Dr Mark O'Donnell B.D.S
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News - September 2016
Isotopic analysis of teeth may identify starvation in victims of the Great Famine
Isotopic analysis of teeth may identify signs of starvation in human tissues from 19th century Irish workhouse residents, according to a study published in the journal PLOS ONE by Julia Beaumont from the University of Bradford, UK, and colleagues.
To investigate dietary and physiological changes during the Great Famine, the authors analysed the carbon and nitrogen isotope ratios of one tooth each from 20 Kilkenny Union workhouse residents, including some who died in childhood.
The authors compared the dentine collagen in tiny sections of the teeth, which represents diet at the time of tooth growth, with bone collagen from ribs, which represents the final few years of life, and historical records on food availability at the time.
The researchers' isotopic analysis not only recorded the expected dietary change from potatoes to maize, which was imported from America to provide relief during the famine, but it also revealed prolonged nutritional and other physiological stress resulting from insufficient sustenance during childhood.
This study shows that incremental dentine collagen isotope analysis may identify periods of physiological stress such as famine in both adult and juvenile skeletons if it occurred during tooth development. These findings may have forensic and archaeological applications for the identification of populations and individuals for whom nutritional stress may have contributed to their death.
Beaumont said: "Because the workhouse residents were given maize as a famine relief food, we could identify a marker for starvation in the teeth formed just before the change”.
Injected agents cause new bone growth in mouse jaws
A team at Tokyo Medical and Dental University, Japan has stimulated bone growth in mice jaws by injecting a solution into them. The part of the jawbone containing tooth sockets is known as alveolar bone, and its loss over time or following dental disease may ultimately result in tooth loss. While dentures can be used as tooth replacement, the mechanical stimuli under them causes further bone loss. An alternative and more permanent solution is strongly hoped for.
Human bone morphogenetic protein 2 (BMP-2) has been used to stimulate bone formation in humans, but high levels can cause inflammation and tumours. Therefore, agents such as peptide drugs for accelerating bone augmentation need to be developed, even in the presence of lower levels of BMP-2. Additionally, there are no known means of stimulating local bone augmentation without performing surgery.
The peptide OP3-4 has been shown to inhibit bone decay and stimulate the differentiation of cells that form bone. The team in Tokyo injected a gelatin-based gel carrying OP3-4 and BMP-2 into mice jawbones to trigger local augmentation of bone around the injection site. The study was recently reported in the Journal of Dental Research.
Use of this injectable gel to carry the agents avoids the need for surgical implantation and resulted in no swelling or other such complications in the mice. The researchers observed a region of increased bone mass around the injection site that was larger than that seen in mice injected with BMP-2 alone. This mass also had a significantly higher bone mineral content and density.
Hidden tooth infections may predispose people to heart disease
According to a study carried out at the University of Helsinki, Finland and published in the Journal of Dental Research, an infection of the root tip of a tooth increases the risk of coronary artery disease, even if the infection is symptomless. Hidden dental root tip infections are very common and are usually only detected by chance from x-rays.
Researcher John Liljestrand said: "Acute coronary syndrome is 2.7 times more common among patients with untreated teeth in need of root canal treatment than among patients without this issue”.
Dental root tip infection is a bodily defence reaction against microbial infection in the dental pulp. Tooth decay is its most common cause.
Today, information is increasingly available about the connection between oral infections and many common chronic diseases. For example, periodontitis, an inflammatory disease affecting the tissues that surround the teeth, causes low-grade inflammation and is regarded as an independent risk factor for coronary artery disease and diabetes.
The study consisted of 508 patients with a mean age of 62, who were experiencing heart symptoms. Their coronary arteries were examined, and 36% of them were found to be suffering from stable coronary artery disease, 33% had acute coronary syndrome, and 31% did not suffer from coronary artery disease to a significant degree. Their teeth were examined and as many as 58% were found to be suffering from one or more inflammatory lesions.
Root canal treatment of an infected tooth may reduce the risk of heart disease, but more research is needed.
Recording selfies while brushing teeth can improve oral healthcare skills
Recording smartphone video ‘selfies’ of tooth brushing can help people learn to improve their oral healthcare techniques, according to a new study published in the Indian Journal of Dental Research.
Using smartphones propped on stands, study participants filmed their brushing. Researchers saw an increase in the accuracy of brush strokes, an increase in number of strokes and an overall 8% improvement in tooth-brushing skill. The length of time a person brushed did not change.
Some people do not brush their teeth properly and opportunities to improve such skills can be few. Lance T. Vernon, co-author of the study said: "Often, tooth brushing is learned and practiced without proper supervision. Changing tooth brushing behaviours – which are ingrained habits tied to muscle memory – can take a lot of time and guidance”.
Vernon added: "Our study suggests that, in the future, recording these selfies can help shift some of this time investment in improving brushing to technology. Patients can then receive feedback from dental professionals”.
The very act of recording a selfie may disrupt ingrained habits, making participants conscious of their brushing and reinforce staples of behaviour change, including the process of memory formation, association and creating new muscle memory.
Before the study, participants' brushing habits were assessed and corrected until each were able to demonstrate proper technique. During the study, they were scored on time spent brushing and skill mastery, including brushing in a circular motion, obtaining a 45-degree angle while brushing facial surfaces of teeth and correct positioning of the arm.