Background: Bisphosphonates are compounds similar to inorganic pyrophosphates, with anti-angiogenic, anti-inflammatory, anti-bone resorption, and antitumor effects. They are used to prevent bone metastases in cancer a...Background: Bisphosphonates are compounds similar to inorganic pyrophosphates, with anti-angiogenic, anti-inflammatory, anti-bone resorption, and antitumor effects. They are used to prevent bone metastases in cancer and treat osteoporosis. However, a major side effect is osteonecrosis of the jaw (ONJ), first reported in 2003, which is the exposure of necrotic bone in the mouth, often accompanied by infection. Prevention and treatment of ONJ remain challenging due to a lack of reliable epidemiological data on its incidence and risk factors. The aim of our work is to estimate the prevalence of bisphosphonate-related osteonecrosis of the jaw (BRONJ) and to analyze its correlations with different risk factors reported in the literature. Methods: A retrospective observational study was conducted in the Oncology, Rheumatology and Maxillofacial Surgery Department of the Mohamed VI University Hospital;Marrakech, based on complete medical records during the period 2017 to 2022, as well as consultations of patients under bisphosphonates in these departments during July and August 2022. Statistical analysis was performed using IBM SPSS version 16.0. Results: Of the 107 patients included in this study, 60.7% were women, and 56.1% were between 40 and 65 years old. 100% of the patients suffered from a general pathology. Regarding treatment with BP, 103 patients were treated with Zoledronate, 4 with Risedronate, and 5 with Ibandronate. 103 patients received this treatment intravenously, while 4 patients received it orally. Regarding Oral health, only 12.1% of patients reported a poor oral health. 99.1% of patients were informed of the need for oral preparation prior to BP treatment, but only 71.02% received dental treatment, mainly tooth extraction. None of the patients were diagnosed with BRONJ. Conclusions: While the global incidence of ONJ ranges from 0.8% to 12%, our finding is zero. Most previous studies are retrospective with limited patient numbers like our study. To accurately assess the prevalence of ONJ, further prospective epidemiological studies with standardized protocols and thorough follow-up over several years are essential.展开更多
背景与目的：近年来，随着技术发展，越来越多的基于能量传递的止血工具广泛问世并应用于开放性外科手术中。超声刀Focus刀头（Harmonic Focus，HF）及Ligasure Small Jaw刀头（LSJ）都是专为开放性甲状腺手术量身定做的。本文拟对北京...背景与目的：近年来，随着技术发展，越来越多的基于能量传递的止血工具广泛问世并应用于开放性外科手术中。超声刀Focus刀头（Harmonic Focus，HF）及Ligasure Small Jaw刀头（LSJ）都是专为开放性甲状腺手术量身定做的。本文拟对北京协和医学院中国医学科学院肿瘤医院HF及LSJ完成的开放性甲状腺手术患者的临床资料进行病例对照分析，以期比较HF及LSJ在开放性甲状腺手术中的应用效果。探讨HF及LSJ用于开放性甲状腺手术的有效性及安全性。方法：选取本院过去1年内甲状腺癌初治患者，由同一外科医师主刀使用HF或LSJ完成甲状腺全切除＋中央区清扫术，纳入HF组100例，LSJ组104例。通过比较两组手术时间及术后第1天引流量，比较两者在甲状腺手术中应用的有效性。通过比较两组术后并发症来评估安全性。结果：有效性：HF组平均手术时间为（95．8±18．0）min，LSJ组平均手术时间为（97．8±19．1）min，差异无统计学意义（P=-0．363）；术后首日引流量HF组为（35．2±20．3）mL，LSJ组为（36．3±23．8）mL，差异无统计学意义（P=0．977）。安全性：HF组出现暂时性声带麻痹者1例（1．0％），LSJ组术后伤口出现术区血肿者1例（1．0％）；暂时I生甲状旁腺功能低下者HF组18例（18．O％），LSJ组16例（15．4％）；HF组术后首日甲状旁腺素平均下降（12．3±12．8）pg／mL，LSJ组平均下降（13．9±13．4）μg／mL；血清离子钙HF组平均下降（0．20±0．13）mg／dL，LSJ组平均下降（0．20±0．16）mg／dL，差异均无统计学意义（P均〉0．05）。结论：HF及LSJ在开放性甲状腺手术中均安全、有效，手术并发症相当。展开更多
Objective: To study the prevalence of bisphosphonate-related osteonecrosis of the jaw (BRONJ) and to determine the risk factors associated with the occurrence of this pathology. Method: An observational retrospective ...Objective: To study the prevalence of bisphosphonate-related osteonecrosis of the jaw (BRONJ) and to determine the risk factors associated with the occurrence of this pathology. Method: An observational retrospective study was conducted in the Department of Oncology, Rheumatology, and Maxillofacial Surgery of Ibn Rochd University Hospital, Casablanca. The study utilized complete medical records from 2014 to 2022 and included consultations of patients receiving bisphosphonates (BPs) in July and September 2022. Statistical analysis was performed using SPSS version 16.0. Results: Our study population comprised 104 patients, of whom 91% were women and 49% were over 65 years old. Seventy-two percent of patients had a general pathology. Among them, 64 patients were treated with zoledronate, 43 with alendronate, and the remainder with risedronate, ibandronate, and pamidronate. The most common indications for treatment were bone metastasis following breast cancer (29.8%) and osteoporotic fractures (19.2%). Sixty-seven patients received intravenous (IV) treatment;only 10.5% exhibited good oral health. Fifty percent of patients underwent dental treatment, primarily tooth extractions. Osteonecrosis of the jaw (ONJ) was diagnosed in 1.9% of patients, predominantly in stages 1 and 2. Conclusion: Second and third-generation bisphosphonates are more strongly associated with the development of ONJ. Risk factors include monthly IV administration, poor oral health, comorbidities such as diabetes, medications like corticosteroids, invasive dental procedures, and not only oncological conditions but also rare indications such as bone algodystrophy. Nevertheless, our observed prevalence of 1.9% aligns with international rates ranging from 0.8% to 12%. However, most of the studies that have been carried out have been retrospective studies with insufficient numbers of patients. Further prospective epidemiological studies based on standardized protocols with rigorous and appropriate follow-up over several years are essential to determine the exact prevalence of ONJ.展开更多
Objective: to explore the significance of combined guided bone regeneration technique on the basis of jaw cyst curettage in the treatment of patients with odontogenic jaw cyst to improve the treatment quality of patie...Objective: to explore the significance of combined guided bone regeneration technique on the basis of jaw cyst curettage in the treatment of patients with odontogenic jaw cyst to improve the treatment quality of patients. Methods: the project started in October 2020 and the project ended in January 2022. The data composition of the project were all confirmed patients in our hospital, with a total of 54 cases. The project was divided into the general group and the study group, with 27 cases in each group. The treatment parameters, changes in jaw height and width after surgery, treatment efficiency and surgical treatment indexes of the two groups were compared. Results: compared with other groups, the volume and area of cysts in the study group changed more significantly, and the bone mineral density of the patients increased more than that in the general group. Comparing the changes of jaw height and width, the parameters of the study group were higher than those of the conventional group. The number of patients in the study group who showed significant improvement in treatment was larger, and the total effective rate was significantly higher than that in the general group. Compared with the surgical treatment, although the treatment time and blood loss of the study group were more, the incidence of postoperative complications and recurrence rate were lower than those of the general group (P≤0.05). Conclusion: for the patients with odontogenic jaw cyst, the application of combined therapy is of positive significance in improving the disease pathological changes of the patients, improving the overall recovery quality, and reducing the influence of disease complications and recurrence rate.展开更多
