Dental Tribune United Kingdom Edition

United Kingdom Edition March 11-17, 2013 P atient age can play a role in the presence of artifacts due to movement during a dental cone-beam CT (CBCT) scan, according to a short com- munication in Dentomaxillofa- cial Radiology. Researchers from Glasgow Dental Hospital and School wrote: “Our aims were to as- sess the number of patients who showed signs of movement ar- tifact during CBCT acquisition and how many of these required retakes for diagnostic reasons,” they wrote. “Our hypothesis was that patients at the extremes of age were more likely to move during scan acquisition.” The research team used Xo- ran i-CAT Classic software to ana- lyse 200 randomly selected dental cone-beam CT scans in patients whose ages ranged from eight to 89 years. They assessed the images in cross-sections at the coronal, sagittal, and axial views. After analysing the selected CBCT images, they found signs of movement artifacts in nine scans from the 200 included in the study, although only 0.5 per cent of the scans required a retake for diagnostic reasons. These nine scans were primarily in patients younger than 16 years of age and older than 65 years of age. The researchers thus ana- lysed a second sampling of dental CBCT scans specific to these two age groups: 65 scans for those younger than age 16 and 37 for those older than 65. In this analysis, seven pa- tients younger than age 16 (10.7 per cent) showed double bony contours, and 86 per cent of these scans were in male pa- tients. In the over-65 age group, they found that eight patients moved (21.6 per cent) and that 62.5 per cent of them were fe- male. While some movement may not affect image quality, it can affect the spatial resolution, the researchers noted. They suggest using a removable chin rest and shorter acquisi- tion times, although the latter can increase signal-to-noise ratio in the resulting images, they added. DT Age affects presence of artifacts in CBCT scan 6 News T he body representing the Irish dental industry has expressed reservations that companies offering cosmetic tooth whitening services in Ire- land may not be operating in com- pliance with new European laws. As reported in thejournal.ie, a European directive which came into force last October places a limit on the amount of hydro- gen peroxide – the key bleach- ing agent – that can be used in a whitening solution administered by dentists. However, the Irish Dental As- sociation says it asked four tooth whitening businesses to provide details on the whitening gels they used, and none could do so. Meanwhile, only one of the four said their practice was overseen by a qualified dentist. The European rules also re- quire a dentist to approve the ad- ministration of the whitening gel in the first instance, and requires a full clinical exam of the patient before the process can begin. IDA representative Tom Feeney said the purpose of the directive was to ensure patient safety but that this was being threatened by the continued op- eration of others outside the law. He also warned that tooth whitening products bought over the internet may not be in com- pliance with the European rules, and that their safety could there- fore not be guaranteed. The issue is to be discussed at the Irish Dental Association’s next national council meeting in three weeks’ time. DT D NA preserved in calcified bacteria on the teeth of ancient human skeletons has shed light on the health con- sequences of the evolving diet and behaviour from the Stone Age to the modern day. The ancient genetic record reveals the negative changes in oral bacteria brought about by the dietary shifts as humans became farmers, and later with the intro- duction of food manufacturing in the Industrial Revolution. An international team, led by the University of Adelaide’s Centre for Ancient DNA (ACAD) where the research was per- formed, has published the results in Nature Genetics. Other team members include the Department of Archaeology at the University of Aberdeen and the Wellcome Trust Sanger Institute in Cambridge (UK). “This is the first record of how our evolution over the last 7,500 years has impacted the bacteria we carry with us, and the impor- tant health consequences,” says study leader Professor Alan Coop- er, ACAD Director. “Oral bacteria in modern man are markedly less diverse than historic populations and this is thought to contribute to chronic oral and other diseases in post- industrial lifestyles.” The researchers extracted DNA from tartar (calcified dental plaque) from 34 prehistoric north- ern European human skeletons, and traced changes in the nature of oral bacteria from the last hunt- er-gatherers, through the first farmers to the Bronze Age and Medieval times. “Dental plaque represents the only easily accessible source of preserved human bacteria,” says lead author Dr Christina Adler, who conducted the research while a PhD student at the University of Adelaide, now at the University of Sydney. “Genetic analysis of plaque can create a powerful new record of dietary impacts, health changes and oral pathogen genomic evolu- tion, deep into the past.” Professor Cooper says: “The composition of oral bacteria changed markedly with the introduction of farming, and again around 150 years ago. With the introduction of pro- cessed sugar and flour in the Industrial Revolution, we can see a dramatically decreased diversity in our oral bacteria, allowing domination by caries- causing strains. The modern mouth basically exists in a per- manent disease state.” DT Ancient teeth bacteria record disease evolution Teeth hold the key to bacterial change history M ore than a hundred dentists from fifty dental practices across the UK have started the Mouth Cancer Screening Ac- creditation Pilot Scheme. The scheme, which is supported by Henry Schein, DPAS and ProDentalCPD, is the brainchild of Dr Vi- nod Joshi, Founder of the Mouth Cancer Foundation. It will recognise dental practic- es that demonstrate a visible commitment to increasing public awareness of mouth cancer screening to all patients and to establish a documented referral path- way with a local specialist department. The practices who have signed up to take part in the pilot will start the annual membership programme today ahead of the official launch at the BDA Conference on Saturday 27th April 2013. They will road test all aspects of the initiative to ensure it runs smoothly. The pilot practices will work through the accreditation process and act in a focus group capacity by feeding back on the scheme, its meth- ods, quality and efficiency. On completion of the rel- evant criteria they will receive full accredita- tion when the Mouth Can- cer Screening Accreditation Scheme launches. Full membership includes access to a dedicated section of the charity website and FREE one hour CPD element as well as professional devel- opment and training modules suitable for all members of the practice team to ensure regu- lar screening benefits practice patients. The Mouth Cancer Screen- ing Accreditation Scheme is open to any dentist registered with the GDC or any den- tal practice whose clinicians are registered with the GDC. Dentists who take part in the pilot scheme will receive as- sociate accreditation when the Mouth Cancer Screening Accreditation Scheme launch- es. For more information or to take part in the pilot scheme please contact the Mouth Cancer Foundation via info@ mouthcancerfoundation.org or call +44 (0) 1924 950 950 for more information. DT Concern over illegal whitening in Ireland Pilot underway for mouth cancer screening scheme