Tantalum is not a medical term, but a chemical element with the symbol Ta and atomic number 73. It is a rare, hard, blue-gray, lustrous transition metal that is highly corrosion-resistant. In the field of medicine, tantalum is often used in the production of medical implants such as surgical pins, screws, plates, and stents due to its biocompatibility and resistance to corrosion. For example, tantalum mesh is used in hernia repair and tantalum rods are used in spinal fusion surgery.

Bronchography is a medical imaging technique that involves the injection of a contrast material into the airways (bronchi) of the lungs, followed by X-ray imaging to produce detailed pictures of the bronchial tree. This diagnostic procedure was commonly used in the past to identify abnormalities such as narrowing, blockages, or inflammation in the airways, but it has largely been replaced by newer, less invasive techniques like computed tomography (CT) scans and bronchoscopy.

The process of bronchography involves the following steps:

1. The patient is sedated or given a local anesthetic to minimize discomfort during the procedure.
2. A radiopaque contrast material is introduced into the bronchi through a catheter that is inserted into the trachea, either via a nostril or through a small incision in the neck.
3. Once the contrast material has been distributed throughout the bronchial tree, X-ray images are taken from various angles to capture detailed views of the airways.
4. The images are then analyzed by a radiologist to identify any abnormalities or irregularities in the structure and function of the bronchi.

Although bronchography is considered a relatively safe procedure, it does carry some risks, including allergic reactions to the contrast material, infection, and bleeding. Additionally, the use of ionizing radiation during X-ray imaging should be carefully weighed against the potential benefits of the procedure.

Osseointegration is a direct structural and functional connection between living bone and the surface of an implant. It's a process where the bone grows in and around the implant, which is typically made of titanium or another biocompatible material. This process provides a solid foundation for dental prosthetics, such as crowns, bridges, or dentures, or for orthopedic devices like artificial limbs. The success of osseointegration depends on various factors, including the patient's overall health, the quality and quantity of available bone, and the surgical technique used for implant placement.

In the context of medical terminology, "porosity" is not a term that is frequently used to describe human tissues or organs. However, in dermatology and cosmetics, porosity refers to the ability of the skin to absorb and retain moisture or topical treatments.

A skin with high porosity has larger pores and can absorb more products, while a skin with low porosity has smaller pores and may have difficulty absorbing products. It is important to note that this definition of porosity is not a medical one but is instead used in the beauty industry.

Photogrammetry is not typically considered a medical term, but rather it is a technique used in various fields including engineering, architecture, and geology. However, it has found some applications in the medical field, particularly in orthopedics and wound care. Here's a definition that covers its general use as well as its medical applications:

Photogrammetry is the science of making measurements from photographs, especially for recovering the exact positions of surface points on an object. It involves the use of photography to accurately measure and map three-dimensional objects or environments. In the medical field, photogrammetry can be used to create 3D models of body parts (such as bones or wounds) by capturing multiple images from different angles and then processing them using specialized software. These 3D models can help healthcare professionals plan treatments, monitor progress, and assess outcomes in a more precise manner.

I'm sorry for any confusion, but "Niobium" is not a medical term. Niobium is a chemical element with the symbol Nb and atomic number 41. It is a soft, grey, crystalline metal that is naturally found in minerals such as columbite and pyrochlore.

Niobium has some applications in the medical field, particularly in the production of implants and medical devices. For instance, niobium alloys are used in orthopedic implants due to their excellent corrosion resistance and biocompatibility properties. However, niobium itself is not a medical term or concept.