The article introduces a new method for three-dimensional reproduction of edentulous dental casts,and wax occlusion rims with jaw relation by using a commercial high-speed line laser scanner and reverse engineering so...The article introduces a new method for three-dimensional reproduction of edentulous dental casts,and wax occlusion rims with jaw relation by using a commercial high-speed line laser scanner and reverse engineering software and evaluates the method’s accuracy in vitro.The method comprises three main steps：（i）acquisition of the three-dimensional stereolithography data of maxillary and mandibular edentulous dental casts and wax occlusion rims;（ii）acquisition of the three-dimensional stereolithography data of jaw relations;and（iii）registration of these data with the reverse engineering software and completing reconstruction.To evaluate the accuracy of this method,dental casts and wax occlusion rims of 10 edentulous patients were used.The lengths of eight lines between common anatomic landmarks were measured directly on the casts and occlusion rims by using a vernier caliper and on the three-dimensional computerized images by using the software measurement tool.The direct data were considered as the true values.The paired-samples t-test was used for statistical analysis.The mean differences between the direct and the computerized measurements were mostly less than 0.04 mm and were not significant（P.0.05）.Statistical significance among 10 patients was assessed using one-way analysis of variance（P,0.05）.The result showed that the 10 patients were considered statistically no significant.Therefore,accurate three-dimensional reproduction of the edentulous dental casts,wax occlusion rims,and jaw relations was achieved.The proposed method enables the visualization of occlusion from different views and would help to meet the demand for the computer-aided design of removable complete dentures.展开更多
Objective:Osteoradionecrosis of the jaws(ORNJ)is among the most serious oral complications of head and neck cancer treatment with radiation therapy.This study aimed to examine the level of symptom distress and interfe...Objective:Osteoradionecrosis of the jaws(ORNJ)is among the most serious oral complications of head and neck cancer treatment with radiation therapy.This study aimed to examine the level of symptom distress and interference of ORNJ in head and neck cancer patients in China.Methods:A cross-sectional study was conducted to profile patient reported symptom severity.Ninetyfive hospitalized ORNJ patients were recruited.Participants completed the MD Anderson Symptom Inventory-Head and Neck Module-Chinese version.Results:The percentage of participants who reported that they experienced at least one type of symptom was 97.9%,and 85.2%patients reported interference.The 10 most severe symptoms were as follows:limited mouth opening,problem with teeth/gums,difficulty swallowing/chewing,dry mouth,oral malodor,difficulty with voice/speech,dental ulcer,tinnitus/ear obstruction,skin pain/burning/rash,and difficulty hearing.The problem of limited mouth opening was more severe in patients with longer time to onset of ORNJ after radiotherapy.The interference of patients positively correlated with core symptoms(r=0.612),head and neck symptoms(r=0.709),and ORNJ symptoms(r=0.440)(P<0.01).The longer time to the onset of ORNJ after radiotherapy was positively and significantly correlated with symptom distress(r=0.479,P<0.001),and mouth opening correlated negatively with symptom distress(r=-0.298,P=0.003).Conclusions:ORNJ patients suffered mainly from limited mouth opening and other maxillofacial symptoms.The problem of limited mouth opening was more severe in patients with longer time to onset of ORNJ after radiotherapy.ORNJ patients commonly had symptom distress,which influenced their quality of life.展开更多
This article provides an overview of metastases to jaws （M J）, mainly concerning the differences between American and Chinese patients, and exploring the relationship between the primary tumors＇ prevalence （PTP） ...This article provides an overview of metastases to jaws （M J）, mainly concerning the differences between American and Chinese patients, and exploring the relationship between the primary tumors＇ prevalence （PTP） and constituent ratio of MJ. Information concerning of 399 MJ cases in 215 papers, including one new case in our hospital, was subjected to statistic analysis. The main clinical features of M J, such as constituent ratio of PTP and that of M J, metastatic sites, treatments, and prognosis were summarized. Breast, lung, kidney, prostate and thyroid （in descending order） were the leading primary sites of MJ. Furthermore, the constituent ratio of MJ was found to be correlated with that of PTP in all subjects including American and Chinese subjects in our study. As to metastatic sites in the mandible, a specific ＂M＂ shaped pattern appeared regardless of the tumor type or constituent ratio,,; of MJ were in all subjects. Almost all subjects received traditionary palliative treatments, and the prognosis was quite poor. The PTP had a significant impact on the constituent ratio of MJ. However, it was the properties of the microenvironment rather than characteristics or constituent ratios of tumor cells, that decided the metastatic sites in various tumor subjects.展开更多
The influence of rock strength properties on Jaw Crusher performance was carried out to determine the effect of rock strength on crushing time and grain size distribution of the rocks.Investigation was conducted on fo...The influence of rock strength properties on Jaw Crusher performance was carried out to determine the effect of rock strength on crushing time and grain size distribution of the rocks.Investigation was conducted on four different rock samples namely marble,dolomite,limestone and granite which were representatively selected from fragmented lumps in quarries.Unconfined compressive strength and Point load tests were carried out on each rock sample as well as crushing time and size analysis.The results of the strength parameters of each sample were correlated with the crushing time and the grain size distribution of the rock types.The results of the strength tests show that granite has the highest mean value of 101.67 MPa for Unconfined Compressive Strength(UCS) test,6.43 MPa for Point Load test while dolomite has the least mean value of 30.56 MPa for UCS test and 0.95 MPa for Point Load test.According to the International Society for Rock Mechanic(ISRM) standard,the granite rock sample may be classified as having very high strength and dolomite rock sample,low strength.Also,the granite rock has the highest crushing time(21.0 s) and dolomite rock has the least value(5.0 s).Based on the results of the investigation,it was found out that there is a great influence of strength properties on crushing time of rock types.展开更多
