Evidence-based dentistry

LETTERS TO THE EDITOR

Evidence-based dentistry To the editor: I read with interest the letter published in the Letters to the Editor section by Dr P. E. Larsen regarding “Oral and Maxillofacial Radiology Parameters of Care,” followed by the response from Drs White and Benson (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2001;92:480-1). I am also well aware of the position paper by White et al,1 which Dr. Larsen assumed was not peer-reviewed because of the simultaneous dates of submission and acceptance and was therefore unscientific and self-aggrandizing. I believe that a standard practice of the American Academy of Oral and Maxillofacial Radiology is the peer review of a document by the members before the Academy endorses it and expedites its acceptance for publication. Position papers are not usually peer-reviewed by someone other than a member or elected official within the Association or Academy. That is a privilege of the Academy or the Association and does not make it any less scientific. I am appalled by Larsen’s comments (personal opinions) regarding the specialty of oral and maxillofacial radiology. In his letter, he mentions, “In the day-to-day practice of dentistry, the presence of an oral and maxillofacial radiologist is nonexistent.” If that is true, why are we still teaching elaborate radiation physics and diagnostic radiology courses to our dental students? The letter lacks the scientific critique that is expected of an accomplished academician. He goes on to say that “the impact that they have on routine patient management is quite limited.” I believe he means oral surgical and related procedures. There are just hundreds of procedures within the scope of restorative dentistry, prosthodontics, orthodontics, and pedodontics requiring a collaborative effort to determine the extent of radiographic involvement or radiographic evidence before beginning any definitive therapy. The list also includes local manifestations of systemic diseases that are radiographically detectable. We are in the era of evidence-based dentistry and medicine, and for every therapeutic procedure we undertake, there should be a sound rationale that should be documented. Surgeons have traditionally relied on a radiograph or a histologic specimen to confirm the clinical diagnosis. What is wrong in having those interpreted properly by someone who

has advanced training in the specialty? No one is dictating how a surgery is to be done or an implant is to be placed, but a maxillofacial radiologist can at least recommend an appropriate radiograph for the visualization of anatomic structures. It is not only irrational to make statements like “hundreds of thousands of implants have been replaced with extremely low morbidity and a high success rate without the use of cross-sectional imaging,” but it is also cavalier. The only purpose of cross-sectional tomograms is to outline the complex and varied anatomic patterns within the mandible or maxilla and to make sure that we do not violate the anatomic boundaries or neurovascular bundles even once. I wonder how one can see through the bony anatomy and have a successful implant placement all the time. I think that performing such procedures by relying on one’s own assumed knowledge of anatomy is totally against the principles and ethics of medical practice and is clearly not an evidence-based practice, which demands higher standards of care. A standard of care is usually what is best for the patient, not a decision on the part of one specialist. Drs White and Benson in their response have taken tremendous care to point out the misinterpretations in Dr Larsen’s letter and to adequately document the need for cross-sectional imaging in any invasive maxillofacial surgical procedures. The decision to prescribe an imaging procedure is the responsibility of the treating specialist, who must bear the consequences medically and legally should there be any adverse situation. There are specific guidelines in the literature2 regarding the radiographic assessment of implant patients, and one should certainly have the patient in mind and set standards for care. In fact, we are increasingly moving toward the use of an imageguided navigation system3 for dental implant surgeries and away from subjective judgment of the structure of the bony anatomy, which, in this age of evidence-based practice, is unscientific and an impediment to a successful surgical outcome. Mel Mupparapu, DMD University of Pennsylvania School of Dental Medicine Philadelphia, Pa REFERENCES 1. White SC, Heslop EW, Hollender LG, Mosier KM, Ruprecht A, Shrout MK. Parameters of radiologic care: an official report of the

