Table of Content

    20 November 2019, Volume 27 Issue 11
    Expert Commentary
    Host modulation therapy in periodontitis
    ZHOU Zheng,QI Xia,YANG Dongru
    2019, 27(11):  681-688.  DOI: 10.12016/j.issn.2096-1456.2019.11.001
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    Host modulation therapy (HMT), as a treatment concept for periodontitis, aims to modulate the host immune responses during the pathogenesis of periodontitis. Various drugs have been evaluated as HMT, including subdose doxycycline (SDD), nonsteroidal anti-inflammatory drugs (NSAIDs), bisphosphonates, and cytokine receptors, to modify or modulate inflammatory mediators and associated signaling pathways in the immune-inflammatory response, as well as connective tissue breakdown and bone resorption. SDD, a member of the tetracycline drug family, has been reported to improve periodontal treatment outcomes by inhibiting periodontal breakdown through inhibiting MMPs. NSAIDs may suppress periodontal inflammation by reducing cyclooxygenase-2(COX-2) activity. Combined application of SSD and NSAIDs may achieve a better clinical outcome. Recent studies of HMT treatment have focused on the prevention of excessive inflammation by regulating mediators using endogenous lipid mediators. Local administration of bisphosphonates and histone deacetylase inhibitors can inhibit osteoclast activity and regulate bone tissue remodeling. Currently, SSD is approved by the FDA for periodontal treatment. Other drugs, such as COX-2 selective inhibitor, nonsteroidal anti-inflammatory drugs, bisphosphonates, triclosan and iNOS inhibitors, have good application prospects in the prevention and treatment of periodontal disease, and the mechanism and side effects of these drugs remain to be further investigated.

    Analysis of causes for non-stone parotid obstructions
    TAO Qian , HUANG Yun
    2019, 27(11):  689-694.  DOI: 10.12016/j.issn.2096-1456.2019.11.002
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    Parotid obstructions can cause repeated swelling of the glands. Previously, duct stones were thought to be the main cause of obstructions, but salivary gland endoscopy examinations have revealed the absence of stones or foreign bodies in the duct system of the parotid glands with obstructive symptoms. Diseases of the parotid gland with obstructive symptoms include chronic recurrent parotitis, non-stone chronic obstructive parotitis, Sj?gren′s syndrome, IgG4-related parotitis and radiation-induced parotitis. The mechanism of obstructions is unknown, and the disease course is prolonged. In this paper, based on a brief analysis of duct stenosis, distortion and mucus emboli, which may lead to parotid obstructions, a new perspective is emphasized: the duct system of the parotid and flowing saliva constitute a microflow field. Based on the principle of fluid mechanics, the flow of saliva in the flow field can be affected by the confluence, diameter changes, and twist of the ducts. This outcome results in changes in the low velocity zone, backflow, counterflow and turbulence; affects saliva flow and normal discharge; and causes symptoms of parotid obstruction. An analysis of the possible mechanisms of parotid obstruction using two variables, duct anatomy and saliva traits, helps explain the causes of nonstone parotid obstructions.

