Clinical retrospective study of dental implant removal : do patients who require implant removal desire implant prosthesis again?

This study investigated the causes of dental implant removal due to complications, and examined whether patients who had dental implant removal desired re-implant prosthesis treatments. A retrospective case?control study was conducted on patients who had their dental implants removed. We investigated whether the removed dental implant was replaced with other implant prostheses. Age, sex, diabetes, smoking, implant site distribution, reason for implant removal, and blade and root-form implants were categorized as predictive variables. The outcome variable was desire for re-implantation or use of other prosthetic methods after implant removal. A logistic regression model was created to identify patient factors that could predict the re-implantation of dental prostheses after implant removal. A total of 215 dental implants were removed from 143 patients. The most common reason for implant removal was peri-implantitis that was identified in 165 implants. After implant removal, re-implantation was performed in 98 implants (45.6%). Bivariate analyses showed that age, diabetes, implant type, and reason for implant removal were associated with the desire for re-implanted prostheses. The multiple regression model revealed that age, implant type, and reason for implant removal were associated with an increased desire for re-implant prostheses after implant removal. Re-implantation of prostheses after the removal of dental implants was desired by patients who were younger, had implants placed in the root form, and had implants removed due to prosthetic-related complications

Original Origin of Osteoblasts Involved in the Mechanism of Ectopic Bone Formation Induced by KUSA/A1 Cells with Honeycomb Carrier

Abstract: The basic principle of bone tissue engineering is to use seeded stem cells in porous scaffold. Stem cells can proliferate and differentiate into various types of mature cells. A kind of stem cell called KUSA/A1 is a marrow stromal cell, capable of differentiating into three mesenchymal phenotypes: osteocyte, adipocyte, and myocyte by treating with 5-azacytidine in cell culture. Moreover, it has been reported that the mechanism of bone induction by KUSA/A1 cells is similar to intramembranous ossification. In order to clarify the origin of osteoblasts implicated in new bone formation, KUSA/A1 cells alone and combined with Honeycomb carrier were implanted in Transgenic Green Fluorescent Protein mice (GFP) mice. The presence of GFP positive host cells with osteoblastic morphology as well as GFP negative cells, clearly of KUSA/A1 cells in origin were observed around the bony trabeculae. These results indicated that the new bone was not only produced by KUSA/A1 cells but also by host cells from the surrounding connective tissues. To our knowledge, this is the first study to describe that host cells play an important role in ectopic bone induced by implanted marrow stromal cells, which would need special attention in bone tissue engineering

Transplanted Bone Marrow-derived Cell Migration into Periodontal Tissues and Cell Differentiation

マウスを用いて、歯周組織に歯科矯正学的メカニカルストレスを負荷することによって生じる牽引側および圧迫側歯根膜組織の変化について、熱ショックタンパクHSP70およびp-HSP70の発現を免疫組織化学的に検討した。HSP70は時間の経過と共に陽性反応が増強した。p-HSP70は、HSP70の発現より遅れて陽性反応の増強を示した。HSP70がホメオスタシスの維持や傷害を受けた細胞の修復、またそのリン酸化したp-HSP70として、牽引側歯根膜組織における骨芽細胞活性化による同部への骨添加傾向へのシフトが正常に行われるよう分子シャペロンとして働き、タンパク質のフォールディングなどの立体構造形成を助けていることが示唆された。Heat shock proteins (HSPs) are induced by not only the heat shock but also the mechanical stress. Orthodontic tooth movement induced mechanical stress in the related periodontal ligament. It is important to examine the inununohistochemical profile change of the Heat shock proteins (HSPs) in the periodontal ligament cells after receiving the mechanical stress for orthodontic treatment. Therefore, we examined the HSPs in the periodontal ligament cells of ddY mice using the Waldo method. In the control group, periodontal ligament was observed as physiological anangement, and which reacted weakly to HSP27 and HSP70. In the experimental group the extension site of the periodontal ligament cells and the expansion of the blood vessel occuned in the traction side. These tissues were strongly reacted to HSP27 and HSP70. The findings suggeste that the HSPsexpression work as the mechanism of maintenance of homeostasis in the periodontal tissues

A pigmented calcifying cystic odontogenic tumor associated with compound odontoma: a case report and review of literature

<p>Abstract</p> <p>Background</p> <p>Pigmented intraosseous odontogenic lesions are rare with only 47 reported cases in the English literature. Among them, pigmented calcifying cystic odontogenic tumor, formerly known as calcifying odontogenic cyst, is the most common lesion with 20 reported cases.</p> <p>Methods</p> <p>A case of pigmented calcifying cystic odontogenic tumor associated with odontoma occurring at the mandibular canine-premolar region of a young Japanese boy is presented with radiographic, and histological findings. Special staining, electron microscopic study and immunohistochemical staining were also done to characterize the pigmentation.</p> <p>Results</p> <p>The pigments in the lesion were confirmed to be melanin by Masson-Fontana staining and by transmission electron microscopy. The presence of dendritic melanocytes within the lesion was also demonstrated by S-100 immunostaining.</p> <p>Conclusion</p> <p>The present case report of pigmented calcifying cystic odontogenic tumor associated with odontoma features a comprehensive study on melanin and melanocytes, including histochemical, immunohistochemical and transmission electron microscopic findings.</p

