250th publication jmos- 4th name

1. REVIEW PAPER
Level of Evidence Analysis in Journal of Maxillofacial Oral
Surgery: A Twelve-Year Bibliometric Analysis of 1300
Publications (2009–2020)
Kirti Chaudhry1 • Rishi Kumar Bali2 • Amanjot Kaur1 • Rahul V. C. Tiwari3 •
Arun K. Patnana1
Received: 26 June 2020 / Accepted: 19 April 2021
Ó The Association of Oral and Maxillofacial Surgeons of India 2021
Abstract
Aim Analysing Level of Evidence (LOE) provides an
insight to evidence-based medicine (EBM). The aim of our
study was to evaluate and analyse trends in Levels of
Evidence (LOE) in Journal of Maxillofacial and Oral
Surgery (MAOS) since inception, i.e. December 2009
along with categorization into subtopics.
Methodology LOE for each article was determined
according to modified American Society of Plastic Sur-
geons (ASPS) scale and National Health and Medical
Research Council (NHMRC) Evidence Hierarchy.
Results A total of 1264 articles were included in the final
analysis, out of which high-quality evidence (Level A)
accounted for 7% of the journal. The percentage of Level
I/II (Level A) has increased from 2.09% in 2009/2010 to
12.74% in 2019/2020, representing a promising trend
toward higher-quality research in just 10 years. Case
reports and narrative reviews with Level of Evidence value
‘‘D’’ account the highest number (36%) of all the published
articles. The majority of articles fell under Class 2 (Max-
illofacial pathology) classification (35%) highlighting
myriad of articles covering pathologies and various
reconstruction methods, followed by trauma (16%).
Conclusion The status of LOE and categorizing of pub-
lished articles are the first step to audit and quantify the
nature of literature published by JMOS and may further
help in refining the quality of research jointly by the
researchers and the editorial board.
Keywords Level of Evidence (LOE) Journal of
Maxillofacial and Oral Surgery (MAOS) Evidence-based
medicine (EBM)
Introduction
Bibliometrics is the discipline where quantitative approa-
ches are applied mainly to scientific fields and are based
principally on various aspects of written articles like sub-
ject, author, citation, title, etc. [1]. It is beneficial for
monitoring growth of the literature and pattern of research
in a journal [2] .
Evidence-based Medical practice (EBM) is the mainstay
for any diagnostic, therapeutics, prognostic, medical or
surgical decision making for the patient care. Predominant
backbone of EBM is the ability to codify any study based
on Level of Evidence (LOE). Oral and Maxillofacial Sur-
gery (OMFS) is an evolving speciality requiring training in
both medicine and dentistry and is specially rooted in
experimentation and innovation. Scientific journals are
excellent platforms for two-way communication of
research findings, latest discoveries and developments, and
Amanjot Kaur
amanjotkaur1992@yahoo.com
Kirti Chaudhry
chaudhry_kirti@yahoo.com
Rishi Kumar Bali
rshbali@yahoo.co.in
Rahul V. C. Tiwari
drrahulvctiwari@gmail.com
Arun K. Patnana
arun0550@gmail.com
1
Department of Dentistry, All India Institute of Medical
Sciences, Jodhpur, India
2
DAV Dental College and MDM General Hospital,
Yamunanagar, India
3
Vizag, Andhra Pradesh, India
123
J. Maxillofac. Oral Surg.
https://doi.org/10.1007/s12663-021-01575-4
Author Personal Copy

2. future research prospects, thus having a pivotal role in
amalgamating EBM in any clinical speciality.
Randomized controlled trials (RCTs), which have been
the gold standard for unbiased evidence, have found a
limited role in surgical specialities, due to lack of under-
standing of RCTs, epidemiological and statistical training
in the surgical community. Ethical considerations like
Sham surgeries (placebo surgeries), lack of funding, sur-
gical learning curve and lack of feasibility of blinding of
surgeons, lack of long-term follow-ups of outcomes are
few of the other major challenges in conducting high-level
RCTs. In defiance of all these odds, OMFS as a speciality
is trying to evolve leaps and bounds from a field driven by
anecdotal evidence and expert opinions to embrace evi-
dence-based medicine.
