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Recommendations for management of trigeminal nerve defects based on a critical appraisal of the literature
R. BRUCE DONOFF J Oral Maxillofac 551387, 1997
1387
Surg
Discussion Recommendations for Management of Trigeminal Nerve Defects Based on a Critical Appraisal of the Literature R. Bruce Dono& DMD, MD School of Dental Medicine,
Harvard
Boston,
Massachusetts
“Recommendations for Management of Trigeminal Nerve Defects Based on a Critical Appraisal of the Literature” by Dodson and Kaban uses the subject of nerve repair to present the concepts of evidence-based medicine (E-BM). Clinicians need to apply the following six skills to practice E-BM: 1) asking evidence-based questions (hypothesis formulation), 2) searching for current best evidence, 3) appraising the information (is the information valid and important?), 4) applying this information, 5) presenting this information ethically and effectively, and 6) completing all of the above in a time-sensitive, cost-effective, patient-centered manner. The subject of the current review is important and well done, but a few points are noteworthy in considering its suggestions. Defining the patient’s clinical problem and framing the clinical question are critical. The question asked might have been whether the inferior alveolar nerve (IAN) injury should be operated on at all rather than what the operation should be. Although the former question is less specific, the authors recognize the importance of framing the right question, and also highlight the need for “more accurate documentation of the natural history of nerve injuries, including spontaneous recovery rates ,” realizing the importance of the first query. The authors appropriately show the second step of clinical appraisal-an efficient review of the literature. It is important to emphasize that the search strategy is a critical part of practicing E-BM. Thirteen sources published in English and pertaining to humans were identified using Medline. The importance of the search strategy is shown by the following example, which also provides a measure of randomized clinical trials (RCTs), the gold standard for gathering evidence. A meta-analysis search for oral or dental involving all journals published in English dealing with humans identified 127 articles, of which 26 (20%) are related to oral health (vs for example: “oral contraceptives”). Repeating the search substituting “cardiac or heart” for “oral or dental” identified 165 articles, of which 112 (68%) related to cardiac disease. This low level screening suggests that evidence may be seen less often for dental care than for medical care, about one fourth in the case of cardiac care. Although meta-analysis still generates controversy,’ it is currently thought to provide the highest level of evidence. Additionally, because meta-analysis is an analysis of RCTs, it is an indirect measure of the availability of high quality studies in a given area. The authors acknowledge the absence of RCTs in nerve repair. Despite the problems of literature searching and lack of
relevant articles, a major contribution of this article is presentation of the Medical Research Council’s Scale as a method of objectively comparing case series reports. Table 1 describes the grading of sensory recovery and deserves careful review. However, readers should be aware that this scale was developed for outcomes in peripheral nerves in the upper extremity. Extrapolation to IAN and lingual nerve repair requires corroboration of objective/subjective functional comparisons. The inclusion of 10 search-identified articles also related to the upper extremity is a problem. This reviewer wonders why unpublished work was included, because it would not have been found by the search. Enhancement of “sample size” by such additions is suspect. The authors acknowledge the importance of variables such as age, size of defect, and elapsed time between injury and repair. Repeatedly reminding the reader of the gold standard of the RCT, they acknowledge the problems in performing such trials. Their call for multicenter case series is an important alternative. This article highlights a new paradigm for practice that makes the following assumptions2.3: 1) Clinical experience and the development of clinical judgment are crucial and necessary, but systematic attempts to record observations in a reproducible and unbiased fashion increase the confidence one can have in knowledge about patient prognosis, the value of diagnostic tests, and the efficacy of treatment. 2) The study and understanding of basic mechanisms of disease are necessary, but they provide insufficient guides for clinical practice. 3) Understanding certain rules of evidence is necessary to correctly interpret the literature on causation, prognosis, diagnostic testing and treatment strategy. This paradigm requires new ways of thinking, teaching, and learning. E-BM does not ignore clinical experience and clinical intuition. It does not relegate basic science and pathophysiology to a meaningless role, nor does it ignore standard aspects of clinical training. This article applies the principles of E-BM by asking a question that can be answered. That is the first and most important point. If the question were “should we operate,” it would be less searchable, with an even lower yield of evidence. This is the first skill to be mastered, and the authors make their point. References 1. LeLorier J, Gregoire G,
Benhaddad A, et al: Discrepancies Between Meta-Analysis and Subsequent Large Randomized Controlled Trials. New Engl J Med 337536, 1997 2. Fletcher RH, Fletcher SW, Wagner EN: Clinical Epidemiology (ed 3). Baltimore, MD, Williams and Williams, 1996 3. Sackert DL, Richardson WS, Rosenberg W, et al: EvidenceBased Medicine. New York, NY, Churchhill Livingstone, 1997
