Retromolar Ridge in Edentulous Patients: Clinical Considerations

PURPOSE: A removable denture base should cover the mandibular retromolar regions to provide proper basal seal and denture function in edentulous patients. The bony residual ridge form, attached muscles, and covering mucosa provide support, stability, and retention of the planned prosthesis. There is insufficient information regarding bone anatomy, mucosal tissues, and muscles in the retromolar region after tooth loss. The purpose of this study was to examine the tissue morphology in the mandibular retromolar area of edentulous subjects and report on the clinical inferences in prosthetic and implant dentistry. MATERIALS AND METHODS: Specimens included 75 edentulous and eight dentate dry mandibles examined by macroscopic observations and linear measurements for size determinants in the left and right retromolar regions. Buccolingual histological sections of the mandibular retromolar region from seven edentulous subjects were also examined. The specimens were from the Department of Anatomy and Anthropology, Sackler School of Medicine, Tel Aviv University. RESULTS: The specimens evaluated in this study revealed that a bony retromolar ridge can be large, with adjacent muscles attached several millimeters below its edentulous bone crest, or small, with muscles attached to the buccal and lingual bone crests. In all examined jaws, bony mylohyoid ridges (MR) and buccal shelves with affixed muscle fibers were present regardless of the remaining mandibular bone form and size. CONCLUSIONS: The mylohyoid muscles attached to MRs and the buccinator muscles affixed to buccal bony shelves are some of the barriers to the chronic but limited bone resorption, following tooth loss, time of edentulism, systemic factors, and denture wear.     

PEMPHIGUS FOLIACEUS AND NON-HODGKIN'S LYMPHOMA

A 56-year-olcl Iraqi woman presented to her general practitioner with an erythematous scaly eruption on the left ear. An initial diagnosis of otitis externa was made and a 7-day-course of penicillin commenced. Three days later, the patient returned complaining of abdominal pain and diarrhea. Examination of the abdomen revealed a large mass. Subsequent investigation with computerized tomography (CT) scanning showed a large paraaortic mass, fine needle biopsy of which showed a diffuse non-Hodgkins lymphoma. The majority of the cells were small follicle center cells with clear nuclei that stained positively for B-lymphocyte antigens (L26, MB2). Bone marrow biopsy showed focal paratrabecular deposition of non-Hodgkins lymphoma cells of a similar nature to those in the paraaortic node. The patient was started on a monthly regimen of chlorambucil 10 mg daily with prednlsolone 40 mg daily for the first 10 days and allopurinol, 200 mg daily. Fourteen days after completing the first monthly course of treatment the patient developed a generalized eruption. This was initially attributed to her allopurinol therapy, which was discontinued. The patient was given a second 10-day course of prednisolone and chlorambucil, at the end of which the eruption had almost completely resolved. Within 9 days the eruption recurred and the patient complained of red eyes. Examination of the skin showed scattered urticated plaques with peripheral vesiculation on the trunk and annular urticated lesions without vesiculation on the legs. A scaly erythematous eruption was also noted on the left ear (Fig. 1). The hemoglobin was 10.9 g/dL, with a normochromic, normocytic picture with rouleaux formation on the blood smear. The WBC was 7.9, with lymphopenia of 1.0 (normal range 1.5–4.0 × 10^?9). Lymphocyte subset analysis showed decreased numbers of cytotoxic/suppressor T cells (0.16 × 10^?9; normal range 0.28–1.35 × 10^?9). The helper T cell num-bers and the platelet count were normal. The erythrocyte sedimentation rate (ESR) was 102. Urea and electrolytes, and liver function tests were normal. Total protein was 85 g/L (normal range 60–80 g/L). Serum electrophoresis showed an acute phase response with increased IgA of 6.0 g/L (normal range 0.8–4.0 g/L). Routine hematoxylin and eosin stain of a biopsy of an urticated vesicular lesion on the trunk and from the erythematous lesion on the ear showed small subcorneal blisters beginning to form that contained eosinophils together with eosinophilic spongiosis. Direct immunofluorescence of perilesional uninvolved skin showed intercellular deposition of igG and C3 typical of pemphigus. Indirect immunoflu-orescence revealed circulating IgG intercellular antibodies to atitre of 1:160. The patient was treated with prednisolone, 80 mg daily. The previous regimen of chlorambucil, 10 days each month, was continued and daily allopurinol recommenced. This was followed by resolution of the eruption, the eruption on the ear being the last area to resolve. Ten-day courses of chlorambucil were given monthly for a further 7 months, following which, a course of palliative radiotherapy was given to the paraaortic nodes. Although repeat CT scan after 3 months of chemotherapy showed a dramatic reduction in the paraaortic mass, this has remained unchanged 1 year later.     

2型糖尿病降糖治疗对癌症风险的影响

2型糖尿病患者实性肿瘤的发生风险可能受降糖治疗的影响。为了了解肿瘤的发生风险与口服降糖药物、人胰岛素、胰岛素类似物治疗的关系,研究者对62809例患者进行了一项回顾性队列研究。所有患者年龄〉40岁,并且在2000年后开始应用胰岛素或口服药物治疗。患者被分成4个治疗组：单独应用二甲双胍、单独应用磺脲类、上述两种药物联用、应用胰岛素。应用胰岛素治疗的患者又被分为4个亚组：甘精胰岛素、长效人胰岛素、双相胰岛素类似物、双相人胰岛素。     

莨菪类药物对大鼠胃粘膜损伤的影响

本文观察了莨菪类药物(东茛菪碱、樟柳碱、山茛菪碱)对大鼠三种实验性胃溃疡的影响,并对其作用机制进行了初步的探讨。结果表明:莨菪类药物有对抗大鼠应激性胃溃疡、药物性胃溃疡及慢性胃溃疡的作用,且有量效依赖关系;对胃液和血液等各项生化指标分析表明,这类药物有抑制胃酸分泌、降低胃蛋白酶活性、增强胃粘液屏障,提高血清胃泌素浓度的作用。提示这些结果可能与其抗溃疡效应有关。