Journal of Maxillofacial and Oral Surgery (MAOS) is a
quarterly, official peer-reviewed publication of the Asso-
ciation of Oral and Maxillofacial Surgeons of India
(AOMSI). MAOS got PubMed indexed in December 2009,
since then it has played a very crucial role in complete
spectrum of academics, disseminative, contemporary,
scholarly, technical, cutting-edge innovations, diagnostic
works and future trends related to extensive field of OMFS.
It focuses on publishing original articles, review articles,
editorials, letter to the editor, case reports, technical notes,
mini reviews and commentaries.
Refining of research quality published in OMFS journals
is an uphill task where assessing the trends of LOEs in a
journal is the first and critical step. The aim of our study
was to evaluate and analyse trends in Levels of Evidence
(LOE) in Journal of Maxillofacial and Oral Surger-
y(MAOS) since inception, i.e. December 2009. A sec-
ondary purpose was to describe the current publication
pattern in terms of LOE and sub-categories.
Methodology
A search team including three authors (AK, AP and RT)
screened and reviewed all the articles of MAOS since
December 2009–April 2020. The team worked in pairs so
that two authors separately screen each article and any
discord was settled by consulting senior author KC and RB.
An explicit data extraction sheet was prepared categorizing
all the articles based on LOE and themes and all the articles
published in MAOS from 2009 (Volume 8 Issue 1) to 2020
(Volume 19 Issue 2). Cataloguing the LOE was done as per
Table 1 that was prepared, objectified and simplified
according to modified American Society of Plastic Sur-
geons (ASPS) scale [3] and National Health and Medical
Research Council (NHMRC) Evidence Hierarchy [4].
Articles were further classified by reviewers according to
the study design: (1) systematic review, (2) RCT, (3)
prospective cohort studies, (4) meta-analysis, (5) case–
control study, (6) retrospective study, (7) analytical cross-
sectional study, (8) descriptive cross-sectional study, (9)
case series, (10) case reports, (11) narrative reviews, (12)
expert opinions, (13) editorials/letter to editor, (14) per-
spectives, (15) technical notes. Published articles on basic
sciences, in vitro studies, animal studies, cadaveric studies,
instructional course lectures and conference proceedings
were excluded from the analysis. Additionally, each article
was assigned an LOE by the reviewers according to
Table 1 with any discrepancy settled by consensus. Highest
quality evidence is produced from randomized controlled
trails or systemic reviews/meta-analysis of the RCTs, thus
given Level A. The lowest Level of Evidence (Level E)
was given to articles of limited study designs like
Table 1 Level of Evidence (LOE) distribution according to modified
American Society of Plastic Surgeons (ASPS) scale [3] and National
Health and Medical Research Council (NHMRC) Evidence Hierarchy
[4]
LOE name LOE value
Level I/II
Prospective RCT’s A
Prospective cohort studies
Systematic review of RCT’s,
Cohort studies
Meta-analysis
Level III
Case–control study B
Retrospective study
Systematic review of case control
Studies
Analytical cross-sectional studies
Level IV
Case series C
Descriptive cross sectional
Systematic review of cross
Sectional or case series
Level V
Case reports D
Narrative reviews
Expert opinion
Editorials/letter to editor E
Perspectives
Technical notes
Excluded
Animal studies, cadaveric studies, X
In vitro studies, erratum,
Conference proceedings
J. Maxillofac. Oral Surg.
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3. editorials, expert opinions or technical notes. Smaller LOE
values (i.e. closer to A) indicate research that presents
higher-quality evidence. The articles were simultaneously
categorized according to the subspeciality as shown in
Tables 1 and 2. The flowchart of methodology was as
depicted in Fig. 1.