BACKGROUND Bone grafts have been applied for many years in orthopedic surgery to assist with bone repair for defects or bone discontinuity caused by trauma and tumors as well as periodontal defects.Jaw cysts are anoth...BACKGROUND Bone grafts have been applied for many years in orthopedic surgery to assist with bone repair for defects or bone discontinuity caused by trauma and tumors as well as periodontal defects.Jaw cysts are another common benign disease of the maxillofacial region which may lead to pathological bone fracture,loss of teeth,and infection.However,whether bone grafts are beneficial for bone regeneration in jaw cystic lesions and when bone grafts should be used remains unclear.AIM To study the efficacy of bone grafts compared to spontaneous healing in the treatment of jaw cystic lesions.METHODS A literature search was performed in Medline,Cochrane Library and Embase to identify related articles published in English in the last ten years.The following key words and Me SH terms were used:“jaw cyst”,“cystic lesion”,“odontogenic cyst”,“periapical cyst”,“dentigerous cyst”,“follicular cyst”,“keratocyst”,“treatment”,“surgery”,“bone graft”,“enucleation”,“cystectomy”,and“bone regeneration”.Case reports,clinical trials,clinical studies,observational studies and randomized controlled trials were included.Study quality was evaluated.RESULTS Ten studies(n=10)met the inclusion criteria.Five studies reported spontaneous bone healing after enucleation,three studies investigated the efficacy of various bone grafts,and two randomized comparative studies focused on the comparison between spontaneous healing and bone grafting.Over 90%of bone regeneration occurred within 6 mo after bone grafting.The bone regeneration rate after cystectomy showed great variation,ranging from 50%to 100%after 6 mo,but reaching over 90%after 12 mo.CONCLUSION While the long-term superiority of bone grafting compared with spontaneous healing after cystectomy is unclear,bone grafts accelerate the process of healing and significantly increase bone quality.展开更多
BACKGROUND The odontogenic jaw cyst is a cavity containing liquid,semifluid or gaseous components,with the development of the disease.In recent years,with the rapid development of oral materials and the transformation...BACKGROUND The odontogenic jaw cyst is a cavity containing liquid,semifluid or gaseous components,with the development of the disease.In recent years,with the rapid development of oral materials and the transformation of treatment of jaw cysts,more options are available for treatment of postoperative bone defect of jaw cysts.Guided bone regeneration(GBR)places biomaterials in the bone defect,and then uses biofilm to separate the proliferative soft tissue and the slow-growing bone tissue to maintain the space for bone regeneration,which is widely used in the field of implantology.AIM To observe the clinical effect of GBR in repairing bone defect after enucleation of small and medium-sized odontogenic jaw cysts.METHODS From June 2018 to September 2020,13 patients(7 male,6 female)with odontogenic jaw cysts were treated in the Department of Oral Surgery,Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine.Adults without hypertension,heart disease,diabetes or other systemic diseases were selected.The diagnosis was based on the final pathological results:11 cases were diagnosed as apical cysts,one as primordial cyst,and one as dentigerous cyst.The lesions were located in the maxilla in seven cases,and in the mandible in six cases.All cases were treated with the same method of enucleation combined with GBR.RESULTS Three to four months after the operation,the boundary between the implant site and the surrounding normal stroma was not obvious in patients with small-sized odontogenic jaw cysts.The patients with tooth defects were treated with implant after 6 mo.For the patients with medium-sized odontogenic jaw cysts,the density of the center of the implant area was close to the normal mass at 6 mo after surgery,and there was a clear boundary between the periphery of the implant area and the normal mass.The boundary between the periphery of the implant area and the normal mass was blurred at 8-9 mo after surgery.Patients with tooth defects were treated with implants at>6 mo after the operation.CONCLUSION Enucleation combined with guided bone regeneration in small and medium-sized odontogenic jaw cysts can shorten the time of osteogenesis,increase the amount of new bone formation,reduce complications,and improve quality of life.展开更多
Medication-related osteonecrosis of the jaw(MRONJ)is primarily associated with administering antiresorptive or antiangiogenic drugs.Despite significant research on MRONJ,its pathogenesis and effective treatments are s...Medication-related osteonecrosis of the jaw(MRONJ)is primarily associated with administering antiresorptive or antiangiogenic drugs.Despite significant research on MRONJ,its pathogenesis and effective treatments are still not fully understood.Animal models can be used to simulate the pathophysiological features of MRONJ,serving as standardized in vivo experimental platforms to explore the pathogenesis and therapies of MRONJ.Rodent models exhibit excellent effectiveness and high reproducibility in mimicking human MRONJ,but classical methods cannot achieve a complete replica of the pathogenesis of MRONJ.Modified rodent models have been reported with improvements for better mimicking of MRONJ onset in clinic.This review summarizes representative classical and modified rodent models of MRONJ created through various combinations of systemic drug induction and local stimulation and discusses their effectiveness and efficiency.Currently,there is a lack of a unified assessment system for MRONJ models,which hinders a standard definition of MRONJ-like lesions in rodents.Therefore,this review comprehensively summarizes assessment systems based on published peer-review articles,including new approaches in gross observation,histological assessments,radiographic assessments,and serological assessments.This review can serve as a reference for model establishment and evaluation in future preclinical studies on MRONJ.展开更多
Objective:Radicular cyst(RC),dentigerous cyst(DC),and odontogenic keratocyst(OKC)are most common odontogenic jaw cysts(OJC).Methods:In order to compare their clinical features,a retrospective study of 669 cases of OJC...Objective:Radicular cyst(RC),dentigerous cyst(DC),and odontogenic keratocyst(OKC)are most common odontogenic jaw cysts(OJC).Methods:In order to compare their clinical features,a retrospective study of 669 cases of OJC was designed including the gender composition,age distribution,localization,and clinical presentation of OKC,RC,and DC,and the results were statistically analyzed with chi-square test.Results:The male:female ratio of OKC was 1.6∶1,RC 1.4∶1,and DC 4.1∶1(P<0.005).The incidence of OJC was seen in almost all age groups except that DC was not seen in 70+years group.The age distribution had a significant difference among the three kinds of OJC or in each cyst group(P<0.005).The incidence rate of OKC or RC in the third decade was the highest among that of all age groups(OKC,27%;RC,20%);the incidence rate of DC in the second decade was the highest(29%).The three kinds of OJC were seen in all areas of the jaw with a different frequency,and the involved locations had significant differences among the three kinds of OJC or in each cyst group(P<0.005).137 cases of OKC,48cases of RC,and 18 cases of DC were secondarily infected(infection rate:OKC,39%;RC,24%;DC,16%)(P<0.005).Conclusions:These results suggest that(1)male predilection appears in OJC;(2)the peak incidence of OKC or RC is the third decade,and that of DC is the second decade;(3)a different location of the jaw has a different susceptibility for OKC,RC,or DC-the predilection localization of OKC is mandibular molar-premolar region,and that of RC or DC is maxillary anterior region;(4)the symptom of infection is helpful for the differential diagnosis among OKC,RC and DC.展开更多