    Basic Study
    Gene ontology analysis of the TNF signaling pathway in early orthodontic tooth movement of rats with periodontitis
    MA Yao,JIANG Zhaowei,JIN Yunyi,MIAO Qian,ZHANG Chunxiang,ZHANG Linkun
    2019, 27(11):  695-702.  DOI: 10.12016/j.issn.2096-1456.2019.11.003
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    Objective To investigate the expression and function of the TNF signaling pathway in the early stage of orthodontic tooth movement with periodontitis and to provide evidence to study the early inflammatory response in patients with periodontitis orthodontic treatment. Methods Sixteen SD rats were randomly divided into four groups: group A--12 h of orthodontic tooth movement of the bilateral maxillary first molars in rats with periodontitis; group B--periodontitis model of the bilateral maxillary first molars without orthodontic tooth movement; group C--12 h of orthodontic tooth movement of the same teeth in rats with healthy periodontium; group D--control group without operations. The bilateral maxillary first molars and surrounding periodontal tissue of each group were collected for gene chip detection. Pathway enrichment analysis, qRT-PCR and GO (gene ontology) analysis were performed to identify differential genes involved in the TNF signaling pathway. Results Gene chip results showed that the TNF signaling pathway was significantly upregulated in group A, group B and group C (P <0.01). Among the differential genes involved in the pathway, 28 were upregulated and 5 were downregulated in group A, 12 were upregulated and 4 were downregulated in group B, and 12 were upregulated and 1 was downregulated in group C (P <0.05). The most significant GO items included "response to lipopolysaccharide", "inflammatory response", "positive regulation of NF-κB transcription factor activity", "positive regulation of NF-κB import into nucleus" and "response to hypoxia"(P <0.001). qRT-PCR results showed no significant difference in TNF-α mRNA expression in group C compared with that in group D, TNF-α was upregulated in both groups A and B (P <0.01), and mRNA expression decreased in the following order: group A > group B > group C (P <0.05). Compared with group D, the expression levels of prostaglandin-endoperoxide synthase 2 (PTGS2) and interleukin-6 ( IL-6) in groups A, B and C were significantly upregulated (P <0.05), but the expression levels of PTGS2 and IL-6 in group A were lower than those in group B (P < 0.05). Conclusion The TNF signaling pathway is activated in the early stage of orthodontic tooth movement in rats with periodontitis. The pathway products participate in many biological processes and play an important role in the inflammatory response and bone absorption.
    Effect of two aging methods on the bonding interface between glass ceramics and dentin
    WU Zhengxi,LI Fenglan
    2019, 27(11):  703-710.  DOI: 10.12016/j.issn.2096-1456.2019.11.004
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    Objective To study the effects of bacterial invasion and artificial saliva immersion on the bond strength and nanoleakage between healthy dentin and glass ceramics-bonded specimens using three types of resin cements and provide a reference for the selection of clinical bonding materials. Methods One hundred eight dentin blocks were selected to prepare bonded specimens with Variolink N, Multilink N, RelyX Unicem and glass ceramics blocks. The adhesive specimens of each type of resin cements were divided into three groups according to the aging method: bacterial invasiveness group (the specimens were cultured under anaerobic conditions for 14 days after inoculation with Streptococcus mutans), artificial saliva immersion group (the specimens were immersed in artificial saliva for 6 months), and control group (the immediate test group). Each group comprised 12 specimens: 6 were selected to test the bonding strength, and 6 were observed by scanning field emission scanning electron microscopy (FESEM). Results The bond strength of Variolink N in the immediate test group was significantly higher than that of Multilink N and RelyX Unicem, and the difference was statistically significant (P < 0.05). However, no significant difference was found in the bacterial invasiveness group and artificial saliva immersion group (P > 0.05). In the bacterial invasion group, the difference in the nanoleakage of the three adhesives was statistically significant (P < 0.05), with a trend of Variolink N > Multilink N > RelyX Unicem, and pairwise comparison was statistically significant (P < 0.05). The nanoleakage of the three resin adhesives showed an increasing trend in the bacterial invasion group and artificial saliva group compared with that of the immediate test group. Conclusion Both artificial saliva soaking and bacterial invasion can reduce the sealing property of the adhesive interface of 3 types of resin cements to different degrees. The presence of Streptococcus mutans in the oral cavity may reduce the sealing performance of the resin dentine adhesive interface.
