三维数字化解剖测量颞下颌关节的骨性结构

BACKGROUND:Guidances for design of Chinese people’s temporomandibular joint prosthesis are urgently needed because foreign prosthesis is unsuitable for Chinese people due to variant anatomy parameters.OBJECTIVE:To provide a reference for improving the design of artificial temporomandibular joint through computer three-dimensional digital measures of the anatomy parameters of the temporomandibular joint. METHODS:Continuous CT data with layer thick 0.625 mm of 30 normal temporomandibular joints were selected. Three-dimensional digital reconstruction and eight related anatomy parameter measurements of the articular fossa and condylar of the joints were performed using Mimics10.01 software. RESULTS AND CONCLUSION:The internal and external diameter of the mandibular fossa, head of mandible and neck of mandible were greater than the anterior and posterior diameter. The mandibular foramen was located at middle-posterior of the ramus of the mandible. The distance between head of the mandible and coronoid process was longer than the depth of the mandibular notch. There were no significant differences between two sides regarding all above-mentioned parameters. There are certain regular patterns in anatomy parameters of the temporomandibular joint. The study results will provide a reference for improving the design of artificial temporomandibular joint. 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程      

Quality assessment of DSA, ultrasound and CT digital images compressed with the JPEG protocol

Digital diagnostic images from subtraction angiography, computer tomography and ultrasound grabbed at 640 x 560 pixel and 320 x 280 pixel, eight-bit resolution were compressed at seven different levels with the 'lossy' JPEG algorithm in order to decrease the computer magnetic memory space required for their storage. After reconstruction, the deformations caused by the process were assessed (i) qualitatively: a perception test was performed twice, by five radiologists, on a total of 14 images compressed at various levels and (ii) quantitatively: the average grey level value per pixel was calculated at each compression level from each system's residual images obtained by subtracting the compressed image from the original and taking the absolute value of the result. It was concluded that images compressed at a ratio of about 10:1 were indistinguishable from the originals and hence could be considered acceptable for clinical use.     

Diagnostic accuracy of second-opinion diagnoses based on still images

Second opinion of histological specimens is an important part of the daily routine in anatomic pathology practices. Today, extramural second opinion can be easily obtained by sending still images via an electronic network. The aim of this study was to examine the diagnostic accuracy of second opinion diagnosis based on still images selected from glass slides of 90 archived cases originally referred for extramural second opinion. Two pathologists together diagnosed first the still images (phase 1) and then the glass slides (phase 2). Phase 1 and phase 2 diagnoses were compared with the original second opinion diagnoses (OSODs). The pathologists achieved the same diagnostic results in phase 1 and in phase 2 measured against the OSOD, 67.8% (n = 61) and 68.9% (n = 62) complete agreement, respectively. In 29 cases in phase 1, the diagnoses were discordant with the OSOD. Three cases had incorrect benign diagnoses and 8 cases had incorrect malignant diagnoses. There were 8 false-negative diagnoses regarding malignancy, 6 false-positive diagnoses regarding malignancy, and 4 other discordant diagnoses. Eleven of the 29 discordant diagnoses could have had clinical implications. In interpreting these results, it is important to acknowledge the observer variability in diagnostic histopathology in general. In conclusion, the results support the concept of using still images to obtain second opinion diagnosis.     

Diagnostic accuracy and image quality using a digital camera for teledermatology.

OBJECTIVE: The study was designed to evaluate the effectiveness of digital photography for dermatologic diagnoses and compare it with in-person diagnoses. MATERIALS AND METHODS: Patients referred for specialty consultations (n = 308) were recruited from a university dermatology clinic. Patients were examined in-person by one of three board-certified dermatologists who provided clinical diagnoses. Digital photos were obtained on all patients and were evaluated as computer images by a panel of dermatologists. RESULTS: There was 83% concordance between in-person versus digital photo diagnoses. Intradermatologist concordance averaged 84%, and interdermatologist concordance averaged 81%. Decision confidence was rated as "very definite" to "definite" 62% of the time. Concordance with biopsy results was achieved in 76% of the cases. Image sharpness and color quality were rated "good" to "excellent" 83% and 93% of the time, respectively. CONCLUSION: Digital photography for store-and-forward teledermatology produces high-quality images and diagnostic concordance rates that compare favorably with in-person clinical diagnoses.     

Diagnostic accuracy of chest X-rays acquired using a digital camera for low-cost teleradiology

Store-and-forward telemedicine, using e-mail to send clinical data and digital images, offers a low-cost alternative for physicians in developing countries to obtain second opinions from specialists. To explore the potential usefulness of this technique, 91 chest X-ray images were photographed using a digital camera and a view box. Four independent readers (three radiologists and one pulmonologist) read two types of digital (JPEG and JPEG2000) and original film images and indicated their confidence in the presence of eight features known to be radiological indicators of tuberculosis (TB). The results were compared to a "gold standard" established by two different radiologists, and assessed using receiver operating characteristic (ROC) curve analysis. There was no statistical difference in the overall performance between the readings from the original films and both types of digital images. The size of JPEG2000 images was approximately 120KB, making this technique feasible for slow internet connections. Our preliminary results show the potential usefulness of this technique particularly for tuberculosis and lung disease, but further studies are required to refine its potential.     