Bacterial biofilms have emerged as potential critical triggers in the pathogenesis of bisphosphonate（BP）-related osteonecrosis of the jaw（ONJ） or BRONJ. BRONJ lesions have shown to be heavily colonized by oral bac...Bacterial biofilms have emerged as potential critical triggers in the pathogenesis of bisphosphonate（BP）-related osteonecrosis of the jaw（ONJ） or BRONJ. BRONJ lesions have shown to be heavily colonized by oral bacteria, most of these difficult to cultivate and presents many clinical challenges. The purpose of this study was to characterize the bacterial diversity in BRONJ lesions and to determine host immune response. We examined tissue specimens from three cohorts（n530）; patients with periodontal disease without a history of BP therapy（Control, n510）, patients with periodontal disease having history of BP therapy but without ONJ（BP, n55） and patients with BRONJ（BRONJ, n515）. Denaturing gradient gel electrophoresis of polymerase chain reaction（PCR）-amplified 16 S r RNA gene fragments revealed less bacterial diversity in BRONJ than BP and Control cohorts. Sequence analysis detected six phyla with predominant affiliation to Firmicutes in BRONJ（71.6%）, BP（70.3%） and Control（59.1%）. Significant differences（P,0.05） in genera were observed, between Control/BP, Control/BRONJ and BP/BRONJ cohorts. Enzyme-linked immunosorbent assay（ELISA）results indicated that the levels of myeloperoxidase were significantly lower, whereas interleukin-6 and tumor necrosis factor-alpha levels were moderately elevated in BRONJ patients as compared to Controls. PCR array showed significant changes in BRONJ patients with downregulation of host genes, such as nucleotide-binding oligomerization domain containing protein 2, and cathepsin G, the key modulators for antibacterial response and upregulation of secretory leukocyte protease inhibitor, proteinase 3 and conserved helix–loop–helix ubiquitous kinase. The results suggest that colonization of unique bacterial communities coupled with deficient innate immune response is likely to impact the pathogenesis of ONJ.展开更多
Objective： To prospectively investigate the value of bone scintigraphy on determining the full extent of tumor involvement in jaw bones and to assess the presence of metastases. Methods： This study had local ethical...Objective： To prospectively investigate the value of bone scintigraphy on determining the full extent of tumor involvement in jaw bones and to assess the presence of metastases. Methods： This study had local ethical committee approval, and all patients gave written informed consent. Thirty seven consecutive patients with primary malignant tumor in jaw bones were recruited for the study. Bone scintigraphy was performed in all patients before surgery to measure the full extent of bony involvement, which was compared with histologic findings. Results： Whole body scan revealed one case with multiple bony metastases. Resection specimens of 36 bone neoplasms were pathologically analyzed to identify type and size of each tumor. The lengths of the tumor involvement in jaw bones defined by bone scintigraphy and pathology were 5.62 ± 1.58 cm, 4.48 ± 1.57 cm, respectively （P 〈 0.05）. The tumor negative margins from removed specimens according to bone scintigraphy were pathologically confirmed. With histologic findings as the standard of reference, the accuracy of bone scintigraphy was 100% （36 of 36 patients） in determining the full extent of tumor involvement in jaw bones. Conclusion： Bone scintigraphy tends to offer specific guidelines in determining the appropriate extent of bone resection while entirely clearing the tumor cells and preserving functions whenever possible and in establishing the bony metastases.展开更多
We describe the cases of three patients, under the care of the rheumatology service, who presented with osteonecrosis of the jaw whist on oral bisphosphonate therapy. The first case is of a 74-year-old woman with a 12...We describe the cases of three patients, under the care of the rheumatology service, who presented with osteonecrosis of the jaw whist on oral bisphosphonate therapy. The first case is of a 74-year-old woman with a 12 year history of sero-negative inflammatory arthritis, having been on oral steroids for 11 years, Methotrexate for the preceding 6 years, and oral bisphosphonates for 9 years. Clinical and radiographic examination revealed extensive jaw necrosis. The second patient was a 72-year-old woman with temporal arteritis, on long term oral steroids, and oral bisphosphonates presenting with jaw osteonecrosis. The third case is of an 81-year-old lady with a diagnosis of Polymyalgia Rheumatica on reducing dose of prednisolone along with calcium and vitamin D3 and oral bisphosphonate therapy as part of steroid induced prophylaxis guidelines. On reviewing the literature regarding bisphosphonate-associated osteonecrosis of the jaw, there is indeed recognition of this occurring with oral bisphosphonates. However, this is far less common than with intravenous preparations. Reports to the UK MHRA regarding adverse reactions have shown 53 cases of osteonecrosis of the jaw associated with oral bisphosphonates, but this is thought to represent under-reporting. We suggest consideration of patient counselling and consent, and preventive dental work prior to initiation of oral bisphosphonate therapy.展开更多
AIM: To discuss important characteristics of the useof dental implants in posterior quadrants and the rehabilitation planning. METHODS: An electronic search of English articles was conducted on MEDLINE(PubM ed) from 1...AIM: To discuss important characteristics of the useof dental implants in posterior quadrants and the rehabilitation planning. METHODS: An electronic search of English articles was conducted on MEDLINE(PubM ed) from 1990 up to the period of March 2014. The key terms were dental implants and posterior jaws, dental implants/treatment planning and posterior maxilla, and dental implants/treatment planning and posterior mandible. No exclusion criteria were used for the initial search. Clinical trials, randomized and non randomized studies, classical and comparative studies, multicenter studies, in vitro and in vivo studies, case reports, longitudinal studies and reviews of the literature were included in this review. RESULTS: One hundred and fifty-two articles met the inclusion criteria of treatment planning of dental implants in posterior jaw and were read in their entirety. The selected articles were categorized with respect to their context on space for restoration, anatomic considerations(bone quantity and density), radiographic techniques, implant selection(number, position, diameter and surface), tilted and pterygoid implants, short implants, occlusal considerations, and success rates of implants placed in the posterior region. The results derived from the review process were described under several different topic headings to give readers a clear overview of the literature. In general, it was observed that the use of dental implants in posterior region requires a careful treatment plan. It is important that the practitioner has knowledge about the theme to evaluate the treatment parameters. CONCLUSION: The use of implants to restore the posterior arch presents many challenges and requires a detailed treatment planning.展开更多
