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Headaches and malocclusion
638 Readers’ forum
There was some concern that strict adherence to EBO might stifle new developments. The example of Chuck Yeager breaking the sound barrier was given by Dr Hayes as a case in point, when conventional wisdom was proven incorrect. Chuck Yeager was an extraordinary man, who well appreciated the dangers of his research. He had commented that there were at least a dozen different ways the X-1 could kill him, before his ninth powered flight in the X-1 broke the sound barrier in October 1947. Research for most of us tends to be a more conservative and cautious pursuit, but new developments still occur. The discipline of clinical pharmacology is highly regulated and has been for a considerable time, yet new drugs continue to appear in the marketplace (some might argue too many!). Dr Hayes noted that not all evidence is valid—ie, not all is of equal quality. This was an important emphasis of my article. He stated that randomized clinical trials (RCTs) can also be flawed. This is also possible. However, the cost of RCTs and the effort that they involve generally result in a much more rigorous scientific method than other studies. No single study is in itself conclusive or gives a definitive answer. In my article, I acknowledged this point, consistent with the Cochrane Collaboration’s hierarchy of evidence,3 stating “Ideally, conclusions should be based on many studies, such as a meta analysis of available research (incorporating as many RCTs as possible).”1 With regard to Class II studies, the findings of the 3 RCTs mentioned in my article agree with many other studies that used sound scientific methods: early treatment does not provide long-term enhancement of mandibular growth. In a recent editorial, Dr David Turpin4 summarized the findings of the Cochrane review of 2-phase treatment, which had examined the same studies and, not surprisingly, reached the same conclusion. I am unaware of any other group of studies based on equal or superior scientific methodology that have obtained a different result. I agree with Dr Hayes that diagnosis is paramount and might influence the choice of appliance. However, this does not explain the striking similarity between the RCTs to date. Of interest is a study by Burkhardt et al.5 They examined the effects of the pendulum and Herbst appliances. It might be expected that 2 such different appliances would provide different outcomes. This was not the case, with neither appliance giving a significant increase in anterior chin position. I also agree that treatment should not proceed blindly when it is obviously not producing the desired effect. Under the heading “Threat and error management,” I detailed the importance of contingency planning and modifying treatment plans while proceeding.1 The experience and skill of the clinician are still required for appropriate management of the treatment. EBO provides a framework for selecting the most trusted information to be used in the decision-making process. Although EBO treatment provides the best chance for
American Journal of Orthodontics and Dentofacial Orthopedics May 2008
success, it should not be viewed as a cookbook or a guarantee for success in any individual patient. Tony Collett Upper Ferntree Gully, Victoria, Australia Am J Orthod Dentofacial Orthop 2008;133:637-8 0889-5406/$34.00 Copyright © 2008 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2008.03.005
REFERENCES 1. Collett T. Evidence, judgment, and the clinical decision: an argument for evidence-based orthodontics. Am J Orthod Dentofacial Orthop 2008;133:190-4. 2. Collett T. Evidence-based orthodontics: friend, not foe. Am J Orthod Dentofacial Orthop 2007;132:574-5. 3. Cochrane Collaboration. Cochrane and systematic reviews. Available at: http://www.cochrane.org/consumers/sysrev.html. Accessed February 15, 2008. 4. Turpin DL. The long-awaited Cochrane review of 2-phase treatment. Am J Orthod Dentofacial Orthop 2007;132:423-4. 5. Burkhardt DR, McNamara JA, Baccetti T. Maxillary molar distalization or mandibular enhancement: a cephalometric comparison of comprehensive orthodontic treatment including the pendulum and the Herbst appliances. Am J Orthod Dentofacial Orthop 2003;123:108-16.
