叩齿紧咬运动中松动牙动态力变化特点的研究

目的:研究紧咬、叩齿运动中松动牙牙合力的动态变化特征。方法:选择19例单侧下颌第一磨牙松动的患者,用PVDF动态牙合力仪测量健侧和患侧下颌第一磨牙节律性叩齿和紧咬运动中牙合力动态变化曲线,分析最大牙合力峰值和到达峰值的时间,对两侧的测量结果进行分析。结果:叩齿运动中健侧下颌第一磨牙牙合力峰值平均为25kg,到达峰值的时间为108ms;患侧的分别为21kg和126ms;紧咬运动中健侧下颌第一磨牙牙合力峰值平均为27kg,到达峰值的时间为768ms;患侧的分别为23kg和1023ms;经配对t检验,健侧与患侧的峰值及到达峰值的时间差异均有显著性。结论:牙齿松动导致咀嚼功能降低,牙合力值和牙合力上升的速度均降低。     

Mucinous adenocarcinoma with neuroendocrine differentiation of the mandibular ramus: report of a case

A rare case of mucinous adenocarcinoma with neuroendocrine differentiation of the mandibular ramus is presented. The patient, an 80-year-old man, was referred to our hospital with chief complaint of swelling and pain in the left buccal mucosa. CT and MRI examination showed an osteolytic tumor mass occupying the upper region of the left mandibular ramus. Macroscopically, the excised tumor was a relatively well-defined, solid mass with diffuse bone resorption, measuring 3 cm x 3.2 cm x 3 cm. Microscopical examination showed that the tumor forming glandular structures with abundant mucous production and high cellular atypia. Immunohistochemical studies demonstrated the positive reactivities for pan-keratin, cytokeratin 7, vimentin,alpha-amylase, alpha-smooth muscle actin, neuron-specific enolase, glial fibrillary acid protein, calcitonin, and somatostatin in tumor cells. These findings suggested that the tumor was originated from heterotopic or misplaced salivary gland in the mandible.     

成年男性下颌角间宽与颧弓深度、长度及下颌角厚度的关系

目的：测量下颌角间宽与颧弓深度、颧弓长度及下颌角厚度并进行相关分析，以期在活体上通过测量下颌角间宽来推算颧弓深度、颧弓长度、下颌角厚度，为临床行颜面美容矫治术及复合体的制作提供相关资料。方法：经福尔马林固定、颜面骨正常的成人男性尸体50具，按《人体测量方法》，用游标卡尺直接测量下颌角间宽、左右两侧颧弓深度与长度、下颌角厚度。结果：颧弓深度、颧弓长度、下颌角厚度与下颌角间宽其相关系数分别是，颧弓深度为0．649(P=0．001)，颧弓长度为0．584(P=0．001)，下颌角厚为1．0(P=0．001)，颧弓深度、长度左、右无明显差别。结论：临床采用测量下颌角间宽来推算颧弓深度、颧弓长度及下颌角厚度具有显著性意义。     

下颌角截骨术与下颌角外板矢状劈开术联合矫治低角型下颌角肥大

目的：下颌角肥大有多种式术可选,对于低角型下颌角肥大,往往一种式术很难达到满意的矫治效果,本文选择了一组低角型下颌角肥大患者,来研究下颌角截骨术与下颌角外板矢状劈开术联合应用治疗低角型下颌角肥大的治疗效果。方法：选择本科室2005年8月～2005年11月间治疗的24例低角型下颌角肥大患者,完善术前检查与分析。在全麻下应用下颌角截骨术与下颌角外板矢状劈开术进行联合矫治。术后观察治疗效果,并在8周后对所有患者进行随访,调查患者满意度。结果：所有24例患者矫治后Ⅰ期愈合,所有患者下颌角角度增大,两下颌角间宽度明显减小,达到了下颌角的正常美学标准。8周后随访,所有患者均对治疗效果表示满意。结论：下颌角截骨术与下颌角外板矢状劈开术联合应用,可有效地矫治低角型下颌角肥大,使患者下颌角达到一个理想的美学标准。     