A new method for filling bone cavity with a graft of frozen-decalcified-defatted-driedallogeneic (FDDDA) cancellous bone was described.This method was used for the treatment of cavi-ties after the enucleation of jaw c...A new method for filling bone cavity with a graft of frozen-decalcified-defatted-driedallogeneic (FDDDA) cancellous bone was described.This method was used for the treatment of cavi-ties after the enucleation of jaw cysts in 10 patients from December 1985 to February 1990.Thewounds of 9 patients healed by first intension,but wound infection occurred in one case postopera-tively.The 9 patients,besides the patient who suffered from wound infection,were followed up for5 to 56 months,with an average of 41.1 months.Evidence of recurrence with jaw cyst.was not ob-served.展开更多
Jaw crusher is a kind of machine widely used in mining and aggregates industry,but it still has some shortcom-ings,such as liners wear,terrible power draw etc.The lack of research on material flow strongly limits the ...Jaw crusher is a kind of machine widely used in mining and aggregates industry,but it still has some shortcom-ings,such as liners wear,terrible power draw etc.The lack of research on material flow strongly limits the design improvement.The size reduction of the jaw crusher relies on the moving jaw movement that is a kind of complicated swing.Based on the move-ment analysis of the moving jaw and the single particle breakage characters,the material flow is analyzed.The measure of the breakage force is carried out.Material flow analysis is partly confirmed by the experimental results and some new information is also learned from the crushing force distribution.The job on the material flow will be helpful to the jaw crusher design improve-ment.展开更多
文摘Background: Bisphosphonates are compounds similar to inorganic pyrophosphates, with anti-angiogenic, anti-inflammatory, anti-bone resorption, and antitumor effects. They are used to prevent bone metastases in cancer and treat osteoporosis. However, a major side effect is osteonecrosis of the jaw (ONJ), first reported in 2003, which is the exposure of necrotic bone in the mouth, often accompanied by infection. Prevention and treatment of ONJ remain challenging due to a lack of reliable epidemiological data on its incidence and risk factors. The aim of our work is to estimate the prevalence of bisphosphonate-related osteonecrosis of the jaw (BRONJ) and to analyze its correlations with different risk factors reported in the literature. Methods: A retrospective observational study was conducted in the Oncology, Rheumatology and Maxillofacial Surgery Department of the Mohamed VI University Hospital;Marrakech, based on complete medical records during the period 2017 to 2022, as well as consultations of patients under bisphosphonates in these departments during July and August 2022. Statistical analysis was performed using IBM SPSS version 16.0. Results: Of the 107 patients included in this study, 60.7% were women, and 56.1% were between 40 and 65 years old. 100% of the patients suffered from a general pathology. Regarding treatment with BP, 103 patients were treated with Zoledronate, 4 with Risedronate, and 5 with Ibandronate. 103 patients received this treatment intravenously, while 4 patients received it orally. Regarding Oral health, only 12.1% of patients reported a poor oral health. 99.1% of patients were informed of the need for oral preparation prior to BP treatment, but only 71.02% received dental treatment, mainly tooth extraction. None of the patients were diagnosed with BRONJ. Conclusions: While the global incidence of ONJ ranges from 0.8% to 12%, our finding is zero. Most previous studies are retrospective with limited patient numbers like our study. To accurately assess the prevalence of ONJ, further prospective epidemiological studies with standardized protocols and thorough follow-up over several years are essential.
文摘背景与目的：近年来，随着技术发展，越来越多的基于能量传递的止血工具广泛问世并应用于开放性外科手术中。超声刀Focus刀头（Harmonic Focus，HF）及Ligasure Small Jaw刀头（LSJ）都是专为开放性甲状腺手术量身定做的。本文拟对北京协和医学院中国医学科学院肿瘤医院HF及LSJ完成的开放性甲状腺手术患者的临床资料进行病例对照分析，以期比较HF及LSJ在开放性甲状腺手术中的应用效果。探讨HF及LSJ用于开放性甲状腺手术的有效性及安全性。方法：选取本院过去1年内甲状腺癌初治患者，由同一外科医师主刀使用HF或LSJ完成甲状腺全切除＋中央区清扫术，纳入HF组100例，LSJ组104例。通过比较两组手术时间及术后第1天引流量，比较两者在甲状腺手术中应用的有效性。通过比较两组术后并发症来评估安全性。结果：有效性：HF组平均手术时间为（95．8±18．0）min，LSJ组平均手术时间为（97．8±19．1）min，差异无统计学意义（P=-0．363）；术后首日引流量HF组为（35．2±20．3）mL，LSJ组为（36．3±23．8）mL，差异无统计学意义（P=0．977）。安全性：HF组出现暂时性声带麻痹者1例（1．0％），LSJ组术后伤口出现术区血肿者1例（1．0％）；暂时I生甲状旁腺功能低下者HF组18例（18．O％），LSJ组16例（15．4％）；HF组术后首日甲状旁腺素平均下降（12．3±12．8）pg／mL，LSJ组平均下降（13．9±13．4）μg／mL；血清离子钙HF组平均下降（0．20±0．13）mg／dL，LSJ组平均下降（0．20±0．16）mg／dL，差异均无统计学意义（P均〉0．05）。结论：HF及LSJ在开放性甲状腺手术中均安全、有效，手术并发症相当。
文摘Objective: To study the prevalence of bisphosphonate-related osteonecrosis of the jaw (BRONJ) and to determine the risk factors associated with the occurrence of this pathology. Method: An observational retrospective study was conducted in the Department of Oncology, Rheumatology, and Maxillofacial Surgery of Ibn Rochd University Hospital, Casablanca. The study utilized complete medical records from 2014 to 2022 and included consultations of patients receiving bisphosphonates (BPs) in July and September 2022. Statistical analysis was performed using SPSS version 16.0. Results: Our study population comprised 104 patients, of whom 91% were women and 49% were over 65 years old. Seventy-two percent of patients had a general pathology. Among them, 64 patients were treated with zoledronate, 43 with alendronate, and the remainder with risedronate, ibandronate, and pamidronate. The most common indications for treatment were bone metastasis following breast cancer (29.8%) and osteoporotic fractures (19.2%). Sixty-seven patients received intravenous (IV) treatment;only 10.5% exhibited good oral health. Fifty percent of patients underwent dental treatment, primarily tooth extractions. Osteonecrosis of the jaw (ONJ) was diagnosed in 1.9% of patients, predominantly in stages 1 and 2. Conclusion: Second and third-generation bisphosphonates are more strongly associated with the development of ONJ. Risk factors include monthly IV administration, poor oral health, comorbidities such as diabetes, medications like corticosteroids, invasive dental procedures, and not only oncological conditions but also rare indications such as bone algodystrophy. Nevertheless, our observed prevalence of 1.9% aligns with international rates ranging from 0.8% to 12%. However, most of the studies that have been carried out have been retrospective studies with insufficient numbers of patients. Further prospective epidemiological studies based on standardized protocols with rigorous and appropriate follow-up over several years are essential to determine the exact prevalence of ONJ.
