Salivary duct carcinoma in the mandible: a case report

Salivary duct carcinoma (SDC) is a distinctive and aggressive neoplasm. The most frequent site of origin is the parotid gland, followed by the submandibular gland. SDC originating in the minor salivary glands, particularly in the ectopic glands within the mandible, is extremely rare. We describe a 62-year-old man with SDC in the mandible, who presented with a painless lump in the right submandibular region (later identified as lymph node metastasis) and ipsilateral mental nerve palsy. Histologic examination after ablative surgery revealed SDC originating in the mandible and cervical nodal metastases spreading to levels I-III. The patient remains alive 59 months after presentation as a result of postoperative full-dose irradiation and regular intensive chemotherapy using TXT, 5-FU, and CDDP. However, the patient has local recurrence and distant metastases to the lung and brain. In this report, we also discuss the specific diagnostic criteria and developmental theories of intraosseous salivary gland tumors.     

Cement-retained versus screw-retained implant restorations: a critical review

This article presents a comparison of screw-retained and cement-retained implant prostheses based on the literature. The advantages, disadvantages, and limitations of the 2 different types of restorations are discussed, because it is important to understand the influence of the attachment mechanism on many clinical aspects of implant dentistry. Several factors essential to the long-term success of any implant prosthesis were reviewed with regard to both methods of fixation. These factors include: (1) ease of fabrication and cost, (2) passivity of the framework, (3) retention, (4) occlusion, (5) esthetics, (6) delivery, and (7) retrievability. (More than 50 references).     

Expression of osteoprotegerin in synovial tissue and degradation of articular cartilage: comparison with arthroscopic findings of temporomandibular joint disorders

OBJECTIVE: The aim of this study was to investigate the correlations among the expression of osteoprotegerin (OPG) in synovial tissue and the degree of synovitis, the degeneration of articular cartilage, and the adhesions in patients with internal derangement and osteoarthritis of the temporomandibular joint (TMJ).Study design The expression of OPG, which was detected immunohistochemically, and the degree of arthroscopy of 31 patients with internal derangement and osteoarthritis of the TMJ were assessed and the correlations between them were analyzed statistically. RESULTS: OPG was expressed in the cytoplasm of the endothelial cells, synovial lining cells, and fibroblast cells. TMJs with osteoarthritis had a higher degree of articular cartilage degeneration than did TMJs with internal derangement. There was a correlation between the expression of OPG in the endothelial cells and the degree of the articular cartilage degeneration (P <.01). CONCLUSION: The expression of OPG might be associated with the development of degenerative changes of articular cartilage.     

Dental rehabilitation using an implant-carrying plate system in a severely resorbed edentulous maxilla: a case report

This clinical article describes a case of dental rehabilitation using an implant-carrying plate system (EPITEC) for a patient with severely resorbed edentulous maxilla and microstomia. In this case, the presence of microstomia prevented bone augmentation procedures through an intraoral approach. Treatment using 2 endosseous implants inserted in the canine regions and an implant-supported overdenture was planned. However, endosseous implants were not feasible on the right side because of insufficient available bone volume. An implant-carrying plate system was then utilized on the right side. Four months later, an implant-supported ball-attachment overdenture was fabricated. At the 2-year follow-up, the clinical course remained uneventful, and the patient remained satisfied with the treatment.     

Effect of infection with Eikenella corrodens on the progression of ligature-induced periodontitis in rats

The periodontopathic ability of Eikenella corrodens 1073-R (EcR) on ligature-induced periodontal defects in immunosuppressed and non-immunosuppressed rats was studied bacteriologically and histologically. Silk ligatures were placed around the maxillary second molars of rats, and the rats were divided into eight groups. Four groups received cyclophosphamide (CY), an immunosuppressive agent, the day after ligature placement. On days 3 and 4, the oral cavities of the rats in all four groups were inoculated with 8 x 10(8) cells of live EcR. Rats were sacrificed on d 1, 3, 5, 8, 11 and 18. Alveolar bone resorption of ligated rats was enhanced by the implantation of EcR, although the number of total cultivable bacterial cells from ligated sites was not changed by the implantation of EcR. CY suppressed the number of white blood cells, inflammatory cellular infiltrates in gingival tissue, and repair of periodontal tissue, and enhanced bone destruction. The implantation of EcR in the ligature- and CY-treated rats also enhanced osteoclastic bone resorption. Without ligatures, high doses of CY or EcR inoculum did not result in periodontal destruction. These results indicate that it is possible to establish EcR in conventional rat flora with a ligature and that EcR causes osteoclastic bone resorption in this model.     