Statistical Analysis
The descriptive statistics of the number of articles pub-
lished according to the year, Level of Evidence and cate-
gory of the topic were done to evaluate the percentages of
each variable. Chi-square test was done to evaluate the
distribution of number of articles according to the year,
Level of Evidence and category of the topic. The variations
in the publication of different levels of evidence were
analysed using the bar charts. All statistical tests were done
using the SPSS software version 21, and the P value of less
than 0.05 was considered statistically significant.
Results
The descriptive statistics of the number of articles pub-
lished according to the year, Level of Evidence and cate-
gory of the topic are presented in Figs. 2, 3 and 4,
respectively. Maximum of the articles (20%) were pub-
lished during the year 2015. Case reports and narrative
reviews with Level of Evidence value ‘‘D’’ account the
highest number (36%) of all the published articles from
2009 to 2020. Maxillofacial pathology category ranks the
highest number of publications (35%) from 2009 to 2020.
The distribution of year of publication and Level of
Evidence of the published articles from 2009 to 2020 are
presented in Fig. 5. The Chi-square test showed significant
difference (P = 0.000) in the distribution of articles from
2009 to 2020 according to different Level of Evidence
values (Table 3). The distribution of year of publication
and category of the topic of the published articles are
shown in Fig. 4. The Chi-square test showed significant
difference (P = 0.009) in the distribution of articles from
2009 to 2020 according to categories of the topics pub-
lished (Table 4). The distribution of articles published
according to different levels of evidence and category of
the topics are presented in Fig. 5. The Chi-square test
showed significant difference (P = 0.000) in the distribu-
tion of articles according to different levels of evidence and
different categories of the topics published (Table 5). The
variations in the publication of articles with different levels
of evidence are presented in Fig. 5.
Discussion
Bibliometrics is a set of statistical methods to analyse
academic literature quantitatively and its changes over
time. However, subfield of bibliometric, i.e. restricted to
analysis of scientific publications, is called scientometrics.
The term ‘‘bibliometrie’’ was coined by Paul Otlet in 1934
[5]. Peer-reviewed publication is primary mode of com-
munication and recorded for scientific research which
forms the basis of LOE and EBM. Individual studies can be
judged for its quality if it is peer-reviewed publication, if it
has followed reporting guidelines and its citation indices
for healthcare stimulation research.
Different study designs based on the research questions
have found use in different conditions. For therapeutic,
RCTs are the best form of study and for prognostics well-
designed cohorts are the best form of study. Former is the
highest form in interventional studies and later being in
observational study. Depending on the quality of study
conducted and type of research question sometimes LOE
may vary. For example, cigarette smoking association with
oral cancer cannot be assessed with RCT; here, depending
on this research question, well-designed cohort will form
the Level 1 evidence. Levels I and II were combined in our
study to minimize subjectivity in high- and low-quality
RCT. In vitro, animal studies and pilot studies are the
building blocks and finally pave way for future clinical
research formed 3% of the journal publications. The animal
studies may not necessarily be able to reliably predict the
safety and efficacy of an intervention when trailed in
humans [6]. They were excluded from the LOE as guide-
lines and were given Level X [3].
There has been a growth in levels A, B and C evidence,
with a reduction in the publication in lower-quality evi-
dence. In total, high-quality evidence (Level A) accounted
for 7% of the journal which is much lower than orthopaedic
literature (21.6%) [7], neurosurgical (10.3%) [8] but higher
than the previously published maxillofacial research in
2007 showing 0% articles in Level I evidence and 2% for
Level II evidence [9] and plastic surgery having 2% Level I
evidence in 2018 [10]. This finding corresponds well to the
field of surgery, because it is difficult to conduct a standard
RCT in a surgery. The major difficulties include the fea-
sibility of randomization and compliance with random
allocations. Moreover, it is difficult to persuade a patient to
comply with newer drugs or surgery based on hypothesis of
animal studies.