文摘Objective: to explore the significance of combined guided bone regeneration technique on the basis of jaw cyst curettage in the treatment of patients with odontogenic jaw cyst to improve the treatment quality of patients. Methods: the project started in October 2020 and the project ended in January 2022. The data composition of the project were all confirmed patients in our hospital, with a total of 54 cases. The project was divided into the general group and the study group, with 27 cases in each group. The treatment parameters, changes in jaw height and width after surgery, treatment efficiency and surgical treatment indexes of the two groups were compared. Results: compared with other groups, the volume and area of cysts in the study group changed more significantly, and the bone mineral density of the patients increased more than that in the general group. Comparing the changes of jaw height and width, the parameters of the study group were higher than those of the conventional group. The number of patients in the study group who showed significant improvement in treatment was larger, and the total effective rate was significantly higher than that in the general group. Compared with the surgical treatment, although the treatment time and blood loss of the study group were more, the incidence of postoperative complications and recurrence rate were lower than those of the general group (P≤0.05). Conclusion: for the patients with odontogenic jaw cyst, the application of combined therapy is of positive significance in improving the disease pathological changes of the patients, improving the overall recovery quality, and reducing the influence of disease complications and recurrence rate.
基金the Twelfth Five-Year National Key Technologies Research and Development Program of China(grant no.2012BAI07B00)the National High Technology Research and Development Program(‘863’Program)of China(grant nos.2013AA040801 and 2013AA040802)+1 种基金the National Natural Science Foundation of China(grant no.81271181)the Scientific Research Innovation Foundation for Youth Doctors of Peking University School of Stomatology(2011)
文摘The article introduces a new method for three-dimensional reproduction of edentulous dental casts,and wax occlusion rims with jaw relation by using a commercial high-speed line laser scanner and reverse engineering software and evaluates the method’s accuracy in vitro.The method comprises three main steps：（i）acquisition of the three-dimensional stereolithography data of maxillary and mandibular edentulous dental casts and wax occlusion rims;（ii）acquisition of the three-dimensional stereolithography data of jaw relations;and（iii）registration of these data with the reverse engineering software and completing reconstruction.To evaluate the accuracy of this method,dental casts and wax occlusion rims of 10 edentulous patients were used.The lengths of eight lines between common anatomic landmarks were measured directly on the casts and occlusion rims by using a vernier caliper and on the three-dimensional computerized images by using the software measurement tool.The direct data were considered as the true values.The paired-samples t-test was used for statistical analysis.The mean differences between the direct and the computerized measurements were mostly less than 0.04 mm and were not significant（P.0.05）.Statistical significance among 10 patients was assessed using one-way analysis of variance（P,0.05）.The result showed that the 10 patients were considered statistically no significant.Therefore,accurate three-dimensional reproduction of the edentulous dental casts,wax occlusion rims,and jaw relations was achieved.The proposed method enables the visualization of occlusion from different views and would help to meet the demand for the computer-aided design of removable complete dentures.
基金Nurturing funds for nursing young talents of Sun Yat-sen University(N2018Y02)
文摘Objective:Osteoradionecrosis of the jaws(ORNJ)is among the most serious oral complications of head and neck cancer treatment with radiation therapy.This study aimed to examine the level of symptom distress and interference of ORNJ in head and neck cancer patients in China.Methods:A cross-sectional study was conducted to profile patient reported symptom severity.Ninetyfive hospitalized ORNJ patients were recruited.Participants completed the MD Anderson Symptom Inventory-Head and Neck Module-Chinese version.Results:The percentage of participants who reported that they experienced at least one type of symptom was 97.9%,and 85.2%patients reported interference.The 10 most severe symptoms were as follows:limited mouth opening,problem with teeth/gums,difficulty swallowing/chewing,dry mouth,oral malodor,difficulty with voice/speech,dental ulcer,tinnitus/ear obstruction,skin pain/burning/rash,and difficulty hearing.The problem of limited mouth opening was more severe in patients with longer time to onset of ORNJ after radiotherapy.The interference of patients positively correlated with core symptoms(r=0.612),head and neck symptoms(r=0.709),and ORNJ symptoms(r=0.440)(P<0.01).The longer time to the onset of ORNJ after radiotherapy was positively and significantly correlated with symptom distress(r=0.479,P<0.001),and mouth opening correlated negatively with symptom distress(r=-0.298,P=0.003).Conclusions:ORNJ patients suffered mainly from limited mouth opening and other maxillofacial symptoms.The problem of limited mouth opening was more severe in patients with longer time to onset of ORNJ after radiotherapy.ORNJ patients commonly had symptom distress,which influenced their quality of life.
文摘This article provides an overview of metastases to jaws （M J）, mainly concerning the differences between American and Chinese patients, and exploring the relationship between the primary tumors＇ prevalence （PTP） and constituent ratio of MJ. Information concerning of 399 MJ cases in 215 papers, including one new case in our hospital, was subjected to statistic analysis. The main clinical features of M J, such as constituent ratio of PTP and that of M J, metastatic sites, treatments, and prognosis were summarized. Breast, lung, kidney, prostate and thyroid （in descending order） were the leading primary sites of MJ. Furthermore, the constituent ratio of MJ was found to be correlated with that of PTP in all subjects including American and Chinese subjects in our study. As to metastatic sites in the mandible, a specific ＂M＂ shaped pattern appeared regardless of the tumor type or constituent ratio,,; of MJ were in all subjects. Almost all subjects received traditionary palliative treatments, and the prognosis was quite poor. The PTP had a significant impact on the constituent ratio of MJ. However, it was the properties of the microenvironment rather than characteristics or constituent ratios of tumor cells, that decided the metastatic sites in various tumor subjects.
文摘The influence of rock strength properties on Jaw Crusher performance was carried out to determine the effect of rock strength on crushing time and grain size distribution of the rocks.Investigation was conducted on four different rock samples namely marble,dolomite,limestone and granite which were representatively selected from fragmented lumps in quarries.Unconfined compressive strength and Point load tests were carried out on each rock sample as well as crushing time and size analysis.The results of the strength parameters of each sample were correlated with the crushing time and the grain size distribution of the rock types.The results of the strength tests show that granite has the highest mean value of 101.67 MPa for Unconfined Compressive Strength(UCS) test,6.43 MPa for Point Load test while dolomite has the least mean value of 30.56 MPa for UCS test and 0.95 MPa for Point Load test.According to the International Society for Rock Mechanic(ISRM) standard,the granite rock sample may be classified as having very high strength and dolomite rock sample,low strength.Also,the granite rock has the highest crushing time(21.0 s) and dolomite rock has the least value(5.0 s).Based on the results of the investigation,it was found out that there is a great influence of strength properties on crushing time of rock types.
