ian anderson, bds, bms(hons) -...

677VOLUME XLIII NUMBER 11

The opinions expressed in the Journal of Clinical Orthodontics are those of the writers and do not necessarily reflect the opinions and policies of JCO. Copyright © 2009 JCO, Inc. Journal of Clinical Orthodontics (USPS 802-120, ISSN 0022-3875) is published monthly for $235 per year (U.S. individual rate) by JCO, Inc., 1828 Pearl St., Boulder, CO 80302-5519. Periodicals postage paid at Boulder, CO, and additional mailing office. POSTMASTER: Send address changes to JCO, 1828 Pearl St., Boulder, CO 80302-5519. Phone: (303) 443-1720; e-mail: [email protected].

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DEPARTMENTSThe Editor’s Corner � � � 681Continuing Education � � 721Contributors’ Guide � � � 728Product News � � � � � � � � 729Classified � � � � � � � � � � � � 730Index of Advertisers � � � 731

The CoverA method of treating

pseudo-Class III malocclu-sion, as described by Drs�

Anderson, Rabie, and Wong, is illustrated on the cover�

Early Treatment of Pseudo-Class III Malocclusion: A 10-Year Follow-Up StudyIAN ANDERSON, BDS, BMS(Hons)A. BAKR M. RABIE, MS, PHD, FHKAM, FCDSHKRICKY W.K. WONG, BDS, MOrth, MOrth RCS, FRACDS, FHKAM, FCDSHKDentofacial and skeletal changes are analyzed 10 years after treatment with a 2 × 4 appliance�

2009 JCO Orthodontic Practice StudyPart 2 Practice SuccessROBERT G. KEIM, DDS, EDD, PHDEUGENE L. GOTTLIEB, DDSALLEN H. NELSON, PHDDAVID S. VOGELS IIIThe authors review management methods that appear related to success in terms of net income and case starts�

PEARLSA Spring-Loaded Stripping ToolANKUR AGGARWAL, BDS, MDSU.S. KRISHNA NAYAK, BDS, MDSA simple device for interproximal stripping is described�

A New Device for Traction of Dilacerated Maxillary Central IncisorsALDO GIANCOTTI, DDSPAOLA MOZZICATO, DDSFRANCESCO GERMANO, DDSThis article describes a biomechanical approach for treat-ing an impacted, dilacerated maxillary central incisor�

CASE REPORTManagement of a Transposed Maxillary Canine and Lateral IncisorVINAY K. CHUGH, BDS, MDS, MOrth RCS EDVIJAY P. SHARMA, BDS, MDS PRADEEP TANDON, BDS, MDS GYAN P. SINGH, BDS, MDSTransposed teeth are sequentially brought into the arch�

JCO INTERVIEWSDr. Robert M. Littleon the University of Washington Post-Retention StudiesDr� Little identifies factors that contribute to stability�

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http://www.jco-online.com/archive/list-issue.aspx?year=2009&month=11

THE EDITOR’S CORNER

VOLUME XLIII NUMBER 11 681

How Predictable Is Stability?In last month’s issue of JCO, Dr� Robert Little pre-

sented some fascinating conclusions on orthodontic stabil-ity and relapse from the exhaustive University of Wash-ington post-retention studies� He illustrated the rather sobering fact that the majority of orthodontic corrections, most notably those involving lower incisor crowding or dental rotations, are highly unstable over a period of 10-20 years� In other words, at least some relapse occurs in most ortho dontic cases� The logical corollary to this conclusion is that the only way to achieve lifetime stability following orthodontic treatment is to employ lifetime retention methods�

This month, Dr� Peter Sinclair interviews Dr� Little, who takes a closer look at how the research sample that led to these conclusions was developed and suggests clini-cal steps to maximize the quality of case outcomes while minimizing relapse�

