion Our study found that zoledronate was able to suppress preosteoclasts releasing PDGF-BB, resulting in suppression of angiogenesis and osteogenesis. Our study may partly contributed to the mechanism of BRONJ.

Microvascular Submandibular Gland Transplantation for Severe Keratoconjunctivitis Sicca: A Single-Institution Experience of 61 Grafts

PURPOSEnKeratoconjunctivitis sicca (KCS) is a relatively common disease that results in discomfort, tear film instability, visual impairment, and ocular surface damage. Artificial tear substitutes may be suitable for the treatment of mild KCS, but no effective treatment currently exists for severe KCS. Therefore, this study evaluated the effectiveness of autologous microvascular submandibular gland transplantation in the treatment of severe KCS.nnnPATIENTS AND METHODSnA total of 61 eyes (56 patients) with severe KCS were treated with autologous submandibular gland transplantation from June 2002 to June 2017. The cephalic vein or the great saphenous vein was applied to solve the problem of unmatched veins.nnnRESULTSnIn 53 cases (53 of 56, 94.6%), 58 glands (58 of 61, 95.1%) were transplanted successfully. The mean Schirmer I test value improved from 0.78xa0±xa00.84xa0mm preoperatively to 18.83xa0±xa05.72xa0mm in the stable period after transplantation. Epiphora (14 of 58, 24.14%) was the most common complication of this procedure. Other postoperative complications included venous thrombosis (6 of 61, 9.84%), local infection (2xa0of 58, 3.45%), xerostomia (2 of 53, 3.77%), duct fistula (1 of 58, 1.72%), sialolithiasis (1 of 58, 1.72%), and ranula (1 of 58, 1.72%).nnnCONCLUSIONSnAutologous microvascular submandibular gland transplantation is a credible and effective solution for severe KCS.

Elevated hydrostatic pressure promotes ameloblastoma cell invasion through upregulation of MMP-2 and MMP-9 expression via Wnt/β-catenin signalling

BACKGROUNDnThe process of marsupialization involves the release of intracystic pressure and the fluid contained within. Marsupialization of cystic ameloblastoma is controversial; therefore, we investigated how hydrostatic pressure influences biological behaviours of ameloblastoma cells and its underlying mechanisms.nnnMATERIALS AND METHODSnAn ameloblastoma epithelial cell line, hTERT+ -AM, was exposed to different hydrostatic pressures with or without Dickkopf-related protein 1 (also known as DKK), a canonical Wnt signalling pathway inhibitor. A CCK-8 assay, a monolayer wound assay, and a Transwell assay were used to determine cell proliferation, migration and invasion, respectively. qRT-PCR and Western blot were used to detect expression of MMP-2, MMP-9, RANKL and other downstream targets of Wnt signalling.nnnRESULTSnElevated hydrostatic pressure promoted migration and invasion of ameloblastoma cells, but inhibited proliferation. Expression of MMP-2, MMP-9, LEF-1, cyclin D1, c-Jun and c-Myc was significantly upregulated under elevated hydrostatic pressure, and these effects could be abolished by DKK1. Expression of RANKL, which is thought to be a downstream target of Wnt signalling, did not significantly change under elevated hydrostatic pressure.nnnCONCLUSIONSnThis study indicates that elevated hydrostatic pressure promotes the migration and invasion of ameloblastoma cells by activating the Wnt/β-catenin pathway, thereby increasing expression of MMP-2, MMP-9 and other Wnt signalling downstream targets. This suggests that marsupialization may reduce invasiveness and reverse the bone resorption process by lowering intracystic hydrostatic pressure in cystic ameloblastoma.

Marsupialization of mandibular cystic ameloblastoma: Retrospective study of 7 years

This retrospective study investigated the reduction rate and speed of shrinkage after marsupialization in mandibular cystic ameloblastoma and clarified whether marsupialization is appropriate for unicystic ameloblastoma and multicystic ameloblastoma.