    Cinical Study
    Prediction of the relationship between the mandibular and craniofacial bone and cervical vertebrae based on a genetic algorithm in patients with skeletal class Ⅱ malocclusion
    MU Qili,YANG Luyi,ZHAO Xuejiao,YAN Jing,YU Miao,WANG Liyao,WANG Huan
    2019, 27(11):  711-717.  DOI: 10.12016/j.issn.2096-1456.2019.11.005
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    Objective To explore the correlation between the parameters of the mandible and parameters of cervical vertebrae and craniofacial bone in class Ⅱ skeletal patients in Northeast China and to establish correlation equations expressing the relationship between the mandible and cervical vertebrae and craniofacial bone directly and quantitatively for the clinical diagnosis and treatment of orthodontics and orthognathics and for prediction. Methods The mandible, cranial facial bone and cervical vertebrae of 201 children and adolescents aged 8 to 20 years were measured using digital cranial lateral tablets. All of the cases were divided into male (n=75) and female (n=126) groups using a sensitivity analysis method based on genetic algorithms to select the craniofacial bone and cervical bone with strong sensitivity to mandible parameters and to establish relevant equations. Results Through sensitivity analysis, the parameters with the strongest correlation between the measured values of the mandible were H4 and SN, those with a strong correlation were SN-Ar, the anterior and posterior high ratio SGo/NGn, the Y axis angle and mandibular angle Ar-Go-Gn. The established equation was as follows: males: Ar-Pg=28.415+1.818×H4+0.746×SN(r2=0.056 8, P < 0.001); females: Ar-Pg=15.168+1.706×H4+0.675×SN+0.31×SN-Ar-0.29×Y axis angle (r2=0.611, P < 0.001). No significant difference was found between the predicted values obtained by the established equations and measured values (P > 0.05). Conclusion The mandibular length equation established by sensitivity analysis and genetic algorithms is statistically significant and can predict a certain degree of growth and development.
    Study of the therapeutic effect of oral propranolol combined with topical timolol maleate in the treatment of mixed maxillofacial hemangioma in infants
    LI Jiapeng,CHEN Jufeng,ZHANG Guorun,XIAN Dan,LI Jin,WANG Lei,ZHANG Guoyi
    2019, 27(11):  718-722.  DOI: 10.12016/j.issn.2096-1456.2019.11.006
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    Objective To observe the treatment effect of oral propranolol combined with topical timolol maleate for infantile maxillofacial mixed hemangioma and provide evidence for clinical treatment. Methods Ninety-seven cases of infantile maxillofacial mixed hemangioma were enrolled. The cases were randomly divided into A and B groups: 50 cases in group A were treated with oral propranolol combined with topical timolol maleate, and 47 cases in group B were treated with oral propranolol only. The changes in the color, volume, and texture of the tumors were recorded before and after treatment, and color ultrasonography of the lesion area was performed. The follow-up time was 1-12 months. The differences in the curative effect, effective time and adverse reaction between the two groups were compared. Results The effective rate of group A was 92.0% (46/50) and that of group B was 74.5% (35/47), with a statistical significance (P < 0.05). The mean time of treatment in group A was 4.2 months and that in group B was 5.5 months. Compared with group B, the treatment time of group B was shorter (t=3.211, P < 0.05), and no serious adverse reactions occurred in both groups. Conclusion Oral propranolol combined with topical timolol maleate is effective in the treatment of mixed hemangioma of the maxillofacial region in infants.
