A large volume of literature has accumulated in dentistry over the last 30 years, making it difficult for general practitioners to follow, much less assimilate, the
results of the various studies into their everyday practices. The evidence-based dentistry process—following that of evidence-based medicine—employs a systematic
approach to review the literature and extract the scientific evidence applicable to specific clinical questions. Thus, evidence-based dentistry aids clinicians in providing the best care to their patients by bridging the gap between
research and dental practice. Nevertheless, where is this best evidence coming from? According to the ADA, best evidence is a term that refers to information obtained from randomized controlled clinical trials, nonrandomized controlled clinical trials, cohort studies, case-control studies, crossover studies, cross-sectional studies, case studies, or, in the absence of scientific evidence, the consensus opinion of experts in the appropriate fields of research or clinical practice. The strength of the evidence follows the order of the studies or opinions listed above.
Does this hold true for orthodontics, as well? Although it is well-documented that data derived from randomized controlled clinical trials or systematic reviews in orthodontics are of great value in decision-making and the provision of health care, there are inherent problems associated with them. These problems are discussed in this issue’s “Frontiers in Clinical Research” article written by Donald J. Rinchuse, Daniel J. Rinchuse, Sanjivan Kandasamy, and Marc B. Ackerman from the University of Pittsburgh, University of Western Australia, and Jacksonville University School of Orthodontics. In their excellent review, the authors suggest that “orthodontic practitioners and journal editors alike should not erroneously accept as ‘holy writ’ the
conclusions of all systematic reviews.” The authors point out and discuss “the shortcomings of systematic reviews, randomized clinical trials, and meta-analyses in full awareness and appreciation of the benefits of such reviews.”
This article comes at a time when more “voices”1,2
appear in orthodontic literature, posing critical evaluation of the evidence coming from even prospective randomized clinical trials, systematic reviews, and meta-analyses.
Editors of orthodontic journals especially should see the “scientific evidence” derived from systematic reviews and meta-analyses more cautiously, as an unacceptably high number of systematic reviews related to orthodontics published between January 1, 2000, and January 31, 2007, were found to be “inconclusive, reflecting methodological inadequacies of the review process and exposing inadequacies in our evidence base.”3,4 I am sure that more articles discussing the issue of the validity of the “evidence” originating from systematic reviews in orthodontics will surface in the future. A controlled trial on soft profile changes during orthodontic treatment with a banded Herbst appliance compared to a control group
appears in this issue (Almeida et al, pages 121–131; see also below).
Further on the articles in this issue: In a 2-part article, Drs Chung, Kim, Kook, Choo, and Son from South Korea report on the effectiveness of the osseointegration-based mini-implant (C-Implant) in managing anterior torque
control during en masse retraction of anterior dentition by
employing the biocreative therapy type I and type II.
Drs Tibana, Palagi, Carneiro, Almeida, and Miguel from Rio de Janeiro, Brazil, evaluate the cephalometric changes in the facial profile of young adults in a longitudinal study, suggesting that facial profile alters throughout the third decade of life for both sexes, with more
pronounced changes in nose depth.
Drs Almeida, Flores-Mir, Brandão, Almeida, and Almeida-Pedrin, from the University of São Paulo, Brazil, and the University of Alberta, Canada, in a prospective controlled trial, conclude that although the changes in the soft tissue profile produced by a banded-type Herbst appliance were statistically different from the control group, they were not clinically significant.
A smile is a powerful tool for the face. The study
results of Drs Gul-e-Erum and Fida, coming from Pakistan, point out the responsibility of orthodontists to provide a systematic evaluation of smile attractiveness in order to better rehabilitate our patients’ smiles.
When the effects on the shear bond strength of Pro Seal light-cure varnish applied to the enamel surface
before or after the application of sealant were compared, Drs El-Bokle and Munir, from Cairo University, Egypt, found no effect on the mean shear bond strength of
orthodontic brackets for either way of application.
The vertical position of the maxillary lateral incisors seems to greatly influence the smile and the best
perceived position is when they are slightly offset from the incisal plane, as Drs King, Evans, Viana, BeGole, and Obrez, from the University of Illinois at Chicago, report.
This issue’s case report describes the treatment of an adult female with a severe Class II malocclusion and
congenitally missing mandibular incisors. Drs Nagaraj, Upadhyay, and Yadav, from KLE University, India, and
Indiana University–Purdue University, USA, decided to
extract the maxillary first premolars and use mini-
implants for en masse retraction of the maxillary anterior teeth. Mini-implants proved to be an effective alternative to orthognathic surgery for this patient.
The online articles for this issue include “Response of maxillary retrusion cases to face mask treatment” by Dr Ramadan of the Suez Canal University, Egypt; “Combined orthodontic-orthopedic approach: A second choice in some surgical cases” by Dr Dahan from the University of Louvain, Belgium; and “Comparison of white spot lesion formation between a self-ligating bracket and a conventional preadjusted straight wire bracket” by Drs Polat, Gökçelik, Arman, and Auhun of Baskent University, Turkey.
Efthimia K. Basdra, DDS, PhD
1. Meikle MC. What do prospective randomized clinical trials tell us about the treatment of class II malocclusions? A personal viewpoint. Eur J Orthod 2005;27:105–114.
2. Darendeliler MA. Validity of randomized clinical trials in evaluating the outcomes of class II treatment. Semin Orthod 2006;12:67–79.
3. Flores-Mir C, Major MP, Major PW. Search and selection methodology of systematic reviews in orthodontics (2000-2004). Am J Orthod Dentofacial Orthop 2006;130:214–217.
4. Fleming PS, DiBiase AT. Systematic reviews in orthodontics: What have we learned? Int Dent J. 2008;58:10–14.