A digital optoelectronic method for recording mandibular movement in association with oral electromyograms and temporomandibular joint noises

In order to obtain a better understanding of jaw movement and its relationship to other parameters such as muscle activity or noises from the temporomandibular joint, it is necessary to correlate these activities. A digital optoelectronic method was therefore designed to record these activities simultaneously. It uses a closed-circuit television camera to view the movement of a light source attached to the patient's lower jaw; this is then discriminated and provides an analogue or digital output (x and y axes) based on a matrix of 300 vertical division and 400 horizontal divisions covering an area of 60×80 mm in the recording plane. The recording error for static or dynamic movement is ±2·5% and movement in the z axis increases this by an additional 2·0% per cm z axis movement. Electromyograms or temporomandibular joint noises are related using adjacent channels on a recording polygraph.     

Development of the human temporomandibular joint

A great deal of research has been published on the development of the human temporomandibular joint (TMJ). However, there is some discordance about its morphological timing. The most controversial aspects concern the moment of the initial organization of the condyle and the squamous part of the temporal bone, the articular disc and capsule and also the cavitation and onset of condylar chondrogenesis. Serial sections of 70 human specimens between weeks 7 and 17 of development were studied by optical microscopy (25 embryos and 45 fetuses). All specimens were obtained from collections of the Institute of Embryology of the Complutense University of Madrid and the Department of Morphological Sciences of the University of Granada. Three phases in the development of the TMJ were identified. The first is the blastematic stage (weeks 7–8 of development), which corresponds with the onset of the organization of the condyle and the articular disc and capsule. During week 8 intramembranous ossification of the temporal squamous bone begins. The second stage is the cavitation stage (weeks 9–11 of development), corresponding to the initial formation of the inferior joint cavity (week 9) and the start condylar chondrogenesis. Week 11 marks the initiation of organization of the superior joint cavity. And the third stage is the maturation stage (after week 12 of development). This work establishes three phases in TMJ development: 1) the blastematic stage (weeks 7–8 of development); 2) the cavitation stage (weeks 9–11 of development); and 3) the maturation stage (after week 12 of development). This study identifies the critical period of TMJ morphogenesis as occurring between weeks 7 and 11 of development. Anat Rec 255:20–33, 1999. © 1999 Wiley‐Liss, Inc.     

Functional anatomy of the temporomandibular joint

Summary A study of 72 temporomandibular joints of adults without any gross signs of degenerative changes was made, in order to analyse the stress on individual regions of the joint, and to determine the path of the split line pattern in the articular cartilage. The cancellous architecture and the material distribution in the juxta-articular bone were also investigated. Zones of high-density compact substance in the lateral region of the joint, and the presence of attractive singular points in the split line orientation in this localization, suggest great stress on the lateral part of the temporomandibular joint. This increased stress in the lateral region is confirmed by the fact that arthrotic changes in the temporomandibular joint first almost always appear laterally. Degenerative changes usually originate at the articular disc, affect the articular tubercle after a delay, and finally spread to the condyle. Besides the greater physiological, mechanical stress on the lateral region of the joint, the force acting on every individual temporomandibular joint is influenced by the dental condition. The molars and bicuspids serving as a support zone play a decisive role in this context.Dedicated to Professor Dr. H. Haug on the occasion of his 70th birthday     

Teleradiology image transmission system: Diagnostic accuracy at three matrix sizes for various types of images

The interpretability of transmitted digitized radiographic images is an important factor in the operation and use of teleradiology systems. Matrix size may influence diagnostic accuracy of the interpretation. Commercially available equipment has certain built-in image enhancement controls that may increase the interpretability of the image received. Evaluation of the effect of varying the matrix size and other factors on diagnostic accuracy are described.     

Vector quality measure of lossy compressed medical images

A numerical measure, which is able to predict diagnostic accuracy rather than subjective quality, is required for compressed medical image assessment. The objective of this study is to present a proposal for a new vector measure of image quality, reflecting diagnostic accuracy. Construction of such measure includes the formation of a diagnostic quality pattern based on the subjective ratings of local image features playing an essential role in the detection and classification of any lesion. Experimental results contain the opinions of 9 radiologists: 2 test designers and 7 observers who rated digital mammograms. The correlation coefficient between the numerical equivalent of the vector measure and subjective pattern is over 0.9.     