However, there has been rapid expansion in technology
and heightened awareness of RCTs, and the quality of the
articles is improving with time. In this study, evaluating
LOE of over 1264 articles over the last decade, analysis
showed that the percentage of Level I/II (Level A) has
J. Maxillofac. Oral Surg.
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4. Table 2 Categorical distribution of the articles
Category name Category value Category name Category value
Minor oral surgery
Exodontia
Impaction
Endodontic surgery
Pre-prosthetic surgery
Orthodontic/paediatric
Tooth exposure
1 Trauma
Dentoalveolar fracture
Maxillary fracture
Mandibular fracture
NOE fracture
Orbito-zygomatic fracture
Naso-orbito-ethmoid fracture
Frontal fracture
Pan facial fracture
Soft tissue injuries
Ballistic injuries
5
Maxillofacial pathology
Cysts of the oral cavity
Odontogenic and
Nonodontogenic tumours
Oral cancer
Head and neck tumours
Salivary gland pathologies
Maxillary sinus pathologies
Premalignant lesions
Vascular lesions
Reconstructive surgery and
Tissue engineering
2 Dental implants 6
Dentofacial deformity and aesthetics
Orthognathic surgery
Distraction Osteogenesis
Aesthetic Surgery/Procedures
Hair Transplant
Sleep Apnoea procedures
Orofacial cleft
3 Space infection and systemic infectious
Diseases
Head Neck Space Infections
Osteomyelitis, Osteoradionecrosis,
Osteochemonecrosis
Systemic manifestations of infectious
diseases
7
TMJ and orofacial pain
Orofacial neuropathy and
Neurological disorders
TMJ disorders, TMD
Myofascial pain
All neuralgias
4 Miscellaneous
Armamentarium
Diagnostics
Sterilization and disinfection
Suturing materials and techniques
Haemorrhage and shock
Wound care
Local anaesthesia
General anaesthesia
Medically compromised patients
Medical emergencies and their
Management
Burns
8
J. Maxillofac. Oral Surg.
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5. increased from 2% in 2009/2010 to 12.74% in 2019/2020,
representing a significant and promising trend toward
higher-quality research in just 10 years.
Case series are the backbone of surgical research as they
comprise of similar group of patients with a common
intervention. No doubt, the absence of control group has
shifted its value to quite a lower level, but its value is
special in surgery. Level C which includes case series
forms 16% of the literature. Case reports are important
although they cannot be regarded as clinical evidence and
forms the bulk of the journal (36%). Further, there were
two supplemental issues in the year 2015 and 2016 of case
reports only; lower Level of Evidence was seen in these
two years. As it is said never judge a book by its cover, and
Fig. 1 Flowchart of the
methodology of the study
Fig. 2 Pie chart showing % distribution of the article’s yearwise from 2009 to 2020
J. Maxillofac. Oral Surg.
123

6. the same is true for case reports. Most of the time, the
large-scale and extensive clinical trials are planned on the
basis of results of a single case report. Editorials, expert
opinions and technical notes form a total of 13% of all
articles, having similar advantage as of a case report. They
were excluded from the LOE as guidelines in spite of that
we computed and were found as capitulations/submissions
in Level E [3].
Also, the majority of articles fell under Class 2 (Max-
illofacial pathology) classification (35%) highlighting
myriad of articles covering pathologies and various
reconstruction methods, followed by trauma (16%). Both
Fig. 3 Pie chart showing % distribution of the article’s Level of Evidence (LOE) from 2009 to 2020 with major contribution by Level D studies
Fig. 4 Pie chart showing % distribution of the article’s sub-topic categorization from 2009 to 2020 with major contribution by Category 2 studies
J. Maxillofac. Oral Surg.
123

7. these categories form major bulk due to emphasis placed
during training in these aspects. However, there is still long
way to go in the field of dental implants forming only 3%
of the literature.
