L E T T E R S
aligned incisors than from crowded incisors. One could suppose that the answers to some questions can be intuitive. Ask a dentist about crowded incisors and plaque accumulation. Accordingly, we believe that the American Association of Orthodontists is correct in its assessment that orthodontics can help with periodontal issues.1,2 Our office pilot periodontal study of posterior teeth positioned with little-to-no inclination (and centered on the alveolar crest) versus pretreatment inclined and noncentered teeth has convinced us.3 The authors have performed an important service by way of clear analysis and criticism of the best available studies on their topic. Their point is welltaken—there is a lack of good, published research. One would hope that a study of posterior teeth centered on alveolar crest versus nontreated teeth (noncentered and inclined) might have a higher priority than a study regarding the ease of plaque removal from aligned or crowded incisors. John L. Hayes, DMD Williamsport, Pa. 1. American Association of Orthodontists. Why straighten teeth? “www.webcitation.org/ 5RDWqElut”. Accessed April 15, 2008. 2. Vanarsdall RL, Jr, Secchi AG. Periodontal-orthodontic interrelationships. In: Graber TM, Vanarsdall RL, Vig KWL, eds. Orthodontics: Current Principles and Techniques. 4th ed. St. Louis: Elsevier Mosby; 2005:901-936. 3. Hayes JL. Rapid maxillary expansion. Am J Orthod Dentofacial Orthop 2006;130(4):432-433.
Author’s response: My coauthors and I thank Drs. Hayes, Peterson and Ostreicher for their interest in our article. Their letters express concern regarding the findings of our systematic review on the relationship between periodontal health and orthodontic therapy.
Dr. Peterson suggests that the systematic review regarding orthodontic therapy and periodontal health is an example of useless research and that the efforts would be better spent on real research projects and real patients. This systematic review was commissioned and funded by the ADA Foundation. This organization identified the most pressing questions to be addressed with systematic reviews based on a survey of more than 5,000 general practitioners and specialists. An unbiased review of all available studies is the most objective way to find ‘the truth,’ even if the results are not what we thought they should be or what we would have liked to see. The ADA also organized a symposium to identify these pressing questions, at which professional organizations, insurance companies and government agencies were present. On the basis of this work, four topics were selected and requests for proposals were publicized. The ADA Council on Scientific Affairs selected the most meritorious applications. Even if one agrees with Dr. Peterson’s viewpoint that the identified evidence is arcane, an important goal was nonetheless achieved: there is an absence of controlled evidence to support the common claim that orthodontic therapy provides periodontal benefits. We agree that the quality of
the studies included in the review was not as high as one may have liked, a weakness we addressed thoroughly in our discussion. However, using strict inclusion criteria, we have included all available studies on this topic, which reported on more than 1,670 patients on four continents. This needs to be compared with the “evidence” that convinced Dr. Hayes that orthodontics can help with periodontal issues (a pilot study, which is not mentioned in his cited reference1). Dr. Hayes’ comment that the answer to some questions can be intuitive (“Ask a dentist about crowded incisors and plaque accumulation”) indicates a lack of understanding of the question our systematic review addressed: the relationship between periodontal health and orthodontic therapy. This is different from the relationship between crowding and plaque accumulation. Dr. Ostreicher also fails to make this distinction and bases his statement that “frequently orthodontic treatment is of great benefit to periodontal health” on a study that reports worse periodontal health in malpositioned and crowded incisors.2 The other four references he cites also relate malocclusions to periodontal health and do not evaluate the effects of orthodontic treatment. While it makes sense to “assume” that straightening teeth would have to improve periodontal conditions, this does not provide evidence; it only provides biological plausibility, the lowest level of evidence. We disagree with Dr. Ostreicher that we failed to disclose the entire truth. We believe an unbiased review of all available studies is the most
JADA, Vol. 139
http://jada.ada.org
Copyright © 2008 American Dental Association. All rights reserved.
July 2008
889
L E T T E R S
objective way to find “the truth,” even if the results are not what we thought they should be or what we would have liked to see. Interestingly, another recent review reported the same results as we did.3 If the need for scientific evidence regarding the positive periodontal effects of orthodontic therapy is important, then we
890
JADA, Vol. 139
http://jada.ada.org
hope that the profession will follow Dr. Peterson’s suggestion and initiate new research with the confidence that the existing evidence is inadequate. Anne-Marie Bollen, DDS, MS, PhD Professor Department of Orthodontics School of Dentistry University of Washington Seattle
1. Hayes JL. Rapid maxillary expansion. Am J Orthod Dentofac Orthop 2006;130(4): 432-433. 2. Ngom PI, Diagne F, Benoist HM, Thiam F. Intraarch and interarch relationships of the anterior teeth and periodontal conditions. Angle Orthod 2006;76(2):236-242. 3. Van Gastel J, Quirynen M, Teughels W, Carels C. The relationships between malocclusion, fixed orthodontic appliances and periodontal disease: a review of the literature. Aust Orthod J 2007;23(2):121-129.