Diagnostic accuracy of droplet digital PCR analysis of cerebrospinal fluid for tuberculous meningitis in adult patients

ObjectivesTuberculous meningitis (TBM) is difficult to diagnose. Digital PCR (dPCR) is a novel method which can quantify trace nucleic acids. This study sought to evaluate the diagnostic accuracy of dPCR analysis of cerebrospinal fluid (CSF) for TBM.MethodsWe collected CSF specimens from hospitalized TBM and non-TBM patients. Total CSF DNA was purified and the concentrations of Mycobacterium tuberculosis insert sequence 6110 (IS6110) and gyrase subunit B (gyrB) were quantified using droplet dPCR. The receiver operating characteristic curves of dPCR were established and the diagnostic performances were obtained. We also compared the sensitivity of dPCR with routine diagnostic tests.ResultsA total of 101 patients were recruited, 68 of whom suffered from TBM (26 definite, 34 probable and eight possible TBM) and 33 from non-TBM. The sensitivity of IS6110-dPCR assay for total TBM was higher than that of gyrB-dPCR assay (57.4% (44.8–69.3%) vs. 22.1% (12.9–33.8%)), and there was no significant difference for specificity between them (97.0% (84.2–99.9%) vs. 100% (89.4–100.0%)). The sensitivity of IS6110-dPCR in definite TBM was higher than that in probable and possible TBM (73.1% vs. 52.9% and 25.0%, respectively). IS6110-dPCR assay showed a higher sensitivity than smear microscopy (53.3% vs. 6.7%), mycobacterial culture (50.0% vs. 12.5%), IS6110-quantitative PCR (53.1% vs. 21.9%) and Xpert MTB/RIF (70.4% vs. 29.6%). Long anti-tuberculosis treatment time was found to be significantly associated with negative dPCR results.ConclusionCSF IS6110-dPCR assay is a rapid and sensitive molecular test, which has the potential to be used to enhance the diagnosis of TBM.     

Development of the human temporomandibular joint.

A great deal of research has been published on the development of the human temporomandibularjoint (TMJ). However, there is some discordance about its morphological timing. The most controversial aspects concern the moment of the initial organization of the condyle and the squamous part of the temporal bone, the articular disc and capsule and also the cavitation and onset of condylar chondrogenesis. Serial sections of 70 human specimens between weeks 7 and 17 of development were studied by optical microscopy (25 embryos and 45 fetuses). All specimens were obtained from collections of the Institute of Embryology of the Complutense University of Madrid and the Department of Morphological Sciences of the University of Granada. Three phases in the development of the TMJ were identified. The first is the blastematic stage (weeks 7-8 of development), which corresponds with the onset of the organization of the condyle and the articular disc and capsule. During week 8 intramembranous ossification of the temporal squamous bone begins. The second stage is the cavitation stage (weeks 9-11 of development), corresponding to the initial formation of the inferior joint cavity (week 9) and the start condylar chondrogenesis. Week 11 marks the initiation of organization of the superior joint cavity. And the third stage is the maturation stage (after week 12 of development). This work establishes three phases in TMJ development: 1) the blastematic stage (weeks 7-8 of development); 2) the cavitation stage (weeks 9-11 of development); and 3) the maturation stage (after week 12 of development). This study identifies the critical period of TMJ morphogenesis as occurring between weeks 7 and 11 of development.     

Soft tissue mechanics of the temporomandibular joint

Direct measurement of temporomandibular joint (TMJ) tissue deformation requires animal experimentation. Most of the available data pertain to the mechanical strain on the bone surfaces around the joint. However, bone is rarely the first joint tissue to show injury, being affected after damage to collagenous tissues such as the disc or capsule. Capsular ligaments guide or limit movement, while the intra-articular disc may also distribute joint loads. However, these tissues are difficult to visualize dynamically and not suitable for strain gage attachment, so in vivo deformations are poorly understood. Using pigs as the best nonprimate model for human TMJ function, we implanted differential variable reluctance transducers to measure antero-posterior strain in the lateral aspect of the intra-articular disc. The results were compared to previously published data on the TMJ capsule. Passive manipulation in anesthetized animals indicated that opening, protrusion, and contralateral movements caused the disc to elongate. On the contrary, closing, retrusion and ipsilateral movements caused disc shortening. These strains are opposite to those observed in the capsule and are expected on anatomical grounds. Surprisingly, disc strain during mastication differed from that during manipulation. The disc elongated during jaw closure, more on the retruding balancing side (16% +/- 1) than on the working side (8% +/- 2). This anomalous behavior may reflect compressive loading, such that the disc elongates as a result of the Poisson effect rather than condylar movement. Because the capsule also elongates during the power stroke, especially on the balancing side, both disc and capsule are maximally loaded on the same side at the same moment.     

Kinematic analysis of the human temporomandibular joint

A kinematic analysis of the temporomandibular joint (TMJ) is developed to determine the range of motion of the mandible during normal opening and during special motions required for arthroscopic surgery. The translation of the mandible is restricted by the constraint of the ligaments. By accounting for the maximum allowable stretch of a ligament, limits of translation are determined for any normal opening angle of the mandible. The present analysis provides information useful in securing the maximum available space for the protrusion of arthroscopic instruments during TMJ surgery.