Even though bibliographic studies are a hefty job, still
our analysis has several limitations. Mostly bibliometric
analysis is computing citation index which was not calcu-
lated in our study. Citation index though important may be
erroneous as usually narrative reviews, and case reports
which form lowest step in LOE pyramid usually have high
citation. It has been found many articles downloaded,
discussed but not cited, thus skewing citation index as a
wide criterion for evaluating a study. This bibliometric
study has just quantified all the articles based on type of
study. No attempt was made to assess the quality of each
article using any tool or software. Our results lack critical
Fig. 5 Histogram showing yearly distribution of the article’s Level of Evidence (LOE) from 2009 to 2020
Table 3 Distribution of year of publication and Level of Evidence of the published articles
Number of articles published in each Level of
Evidence (percentages)
Total number of articles
published
Chi-square
value
P value
A B C D E
Year of
publication
2009 3 (3) 43 (46) 3 (3) 35 (38) 9 (10) 93 (100) 198.345a
0.000*
2010 1 (1) 33 (34) 3 (3) 48 (49) 13 (13) 98 (100)
2011 4 (5) 20 (27) 6 (8) 34 (45) 11 (15) 75 (100)
2012 2 (2) 41 (43) 10 (11) 35 (37) 7 (7) 95 (100)
2013 11 (12) 22 (25) 17 (20) 24 (27) 14 (16) 88 (100)
2014 12 (12) 20 (20) 34 (35) 21 (22) 11 (11) 98 (100)
2015 25 (10) 35 (14) 41 (16) 32 (51) 24 (9) 257 (100)
2016 7 (6) 30 (25) 12 (10) 52 (43) 20 (16) 121 (100)
2017 6 (7) 37 (32) 24 (22) 15 (18) 17 (21) 83 (100)
2018 6 (6) 37 (38) 24 (24) 18 (18) 14 (14) 99 (100)
2019 11 (10) 34 (32) 24 (22) 23 (21) 16 (15) 108 (100)
2020 5 (10) 12 (25) 13 (26) 12 (25) 7 (14) 49 (100)
Total 93 (7) 354
(28)
205
(16)
449
(36)
163
(13)
1264 (100)
The values in the tables were presented as percentages of total number of articles published
Chi-square test was used to analyse the significant difference between the year and Level of Evidence values of the published articles
*
P value of less than 0.05 was considered significant
J. Maxillofac. Oral Surg.
123

8. appraisal of each article’s methodology, bias and power
[3]. There is a critical distinction between a study LOE and
its inherent quality, exemplified by the fact that even RCTs
are susceptible to flaws in design and may suffer from poor
Jadad scores, which are used to quantify the strength of the
trial design [11]. Thus, in this study articles have been
quantified for the LOE; individual articles have not been
assessed for their quality.
Last few decades have shown a surge in publications of
various qualities which may be attributed to multitude of
reasons including widespread use of Internet facility, faster
dissemination, current publish and perish culture in aca-
demia. All of this has led to an explosion of scientific
publications that has overwhelmed the publication system
and has made it impossible either for the traditional, and
generally effective, peer-reviewed system to work or for
the scientific community to evaluate a lot of scientific
research. Efforts to improve the reproducibility and integ-
rity of science are needed as the published results are
unreliable due to growing problems with research and
publication practices [12].
To improve the quality of research, we should invest
sufficient time for strategic research and should be able to
identify the barriers in the implementation of the methods.
Also, research methodology courses should be made
mandatory for the trainees to fill the lacunae left behind in
the undergraduate days and to avoid research misconduct.
Plan-Do-Study-Act (PDSA) should be the motto for every
thesis topic or project allotted to postgraduate students and
researchers [13] .
Conclusion
Seglenonce said, ‘‘Science deserves to be judged by its
contents, not by its wrapping,’’ which remains true for
characterization of individual papers and scientists [14].
