Scientists create jaw bone from stem cells

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New York: Scientists have created part of the jaw bone for the first time in the lab using human adult stem cells.

The technique, which created the joint, may be useful for other areas of the body.

The Columbia University study appears in Proceedings of the National Academy of Sciences.

The bone which has been created in a lab, by scientists at Columbia University is called the temporomandibular joint (TMJ). This joint which is complex to repair can be damaged by defects at birth, arthritis or injury. Treatment is notoriously difficult as the joint has a complex structure and is difficult to replicate using bone grafts.

Scientists used human stem cells taken from bone marrow which were then planted into a “tissue scaffold” in the shape of a human jaw bone.

The cells were then cultured nutrients found during natural bone development.

Lead researcher Dr Gordana Vunjak-Novakovic said: “The availability of personalised bone grafts engineered from the patient’s own stem cells would revolutionise the way we currently treat these defects.”

She said the new technique could also be applied to other bones in the head and neck, including skull bones and cheek bones, which are similarly difficult to graft.

She stressed that the joint created in the lab was bone only, and did not include other tissue, such as cartilage which the team is also working on.

Jaw Problems and Headaches – animation and Qs & As

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JAW PROBLEMS & HEADACHES

Q What is dental occlusion?

A Dental occlusion is another name for the way your teeth meet when your jaws bite together.

Q What is TMJ?

A The letters TMJ are short for of ‘temporo-mandibular joint’, which is the joint connecting your lower jaw and your skull. The movement in this joint lets you open and close your mouth and chew from side to side.

Q What kind of problems might I have?

A If your teeth don’t fit together properly, you can have problems not only in your teeth themselves, but also the gums, the temporo-mandibular joint or the muscles that move your jaw. These problems are called ‘occlusal’ problems.

Teeth

Teeth that are out of line, heavily worn or constantly breaking, fillings that fracture or crowns that work loose may all be signs of occlusal problems. Your teeth may also be tender to bite on or may ache constantly.

Gums
Loose teeth or receding gums can be made worse by a faulty bite.
TMJ
Clicking, grinding or pain in your jaw joints, ringing or buzzing in your ears and difficulty in opening or closing your mouth could all be due to your teeth not meeting each other properly.

Muscles

If your jaw is in the wrong position, the muscles that move the jaw have to work a lot harder and can get tired. This leads to muscle spasm. The main symptoms are continual headaches or migraine, especially first thing in the morning; pain behind your eyes; sinus pain and pains in your neck and shoulders. Sometimes even back muscles are involved.

Q How can I tell if I have a problem?

A You may find that you clench or grind your teeth, although most people who do aren’t aware of it. Sometimes can be caused by anxiety, but generally most people clench their teeth when they are concentrating on a task – housework, gardening, car mechanics, typing and so on.

You may wake up in the morning with a stiff jaw or tenderness when you bite together. This could be due to clenching or grinding your teeth in your sleep. Most people who grind their teeth do it while they are asleep and may not know they are doing it.

If you suffer from severe headaches, or neck and shoulder pain, you may not have linked this with possible jaw problems. Or you may keep having pain or discomfort on the side of your face around your ears or jaw joints or difficulty in moving your jaw. These are all symptoms of TMJ problems.

If you are missing some teeth at the back of your mouth, this may lead to an unbalanced bite, which can cause uneven pressure on your teeth.

Together, all these symptoms are called ‘TMJ syndrome’.

Q How are occlusal problems treated?

A See your dentist. He or she may be able to help you or may refer you to a specialist who deals with occlusal problems.

Depending on the problems you are having, it can be possible to spot the signs of an occlusal problem. Various muscles may be sore when tested, or the broken and worn areas of your teeth will show you are grinding your teeth – a common sign of an incorrect bite.

If your dentist suspects that your problems are due to an incorrect bite, he or she may help to diagnose the problem by supplying a temporary soft nightguard or hard plastic appliance that fits over your upper or lower teeth. This appliance needs to be measured and fitted very accurately so that when you bite on it, all your teeth meet at exactly the same time in a position where your muscles are relaxed. You may have to wear this all the time or, just at night. If the appliance relieves your symptoms then your bite may need to be corrected permanently.

Tooth Adjustment (equilibration)
Your teeth may need to be carefully adjusted to meet evenly. Changing the direction and position of the slopes that guide your teeth together can often help to reposition the jaw.

Replacement of teeth
The temporo-mandibular joint needs equal support from both sides of both jaws. The chewing action is designed to work properly only when all your teeth are present and in the correct position. Missing teeth may need to be replaced either with a partial denture or bridgework.

Replacement is not usually done until a diagnosis has been confirmed by using an appliance and this has fully relieved the symptoms. Relief in some patients is instant: in others it can take a long time.

Medication
Some drugs can help in certain cases, but this is usually only temporary. Hormone replacement therapy may also help some women.

Diet and Exercise
As with any joint pain, it can help to put less stress on the joint. So a soft diet can be helpful, as can Corrective exercises and external heat. Physiotherapy exercises can often help, and your dentist may be able to show some of these to you.

Relaxation
Counselling and relaxation therapy may help in some cases. These techniques help the patient to become more aware of stressful situations and to control tension.

Q Will straightening my teeth help?

A If your teeth are too far out of line or in a totally incorrect bite position, it may be necessary to fit an orthodontic appliance to move them into a better position.

Q How many people suffer from these problems?

A Up to 1 in 4 people may have some symptoms. Both men and women are affected equally, although women tend to seek
treatment more often than men. The symptoms can often start with the menopause or other hormonal changes.

Many people have imperfect occlusion and missing teeth, yet never have symptoms because they adjust to their problems. Occasionally, in times of increased stress and tension, the symptoms may appear and then go away immediately. Or, your teeth and gums may be affected straight away and instead of headaches, you may suffer:

 flattened, worn teeth
 broken teeth, fillings and crowns
 loose teeth
 continual sensitivity of your teeth to temperature change
 toothache with no apparent cause.

If you think you have any of these problems, ask your dentist.

German doctors grow new jawbone from stemcells

Kiel: A German man was able to chow down on a bratwurst sandwich after surgeons grew a new jaw bone on his back muscle and transplanted the bone to his mouth.

The 56-year-old man had part of his lower jaw removed because of mouth cancer. Until the transplant, his diet was limited to soft food and soup for nine years.

Doctors in Kiel, Germany have rebuilt a man’s face using a new jaw grown on his back.

Dr Patrick Warnke, a reconstructive facial surgeon at the University of Kiel in Germany and his colleagues used CT scans and computer-aided designs to build a virtual jaw replacement.

The researchers used the model to construct a mesh cage, which they filled with bone mineral, protein and stem cells from the patient’s bone marrow. They then transplanted the implant below his right shoulder blade.

Seven weeks later, surgeons transplanted the new bone graft into the mouth gap in the patient’s face.A month after the surgery, he was able to eat his celebratory supper.The experiment is described in the medical journal The Lancet.

“We suggest that our results represent a proof of principle,” Warnke said in a release, noting the patient needs to be followed in the long term before drawing conclusions.

Researchers need to investigate appropriate combinations of biomaterials, growth factors and “blank slate” stem cells needed to build strong, resilient substitutes for bone, said Stan Gronthos, a stem cell expert at the Hanson Institute in Adelaide, Australia.

“A patient who had previously lost his mandible through the result of a destructive tumour can now sit down to chew his first solid meals in nine years … resulting in an improved quality of life for that individual,” Gronthos wrote in a commentary accompanying the study.