Indian Journal of Dental Research

: 2011  |  Volume : 22  |  Issue : 1  |  Page : 175--176

Are citations required for a biomedical review article?

Irulandy Ponniah 
 Associate Professor and Head, Department of Oral and Maxillofacial Pathology, Tamil Nadu Government Dental College and Hospital, Chennai, India

Correspondence Address:
Irulandy Ponniah
Associate Professor and Head, Department of Oral and Maxillofacial Pathology, Tamil Nadu Government Dental College and Hospital, Chennai

How to cite this article:
Ponniah I. Are citations required for a biomedical review article?.Indian J Dent Res 2011;22:175-176

How to cite this URL:
Ponniah I. Are citations required for a biomedical review article?. Indian J Dent Res [serial online] 2011 [cited 2020 Apr 4 ];22:175-176
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The journal home page mentions that among other things, it also publishes invited reviews. Such reviews, however, normally do not cover original research findings, but rather present a classical review of the current knowledge of a given topic, fitting together data from a number of sources of remarkable research articles, to draw a conclusion about a given disease or diseases. In this context, I am concerned about a 'review' article entitled, "Role of genes in oro-dental diseases" by Kavitha et al., [1] The main purpose(s) stated in the abstract include, a review of genetic alterations ranging from the development of oro-facial structures to the tumors in the head and neck region, with further emphasis on the regulatory aspect of genes involved in the oro-facial structures, genes related to tooth development, and the genetic basis of disorders of tooth development.

At the outset the authors' attempt to review a topic of this magnitude is commendable. However, it is important to be well-versed in a given topic before one decides to write a review of this nature. Kavitha et al., might have been well aware, and therefore, have deemed to write an all-inclusive article on such a difficult topic(s), and in the process, they failed to acknowledge the original sources (this will help the readers for further reading or to verify the veracity of the information provided) in many instances and have wrongly attributed and / or interpreted in cases of those cited.

Under the heading 'Tooth Genesis' a figure shows the expression of different genes, with coded colors, to illustrate the expression zones, which convey that mesenchymal genes are instructive to tooth initiation and are linked to morpho- and histodifferentiation. Does the epithelium have any role in tooth genesis (odontogenesis)? It does not appear so, as illustrated in the figure. Even as the purpose states that the functional regulatory aspect of genes in relation to….., are discussed, there is not even a brief description about such regulatory mechanism(s) in the genesis of tooth formation or elsewhere.

Under the heading Parx-9 gene, Lines 1 - 11; "Parx 9 belong to…………………lack thymus, parathyroid glands, and show absence of teeth." What is intriguing is the fact that none of the lines were supported by a reference citation, but this is made good by an abrupt insertion of a sentence between lines 11 - 13; which read, "Parx-9 is expressed in the dental mesenchyme prior to the first morphological manifestation of odontogenesis," with cited reference, Neubuser et al.[2] Further lines of the same paragraph also lack a reference citation. Should one assume that the entire paragraph could be credited to Neubuser et al.,? However, this will not be the case if one goes through the article by Neubuser et al.

Under the heading MSX-1gene, Lines 10 - 14; "The expression of this gene………………….that are proliferating or dying and they provide positional information, and regulate epithelial-mesenchymal signaling in craniofacial development." How could dying cells, which are neither dividing nor capable of differentiation, interpret positional information to regulate developmental processes?

Under the heading Barx gene, the paragraph consists of nine lines, and at the end of the paragraph, Jones et al., [3] has been cited as the reference source. Off the nine lines, lines three to five, which read, "and palates are the expression sites ……………..failure of nervous system to develop and cleft palate formation," and lines seven to nine, which read, "while Barx-2 is expressed in the oral epithelium prior to tooth development" could not be correctly attributed to the Jones et al. article. Neither the purpose nor the conclusion of the Jones et al. article was to show that lack of expression of Barx gene would result in failure of the nervous system to develop or result in cleft palate formation.

Under the heading DLX gene, Lines one to two read, "DLX (Distal less) family of genes consists of six members (DLX 1-6)." This means that there are six DLX genes namely, Dlx-1, Dlx-2, Dlx-3, Dlx-4, Dlx-5, and Dlx-6. However, there are seven genes and they are arranged in pairs (Dlx 1 and 2; Dlx 3 and 7; Dlx 5 and 6) within the genome of mouse and man. [4] If one says there are six Dlx genes (1 - 6), [1] it refers to the numbers between 1 and 6. However, if one notices the arrangement of pairs, Dlx 4 is missing. This is an exception, because there is no known partner for Dlx-4. [4]

A cursory reading of the article will show the lack of appropriate citations in many places, and in particular, an entire paragraph under the heading 'Down syndrome' has still escaped the scrutiny by peer review (reviewers / editors) in an indexed journal! Although, the authors (Kavitha et al.) have stated their objectives in their abstract section, they have not written their article in conformity to the stated objectives and in line of a review article. Neither the author nor reviewer could be held responsible for the omissions, as humans are only fallible.


1Kavitha B, Priyadarshini V, Sivapathasundharam B, Saraswathi TR. Role of genes in oro-dental diseases. Indian J Dent Res 2010;21:270-4.
2Neubuser A, Peters H, Balling R, Martin GR. Antagonisitc interactions between FGF and BMP signaling pathways: A mechanism for positioning the sites of tooth formation. Cell 1997;90:247-55.
3Jones FS, Kioussi C, Copertino DW, Kallunki P, Holst BD, Edelman GM. Barx2, a new homeobox gene of the Bar class, is expressed in neural and craniofacial structures during development. Proc Natl Acad Sci U S A 1997;94:2632-37.
4Merlo GR, Zerega B, Paleari L, Trombino S, Mantero S, Levi G. Multiple functions of Dlx genes. Int J Dev Biol 2000;44:619-26.