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Are we moving in the right direction?
788 Readers’ forum
American Journal of Orthodontics and Dentofacial Orthopedics June 2008
evaluating the amount of resorption with pretreatment and posttreatment recordings will probably provide the same results as analyzing the effects of the wires just before and after use, once the other independent variables are controlled. Reversing and accentuating the curve of Spee in rectangular archwires will evidently incorporate some torsion to the teeth.7-9 This is an intrinsic factor when using the mechanics of reversed and accentuated curve of Spee in the archwires to correct the deep overbite and, of course, might play a role in the resorption amount. This is exactly what the study was concerned about—to investigate the differences between the complete mechanotherapy (including rectangular archwires) of correcting the deep overbite with reversed and accentuated curve of Spee compared with similar mechanics without reversing and accentuating the curve of Spee. Intergroup root resorption was compared with the nonparametric Mann Whitney U test.10 Although the amount of root resorption was greater in group 1, both groups had the same median of 2. Therefore, only with the intention of illustrating the statistically significant difference between the groups, the mean score was calculated for each group and placed in Table IV beside the mean rank, which is statistically valid.11-13 The resorption score for each patient was calculated as the mean resorption score of the 8 evaluated teeth. This is possible with ordinal categorical data.10,14 As suggested, we investigated the influence of the 5 teeth that had grade 4 root resorption by excluding them from an additional off-the-records checking comparison, but group 1 still had statistically greater root resorption than group 2 (P ⫽ 0.026). Additionally, these teeth came from patients with no specific genetic linkage. Perhaps we should have emphasized this in the text for clarity. Knowledge of the objectives and variables involved in an investigation is essential before any calculation attempt. Kelly Chiqueto Guilherme Janson Bauru, São Paulo, Brazil
effects of rectangular and round arch wires in leveling the curve of Spee. Am J Orthod Dentofacial Orthop 1999;116:522-9. Clifford PM, Orr JF, Burden DJ. The effects of increasing the reverse curve of Spee in a lower archwire examined using a dynamic photo-elastic gelatine model. Eur J Orthod 1999;21: 213-22. Ferguson JW. Lower incisor torque: the effects of rectangular archwires with a reverse curve of Spee. Br J Orthod 1990;17: 311-5. Conover WJ. Practical nonparametric statistics. New York: Wiley; 1998. de Freitas MR, Beltrão RT, Janson G, Henriques JF, Chiqueto K. Evaluation of root resorption after open bite treatment with and without extractions. Am J Orthod Dentofacial Orthop 2007;132: 143 e115-22. Janson G, Nakamura A, de Freitas MR, Henriques JF, Pinzan A. Apical root resorption comparison between Fränkel and eruption guidance appliances. Am J Orthod Dentofacial Orthop 2007;131: 729-35. Mandall N, Lowe C, Worthington H, Sandler J, Derwent S, Abdi-Oskouei M, et al. Which orthodontic archwire sequence? A randomized clinical trial. Eur J Orthod 2006;28:561-6. Siegel S, Castellan NJJr. Nonparametric statistics for the behavioral sciences. New York: McGraw-Hill; 1998.