The LOE of MAOS literature has increased over time, as
Table 4 Distribution of year of publication and category of the topic of the published articles
Number of articles in each category of the topic (percentage) Total number of articles
published
Chi-square
value
P value
1 2 3 4 5 6 7 8
Year of
publication
2009 8 (9) 34
(37)
11
(12)
4 (4) 18
(19)
3 (3) 2 (2) 13
(14)
93 (100) 109.584a
0.009*
2010 4 (4) 42
(43)
11
(11)
5 (5) 20
(21)
1 (1) 3 (3) 12
(12)
98 (100)
2011 8 (11) 29
(39)
9 (12) 1 (1) 14
(19)
0 (0) 1 (1) 13
(17)
75 (100)
2012 7 (7) 35
(37)
11
(12)
4 (4) 20
(21)
2 (2) 2 (2) 14
(15)
95 (100)
2013 14
(16)
22
(25)
13
(15)
6 (7) 9 (10) 2 (2) 6 (7) 16
(18)
88 (100)
2014 5 (5) 28
(29)
15
(16)
8 (8) 12
(12)
6 (6) 8 (8) 16
(16)
98 (100)
2015 20 (8) 110
(43)
24 (9) 18
(7)
42
(16)
7 (3) 18
(7)
18 (7) 257 (100)
2016 11 (9) 41
(34)
21
(17)
6 (5) 19
(16)
5 (4) 4 (3) 14
(12)
121 (100)
2017 10
(12)
28
(34)
10
(12)
9
(11)
9 (11) 2 (2) 4 (5) 11
(13)
83 (100)
2018 10
(10)
25
(26)
13
(13)
9 (9) 23
(23)
2 (2) 4 (4) 13
(13)
99 (100)
2019 12
(13)
33
(31)
14
(13)
10
(9)
11
(10)
3 (3) 9 (8) 15
(14)
108 (100)
2020 0 (0) 13
(26)
4 (8) 6
(13)
6 (12) 5
(10)
5
(10)
10
(21)
49 (100)
Total 110
(9)
440
(35)
156
(12)
86
(7)
203
(16)
38
(3)
66
(5)
165
(13)
1264 (100)
The values in the tables were presented as percentages of total number of articles published
Chi-square test was used to analyse the significant difference between the year and Level of Evidence values of the published articles
*
P value of less than 0.05 was considered significant
J. Maxillofac. Oral Surg.
123

9. demonstrated by increased proportion of Level I/II evi-
dence. The main critic remains the readers which should
judge on the basis of quality. Thus, a bibliometric study
like this would help us to gauze the status of LOE of
published MAOS articles, thus paving way for improving
the quality of research conduction by researchers and
acceptance by the editors.
Authors’ Contributions Dr. Rishi Bali (RB) and Dr. Kirti Chaudhry
(KC) helped in study conception and design. Dr. Amanjot Kaur (AK),
Dr. Arun K. Patnana (AP) and Dr. Rahul VC Tiwari (RT) acquired the
data. AP and AK analysed and interpreted the data. KC and AK
drafted the manuscript. KC and RB critically revised.
Funding No funding was taken for this study.
Declarations
Conflict of interest The authors have no conflict of interest to
disclose.
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Table 5 Distribution of Level of Evidence and category of the topic of the published articles
Number of articles in each category of the topic (Percentage) Total number of articles
published
Chi-square
value
P value
1 2 3 4 5 6 7 8
Level of
Evidence
A 34
(36)
7 (7) 8 (9) 8 (9) 21
(23)
2 (2) 1 (1) 12
(13)
93 (100) 387.019a
0.000*
B 49
(14)
87
(25)
54
(15)
27
(8)
83
(23)
14
(4)
11
(3)
29 (8) 354 (100)
C 11
(5)
47
(23)
33
(16)
22
(11)
36
(18)
9 (4) 16
(8)
31
(15)
205 (100)
D 9 (2) 260
(58)
44
(10)
18
(4)
43
(10)
6 (1) 34
(7)
35 (8) 449 (100)
E 7 (4) 39
(24)
17
(11)
11
(7)
20
(12)
7 (4) 4 (2) 58
(36)
163 (100)
Total 110
(9)
440
(35)
156
(12)
86
(7)
203
(16)
38
(3)
66
(5)
165
(13)
1264 (100)
The values in the tables were presented as percentages of total number of articles published
Chi-square test was used to analyse the significant difference between the year and Level of Evidence values of the published articles
*
P value of less than 0.05 was considered significant
J. Maxillofac. Oral Surg.
123