1387
Surg
Discussion Recommendations for Management of Trigeminal Nerve Defects Based on a Critical Appraisal of the Literature R. Bruce Dono& DMD, MD School of Dental Medicine,
Harvard
Boston,
Massachusetts
“Recommendations for Management of Trigeminal Nerve Defects Based on a Critical Appraisal of the Literature” by Dodson and Kaban uses the subject of nerve repair to present the concepts of evidence-based medicine (E-BM). Clinicians need to apply the following six skills to practice E-BM: 1) asking evidence-based questions (hypothesis formulation), 2) searching for current best evidence, 3) appraising the information (is the information valid and important?), 4) applying this information, 5) presenting this information ethically and effectively, and 6) completing all of the above in a time-sensitive, cost-effective, patient-centered manner. The subject of the current review is important and well done, but a few points are noteworthy in considering its suggestions. Defining the patient’s clinical problem and framing the clinical question are critical. The question asked might have been whether the inferior alveolar nerve (IAN) injury should be operated on at all rather than what the operation should be. Although the former question is less specific, the authors recognize the importance of framing the right question, and also highlight the need for “more accurate documentation of the natural history of nerve injuries, including spontaneous recovery rates ,” realizing the importance of the first query. The authors appropriately show the second step of clinical appraisal-an efficient review of the literature. It is important to emphasize that the search strategy is a critical part of practicing E-BM. Thirteen sources published in English and pertaining to humans were identified using Medline. The importance of the search strategy is shown by the following example, which also provides a measure of randomized clinical trials (RCTs), the gold standard for gathering evidence. A meta-analysis search for oral or dental involving all journals published in English dealing with humans identified 127 articles, of which 26 (20%) are related to oral health (vs for example: “oral contraceptives”). Repeating the search substituting “cardiac or heart” for “oral or dental” identified 165 articles, of which 112 (68%) related to cardiac disease. This low level screening suggests that evidence may be seen less often for dental care than for medical care, about one fourth in the case of cardiac care. Although meta-analysis still generates controversy,’ it is currently thought to provide the highest level of evidence. Additionally, because meta-analysis is an analysis of RCTs, it is an indirect measure of the availability of high quality studies in a given area. The authors acknowledge the absence of RCTs in nerve repair. Despite the problems of literature searching and lack of
relevant articles, a major contribution of this article is presentation of the Medical Research Council’s Scale as a method of objectively comparing case series reports. Table 1 describes the grading of sensory recovery and deserves careful review. However, readers should be aware that this scale was developed for outcomes in peripheral nerves in the upper extremity. Extrapolation to IAN and lingual nerve repair requires corroboration of objective/subjective functional comparisons. The inclusion of 10 search-identified articles also related to the upper extremity is a problem. This reviewer wonders why unpublished work was included, because it would not have been found by the search. Enhancement of “sample size” by such additions is suspect. The authors acknowledge the importance of variables such as age, size of defect, and elapsed time between injury and repair. Repeatedly reminding the reader of the gold standard of the RCT, they acknowledge the problems in performing such trials. Their call for multicenter case series is an important alternative. This article highlights a new paradigm for practice that makes the following assumptions2.3: 1) Clinical experience and the development of clinical judgment are crucial and necessary, but systematic attempts to record observations in a reproducible and unbiased fashion increase the confidence one can have in knowledge about patient prognosis, the value of diagnostic tests, and the efficacy of treatment. 2) The study and understanding of basic mechanisms of disease are necessary, but they provide insufficient guides for clinical practice. 3) Understanding certain rules of evidence is necessary to correctly interpret the literature on causation, prognosis, diagnostic testing and treatment strategy. This paradigm requires new ways of thinking, teaching, and learning. E-BM does not ignore clinical experience and clinical intuition. It does not relegate basic science and pathophysiology to a meaningless role, nor does it ignore standard aspects of clinical training. This article applies the principles of E-BM by asking a question that can be answered. That is the first and most important point. If the question were “should we operate,” it would be less searchable, with an even lower yield of evidence. This is the first skill to be mastered, and the authors make their point. References 1. LeLorier J, Gregoire G,
Benhaddad A, et al: Discrepancies Between Meta-Analysis and Subsequent Large Randomized Controlled Trials. New Engl J Med 337536, 1997 2. Fletcher RH, Fletcher SW, Wagner EN: Clinical Epidemiology (ed 3). Baltimore, MD, Williams and Williams, 1996 3. Sackert DL, Richardson WS, Rosenberg W, et al: EvidenceBased Medicine. New York, NY, Churchhill Livingstone, 1997