A spindle cell carcinoma presenting with osseous metaplasia in the gingiva: a case report with immunohistochemical analysis

<p>Abstract</p> <p>Background</p> <p>Spindle cell carcinoma (SpCC) is a rare, high malignant variant of squamous cell carcinoma (SCC), which shows biphasic proliferation of conventional SCC component and malignant spindle shape cells with sarcomatous appearance.</p> <p>Methods</p> <p>A case of Spindle cell carcinoma with bone-like calcified materials, occurring at the mandibular molar region of 71-years-old Japanese male patient was presented with gross finding, histological findings and MRI image. To identify the characteristics of the bone-like materials, immunohistochemistry were performed.</p> <p>Results</p> <p>Histologically, the cancer cells were composed of spindle cells and epithelial cells which form nests with prominent keratinization. Histological findings showed typical histology of the SpCC, however, as an uncommon finding, spatters of calcified, bone-like materials were observed in between the cancer cells. Immunohistochemistry revealed that cancer cells were positive for cytokeratins and vimentin to a varying degree and negative for Desmin, S-100, Osteopontin, BMP-2 or BMP-4. These findings implied that the calcified materials were formed by metaplasia of the stromal cells.</p> <p>Discussion</p> <p>Bone-like materials formation by osseous and/or cartilaginous metaplasia of the stroma in the carcinoma has been reported. However, the detailed mechanism of these metaplasia and affection on the clinical feature, prognosis and therapies are not well established. In summary, we presented an unique case of SpCC, which has not been described in the literature.</p

Proton beam therapy is a safe and effective treatment in elderly patients with esophageal squamous cell carcinoma

Background: There are many elderly patients with esophageal squamous cellcarcinoma (ESCC). However, there are currently few articles regarding the clinical outcome following proton beam therapy in these patients. The purpose of this study was to evaluate the clinical results of proton beam therapy in elderlypatients with ESCC.Methods: Between January 2009 and December 2013, patients aged ≥75 yearswho underwent proton beam therapy were examined using multi-institutionaldata from Japan.Results: There were 38 inoperable patients (70.4%) and 16 operable patients(29.6%). More than 40% of patients had stage III/IV ESCC. The five-year overalland cancer-specific survival rates were 56.2% and 71.7%, respectively. Performance status was the only factor that significantly influenced overall survival during the multivariate analysis. The five-year local control rate was 61.8%, and local recurrence occurred within 13 months in 82.4% of patients,. There was no grade 3 or higher toxicity, excluding three patients with grade 3 esophageal ulcers.Conclusions: In conclusion, proton beam therapy may become an alternativetreatment with lower toxicity in elderly patients with ESCC, compared to surgeryor conventional X-ray radiotherapy. This includes inoperable patients

Clinical Results of Proton Beam Therapy for Esophageal Cancer: Multicenter Retrospective Study in Japan

There are few reports about the clinical results of proton beam therapy for esophageal cancer in a large population. The purpose of this study was to evaluate the clinical results of proton beam therapy for esophageal cancer in a large population using a multicentered database. Between January 2009 and December 2013, patients newly diagnosed with esophageal cancer and who had received proton beam therapy were retrospectively recruited from a database of four proton beam therapy centers in Japan. Two hundred and two patients (including 90 inoperable patients) fulfilled the inclusion criteria, and 100 patients (49.5%) had stage III/IV cancer (Union for International Cancer Control 8th). The 3-year and 5-year overall survival rate was 66.7% and 56.3%, respectively. The five-year local control rate was 64.4%. There were two patients with grade three pericardial effusion (1%) and a patient with grade three pneumonia (0.5%). No grade 4 or higher cardiopulmonary toxicities were observed (Common Terminology Criteria for Adverse Events version 4.0). This study suggests that proton beam therapy for esophageal cancer was not inferior in efficacy and had lower rates of toxicities in comparison to photon radiotherapy. Therefore, proton beam therapy can serve as an alternate treatment for patients with esophageal cancer

Clinical Results of Proton Beam Therapy for Esophageal Cancer: Multicenter Retrospective Study in Japan.

There are few reports about the clinical results of proton beam therapy for esophageal cancer in a large population. The purpose of this study was to evaluate the clinical results of proton beam therapy for esophageal cancer in a large population using a multicentered database. Between January 2009 and December 2013, patients newly diagnosed with esophageal cancer and who had received proton beam therapy were retrospectively recruited from a database of four proton beam therapy centers in Japan. Two hundred and two patients (including 90 inoperable patients) fulfilled the inclusion criteria, and 100 patients (49.5%) had stage III/IV cancer (Union for International Cancer Control 8th). The 3-year and 5-year overall survival rate was 66.7% and 56.3%, respectively. The five-year local control rate was 64.4%. There were two patients with grade three pericardial effusion (1%) and a patient with grade three pneumonia (0.5%). No grade 4 or higher cardiopulmonary toxicities were observed (Common Terminology Criteria for Adverse Events version 4.0). This study suggests that proton beam therapy for esophageal cancer was not inferior in efficacy and had lower rates of toxicities in comparison to photon radiotherapy. Therefore, proton beam therapy can serve as an alternate treatment for patients with esophageal cancer