    Prevention and Treatment Practice
    Depression status of 136 patients with adjuvant radiotherapy after reconstruction of the oral cancer flap and analysis of influencing factors
    WANG Cuiping,WANG Mengxi,LV Bo
    2019, 27(11):  723-728.  DOI: 10.12016/j.issn.2096-1456.2019.11.007
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    Objective To explore the depression and influencing factors of patients with adjuvant radiotherapy after reconstruction of oral cancer flaps and to provide evidence for postoperative care. Methods One hundred thirty-six patients with oral cancer who had undergone adjuvant radiotherapy after reconstruction of skin flaps at 4 affiliated hospitals in Harbin Medical University were selected by convenience sampling. The basic information of the patients with adjuvant radiotherapy after reconstruction of skin flaps was collected, a self-rating scale for depression was used to assess depression, and a questionnaire was used to assess symptom distress. Depression and its influencing factors were determined by multiple stepwise regression analysis. Results The average score of depression in patients with oral cancer after skin flap reconstruction was (52.32±13.11): 33.1% of the patients showed mild depression, 21.3% showed moderate depression, and 2.2% showed severe depression. Postoperatively, the patients had pain, dysphagia, taste disorders, temporomandibular joint and salivary gland dysfunction, as well as marital and financial problems. The results showed that dysphagia (P < 0.001), taste disorder (P < 0.001), marital status (P=0.004) and family income per month (P= 0.011) could be the influencing factors of depression in patients with oral cancer during radiotherapy, and a significant correlation was found between them. Conclusion Patients with adjuvant radiotherapy after reconstruction of oral cancer flaps have depressive symptoms, which will seriously affect the quality of life. Therefore, the care of such patients should focus on improving the postoperative depression of patients.
    Sclerosing polycystic adenosis of the parotid gland: a case report and literature review
    CHEN Zengquan,JIN Tingting,WANG Yan,WANG Lin,MAI Lianxi,HUANG Zhiquan
    2019, 27(11):  729-732.  DOI: 10.12016/j.issn.2096-1456.2019.11.008
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    Objective To explore the clinicopathological features, diagnosis, treatment and prognosis of sclerosing polycystic adenosis (SPA) and provide a reference for clinics. Methods A case of sclerosing polycystic adenosis of the parotid glands was retrospectively analyzed, and the relevant literature was reviewed. Results A 57-year-old female patient presented with a tumor, which she had noticed for half a month, on the left side of the lower ear, with occasional paroxysmal numbness and no complaint of other discomfort. Resection of the left submandibular area tumor was performed, and the tumor specimen pathological results showed sclerosing polycystic adenosis of the left parotid gland, with no recurrence after six-months follow-up. Sclerosing polycystic adenosis is rare, occurs in the parotid gland and is characterized by a frequently painless, slow-growing mass of the parotid gland. Imaging examination and fine needle aspiration biopsy can only be used as a reference; the diagnosis must include a pathology examination. Histological manifestations showed that abundant sclerotic collagenous stroma was permeated by ductal and acinar lobules, and cystic dilatation of the duct was accompanied by epithelial hyperplasia and diverse ductal cells. Immunohistochemistry of the ductal and acinar cells showed positive expression of cytokeratin (AE1-3 and CAM5.2) and S100 protein. The ducts filled with hyperplastic and dysplastic epithelium were surrounded by an intact myoepithelial layer that was positive for SMA, p63, and calponin, with a Ki-67 index less than 3%. Treatment comprised mainly surgical resection, with a good prognosis. However, one-third of cases relapse: low-grade malignant tumors may occur, with at least one report of invasive cancer. Conclusion Sclerosing polycystic adenosis of the salivary gland is rare and has a good prognosis, but patients may relapse easily after surgery. The diagnosis depends primarily on pathological examination. The main treatment is surgical resection, the prognosis is good, and follow-up should be strengthened after surgery.