Local ofloxacin delivery using a controlled-release insert (PT-01) in the human periodontal pocket

PT-01, a controlled-release insert, was developed for topical chemotherapy in periodontal disease. It is a soluble insert that consists of fast-release and sustained-release parts containing ofloxacin (OFLX) as an antibacterial agent. In this study, the release profile of OFLX from PT-01 was investigated in vitro. Twelve adult volunteers were administered OFLX as PT-01 or as an aqueous solution into their periodontal pockets, OFLX concentrations in gingival crevicular fluid (GCF) were evaluated from the viewpoint of pharmacokinetics. The in vitro release profile of OFLX from PT-01 showed a biphasic pattern. The release rate of OFLX was relatively rapid in the early phase and slow thereafter. When OFLX aqueous solution was administered into periodontal pockets, the OFLX level in GCF rapidly decreased to be about 1/100 after 30 minutes. When PT-01 was inserted into the pockets, the OFLX level in GCF immediately reached a peak (about 12 mg/ml), and gradually decreased until the 3rd day, and maintained a constant level above 2 micrograms/ml, the effective minimum antibacterial concentration for periodontopathic microorganisms, from the 3rd to 7th day after insertion. No side-effects were observed in the volunteers who received the PT-01 insert. The above results suggest that PT-01 is a suitable pharmaceutical preparation for periodontal chemotherapy.     

儿童口腔科患儿家长对儿童牙齿排列与咬合关注情况的调查

目的:了解目前儿童口腔科就诊的初诊患儿家长对子女牙齿排列与咬合情况,即儿童早期错畸形的关注现状.方法:采用填写问卷方法对2007-03～09期间来第四军医大学口腔医院儿童口腔科就诊的初诊患儿家长进行调查,最终获得有效问卷783 份.结果:783 例患儿中, 因龋病及其并发症就诊者占51.3%,以牙齿排列和咬合异常为主诉就诊患儿占35.0%.注意到孩子的牙齿排列和咬合问题的家长有510 名,其中希望治疗者474 名,不希望治疗者36 名;从未关注过孩子牙齿排列和咬合情况者273 名.对上前牙和下前牙排列不齐的关注率分别为56.6%和47.4%,注意到前牙咬合异常者占50.5%.有71.5%的家长是通过自己注意的途径得知子女的牙齿排列和咬合异常.48.7%的家长填写了个人资料,其中大学及大学以上文化程度者占73.9%. 结论:越来越多家长关注到自己孩子的牙齿排列与咬合状况,有必要通过各种途径进一步加强对社会及家长相关知识的普及.     

Comparison of malignant tumors and sinusitis of maxilla on CT images: Sites of bone destruction

We used CT to examine the bone destruction sites of the entire bone wall of the maxillary sinus in cases of malignant tumors of the maxilla and in maxillary sinusitis cases to investigate the differences between the destructive findings of the bone of both patient groups. The study subjects consisted of 13 patients with malignant tumors of the maxilla and 45 patients with maxillary sinusitis. Destruction of the bone wall was seen in 100% of the patients with malignant tumor of maxilla patients and in 57.8% with the maxillary sinusitis, hence showing a significantly higher incidence in malignant tumors of the maxilla. Neither group of patients exhibited disease-specific characteristics of their bone destruction. The incidence of posterolateral bone destruction in patients with malignant tumor of the maxilla patients was 61.5%, while it was significanty lower at 23.1% in the maxillary sinusitis patients. The number of bone walls affected was 2 or more walls in 84.5% of the malignant tumor patients of the maxilla patients and in 42.3% of the maxillary sinusitis patients.