Bone Tissue Engineering for Tempero Mandibular Joint Application

The temporomandibular joint (TMJ) is a hinge like joint that connects the mandible to the temporal bone of the skull. The TMJ consists of two components; soft and bony tissue. Temporomandibular disorders (TMD's) refer to problems or conditions related to the TMJ which affect the whole or part of the joint. TMD's affect around 10.5 million adults worldwide and 25% of the overall UK population. Surgical procedures currently include: arthrocentesis (needles inserted into upper jaw cavity and a solution is injected to loosen up the joint and wash out any microscopic particles), arthroscopy (a small incision is made in front of the ear and an instrument is used to remove any inflamed tissue or to realign the jaw), open joint surgery (repairs, realigns or removes articular disc) and total joint replacement. Bone tissue engineering is a process which involves biomaterials and cell therapy which work together to regenerate bone and tissue that is lost due to various reasons such as injury or disease. Hydrogels are three-dimensional polymer networks that are crosslinked to create matrices with large water content. As well as hydrogels, bioactive glasses are also considered as a suitable material for scaffolds and are composed of silica, sodium, calcium and phosphate oxides. Previous studies in this area have heavily been based on the regeneration of the articular disc as this is the component that is commonly associated with the majority of temporomandibular disorders due to high rates of disc displacement and degeneration. There is a clinical need for bone tissue engineering of the TMJ as current techniques are not cost efficient and most importantly not successful for long term purposes. As the TMJ is of an avascular nature, bone and tissue regeneration for replacement purposes is the most credible technique to use in this research area. This project aims to regenerate this complex osteochondral joint (lower mandible) through bone tissue engineering using novel techniques, which on a wider clinical scope could potentially minimise the surgical risks, limit the downtime-making it a safer experience for the patient. The following important factors will be carefully considered when selecting the biomaterials: the suitable cell type to carry out the required task, the correct environment (through careful selection of the hydrogel/bioactive glass), the right biomolecules for growth factors and the suitable physical and mechanical forces to influence the development of cells. The 3D Discovery Evolution will be used for bio-printing. This is a novel piece of equipment that has not been used in any previous studies relating to the regeneration of the TMJ. The machine offers modularity, flexibility and customisation which are all important factors.