    Review Articles
    Application and research progress of the surgery-first approach in the treatment of dento-maxillofacial deformities
    LIU Jiaqi,CAO Zhiwei,BI Ruiye
    2019, 27(11):  733-738.  DOI: 10.12016/j.issn.2096-1456.2019.11.009
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    For patients with dento-maxillofacial deformities who receive orthodontic-orthognathic combined treatment, the conventional treatment approach is preoperative orthodontic-orthognathic surgery-postoperative orthodontics. However, with the development of techniques used in orthodontic and orthognathic treatment, the surgery-first approach (SFA), namely, orthodontic surgery-postoperative orthodontics, has been widely used currently and displays several advantages, such as improving the treatment efficiency and providing patients with more satisfaction. This review provides a brief discussion and review of SFA concerning its development, indications, advantages and disadvantages, outcomes and stability, and the application and research progress of SFA in orthodontic-orthognathic combined treatment for patients with maxillofacial deformity. The literature review results showed that compared with the conventional treatment approach, SFA has relatively strict indications, which usually include patients with skeletal class Ⅱ/Ⅲ malocclusion, skeletal open bite, and bimaxillary protrusion or patients with facial asymmetry but who require little preoperative orthodontic treatment or removal of the compensation of the dental arch, specifically as follows: ①well-aligned to mildly crowded anterior teeth, ②flat to mild curve of Spee, ③normal to mildly proclined/retroclined incisor inclination, ④acceptable arch coordination, ⑤extensive occlusal contact between the upper and lower dentition requiring at least 3 occlusal contacts. Any occlusion that may affect the outcome of surgery or final result of the overall treatment, as well as any disease that may jeopardize the healing process after surgery, is regarded as a contraindication. Furthermore, SFA has potential disadvantages, such as a possible higher incidence of complications, including unstable occlusion and malunion of bones, which still require further research to be confirmed. Most researchers believe that no significant difference occurs between the outcome and stability of the two approaches. However, currently, we still need a sufficient sample size of prospective studies to provide accurate evidence.

    Research progress of periodontitis and periodontal dysbiosis
    GUO Xinwei,ZHAO Hongyan,YANG Yaoyao,QIAN Xin,LING Xiaoxu,ZHANG Zhimin
    2019, 27(11):  739-744.  DOI: 10.12016/j.issn.2096-1456.2019.11.010
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    In recent years, the etiology of periodontitis has tended to be based on the theory of flora imbalance. That is, periodontitis is not caused by specific bacteria but by the breakdown of the oral flora balance, which leads to an immune imbalance. Imbalanced bacterial flora cooperate with each other to produce virulent factors that destroy organism tissues and induce immune cells to produce abnormal levels of cytokines, causing greater damage. This article reviews the initiation of a flora imbalance, the interaction between bacteria, the immune damage of the host and the prevention and treatment of the flora imbalance. The literature review shows that peroxidase released by inflammatory reactions, host immune responses to pathogenic microorganisms and some systemic factors, such as diabetes, can trigger flora imbalance. As a result, ion transport, substance synthesis and metabolism of bacteria change; virulence factors increase; and the oral flora balance is disrupted. Red complex bacteria enter gingival epithelial cells, produce adhesin, and selectively inhibit the expression of specific chemokines, which is beneficial for other pathogenic bacteria to enter gingival epithelial cells. Toxicity factors increase throughout the body, directly destroying body tissues and inducing innate and adaptive immune responses, thus causing related immune damage. The dysbacteriosis model of periodontitis provides a new idea for the prevention and treatment of periodontitis, such as using biological factors, bacteriophages, probiotics and other methods to reduce the number of periodontal pathogens to restore the steady state of periodontal flora.

    Material properties and clinical application status of Biodentine
    WANG Ping,ZHANG Yingjuan
    2019, 27(11):  745-748.  DOI: 10.12016/j.issn.2096-1456.2019.11.011
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    Biodentine is a bioactive dentin replacement material whose main component is high-purity tricalcium silicate without dicalcium silicate. It has a shorter cure time; although it has a higher solubility, it hardly affects the volume of the material. It has a low X-ray barrier property, low porosity, high bulk density, and high compressive strength and is not affected by moisture or a dry environment. It has strong acid corrosion resistance, can increase dentin resistance, and has biocompatibility due to the lack of cytotoxicity. It has antibacterial activity against various bacteria, with strong antibacterial activity against Streptococcus sanguis. Since 2010, Biodentine has been widely used in clinical treatments such as dental restoration, pulp capping, pulpectomy, et al. In clinical applications, Biodentine is primarily used as a permanent dentin substitute or as a temporary enamel substitute within 6 months. As a new dentin substitute material with a short clinical application time, the long-term efficacy of Biodentine requires further follow-up observation studies.