part of the solution to a serious orthodontic concern.13,17 There can be shortcomings with different research designs, and the present pilot study research is no exception. For this investigation, it would have been better to randomly place the patients into two groups (treatment and control), while also controlling for degree of skeletal deficiency, age, and sex). One group would be treated while the other group waited. At a later time, approximately age 12 or 13, data would be collected and analyzed to compare effectiveness of the treatment. This would then constitute a prospective, randomized, clinical trial — the research of choice. In the future, with insight from this study and outside of a private practice, groups could be studied in a prospective, randomized, clinical trial; it is possible that such a study could likely be completed in less than 10 years given a high enough volume of young patients – with the understanding that some patients would act as controls and would be required to forgo intervention. This study’s simple design helped minimize research biases. No braces or active retainers were used for canine deimpactions. Treatment involved:
1. The elimination of maxillary deficiency by way of RPE; new skeletal transverse criteria were used to help define maxillary deficiency. 2. Preservation of leeway space. 3. Treatment biases were minimized. In our experience, the 10 case studies and the canine treatment results presented in this manuscript were not exceptional — they were, in fact, representative of hundreds of other similar potentially impacted canine cases that received the same Phase I care regimen.
Conclusions 1. Early Phase I diagnosis and RPE correction of maxillary transverse deficiency, by way of Harmony criteria, and the CAC measurement technique may be helpful for potentially impacted maxillary canines. 2. A deficient maxilla may be more prevalent than previously thought as determined by CAC measurement and Harmony criteria. 3. More study is recommended with control and treatment groups matched for maxillary deficiency determined by Harmony criteria and measured with the CAC technique. OP
References 1. Baccetti T, Mucedero M, Leonardi M, Cozza P. Interceptive treatment of palatal impaction of maxillary canines with rapid maxillary expansion: a randomized clinical trial. Am J Orthod Dentofacial Orthop. 2009;136(5):657-661. 2. Fernández E, Bravo LA, Canteras M. Eruption of the permanent upper canine: a radiologic study. Am J Orthod Dentofacial Orthop. 1998;113(4):414-420. 3. Sambataro S, Baccetti T, Franchi L, Antonini F. Early predictive variables for upper canine impaction as derived from posteroanterior cephalograms. Angle Orthod. 2005;75(1):28-34. 4. Schindel RH, Duffy SL. Maxillary transverse discrepancies and potentially impacted maxillary canines in mixed-dentition patients. Angle Orthod. 2007;77(3):430-435. 5. Shapira Y, Kuftinec MM. Early diagnosis and interception of potential maxillary canine impaction. J Am Dent Assoc. 1998;129(10):1450-1454. 6. Warford JH Jr, Grandhi RK, Tira DE. Prediction of maxillary canine impaction using sectors and angular measurement. Am J Orthod Dentofacial Orthop. 2003;124(6):651-655. 7. Williams BH. (1981) Diagnosis and prevention of maxillary cuspid impaction. Angle Orthod. 1981;51(1):30-40. 8. Sajnani AK, King NM. Early prediction of maxillary canine impaction from panoramic radiographs. Am J Orthod Dentofacial Orthop. 2012;142(1):45-51.
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9. Ericson S. Kurol J. Early treatment of palatally erupting maxillary canines by extraction of the primary canines. Eur J Orthod. 1988;10(4):283-295. 10. Olive RJ. Orthodontic treatment of palatally impacted maxillary canines. Aust Orthod J. 2002;18:6470. 11. Peck S, Peck L, Kataja M. The palatally displaced canine as a dental anomaly of genetic origin. Angle Orthod. 1994;64(4):249-256. 12. Leonardi M, Armi P, Franchi L, Baccetti T. Two interceptive approaches to palatally displaced canines: a prospective longitudinal study. Angle Orthod. 2004;74(5);581-586. 13. Hayes JL. The Williamsport Orthodontic Study. Practice Based Research Network, Univ. of Pennsylvania, School of Dental Medicine, Orthodontic Department; 2008. 14. Hayes JL. A clinical approach to identify transverse discrepancies. Presentation at: Pennsylvania Association of Orthodontists; March 2003; Philadelphia, PA. 15. Hayes JL. In search of improved skeletal transverse diagnosis. Part 1: traditional measurement techniques. Ortho Prac US. 2010;1(3);34-39. 16. Hayes JL. In search of improved skeletal transverse diagnosis. Part 2: A new measurement technique used on 114 consecutive untreated patients. Ortho Prac US. 2010;1(4):34-39.
17. Hayes JL. A new regimen of phase I care applied to anterior open bite—10 case studies: an etiology proposed by the strategy of triangulation. Ortho Prac US. 2012;3(3):18-26. 18. Lundström AF. Malocclusion of the teeth regarded as a problem in the connection with the apical base. Stockholm: A. B. Fahlcrantz; 1923. 19. Peck S, Peck L, Kataja M. Sense and nonsense regarding palatal canines. Angle Orthod. 1995;65(2):99102. 20. Becker A, Peck S, Peck L, Kataja M. Palatal canine displacement: guidance theory or an anomaly of genetic origin? Angle Orthod. 1995;65(2):95-102. 21. Jacoby H. The etiology of maxillary canine impactions. Am J Orthod. 1983;84:125-132. 22. Mew JRC. Re Jacoby: Etiology of maxillary canine impactions [letter to the editor]. Am J Orthod. 1983;84:125-139. 23. McConnell TL, Hoffman DL, Forbes DP, Janzen EK, Weintraub NH. Maxillary canine impaction in patients with transverse maxillary deficiency. ASDC J Dent Child. 1996;63(3):190-195. 24. Langberg BJ, Peck S. Adequacy of maxillary dental arch width in patients with palatally displaced canines. Am J Orthod Dentofacial Orthop. 2000;118(2):220-223. 25. Saiar M, Rebellato J, Sheats RD. Palatal displacement of canines and maxillary skeletal width. Am J Orthod Dentofacial Orthop. 2006;129(4):511-519.
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RESEARCH
normalization of the previously deformed arches somehow caused improvement in canine guidance as in the guidance theory of canine impaction, and that the skeletal expansion also somehow “reset or overcame” some of the genetic disturbances as in the genetic theory of canine impaction. Comments: Gaining space to help with canine impactions is not a new idea.1,3,12 Accordingly, based on triangulation, a new Phase I regimen can be helpful for potential canine impactions. By way of normalization of the maxillary skeletal transverse, potentially impacted canines were able to erupt into good position. A new definition of what constitutes maxillary deficiency -determined by a new center of alveolar crest (CAC) skeletal measurement technique and by Harmony criteria — was helpful.13,14,16 It may be important to note again that we chose the most severe cases we could find at T1. This new regimen of Phase I care is likely not a perfect answer to canine impactions – it is not a perfect world. However, we do believe that this study and other similar studies confirm that CAC measurement and Harmony criteria can be