Am J Orthod Dentofacial Orthop 2008;133:787-8 0889-5406/$34.00 Copyright © 2008 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2008.04.010
REFERENCES 1. Burstone CR. Deep overbite correction by intrusion. Am J Orthod 1977;72:1-22. 2. Costopoulos G, Nanda R. An evaluation of root resorption incident to orthodontic intrusion. Am J Orthod Dentofacial Orthop 1996;109:543-8. 3. Drenker E. Calculating continuous archwire forces. Angle Orthod 1988;58:59-70. 4. Hamdan AM, Rock WP. The effects of archwire forces on incisor intrusion. Br J Orthod 1995;22:155-60. 5. Ricketts RM. Bioprogressive therapy as an answer to orthodontic needs. Part II. Am J Orthod 1976;70:359-97. 6. Rinchuse DJ, Sweitzer EM, Rinchuse DJ, Rinchuse DL. Understanding science and evidence-based decision making in orthodontics. Am J Orthod Dentofacial Orthop 2005;127:618-24. 7. Al Qabandi AK, Sadowsky C, BeGole EA. A comparison of the
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Are we moving in the right direction? When I spotted my name in the first sentence of Dr Hassan Noroozi’s March letter to the editor, “Are we moving in the right direction to improve Angle’s classification?” (Am J Orthod Dentofacial Orthop 2008;133:336), I naturally read on. Dr Noroozi suggested that orthodontists should adopt “fuzzy logic” when assessing classification of malocclusion and treatment planning. I was intrigued, because I have also found Angle’s classifications to be poor discriminators of malocclusion1 and have proposed a numerical system of classification2 that some investigators3,4 have found to be more reliable. But Dr Noroozi’s “logic,” that patients could be both Class I and Class II at the same time but with different degrees of membership (in those classes), was confusingly fuzzy. So, to better understand his point, I pulled out my June 2006 copy of the AJO-DO to read his cited article.5 The article seemed to be an unpaid advertisement for a commercial software product that his disclaimer admitted he had a financial interest in, without divulging enough methodology to fully inform the reader, short of buying the product described but not named. The bone I have to pick with our specialty is that so many innovations or creative efforts are today being turned into commercial products. Are we not being misled when we attend continuing education programs and the doctor at the front of the room reports glowingly, in uncritical terms, about his own better-than-sliced-bread creation (be it bracket system, software, or hardware), while, in the back of the room, a dental product company’s detail man waits with order pad in hand. Are we not tired of being sandwiched between the shill and the sales guy? Orthodontists can make a decent living just correcting malocclusions. Do we have to wring further dollars from the specialty by patenting and copyrighting our innovations and
Readers’ forum 789
American Journal of Orthodontics and Dentofacial Orthopedics Volume 133, Number 6
marketing them to our professional brethren? Some might counter with the argument that reward fosters invention, but I believe that creative people are spurred on by the intellectual challenge and would innovate anyway. I believe that the entrepreneurial bent of many in our field is not advancing the art and the science of orthodontics, but encouraging false or exaggerated claims and biased conclusions in our literature and lectures. Maybe I’m showing my age, but I recall a time when many orthodontists gave their creative efforts to the specialty, gratis, in appreciation of the many blessings that it had bestowed on them. I’m nostalgic for the good old days when Dr Brainerd F. Swain, attempting to solve root-parallelism problems with Angle’s single-bracket design when used in extraction treatment, developed the Siamese twin bracket in 1949. Swain’s design has been incorporated into almost every edgewise bracket since then, and, to my knowledge, he gave it to our specialty without compensation. Considering how many Siamese twin brackets have been manufactured in the ensuing half century, one can only guess at the untold riches that Barney Swain foreswore. His reward wasn’t dollars, but the satisfaction of knowing that he gave back. Morton I. Katz Baltimore, Md
Editor’s note: In fairness to Dr Noroozi, his article was published in the Techno Bytes section of the journal. In this regular feature, we report on technological innovations, including commercially available products and services, and their application to orthodontic practice and research. Am J Orthod Dentofacial Orthop 2008;133:788-9 0889-5406/$34.00 Copyright © 2008 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2008.04.004
REFERENCES 1. Katz MI. Angle classification revisited 1: is current use reliable? Am J Orthod Dentofacial Orthop 1992;102:173-9. 2. Katz MI. Angle classification revisited 2: a modified Angle classification. Am J Orthod Dentofacial Orthop 1992;102:277-84. 3. Du SQ, Rinchuse DJ, Zullo TG, Rinchuse DJ. Reliability of three methods of occlusion classification. Am J Orthod Dentofacial Orthop 1998;113:463-70. 4. Brin I, Weinberger T, Ben-Chorin E. Classification of occlusion reconsidered. Eur J Orthod 1999;21:169-74. 5. Noroozi H. Orthodontic treatment planning software. Am J Orthod Dentofacial Orthop 2006;129:834-7.
