Another edition of a joint EFP/AAP workshop has just closed in Chicago, and periodontal scientists and teachers all over the world are eagerly awaiting the proceedings to be published in our core scinetific journals, the Journal of Periodontology and the Journal of Clinical Periodontology. The workshop’s agenda had been announced on the EFP website on Thursday this week.
Hallmarks of the previous Classification of Periodontal Diseases and Conditions of 1999 had included a thorough classification of gingival diseases and renaming, once more, juvenile/early-onset periodontitis as “aggressive”, and the more common “adult” form of periodontitis as “chronic”. Many scientists, in particular epidemiologists had considered the latter achievement as highly problematic. Not only that disease definitions included some laboratory tests not available to the common practitioner; progression rates were to be assessed as well. Both is utterly difficult, if impossible, in epidemiological research.
And, as assumed microbiological cause and pathogenesis of either chronic or aggressive periodontitis do not differ fundamentally, does a differentiation even make sense? What comes to one’s mind is, of course, diabetes where types I and II have different causation and can easily be differentiated despite common clinical signs and symptoms.
The above is the conclusion of a recent retrospective evaluation of root-resected molars during a time-span of 30 years in a private practice. I would like to draw attention in particular to the last part of the sentence which is of utmost importance. I shall explain below, what I think is necessary when reporting research findings in an honest way.
When has root resection been reported first?
Root resection, or amputation, is an old story. According to common wisdom, it had been Dr. John N. Farrar from Brooklyn, NY, who had reported first on so-called “radical and heroic treatment” of alveolar abscesses by amputation of roots of teeth , “in order to enable nature to have a better chance for cure.” Dr. Farrar correctly stated that, “if an entire tooth should be extracted from a diseased socket, the treatment might be termed highly radical.” He considered that such a treatment might not only unwise and unnecessary but “absolutely wrong and unscientific [sic].”
It is amazing that, some 130 years ago, reporting couple of cases was considered “science”. The times they are a changin’. Maybe in 100 years our current approach to what is still regarded scholarship and science will be ridiculed as well.
What can be achieved
Root resection or hemisection of furcation-involved molars are still common treatment options based on more rigorous research in the past 45 years. There may be also other indications, endodontic and iatrogenic. Implant dentistry is of course an interesting alternative, and a not so recent case series of patients attending a single private practice by Fugazzotto (2001) from Milton, MA, had shown comparable results regarding successful treatment of either root resection of molars (n=701) or placing implants in molar locations (n=1472) after 15 and more years and 13 years, respectively. Indeed remarkable results, namely success rates of 96.8% for root resected molars and 97% for implants.
Shortly before recent updates of the Global Burden of Disease (GBD) studies (supported by the Bill & Melinda Gates Foundation) sparked considerable attention in the news, dubious metrics like disability-adjusted life years (DALY) and years lived with disability (YLD) had been calculated for a number of oral diseases and conditions such as (severe) periodontitis. These metrics are basically derived from estimates of incidence (and, recently also, prevalence) of the disease, and a disability weighing factor; but interpretation must be regarded spurious. One may intuitively ask the important question, cui bono?
In its recent update on the global burden of oral diseases, Kassebaum et al. (2017) claimed 538 million cases of severe periodontitis worldwide in 2015, 231 million more than estimated for 1990. Disability-adjusted life years (DALY) for severe periodontitis were calculated at 3.518 million. In a recent white paper by Tonetti et al. (2017), this latter figure was emphasized, “3.5 million years lived with disability.” These authors further their arguments about the “Impact of global burden of periodontal diseases on health, nutrition and wellbeing of mankind” by adding estimates provided by Listl et al. (2015) on the global cost of lost productivity from severe periodontitis alone (54 billion USD/yr). Productivity loss values 1 DALY as 1 yr of per capita gross domestic product.
Photo: FZ, under fair use
Shortly after his 84th birthday, Professor Dr. med. dent. Dr. h.c. Dieter E. Lange, former director of Germany’s once largest, independent department of Periodontology at Westfälische-Wilhelms-Universität Münster, passed on 12 September.
At a time when Periodontology in Germany was largely non-existent in the dental curriculum and consequently in dental practice, Professor Lange started, in 1978 after having been appointed in Münster, his crusade for prevention and treatment of periodontal diseases. He was the one who managed to get soon afterwards approval, by the Westphalian-Lippe dental association, of Germany’s first and still only postgraduate education program in Periodontology. I had had my education in Perio in Marburg, Hesse, but if I wanted to get a respective official certificate I had eventually to move to Münster, what I actually did in 1987.
What’s wrong with a Google Scholar account? Everybody loves it, right? Years ago, I had created one (it needs just a Google account) and cleaned it from unrelated (as scientists with my last name and initials are plenty) articles. It neatly lists all my publications (in the order of highest to lowest quotations). It tells me (and others who might be interested in my work) the number of quotations and the number of recent quotations. It calculates my h-index and several other more or less informative metrics. And it alerts me of recent quotations, so I can easily check who quoted me and in which context.
Google Scholar’s algorithm doesn’t consider a “core collection” as Web of Science of Clarivate Analytics does. That means that Google Scholar also regards quotations in articles published in questionable open access journals, cites in doctoral or master theses (but, as far as I know, not books). And also quotes of books. In my opinion, a quotation is a quotation and if correct, it’s okay.