2 July 2002 ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY

ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY Volume 94, Number 1 American Academy of Oral and Maxillofacial Radiology. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2001;91:498-511. 2. Dula K, Mini R, van der Stelt PF, Buser D. The radiographic assessment of implant patients: decision-making criteria. Int J Oral Maxillofac Implants 2001;16:80-9. 3. Siessegger M, Schneider BT, Mischkowski RA, Lazar F, Krug B, Klesper B, et al. Use of an image-guided navigation system in dental implant surgery in anatomically complex operation sites. J Craniomaxillofac Surg 2001;29:276-81. doi:10.1067/moe.2002.124252

In reply: Thank you for the opportunity to respond to Dr Mupparapu’s comments. Specifically, I would like to address comments regarding the use of cross-sectional tomography for routine implant treatment planning. Dr Mupparapu has taken the liberty, incorrectly so, of ascribing meanings to my comments that are absolutely not true. In addition, he has described my approach to imaging for implant surgery as “irrational” and “cavalier.” The disagreement that I have with Dr Mupparapu, as well as with Dr White and Dr Benson’s position paper, is that there are ways other than cross-sectional tomography to obtain the data that are necessary for safe implant placement. My letter did not even imply that adequate imaging is unnecessary for implant surgery. Dr Mupparapu has suggested that I oppose gathering adequate diagnostic information before surgery and that this is “totally against the principles and ethics of medical practice.” He uses a classic debating technique: He says that I oppose the goal, when what I really disagree with is the method of achieving that goal. Any ethical and rational practitioner would agree that careful technique is important and that any information that helps to achieve the best result with lowest morbidity is desirable. However, when placing implants, a thorough clinical examination and a calibrated panoramic radiograph can almost always provide the critical information that is necessary. Despite Dr Mupparapu’s remarks about my comment that “hundreds of thousands of implants have been replaced (successfully) ... without the use of crosssectional tomography,” the fact is, it is true. Countless implants have been placed without the use of computed tomography scanning, and the data clearly show that the morbidity is very, very low. What the proponents of cross-sectional tomography have not shown is that this technique will significantly improve the already low morbidity associated with implant placement. It is incumbent upon them to provide this data if they choose to propagate a new standard of care. Dr Mupparapu states that the purpose of the crosssectional tomogram is “to outline the complex and

Letters to the editor 3

varied anatomic patterns within the mandible or maxilla....” As a surgeon, I would suggest that not all of the anatomic variations within the maxilla or mandible are integral to the placement of implants— only the local features that influence successful implant placement and low morbidity. For many years, chest film radiography was performed on every patient under general anesthesia. There is no argument that the “complex and varied anatomic patterns” of the lungs are more fully demonstrated by chest film than by clinical examination. Nonetheless, we now know that this practice is a catastrophic waste of medical resources. Researchbased guidelines exist outlining when it is appropriate to order a chest x-ray on the basis of a thorough history and physical examination. In fact, chest films are considered unnecessary for most patients undergoing routine surgery and anesthesia induction. Similarly, cross-sectional tomography has not been shown in any prospective or retrospective study to provide better outcomes for implant placement. A “better view of the anatomy” does not guarantee a better outcome. Patient selection, surgical judgment, and surgical skill are all critical components of success. There is not yet scientific evidence that the added expense of this technology will have a significant effect on the morbidity associated with routine implant placement. Dr Mupparapu’s definition of evidence-based dentistry is incorrect. The term does not mean the use of a higher level of technology or collecting “more” data. What it does mean is that a particular therapy has been clearly shown, through conclusive scientific evidence, to provide a better outcome than other options. This is particularly important when considering new and expensive technology. There should be a realistic prospect of improving the care for a significant number of patients. Otherwise, we would have to obtain preoperative chest films on every patient because we might detect an occult tumor or other undiagnosed disease in a statistically insignificant number of people. This is not an appropriate use of resources. Likewise, it is not reasonable to suggest that if one numb lip can be prevented, every patient receiving an implant placement should have a cross-sectional tomogram. In evidence-based dentistry, a prospective study would allow us—regardless of the use or disuse of cross-sectional tomography—to compare the incidence of morbidity among patients undergoing different procedures; only then can an educated decision be made regarding the use of this expensive technology. I expect that some of our radiology colleagues will not agree with this, but is incumbent upon them to generate