Headaches and malocclusion It is really convincing and interesting to read the study on malocclusion and headache (Lambourne C, Lampasso J, Buchanan WC Jr, Dunford R, McCall W. Malocclusion as a risk factor in the etiology of headaches in children and adolescents. Am J Orthod Dentofacial Orthop 2007;132: 754-61). We appreciate the authors’ effort and thought in producing a study of this nature, which has never been addressed before in the literature, at least to our knowledge. Headache is a pandemic phenomenon with many predisposing and perpetuating factors and protean characteristics. In the present scenario, clinicians advise occlusal splints or occlusal equilibration as palliative therapy for many forms of intense headaches and migraines, although there is relatively little data available on the benefit or otherwise of wearing such appliances or occlusal equilibration.1,2 An important factor to consider in formulating a treatment regimen is to determine the association of headaches with muscle dysfunction, temporomandibular dysfunction (TMD), vascular migraine, and other masochistic habits. On this note, the authors of this study took a smart step in analyzing the role of malocclusion in the etiology of headaches in young subjects. We hope that this study will stimulate further research to understand and unlock the mystery of headaches. We would like to raise a small concern pertaining to the study that might help for further analyses. Although the authors admit that nonex-
Readers’ forum 639
American Journal of Orthodontics and Dentofacial Orthopedics Volume 133, Number 5
clusion of a TMD patient in the sample is possible but unlikely because of their sample definition, foolproof research data are possible only when the following are analyzed: a thorough TMJ clinical examination because many TMDs are asymptomatic, clenching, muscle activity patterns, and freeway space. Arunachalam Sivakumar Sumit Gandhi Ashima Valiathan Manipal, India
Am J Orthod Dentofacial Orthop 2008;133:638-9 0889-5406/$34.00 Copyright © 2008 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2008.03.006
REFERENCES 1. Quayle AA, Gray RJ, Metcalfe RJ, Guthrie E, Wastell D. Soft occlusal splint therapy in the treatment of migraine and other headaches. J Dent 1990;18:123-9. 2. Wenneberg B, Nystrom T, Carlsson GE. Occlusal equilibration and other stomatognathic treatment in patients with mandibular dysfunction and headache. J Prosthet Dent 1988;59:478-83.
There was some concern that strict adherence to EBO might stifle new developments. The example of Chuck Yeager breaking the sound barrier was given by Dr Hayes as a case in point, when conventional wisdom was proven incorrect. Chuck Yeager was an extraordinary man, who well appreciated the dangers of his research. He had commented that there were at least a dozen different ways the X-1 could kill him, before his ninth powered flight in the X-1 broke the sound barrier in October 1947. Research for most of us tends to be a more conservative and cautious pursuit, but new developments still occur. The discipline of clinical pharmacology is highly regulated and has been for a considerable time, yet new drugs continue to appear in the marketplace (some might argue too many!). Dr Hayes noted that not all evidence is valid—ie, not all is of equal quality. This was an important emphasis of my article. He stated that randomized clinical trials (RCTs) can also be flawed. This is also possible. However, the cost of RCTs and the effort that they involve generally result in a much more rigorous scientific method than other studies. No single study is in itself conclusive or gives a definitive answer. In my article, I acknowledged this point, consistent with the Cochrane Collaboration’s hierarchy of evidence,3 stating “Ideally, conclusions should be based on many studies, such as a meta analysis of available research (incorporating as many RCTs as possible).”1 With regard to Class II studies, the findings of the 3 RCTs mentioned in my article agree with many other studies that used sound scientific methods: early treatment does not provide long-term enhancement of mandibular growth. In a recent editorial, Dr David Turpin4 summarized the findings of the Cochrane review of 2-phase treatment, which had examined the same studies and, not surprisingly, reached the same conclusion. I am unaware of any other group of studies based on equal or superior scientific methodology that have obtained a different result. I agree with Dr Hayes that diagnosis is paramount and might influence the