Outer-Boundary Assisted Segmentation and Quantification of Trabecular Bones by an Imagej Plugin

Micro-computed tomography (micro-CT) is routinely used to assess bone quantity and trabecular microstructural properties in small animals under different ...

wuhan university

With age, there is a progressive loss of body balance function. Yet, the potential influence of osteoporosis on body balance is largely unknown. Dentin matrix protein 1 (DMP1) is highly expressed in bone and required for phosphate homeostasis and mineralization. Dmp1 null mice display striking defects in bone structure. In this study we reported circling behavior and hyper reaction to touching in Dmp1 null mice. Our histology, tartrate resistant acid phosphatase (TRAP) staining and µCT data showed dramatic changes, such as an expansion of poorly mineralized matrices, in the Dmp1 null porous bony structure in the vestibular apparatus. The targeted re-expression of DMP1 in the Dmp1 null bone fully rescued not only the bone phenotype, but also circling behavior and hyper reaction. Furthermore, X-gal stain and DMP1 immunohistochemistry assay showed that DMP1 was not expressed in neuron cells or balance related cells in the inner ear, suggesting that a defect in the bony labyrinth of the internal ear is indirectly responsible for the circling behavior and/or hyper reaction to touching. Finally, discovery of DMP1 lacZ signal in pericyte-like cells may suggest a new function of DMP1 in angiogenesis.

Circling behavior developed in Dmp1 null mice is due to bone defects in the vestibular apparatus.

As a model animal, the mouse has already been widely used in bone-related research. However, there is a lack of ideal long bone segmental defect mouse model. Since external fixation has disadvantages of heavy weight, penetrating the skin, and hampering mobility, an internal fixation device is probably more preferable to maintain the segmental bone defect. The aim of this study was to establish a simple, reproducible, and standardized murine critical-size defect model through designing an internal fixation system, verifying its adaptability, and investigating the critical size of femoral segmental defect.

A murine femoral segmental defect model for bone tissue engineering using a novel rigid internal fixation system.

It has traditionally been difficult to create full-thickness defects in the mandibles of rodent animals because of dissimilar anatomic structures with humans, interference from teeth of jaws, and limited surgical access. To better mimic the cellular situation and the unique masticatory stresses in maxillofacial regions of humans, we developed an animal model of mandibular defects, in which rabbits were implanted with the beta-tricalcium phosphate/chitosan (β-TCP/CS) scaffolds after a dental extraction and the creation of a full-thickness bone defect.

A novel animal model treated with tooth extraction to repair the full-thickness defects in the mandible of rabbits.

This study was designed to evaluate the results in isolated mandibular angle fractures treated with resorbable plates and to summarize experiences of the application of resorbable plates.

Resorbable plates for the fixation of isolated mandibular angle fracture.

The purpose of this study was to describe the application of computer-assisted navigation for the retrieval of accidentally displaced mandibular third molars.

Use of Computer-Assisted Navigation in the Retrieval of Accidentally Displaced Third Molars.

As the mandible is susceptible to fracture, the aim of this study was to use multivariate logistic regression analysis to identify and distinguish various internal factors that may influence the location of mandibular fractures. The study included 1131 patients with maxillofacial fractures during the period from January 2000 to December 2009 to evaluate the association of mandibular fracture location (unilateral symphysis, body, angle, condylar, or bilateral condylar fractures) with various internal factors. Among the 1131 patients, 869 had mandibular fractures. Data on age, sex, soft tissue injuries, dental trauma, and maxillofacial fracture type were collected and analyzed using multivariate logistic regression. In total, 387, 210, 139, 319, and 172 patients were diagnosed with unilateral symphysis, body, angle, unilateral, or bilateral condylar fractures, respectively. The dental trauma in patients with bilateral condylar fractures differed from that in patients with unilateral condylar fractures. Patients with mandibular fracture (unilateral symphysis, body, unilateral or bilateral condylar) possessed an approximately equal risk of soft tissue injuries in the mandible. Patients with either unilateral or bilateral condylar fractures were associated with a low risk of mandibular angle fracture (OR < 1). Similarly, patients with mandibular angle fracture were associated with a low risk of unilateral or bilateral condylar fractures (OR < 1). Moreover, patients with symphysis fracture were associated with a low risk of bilateral condylar fractures (90 of 387 [23.3%], OR 0.899). By contrast, patients with bilateral condylar fractures were associated with a high risk of symphysis fracture (90 of 172 [52.3%], OR 17.38). Patients with condylar fractures, particularly those with bilateral condylar fractures, were infrequently associated with secondary mandibular fractures. Mandibular fractures tended to have less of an association with midfacial fractures. The occurrence of mandibular fractures is strongly correlated with age, sex, soft tissue injuries, dental trauma, and the pattern and position of the maxillofacial fractures in patients.

Mechanics in the Production of Mandibular Fractures: A Clinical, Retrospective Case-Control Study.