One of the main themes that emerges from these two articles is that orthodontic stability is, at best, unpredict-able� While certain factors seem to point toward a better prognosis—maintenance of the leeway space in favorable mixed-dentition cases and preservation of the original mandibular archform, for instance—no pretreatment fac-tors are strong predictors of long-term stability� On the other hand, some factors prove to be fairly accurate in predicting long-term instability� Take, for example, crowd-ed cases treated without extractions through the expedient of “arch development”� The best evidence to date, consist-ing of numerous studies, several systematic reviews, and at least one meta-analysis, still indicates that Charlie Tweed was right more than 50 years ago: Don’t expand the lower canines or the lower archform if you want the best chance at long-term stability� Expansion of a crowded lower arch in almost every case is doomed to relapse� I’ve often won-dered how many times this axiom has to be demonstrated before it is finally considered “proven”�

The current nonextraction-arch-development fad relies heavily on the use of lifetime retention to maintain expanded lower arches� Dr� Little suggests that bonding

© 2009 JCO, Inc.

EDITORRobert G. Keim, DDS, EdD, PhD

SENIOR EDITOREugene L. Gottlieb, DDS

ASSOCIATE EDITORSBirte Melsen, DDS, DORavindra Nanda, BDS, MDS, PhDJohn J. Sheridan, DDS, MSDPeter M. Sinclair, DDS, MSDBjorn U. Zachrisson, DDS, MSD, PhD

TECHNOLOGY EDITORW. Ronald Redmond, DDS, MS

CONTRIBUTING EDITORSR.G. Alexander, DDS, MSDS. Jay Bowman, DMD, MSDRobert L. Boyd, DDS, MEdJohn W. Graham, DDS, MDRobert S. Haeger, DDS, MSWarren Hamula, DDS, MSDJames J. Hilgers, DDS, MSJames Mah, DDS, MS, DMSMelvin Mayerson, DDS, MSDRichard P. McLaughlin, DDSJames A. McNamara, DDS, PhDElliott M. Moskowitz, DDS, MSMichael L. Swartz, DDSJeff Berger, BDS, DO (Canada)Vittorio Cacciafesta, DDS, MSC, PhD (Italy)José Carrière, DDS, MD, PhD (Spain)Jorge Fastlicht, DDS, MS (Mexico)Masatada Koga, DDS, PhD (Japan)Jonathan Sandler, BDS, MSC, FDS RCPS, MOrth RCS (England)Georges L.S. Skinazi, DDS, DSO, DCD (France)

MANAGING EDITORDavid S. Vogels III

ASSISTANT EDITORWendy L. Osterman

BUSINESS MANAGERLynn M. Bollinger

CIRCULATION MANAGERCarol S. Varsos

GRAPHIC DESIGNERJennifer Johnson

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every lower anterior tooth to a fixed lower retain-er is the only way to assure long-term stability in cases of lower anterior crowding, including extraction cases� Vertical stability can be en -hanced in deep-bite cases by building flat-plane biteplates into wraparound removable upper retainers� I have noted personally that adding posterior bite blocks to removable upper retainers can be quite helpful in retaining corrected ante-rior open-bite cases�

Dr� Little also answers a question that has concerned me for some time: In a case where arch development has resulted in expansion of the lower archform, what is the long-term periodon-

tal prognosis? He notes that several instances of gingival dehiscence or recession were seen after expansion in the Washington research sample� I am unaware of any really well-done long-term studies of gingival health secondary to arch-development treatment� Further in-depth research in this area is clearly needed�

Another of Dr� Little’s major themes seems almost instinctive to many orthodontists: Finish to the highest possible standards—as if every case were an ABO case—then maintain those excellent finishes for as long as possible� Who could argue with that?

RGK

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EDITOR’S CORNER

JCO/NOVEMBER 2009

Pseudo-Class III malocclusion is defined as a functional forward displacement of the man-

dible as a result of retroclined maxillary incisors.1-6 About 5% of the Chinese population is affected by Class III malocclusion, and more than half of these cases are pseudo-Class III.7

A crossbite associated with a displacement is a functional indication for orthodontic treatment. Early treatment of a pseudo-Class III malocclusion has a number of advantages: it facilitates the erup-tion of canines and premolars into a Class I occlu-sion5; it eliminates traumatic occlusion to the incisors8,9 (which may lead to dehiscence and gin-gival recession), providing a normal environment for growth of the maxilla10; and it often improves the child’s self-esteem.11-13

Several techniques have been recommended for early treatment of pseudo-Class III malocclu-sion, including removable appliances, functional appliances, reverse headgear, and simple fixed appliances.14-21 These clinical studies have been based on retrospectively selected samples, however, and have not documented long-term stability.