choice of appliance. However, this does not explain the striking similarity between the RCTs to date. Of interest is a study by Burkhardt et al.5 They examined the effects of the pendulum and Herbst appliances. It might be expected that 2 such different appliances would provide different outcomes. This was not the case, with neither appliance giving a significant increase in anterior chin position. I also agree that treatment should not proceed blindly when it is obviously not producing the desired effect. Under the heading “Threat and error management,” I detailed the importance of contingency planning and modifying treatment plans while proceeding.1 The experience and skill of the clinician are still required for appropriate management of the treatment. EBO provides a framework for selecting the most trusted information to be used in the decision-making process. Although EBO treatment provides the best chance for
American Journal of Orthodontics and Dentofacial Orthopedics May 2008
success, it should not be viewed as a cookbook or a guarantee for success in any individual patient. Tony Collett Upper Ferntree Gully, Victoria, Australia Am J Orthod Dentofacial Orthop 2008;133:637-8 0889-5406/$34.00 Copyright © 2008 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2008.03.005
REFERENCES 1. Collett T. Evidence, judgment, and the clinical decision: an argument for evidence-based orthodontics. Am J Orthod Dentofacial Orthop 2008;133:190-4. 2. Collett T. Evidence-based orthodontics: friend, not foe. Am J Orthod Dentofacial Orthop 2007;132:574-5. 3. Cochrane Collaboration. Cochrane and systematic reviews. Available at: http://www.cochrane.org/consumers/sysrev.html. Accessed February 15, 2008. 4. Turpin DL. The long-awaited Cochrane review of 2-phase treatment. Am J Orthod Dentofacial Orthop 2007;132:423-4. 5. Burkhardt DR, McNamara JA, Baccetti T. Maxillary molar distalization or mandibular enhancement: a cephalometric comparison of comprehensive orthodontic treatment including the pendulum and the Herbst appliances. Am J Orthod Dentofacial Orthop 2003;123:108-16.
Headaches and malocclusion It is really convincing and interesting to read the study on malocclusion and headache (Lambourne C, Lampasso J, Buchanan WC Jr, Dunford R, McCall W. Malocclusion as a risk factor in the etiology of headaches in children and adolescents. Am J Orthod Dentofacial Orthop 2007;132: 754-61). We appreciate the authors’ effort and thought in producing a study of this nature, which has never been addressed before in the literature, at least to our knowledge. Headache is a pandemic phenomenon with many predisposing and perpetuating factors and protean characteristics. In the present scenario, clinicians advise occlusal splints or occlusal equilibration as palliative therapy for many forms of intense headaches and migraines, although there is relatively little data available on the benefit or otherwise of wearing such appliances or occlusal equilibration.1,2 An important factor to consider in formulating a treatment regimen is to determine the association of headaches with muscle dysfunction, temporomandibular dysfunction (TMD), vascular migraine, and other masochistic habits. On this note, the authors of this study took a smart step in analyzing the role of malocclusion in the etiology of headaches in young subjects. We hope that this study will stimulate further research to understand and unlock the mystery of headaches. We would like to raise a small concern pertaining to the study that might help for further analyses. Although the authors admit that nonex-
Readers’ forum 639
American Journal of Orthodontics and Dentofacial Orthopedics Volume 133, Number 5
clusion of a TMD patient in the sample is possible but unlikely because of their sample definition, foolproof research data are possible only when the following are analyzed: a thorough TMJ clinical examination because many TMDs are asymptomatic, clenching, muscle activity patterns, and freeway space. Arunachalam Sivakumar Sumit Gandhi Ashima Valiathan Manipal, India
Am J Orthod Dentofacial Orthop 2008;133:638-9 0889-5406/$34.00 Copyright © 2008 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2008.03.006
REFERENCES 1. Quayle AA, Gray RJ, Metcalfe RJ, Guthrie E, Wastell D. Soft occlusal splint therapy in the treatment of migraine and other headaches. J Dent 1990;18:123-9. 2. Wenneberg B, Nystrom T, Carlsson GE. Occlusal equilibration and other stomatognathic treatment in patients with mandibular dysfunction and headache. J Prosthet Dent 1988;59:478-83.