Visualisation of the mandibular canal by different radiographic techniques

6 mandibles were radiographically examined bilaterally to visualise the mandibular canal. 5 imaging techniques were used: periapical radiography, panoramic radiography, hypocycloidal tomography, spiral tomography and computed tomography (CT). Panoramic radiographs were obtained with 2 different X-ray machines. The CT-examinations comprised direct images and standard reconstructions based on axial slices. The specimens were subsequently sectioned for contact radiography. The visibility of the mandibular canal was estimated by 3 observers at special reference points on all radiographs and classified as clearly visible, questionable visibility or not visible. The contact radiographs served as the "gold standard". The inter-observer and the intra-observer agreement were assessed by calculating the overall agreement and the x value. Direct coronal computed tomography, as well as spiral and hypocycloidal tomography, gave better visualisation of the mandibular canal than periapical and panoramic radiography.     

Guided tissue regeneration in the treatment of furcation defects in mandibular molars

The present investigation was designed to evaluate the regenerative potential of the periodontal tissues in degree III furcation defects at mandibular molars using a treatment procedure based on the principle of guided tissue regeneration. The patient sample included 21 patients, 26-65 years of age, who presented periodontal lesions in the right and left molar regions including "through and through" furcation defects. After an initial examination, each patient was subjected to a series of full-mouth scaling and root planing. 2-3 months later, they were recalled for a baseline examination. The furcation-involved molars were randomly assigned in each patient to either a test or a control treatment procedure. The test procedure included the elevation of muco-periosteal flaps at the buccal and lingual aspects of the molars. Granulation tissue was removed and the exposed root surfaces were debrided and planed. The width and the height of the entrance openings to the furcation defects were assessed. A teflon membrane was adjusted to cover the entrances to the defects (buccal and lingual) and was retained in the manner described by Pontoriero et al. (1988). The flaps were repositioned on the outer surface of the membrane and secured by sutures which were removed after 10 days. Following surgery, the patients were instructed to rinse the mouth twice daily for 4 weeks with chlorhexidine gluconate. The membranes were removed after a healing period of 1-2 months. A surgical procedure identical to the test procedure was performed in the control tooth regions with the exception of the placement of membranes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Phenotypic switching of in vitro mandibular condylar cartilage during matrix mineralization

In order to analyze the phenotypic conversion of chondrocytes, mandibular condyles of mice and rabbits were cultured under cell and organ culture systems, and then examined by a combination of morphological and biochemical procedures. In organ culture, mandibular condylar cartilage (MCC) obtained from newborn mice began to mineralize from the central zone and then progressively widened towards the peripheral zone. Electron microscopic observations showed that with the increasing duration of the organ culture, chondrocytes at the central zone converted into spindle-shaped osteoblastic cells accompanying the formation of the bone type of thick-banded collagen fibrils. To obtain a better understanding of the chondrocytic conversion, immunolocalizations for type I and type X collagens and osteocalcin (OC) were examined in mouse MCC cells in cell culture. Type X collagen and OC were expressed almost simultaneously at the late stage of culture, and type I collagen was detected along the calcified nodues after the production of these proteins. Northern blot analysis in cell cultures of rabbit MCC indicated that type II collagen and alkaline phosphatase (ALPase) messenger ribonucleic acids (mRNAs) were highly expressed at day 7, but subsequently decreased. In contrast, mRNA for type I collagen was expressed at a low level on day 7 and peaked on day 12. The present results suggest that, morphologically and biochemically, cellular modification in MCC cells under culture conditions occurs at a cellular morphological level and also at marker-gene-expression level.     

(牙合)夹板治疗髁状突纵形骨折的影像学比较实验研究

观察Ｈｅ夹板治疗髁状突纵形骨折对骨折愈及颞下颌关节的影响。为临床提供参考。方法小型猪１４头随机分为髁状突纵形骨折未治疗组;Ｈｅ夹板治疗组和对照组。分别于骨折后２周,３周,４和１２周行同位素三相骨扫描;３周,６周、１２周做ＣＴ扫描。