We have found a simple 2 × 4 appliance with bands on the first molars, brackets on the incisors,

and an archwire with advancing loops to be as effective as a reverse headgear in producing for-ward movement of the maxilla without mesial movement of the upper molars8 (Fig. 1). Because the appliance is fixed, its success does not depend on patient compliance. We previously reported the successful initial results of this appliance in 27 consecutively treated young patients with pseudo-Class III malocclusion.22 In that study, the patient selection criteria were: Class III incisor relation-ship (at least two incisors in crossbite) in centric occlusion; early mixed dentition, with the second deciduous molars still present; mandibular dis-placement; and no prior orthodontic therapy. A five-year follow-up of these patients was described subsequently23; the present article documents a 10-year follow-up of the same group.

Materials and Methods

Of the 27 patients (12 female and 15 male) in the initial study, 18 (9 male and 9 female) were examined 10 years later (Table 1). Fifteen of the 18 patients had undergone no further treatment after the 2 × 4 appliance; the other three had been

© 2009 JCO, Inc.

Early Treatment of Pseudo-Class III Malocclusion: A 10-Year Follow-Up StudyIAN ANDERSON, BDS, BMS(Hons)A. BAKR M. RABIE, MS, PHD, FHKAM, FCDSHKRICKY W.K. WONG, BDS, MOrth, MOrth RCS, FRACDS, FHKAM, FCDSHK

692 JCO/NOVEMBER 2009

TABLE 1AVERAGE AGE (YEARS) AT START OF TREATMENT (T0),

END OF TREATMENT (T1), AND 10-YEAR FOLLOW-UP (T2)

Treatment Follow-Up N Age (T0) S.D. Age (T1) S.D. Duration Age (T2) S.D. Period

Initial sample 27 10.1 1.54 10.7 1.50 0.63 NA NA NAFollow-up group 18 9.8 1.20 10.6 1.32 0.80 21.4 3.55 10.8Dropout group 9 10.4 1.64 10.8 2.00 0.40 NA NA NA


Dr. Wong Dr. Rabie

Dr. Anderson is a postgraduate student, Dr. Rabie is a Profes-sor, and Dr. Wong is an Associate Professor, Depart ment of Orthodontics, University of Hong Kong, 2/F Prince Philip Dental Hospital, 34 Hospital Road, Sai Ying Pun, Hong Kong SAR, China. E-mail Dr. Rabie at [email protected].

Dr. Anderson


Fig. 1 Pseudo-Class III case showing how malocclusion can cause attrition. A. Patient with deep overbite and reverse overjet could achieve edge-to-edge bite, but had functional shift. Malocclusion contributed to severe attrition of upper right central incisor. B. Upper 2 4 appliance, using .016" round stainless steel archwire with advancing loops. C. Patient after eight months of treatment with the 2 4 appliance.

A

B

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subsequently treated with comprehensive fixed appliances due to crowding. One of these three patients had all four first premolars extracted, while the other two were treated without extractions.

Lateral cephalograms were obtained before treatment (T0), after treatment with the 2 × 4 appliance (T1), and at the 10-year follow-up (T2). Cephalometric data were analyzed according to the method of Pancherz24,25 (Fig. 2). Changes in dentofacial morphology were calculated for T0-T1, T1-T2, and T0-T2 (Fig. 3; detailed data are avail-able in an online appendix to this article). The statistical significance of the differences was ana-lyzed using a two-tailed t-test.