                    
Despite some potential advantages, tissue-engineered constructs have low therapeutic efficacy after transplantation into bone defect sites due to uneven distribution of seed cells, which presents a major obstacle in a clinical setting. The aim of this study was to improve cell distribution within the scaffold, to increase seeding efficiency, to facilitate tissue ingrowth and vascularization of the resultant grafts, and finally to boost the successful rate of transplantation.A syringe-aided inoculation method was designed to anchor bone marrow stromal cells (BMSCs) onto the central pores of the chitosan scaffold by repeat positive aspiration. The cell distribution, cell number, vascularization and mineralization at the central region of the tissue-engineered constructs treated by syringe-aided and regular two-side inoculation methods were evaluated side by side using the WST-8, immunofluorescence staining of CD31 and von Kossa staining.The tissue-engineered constructs treated by the syringe-aided inoculation methods exhibited a larger number of BMSCs with uniform distribution, as well as more robust vascularization and mineralization in the central regions when compared with those treated by the two-side inoculation method bothand.This is the first time that the influence of a syringe-aided inoculation method has been evaluated with respect to the vascularization and mineralization of implanted grafts.The syringe-aided inoculation methods used in this study might provide an approach through which to improve cell distribution within the scaffold, facilitate the subsequent tissue ingrowth into the scaffold, and promote the vascularization and mineralization of tissue-engineered grafts.

Effects of a Novel Inoculation Method on Cell Distribution, Mineralization, and Vascularization of Tissue-Engineered Constructs.

To comparatively assess the effectiveness of the supine position technique versus the conventional method, for the manual reduction of acute nontraumatic temporomandibular joint (TMJ) dislocation.

The Supine Position Technique Method Is Better Than the Conventional Method for Manual Reduction of Acute Nontraumatic Temporomandibular Joint Dislocation.

This study aimed to identify and distinguish various factors that may influence the occurrence of mandibular coronoid fractures. From January 2000 to December 2009, a total of 1131 patients with maxillofacial fractures were enrolled in this statistical study to evaluate the association between mandibular coronoid fractures and other risk factors. Among these patients, 869 had mandibular fractures, and 25 sustained a total of 25 coronoid fractures. More than half (13 of 25 patients, 52%) of the coronoid fractures in these patients were caused by motor vehicle accidents. Among these coronoid fractures, seven were associated with other mandibular fractures, and 23 (92.0%) were related to midfacial fractures. The most common site of midfacial fracture was the zygomatic arch (20 patients, 80%). Multivariate logistic regression analysis revealed that the most important influencing factor was the zygomatic arch fracture (odds ratio, 9.033; 95% confidence interval, 1.658, 49.218; p = 0.011). The majority of coronoid fracture fragments (19 of 25, 76%) were removed during operation. The most commonly used incision is hemicoronal or bicoronal approach (16 of 19, 84.2%).

Risk factor analysis and idiographic features of mandibular coronoid fractures: A retrospective case-control study.

Genetic mouse models are widely used for understanding human diseases but we know much less about the anatomical structure of the auditory ossicles in the mouse than we do about human ossicles. Furthermore, current studies have mainly focused on disease conditions such as osteomalacia and rickets in patients with hypophosphatemia rickets, although the reason that these patients develop late-onset hearing loss is unknown. In this study, we first analyzed Dmp1 lac Z knock-in auditory ossicles (in which the blue reporter is used to trace DMP1 expression in osteocytes) using X-gal staining and discovered a novel bony membrane surrounding the mouse malleus. This finding was further confirmed by 3-D micro-CT, X-ray, and alizarin red stained images. We speculate that this unique structure amplifies and facilitates sound wave transmissions in two ways: increasing the contact surface between the eardrum and malleus and accelerating the sound transmission due to its mineral content. Next, we documented a progressive deterioration in the Dmp1-null auditory ossicle structures using multiple imaging techniques. The auditory brainstem response test demonstrated a conductive hearing loss in the adult Dmp1-null mice. This finding may help to explain in part why patients with DMP1 mutations develop late-onset hearing loss, and supports the critical role of DMP1 in maintaining the integrity of the auditory ossicles and its bony membrane.

A novel auditory ossicles membrane and the development of conductive hearing loss in Dmp1-null mice.

To assess the efficiency of inhaled nitrous oxide (NO) for the reduce the perception pain in extraction of iodoform gauze packing strips in post Caldwell-Luc operation patients. This randomized single blind trial included a total of 47 patients, aged between 14-82 years, in which undergoing radical maxillary sinusotomy. Based on the randomization procedure, patients were treated with (experimental) or without (control) inhaled NO. The visual analogue scale scores (VAS scores) of the pain perception and the headache duration time were comparatively studied. The average VAS score for pain perception was 3.92 in the NO group and 7.87 in the control group. The average headache duration time was 0.12 hour in the NO group and 13.09 hours in the control group. Both VAS scores for pain perception during the treatment and the average headache duration time were significantly reduced in the inhaled NO group (P < 0.01). Reduced pain perception and headache duration time indicated that, the inhaled NO method might be viable in extraction of iodoform gauze packing strips in post Caldwell-Luc operation patients.

Kun Lv

wuhan university

Outer-Boundary Assisted Segmentation and Quantification of Trabecular Bones by an Imagej Plugin