July 2008
Copyright © 2008 American Dental Association. All rights reserved.
aligned incisors than from crowded incisors. One could suppose that the answers to some questions can be intuitive. Ask a dentist about crowded incisors and plaque accumulation. Accordingly, we believe that the American Association of Orthodontists is correct in its assessment that orthodontics can help with periodontal issues.1,2 Our office pilot periodontal study of posterior teeth positioned with little-to-no inclination (and centered on the alveolar crest) versus pretreatment inclined and noncentered teeth has convinced us.3 The authors have performed an important service by way of clear analysis and criticism of the best available studies on their topic. Their point is welltaken—there is a lack of good, published research. One would hope that a study of posterior teeth centered on alveolar crest versus nontreated teeth (noncentered and inclined) might have a higher priority than a study regarding the ease of plaque removal from aligned or crowded incisors. John L. Hayes, DMD Williamsport, Pa. 1. American Association of Orthodontists. Why straighten teeth? “www.webcitation.org/ 5RDWqElut”. Accessed April 15, 2008. 2. Vanarsdall RL, Jr, Secchi AG. Periodontal-orthodontic interrelationships. In: Graber TM, Vanarsdall RL, Vig KWL, eds. Orthodontics: Current Principles and Techniques. 4th ed. St. Louis: Elsevier Mosby; 2005:901-936. 3. Hayes JL. Rapid maxillary expansion. Am J Orthod Dentofacial Orthop 2006;130(4):432-433.
Author’s response: My coauthors and I thank Drs. Hayes, Peterson and Ostreicher for their interest in our article. Their letters express concern regarding the findings of our systematic review on the relationship between periodontal health and orthodontic therapy.
Dr. Peterson suggests that the systematic review regarding orthodontic therapy and periodontal health is an example of useless research and that the efforts would be better spent on real research projects and real patients. This systematic review was commissioned and funded by the ADA Foundation. This organization identified the most pressing questions to be addressed with systematic reviews based on a survey of more than 5,000 general practitioners and specialists. An unbiased review of all available studies is the most objective way to find ‘the truth,’ even if the results are not what we thought they should be or what we would have liked to see. The ADA also organized a symposium to identify these pressing questions, at which professional organizations, insurance companies and government agencies were present. On the basis of this work, four topics were selected and requests for proposals were publicized. The ADA Council on Scientific Affairs selected the most meritorious applications. Even if one agrees with Dr. Peterson’s viewpoint that the identified evidence is arcane, an important goal was nonetheless achieved: there is an absence of controlled evidence to support the common claim that orthodontic therapy provides periodontal benefits. We agree that the quality of
the studies included in the review was not as high as one may have liked, a weakness we addressed thoroughly in our discussion. However, using strict inclusion criteria, we have included all available studies on this topic, which reported on more than 1,670 patients on four continents. This needs to be compared with the “evidence” that convinced Dr. Hayes that orthodontics can help with periodontal issues (a pilot study, which is not mentioned in his cited reference1). Dr. Hayes’ comment that the answer to some questions can be intuitive (“Ask a dentist about crowded incisors and plaque accumulation”) indicates a lack of understanding of the question our systematic review addressed: the relationship between periodontal health and orthodontic therapy. This is different from the relationship between crowding and plaque accumulation. Dr. Ostreicher also fails to make this distinction and bases his statement that “frequently orthodontic treatment is of great benefit to periodontal health” on a study that reports worse periodontal health in malpositioned and crowded incisors.2 The other four references he cites also relate malocclusions to periodontal health and do not evaluate the effects of orthodontic treatment. While it makes sense to “assume” that straightening teeth would have to improve periodontal conditions, this does not provide evidence; it only provides biological plausibility, the lowest level of evidence. We disagree with Dr. Ostreicher that we failed to disclose the entire truth. We believe an unbiased review of all available studies is the most
JADA, Vol. 139
http://jada.ada.org
Copyright © 2008 American Dental Association. All rights reserved.
July 2008
889
L E T T E R S
objective way to find “the truth,” even if the results are not what we thought they should be or what we would have liked to see. Interestingly, another recent review reported the same results as we did.3 If the need for scientific evidence regarding the positive periodontal effects of orthodontic therapy is important, then we
890
JADA, Vol. 139
http://jada.ada.org
hope that the profession will follow Dr. Peterson’s suggestion and initiate new research with the confidence that the existing evidence is inadequate. Anne-Marie Bollen, DDS, MS, PhD Professor Department of Orthodontics School of Dentistry University of Washington Seattle
1. Hayes JL. Rapid maxillary expansion. Am J Orthod Dentofac Orthop 2006;130(4): 432-433. 2. Ngom PI, Diagne F, Benoist HM, Thiam F. Intraarch and interarch relationships of the anterior teeth and periodontal conditions. Angle Orthod 2006;76(2):236-242. 3. Van Gastel J, Quirynen M, Teughels W, Carels C. The relationships between malocclusion, fixed orthodontic appliances and periodontal disease: a review of the literature. Aust Orthod J 2007;23(2):121-129.
July 2008
Copyright © 2008 American Dental Association. All rights reserved.