American Journal of Orthodontics and Dentofacial Orthopedics June 2008
evaluating the amount of resorption with pretreatment and posttreatment recordings will probably provide the same results as analyzing the effects of the wires just before and after use, once the other independent variables are controlled. Reversing and accentuating the curve of Spee in rectangular archwires will evidently incorporate some torsion to the teeth.7-9 This is an intrinsic factor when using the mechanics of reversed and accentuated curve of Spee in the archwires to correct the deep overbite and, of course, might play a role in the resorption amount. This is exactly what the study was concerned about—to investigate the differences between the complete mechanotherapy (including rectangular archwires) of correcting the deep overbite with reversed and accentuated curve of Spee compared with similar mechanics without reversing and accentuating the curve of Spee. Intergroup root resorption was compared with the nonparametric Mann Whitney U test.10 Although the amount of root resorption was greater in group 1, both groups had the same median of 2. Therefore, only with the intention of illustrating the statistically significant difference between the groups, the mean score was calculated for each group and placed in Table IV beside the mean rank, which is statistically valid.11-13 The resorption score for each patient was calculated as the mean resorption score of the 8 evaluated teeth. This is possible with ordinal categorical data.10,14 As suggested, we investigated the influence of the 5 teeth that had grade 4 root resorption by excluding them from an additional off-the-records checking comparison, but group 1 still had statistically greater root resorption than group 2 (P ⫽ 0.026). Additionally, these teeth came from patients with no specific genetic linkage. Perhaps we should have emphasized this in the text for clarity. Knowledge of the objectives and variables involved in an investigation is essential before any calculation attempt. Kelly Chiqueto Guilherme Janson Bauru, São Paulo, Brazil
effects of rectangular and round arch wires in leveling the curve of Spee. Am J Orthod Dentofacial Orthop 1999;116:522-9. Clifford PM, Orr JF, Burden DJ. The effects of increasing the reverse curve of Spee in a lower archwire examined using a dynamic photo-elastic gelatine model. Eur J Orthod 1999;21: 213-22. Ferguson JW. Lower incisor torque: the effects of rectangular archwires with a reverse curve of Spee. Br J Orthod 1990;17: 311-5. Conover WJ. Practical nonparametric statistics. New York: Wiley; 1998. de Freitas MR, Beltrão RT, Janson G, Henriques JF, Chiqueto K. Evaluation of root resorption after open bite treatment with and without extractions. Am J Orthod Dentofacial Orthop 2007;132: 143 e115-22. Janson G, Nakamura A, de Freitas MR, Henriques JF, Pinzan A. Apical root resorption comparison between Fränkel and eruption guidance appliances. Am J Orthod Dentofacial Orthop 2007;131: 729-35. Mandall N, Lowe C, Worthington H, Sandler J, Derwent S, Abdi-Oskouei M, et al. Which orthodontic archwire sequence? A randomized clinical trial. Eur J Orthod 2006;28:561-6. Siegel S, Castellan NJJr. Nonparametric statistics for the behavioral sciences. New York: McGraw-Hill; 1998.
Am J Orthod Dentofacial Orthop 2008;133:787-8 0889-5406/$34.00 Copyright © 2008 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2008.04.010
REFERENCES 1. Burstone CR. Deep overbite correction by intrusion. Am J Orthod 1977;72:1-22. 2. Costopoulos G, Nanda R. An evaluation of root resorption incident to orthodontic intrusion. Am J Orthod Dentofacial Orthop 1996;109:543-8. 3. Drenker E. Calculating continuous archwire forces. Angle Orthod 1988;58:59-70. 4. Hamdan AM, Rock WP. The effects of archwire forces on incisor intrusion. Br J Orthod 1995;22:155-60. 5. Ricketts RM. Bioprogressive therapy as an answer to orthodontic needs. Part II. Am J Orthod 1976;70:359-97. 6. Rinchuse DJ, Sweitzer EM, Rinchuse DJ, Rinchuse DL. Understanding science and evidence-based decision making in orthodontics. Am J Orthod Dentofacial Orthop 2005;127:618-24. 7. Al Qabandi AK, Sadowsky C, BeGole EA. A comparison of the
8.