基金supported by the investigator-initiated trial "The observation of bone healing after filling with bone grafts of cystic lesions in jaws: a single-center prospective study" at First Affiliated Hospital, School of Medicine, Zhejiang University
文摘BACKGROUND Bone grafts have been applied for many years in orthopedic surgery to assist with bone repair for defects or bone discontinuity caused by trauma and tumors as well as periodontal defects.Jaw cysts are another common benign disease of the maxillofacial region which may lead to pathological bone fracture,loss of teeth,and infection.However,whether bone grafts are beneficial for bone regeneration in jaw cystic lesions and when bone grafts should be used remains unclear.AIM To study the efficacy of bone grafts compared to spontaneous healing in the treatment of jaw cystic lesions.METHODS A literature search was performed in Medline,Cochrane Library and Embase to identify related articles published in English in the last ten years.The following key words and Me SH terms were used:“jaw cyst”,“cystic lesion”,“odontogenic cyst”,“periapical cyst”,“dentigerous cyst”,“follicular cyst”,“keratocyst”,“treatment”,“surgery”,“bone graft”,“enucleation”,“cystectomy”,and“bone regeneration”.Case reports,clinical trials,clinical studies,observational studies and randomized controlled trials were included.Study quality was evaluated.RESULTS Ten studies(n=10)met the inclusion criteria.Five studies reported spontaneous bone healing after enucleation,three studies investigated the efficacy of various bone grafts,and two randomized comparative studies focused on the comparison between spontaneous healing and bone grafting.Over 90%of bone regeneration occurred within 6 mo after bone grafting.The bone regeneration rate after cystectomy showed great variation,ranging from 50%to 100%after 6 mo,but reaching over 90%after 12 mo.CONCLUSION While the long-term superiority of bone grafting compared with spontaneous healing after cystectomy is unclear,bone grafts accelerate the process of healing and significantly increase bone quality.
基金Supported by the National Natural Science Foundation of China,No. 31800816Fundamental Research Program Funding of the Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine,No. JYZZ109
文摘BACKGROUND The odontogenic jaw cyst is a cavity containing liquid,semifluid or gaseous components,with the development of the disease.In recent years,with the rapid development of oral materials and the transformation of treatment of jaw cysts,more options are available for treatment of postoperative bone defect of jaw cysts.Guided bone regeneration(GBR)places biomaterials in the bone defect,and then uses biofilm to separate the proliferative soft tissue and the slow-growing bone tissue to maintain the space for bone regeneration,which is widely used in the field of implantology.AIM To observe the clinical effect of GBR in repairing bone defect after enucleation of small and medium-sized odontogenic jaw cysts.METHODS From June 2018 to September 2020,13 patients(7 male,6 female)with odontogenic jaw cysts were treated in the Department of Oral Surgery,Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine.Adults without hypertension,heart disease,diabetes or other systemic diseases were selected.The diagnosis was based on the final pathological results:11 cases were diagnosed as apical cysts,one as primordial cyst,and one as dentigerous cyst.The lesions were located in the maxilla in seven cases,and in the mandible in six cases.All cases were treated with the same method of enucleation combined with GBR.RESULTS Three to four months after the operation,the boundary between the implant site and the surrounding normal stroma was not obvious in patients with small-sized odontogenic jaw cysts.The patients with tooth defects were treated with implant after 6 mo.For the patients with medium-sized odontogenic jaw cysts,the density of the center of the implant area was close to the normal mass at 6 mo after surgery,and there was a clear boundary between the periphery of the implant area and the normal mass.The boundary between the periphery of the implant area and the normal mass was blurred at 8-9 mo after surgery.Patients with tooth defects were treated with implants at>6 mo after the operation.CONCLUSION Enucleation combined with guided bone regeneration in small and medium-sized odontogenic jaw cysts can shorten the time of osteogenesis,increase the amount of new bone formation,reduce complications,and improve quality of life.
基金supported by the National Natural Science Foundation of China(No.81921002,No.81900970)Young Physician Innovation Team Project(No.QC202003)from Ninth People’s Hospital,Shanghai Jiao Tong University School of MedicineShanghai Sailing Program(19YF1426000)jointly。
文摘Medication-related osteonecrosis of the jaw(MRONJ)is primarily associated with administering antiresorptive or antiangiogenic drugs.Despite significant research on MRONJ,its pathogenesis and effective treatments are still not fully understood.Animal models can be used to simulate the pathophysiological features of MRONJ,serving as standardized in vivo experimental platforms to explore the pathogenesis and therapies of MRONJ.Rodent models exhibit excellent effectiveness and high reproducibility in mimicking human MRONJ,but classical methods cannot achieve a complete replica of the pathogenesis of MRONJ.Modified rodent models have been reported with improvements for better mimicking of MRONJ onset in clinic.This review summarizes representative classical and modified rodent models of MRONJ created through various combinations of systemic drug induction and local stimulation and discusses their effectiveness and efficiency.Currently,there is a lack of a unified assessment system for MRONJ models,which hinders a standard definition of MRONJ-like lesions in rodents.Therefore,this review comprehensively summarizes assessment systems based on published peer-review articles,including new approaches in gross observation,histological assessments,radiographic assessments,and serological assessments.This review can serve as a reference for model establishment and evaluation in future preclinical studies on MRONJ.
文摘Objective:Radicular cyst(RC),dentigerous cyst(DC),and odontogenic keratocyst(OKC)are most common odontogenic jaw cysts(OJC).Methods:In order to compare their clinical features,a retrospective study of 669 cases of OJC was designed including the gender composition,age distribution,localization,and clinical presentation of OKC,RC,and DC,and the results were statistically analyzed with chi-square test.Results:The male:female ratio of OKC was 1.6∶1,RC 1.4∶1,and DC 4.1∶1(P<0.005).The incidence of OJC was seen in almost all age groups except that DC was not seen in 70+years group.The age distribution had a significant difference among the three kinds of OJC or in each cyst group(P<0.005).The incidence rate of OKC or RC in the third decade was the highest among that of all age groups(OKC,27%;RC,20%);the incidence rate of DC in the second decade was the highest(29%).The three kinds of OJC were seen in all areas of the jaw with a different frequency,and the involved locations had significant differences among the three kinds of OJC or in each cyst group(P<0.005).137 cases of OKC,48cases of RC,and 18 cases of DC were secondarily infected(infection rate:OKC,39%;RC,24%;DC,16%)(P<0.005).Conclusions:These results suggest that(1)male predilection appears in OJC;(2)the peak incidence of OKC or RC is the third decade,and that of DC is the second decade;(3)a different location of the jaw has a different susceptibility for OKC,RC,or DC-the predilection localization of OKC is mandibular molar-premolar region,and that of RC or DC is maxillary anterior region;(4)the symptom of infection is helpful for the differential diagnosis among OKC,RC and DC.
