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Results for entries tagged with "Dentistry"

Histological Bone Morphometry

Traditional 2D bone morphometric analyses utilize hard-tissue histological sectioning and evaluation of bone cores (human or animal) stained with Toluidine Blue and embedded in PMMA.

Bright Field Immuno-Staining

Non-fluorescent, immuno-staining of histological tissue for specific antigens generally involves enzymatic subtrates that oxidize compounds such as diaminobenzidine (DAB) to precipitate a brown chromogenic product. Unfortunately, "brown" color is composed of a mixture of hues not easily segmented or characterized from background.

Osseointegration of Bone Graft Analysis in CT

Assessment of bone growth into scaffolds or grafts is generally performed qualitatively and thus difficult to consistently replicate across timepoints for a given patient or across multiple patients. This is especially true when CT imaging protocols (resolution, tube potential/current, etc) aren't kept consistent.

Longitudinal Assessment of Fracture Healing

To evaluate efficacy of various treatments on fracture healing, a 1 mm fibular osteotomy was surgically created in rat fibulas. Micro-CT imaging sessions were performed (6 time-points across 36 days) to assess temporal changes in fracture healing. These time-points were spatially registered using a customized software package utilizing mutual information and iterative closest point algorithms.

Multi-modality Volumetric Registration

Spatial registration of longitudinal volumes and subsequent analysis can enable morphometric tracking of implants to evaluate degradation/biocompatibility or assess response of various pathologies/phenotypes to therapeutics or genetic manipulation.

Osseointegration in Bone Substitutes

To determine efficacy of candidate bone substitutes for non-weight bearing applications such as facial reconstruction, rate and extent of osseointegration or mineralization are key assessment parameters. Unfortunately traditional means of evaluation require multiple animals to be sacrificed at each time point followed by exhaustive histological sectioning, staining, imaging and quantitative analysis for bone in-growth for the duration of the study.

Osseointegration of Titanium Bone Screws

To assess the effects of implant surface contaminants on osseointegration, titanium bone screws with variable degrees of cleaning were implanted into the mid-diaphysis of a mouse femur for 5 weeks, explanted and imaged using micro-CT. Subsequent customized image analysis using spectral and morphological filters enabled generation of 3D screw masks.

Trabecular Analysis of Rat Vertebrae

Although not loaded in the same manner as humans, vertebrae in small animals can be used to study structural changes in trabecular bone in response to various drugs and therapies for the treatment of osteoporosis if appropriate controls are in place.

Trabecular Analysis on Human Bone Cores

Trabecular bone quality assessment is generally not performed in patient CT scans due to inadequate resolution, however, bone cores may be extracted from patients in non-weight bearing sites (i.e. illiac crest) or from discards obtained during implant insertion and scanned using micro-computed tomography (micro-CT) for analysis of structural indices.

Trabecular Analysis on Rat/Mouse Proximal Tibias

Trabecular bone quality metrics are commonly extracted from long bones and vertebrae of ovariectomized small animal models (induces osteoporosis in mice and rats) to evaluate effectiveness of various pharmaceuticals or gene therapies in counteracting osteoporosis induced bone loss.

Automated Histological Analysis of Osseointegration

The structure and chemical composition of bone scaffolds or implants will impact their ability to promote bone in-growth and consequently dictate stability of the implant. Small animal models are often utilized for evaluation of bone in-growth in candidate scaffolds. Scaffolds are generally implanted into proximal sites of long bones for a fixed period of time.

In-vivo Histological Bone Growth Assay

Traditional methods of in-vivo bone growth evaluation in small animal models utilize longitudinal micro-CT imaging. Unfortunately, live animal imaging requires low radiation dose protocols that limit spatial resolution to ~20 um which is inadequate for small animals (particularly adults) whose bone growth rates are on the order of a few um/day.

Scaffold/Implant Quality Assessment

Evaluation of devices pre and post implantation can be extremely valuable for assessing wear and degradation or just as a means of quality assurance. This is particularly important for biological scaffolds that have variable geometries post-fabrication. For such an assessment to be valuable, especially for samples evaluated pre-implantation, the imaging modality utilized has to be non-destructive and conducted in a sterile environment.