Interaction of cancer cell-derived Foxp3 and tumor microenvironment in human tongue squamous cell carcinoma

&NA; The forkhead transcription factor, Foxp3, has been proved essential for differentiation and activation of regulatory T cells (Tregs). Recently, Foxp3 expression in tumor cells (cancer cell‐derived Foxp3) has gained increasing interest, but the function has yet to be confirmed. In the current investigation, we identified the interaction of cancer cell‐derived Foxp3 and tumor microenvironment in human tongue squamous cell carcinoma(TSCC) by various in vitro methods. We detected cancer cell‐derived Foxp3 was closely associated with the infiltration of Foxp3 + lymphocytes in TSCC lesions using immunohistochemical staining. The cytokines secretion (IFN‐&ggr;, TGF&bgr;, IL‐2, IL‐6, IL‐1&bgr;, IL‐10, IL‐8, IL‐17, IL‐23) of PBMC and differentiation of CD4 +T cells were modulated by the expression of Foxp3 in TSCC, shown by ELISA and flow cytometry. As feedback, increasing TGF&bgr; and decreasing IL‐17 further up‐regulated cancer cell‐derived Foxp3. Furthermore, CHIP on chip assay showed that both TGF&bgr; and IL‐17 decreased the number of Foxp3‐binding genes in TSCC. GO and pathway analysis suggested that, treated with TGF&bgr; or Th17, Foxp3‐binding genes were inclined to the negative regulation of TGF&bgr; signal pathway. Taken together, this study showed cancer cell‐derived Foxp3 contributed to Tregs expansion in TSCC microenvironment with positive and negative feedbacks. HighlightsCancer cell‐derived Foxp3 modulates cytokines levels in TSCC microenvironment.Cancer cell‐derived Foxp3 modulates differentiation of CD4 +T cells.Feedback between TGF&bgr;, IL‐17 and cancer cell‐derived Foxp3 gradually increased TGF&bgr;.Foxp3 in TSCC contributed to Tregs expansion with positive and negative feedbacks.

Synergistic effects of ischemic preconditioning and immediate post-conditioning in the protection against ischemia/reperfusion injury in rabbit submandibular glands

Submandibular gland autotransplantation is an effective approach for treating severe keratoconjunctivitis sicca. However, ischemia/reperfusion (I/R) injury, which inevitably occurs during transplantation, is involved in the hypofunction and structural damage that occur early after transplantation. Therefore, it is critical to identify effective strategies to ameliorate I/R injury in submandibular glands. In this study, we investigated the ability of immediate post-conditioning combined with ischemic preconditioning to attenuate I/R injury. We observed that after I/R injury, the level of reactive oxygen species was increased, inflammatory response was strengthened, and severe apoptosis had occurred. In addition, the salivary flow rate was greatly decreased. However, the pathogenesis of I/R injury was significantly ameliorated by ischemia post-conditioning or ischemia preconditioning treatments. In addition, the combination of ischemia preconditioning and post-conditioning achieved synergistic protective effects against I/R injury compared with ischemia preconditioning or ischemia post-conditioning alone. The secretion function was restored in the combination group. Furthermore, the combination treatment involved the same mechanisms of ischemia preconditioning or ischemia post-conditioning, including suppression of the inflammatory reaction and neutrophil accumulation, attenuation of oxidation stress, and inhibition of apoptosis. In conclusion, the combination of ischemia preconditioning and ischemia post-conditioning treatment is a simple and effective approach for treating I/R injury in submandibular glands.

Reconstruction of Tongue Defects With the Contralateral Nasolabial Island Flap

PURPOSEnReconstruction of tongue defects after cancer resection is challenging for reconstructive surgeons. Conventional local flaps are usually compromised in patients with suspected ipsilateral neck metastasis. To extend the application of the nasolabial flap, especially in circumstances in which a free flap is unavailable, the contralateral nasolabial island flap was used, with favorable outcomes.nnnPATIENTS AND METHODSnSeven patients presenting with tongue carcinoma underwent surgical resection and neck dissection. Tongue defects were simultaneously reconstructed using a contralateral nasolabial island flap. Clinical outcomes, including locoregional recurrence and distant metastasis, were recorded. Subjective functional outcomes were investigated using the University of Washington Quality of Life Questionnaire.nnnRESULTSnAll flaps survived without partial or complete necrosis. All patients survived without locoregional recurrence or distant metastasis during follow-up (6 months to 2 years). Functional outcomes were satisfactory, especially swallowing and speech functions. Donor-site morbidity was minimal and the scars were inconspicuously hidden in the nasolabial fold.nnnCONCLUSIONSnThe contralateral nasolabial island flap is technically feasible and can be an excellent option for tongue reconstruction without compromising oncologic safety.