基金supported by NIH grants CA172894, CA180277, DE020891New York University Research Funds
文摘Bacterial biofilms have emerged as potential critical triggers in the pathogenesis of bisphosphonate（BP）-related osteonecrosis of the jaw（ONJ） or BRONJ. BRONJ lesions have shown to be heavily colonized by oral bacteria, most of these difficult to cultivate and presents many clinical challenges. The purpose of this study was to characterize the bacterial diversity in BRONJ lesions and to determine host immune response. We examined tissue specimens from three cohorts（n530）; patients with periodontal disease without a history of BP therapy（Control, n510）, patients with periodontal disease having history of BP therapy but without ONJ（BP, n55） and patients with BRONJ（BRONJ, n515）. Denaturing gradient gel electrophoresis of polymerase chain reaction（PCR）-amplified 16 S r RNA gene fragments revealed less bacterial diversity in BRONJ than BP and Control cohorts. Sequence analysis detected six phyla with predominant affiliation to Firmicutes in BRONJ（71.6%）, BP（70.3%） and Control（59.1%）. Significant differences（P,0.05） in genera were observed, between Control/BP, Control/BRONJ and BP/BRONJ cohorts. Enzyme-linked immunosorbent assay（ELISA）results indicated that the levels of myeloperoxidase were significantly lower, whereas interleukin-6 and tumor necrosis factor-alpha levels were moderately elevated in BRONJ patients as compared to Controls. PCR array showed significant changes in BRONJ patients with downregulation of host genes, such as nucleotide-binding oligomerization domain containing protein 2, and cathepsin G, the key modulators for antibacterial response and upregulation of secretory leukocyte protease inhibitor, proteinase 3 and conserved helix–loop–helix ubiquitous kinase. The results suggest that colonization of unique bacterial communities coupled with deficient innate immune response is likely to impact the pathogenesis of ONJ.
文摘Objective： To prospectively investigate the value of bone scintigraphy on determining the full extent of tumor involvement in jaw bones and to assess the presence of metastases. Methods： This study had local ethical committee approval, and all patients gave written informed consent. Thirty seven consecutive patients with primary malignant tumor in jaw bones were recruited for the study. Bone scintigraphy was performed in all patients before surgery to measure the full extent of bony involvement, which was compared with histologic findings. Results： Whole body scan revealed one case with multiple bony metastases. Resection specimens of 36 bone neoplasms were pathologically analyzed to identify type and size of each tumor. The lengths of the tumor involvement in jaw bones defined by bone scintigraphy and pathology were 5.62 ± 1.58 cm, 4.48 ± 1.57 cm, respectively （P 〈 0.05）. The tumor negative margins from removed specimens according to bone scintigraphy were pathologically confirmed. With histologic findings as the standard of reference, the accuracy of bone scintigraphy was 100% （36 of 36 patients） in determining the full extent of tumor involvement in jaw bones. Conclusion： Bone scintigraphy tends to offer specific guidelines in determining the appropriate extent of bone resection while entirely clearing the tumor cells and preserving functions whenever possible and in establishing the bony metastases.
文摘We describe the cases of three patients, under the care of the rheumatology service, who presented with osteonecrosis of the jaw whist on oral bisphosphonate therapy. The first case is of a 74-year-old woman with a 12 year history of sero-negative inflammatory arthritis, having been on oral steroids for 11 years, Methotrexate for the preceding 6 years, and oral bisphosphonates for 9 years. Clinical and radiographic examination revealed extensive jaw necrosis. The second patient was a 72-year-old woman with temporal arteritis, on long term oral steroids, and oral bisphosphonates presenting with jaw osteonecrosis. The third case is of an 81-year-old lady with a diagnosis of Polymyalgia Rheumatica on reducing dose of prednisolone along with calcium and vitamin D3 and oral bisphosphonate therapy as part of steroid induced prophylaxis guidelines. On reviewing the literature regarding bisphosphonate-associated osteonecrosis of the jaw, there is indeed recognition of this occurring with oral bisphosphonates. However, this is far less common than with intravenous preparations. Reports to the UK MHRA regarding adverse reactions have shown 53 cases of osteonecrosis of the jaw associated with oral bisphosphonates, but this is thought to represent under-reporting. We suggest consideration of patient counselling and consent, and preventive dental work prior to initiation of oral bisphosphonate therapy.
文摘AIM: To discuss important characteristics of the useof dental implants in posterior quadrants and the rehabilitation planning. METHODS: An electronic search of English articles was conducted on MEDLINE(PubM ed) from 1990 up to the period of March 2014. The key terms were dental implants and posterior jaws, dental implants/treatment planning and posterior maxilla, and dental implants/treatment planning and posterior mandible. No exclusion criteria were used for the initial search. Clinical trials, randomized and non randomized studies, classical and comparative studies, multicenter studies, in vitro and in vivo studies, case reports, longitudinal studies and reviews of the literature were included in this review. RESULTS: One hundred and fifty-two articles met the inclusion criteria of treatment planning of dental implants in posterior jaw and were read in their entirety. The selected articles were categorized with respect to their context on space for restoration, anatomic considerations(bone quantity and density), radiographic techniques, implant selection(number, position, diameter and surface), tilted and pterygoid implants, short implants, occlusal considerations, and success rates of implants placed in the posterior region. The results derived from the review process were described under several different topic headings to give readers a clear overview of the literature. In general, it was observed that the use of dental implants in posterior region requires a careful treatment plan. It is important that the practitioner has knowledge about the theme to evaluate the treatment parameters. CONCLUSION: The use of implants to restore the posterior arch presents many challenges and requires a detailed treatment planning.
文摘A new method for filling bone cavity with a graft of frozen-decalcified-defatted-driedallogeneic (FDDDA) cancellous bone was described.This method was used for the treatment of cavi-ties after the enucleation of jaw cysts in 10 patients from December 1985 to February 1990.Thewounds of 9 patients healed by first intension,but wound infection occurred in one case postopera-tively.The 9 patients,besides the patient who suffered from wound infection,were followed up for5 to 56 months,with an average of 41.1 months.Evidence of recurrence with jaw cyst.was not ob-served.
文摘Jaw crusher is a kind of machine widely used in mining and aggregates industry,but it still has some shortcom-ings,such as liners wear,terrible power draw etc.The lack of research on material flow strongly limits the design improvement.The size reduction of the jaw crusher relies on the moving jaw movement that is a kind of complicated swing.Based on the move-ment analysis of the moving jaw and the single particle breakage characters,the material flow is analyzed.The measure of the breakage force is carried out.Material flow analysis is partly confirmed by the experimental results and some new information is also learned from the crushing force distribution.The job on the material flow will be helpful to the jaw crusher design improve-ment.