9.
10. 11.
12.
13.
14.
Are we moving in the right direction? When I spotted my name in the first sentence of Dr Hassan Noroozi’s March letter to the editor, “Are we moving in the right direction to improve Angle’s classification?” (Am J Orthod Dentofacial Orthop 2008;133:336), I naturally read on. Dr Noroozi suggested that orthodontists should adopt “fuzzy logic” when assessing classification of malocclusion and treatment planning. I was intrigued, because I have also found Angle’s classifications to be poor discriminators of malocclusion1 and have proposed a numerical system of classification2 that some investigators3,4 have found to be more reliable. But Dr Noroozi’s “logic,” that patients could be both Class I and Class II at the same time but with different degrees of membership (in those classes), was confusingly fuzzy. So, to better understand his point, I pulled out my June 2006 copy of the AJO-DO to read his cited article.5 The article seemed to be an unpaid advertisement for a commercial software product that his disclaimer admitted he had a financial interest in, without divulging enough methodology to fully inform the reader, short of buying the product described but not named. The bone I have to pick with our specialty is that so many innovations or creative efforts are today being turned into commercial products. Are we not being misled when we attend continuing education programs and the doctor at the front of the room reports glowingly, in uncritical terms, about his own better-than-sliced-bread creation (be it bracket system, software, or hardware), while, in the back of the room, a dental product company’s detail man waits with order pad in hand. Are we not tired of being sandwiched between the shill and the sales guy? Orthodontists can make a decent living just correcting malocclusions. Do we have to wring further dollars from the specialty by patenting and copyrighting our innovations and
Readers’ forum 789
American Journal of Orthodontics and Dentofacial Orthopedics Volume 133, Number 6
marketing them to our professional brethren? Some might counter with the argument that reward fosters invention, but I believe that creative people are spurred on by the intellectual challenge and would innovate anyway. I believe that the entrepreneurial bent of many in our field is not advancing the art and the science of orthodontics, but encouraging false or exaggerated claims and biased conclusions in our literature and lectures. Maybe I’m showing my age, but I recall a time when many orthodontists gave their creative efforts to the specialty, gratis, in appreciation of the many blessings that it had bestowed on them. I’m nostalgic for the good old days when Dr Brainerd F. Swain, attempting to solve root-parallelism problems with Angle’s single-bracket design when used in extraction treatment, developed the Siamese twin bracket in 1949. Swain’s design has been incorporated into almost every edgewise bracket since then, and, to my knowledge, he gave it to our specialty without compensation. Considering how many Siamese twin brackets have been manufactured in the ensuing half century, one can only guess at the untold riches that Barney Swain foreswore. His reward wasn’t dollars, but the satisfaction of knowing that he gave back. Morton I. Katz Baltimore, Md
Editor’s note: In fairness to Dr Noroozi, his article was published in the Techno Bytes section of the journal. In this regular feature, we report on technological innovations, including commercially available products and services, and their application to orthodontic practice and research. Am J Orthod Dentofacial Orthop 2008;133:788-9 0889-5406/$34.00 Copyright © 2008 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2008.04.004
REFERENCES 1. Katz MI. Angle classification revisited 1: is current use reliable? Am J Orthod Dentofacial Orthop 1992;102:173-9. 2. Katz MI. Angle classification revisited 2: a modified Angle classification. Am J Orthod Dentofacial Orthop 1992;102:277-84. 3. Du SQ, Rinchuse DJ, Zullo TG, Rinchuse DJ. Reliability of three methods of occlusion classification. Am J Orthod Dentofacial Orthop 1998;113:463-70. 4. Brin I, Weinberger T, Ben-Chorin E. Classification of occlusion reconsidered. Eur J Orthod 1999;21:169-74. 5. Noroozi H. Orthodontic treatment planning software. Am J Orthod Dentofacial Orthop 2006;129:834-7.