Cephalometric measurements were traced twice, with a two-week interval between data col-lection. When the systematic error was assessed with a paired t-test, the differences were not sta-tistically significant. The size of the combined method error in locating and measuring the change of the different landmarks was calculated by the formula SE = ± √Σd2/2n, where d is the difference between two registrations of a pair, and n is the number of double registrations. No error exceeded .5mm.

Results

Pretreatment Dentofacial Morphology (T0)The follow-up group started treatment with

an average overjet of −1.7mm, an overbite of 1.1mm, and a jaw-base relationship in central occlusion of −7.8mm. None of the mean horizon-tal or vertical dimensions were significantly dif-ferent from those of the original sample. The three comprehensive treatment patients showed a more distal mandibular molar position than in the group treated with the 2 × 4 appliance only (p<.05).

Treatment Changes (T0-T1)After 2 × 4 appliance treatment, all patients

in the follow-up group had a positive overjet. In the horizontal plane, the overjet improved signifi-cantly (p<.001, Fig. 3A), along with forward movement of the maxilla (p<.001), protrusion of the maxillary incisors (p<.001), and retrusion of the mandibular incisors (p<.01) and maxillary


Early Treatment of Pseudo-Class III Malocclusion: A 10-Year Follow-Up Study

Fig. 2 Pancherz analysis (developed by Pan-cherz24,25 and Hägg and colleagues28). A. Horizon-tal plane: overjet (is-ii), maxillary base (OLp-ss), mandibular base (OLp-Pg), base relationship (ss-Pg), maxillary incisor (ss-is), mandibular incisor (ii-Pg), maxillary molar (ms-ss), and mandibular molar (mi-Pg). B. Vertical plane: overbite (is-ii), maxillary central incisor (is-NL), mandibular cen-tral incisor (ii-ML), mandibular plane angle (ML/NSL), maxillary plane angle (NL/NSL).

A

B


Anderson, Rabie, and Wong

molars (p<.05). There was a significant increase in lower facial height, accompanied by extrusion of the mandibular incisors (p<.001). The 2 × 4 appliance-only group showed significantly more forward movement of the maxilla (p<.001) com-pared to the comprehensive treatment group, which showed significantly greater forward movement of the mandibular molars (p<.05), extrusion of the maxillary incisors and molars (p<.05), and extru-sion of the mandibular molars (p<.001).

Post-Treatment Changes (T1-T2)At the 10-year follow-up, 17 of the 18 (94%)

patients had a stable overjet. Because mandibular growth was significantly greater than maxillary growth during the post-treatment period, overjet decreased significantly (p<.01), even though the

maxillary incisors moved forward (Fig. 3B). In the vertical plane, there was a significant increase in lower facial height (p<.001), associated with extru-sion of the incisors and molars in both arches (p<.001). Forward mandibular movement was similar in the 2 × 4 appliance and comprehensive groups, but forward movement of the maxilla was significantly less in the 2 × 4 appliance group (p<.05). The maxillary molar moved forward in the 2 × 4 appliance group, but not in the compre-hensive treatment group (p<.01).

In the single patient who had a reverse over-jet at T2, the lower incisors moved 3.5mm back-ward during the post-treatment period. This patient showed much more mandibular growth than the average for the treatment group (19mm vs. 5.7mm), accounting for the reverse overjet (Fig. 4).

Total Changes (T0-T2)During the total observation period, there

were significant changes in overjet, maxillary base, mandibular base, base relationship, and maxillary and mandibular molars and incisors (Fig. 3C). In the vertical plane, all parameters except the overbite, mandibular plane angle, and maxillary plane angle changed significantly. Horizontal molar movement was significantly dif-ferent in the 2 × 4 appliance-only and comprehen-sive treatment groups, with greater forward movement of the maxillary molars in the 2 × 4 appliance patients (p<.01) and greater forward movement of the mandibular molars in the com-prehensive patients (p<.05). In the vertical plane,

Fig. 4 Post-treatment changes (millimeters) for patient who developed reverse overjet (T1-T2).

Overjet−6

U1−2.5

L1−3.5

Dental1

Mx12

Md19

Skeletal−7

Overjet4.8

U13.8

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Dental5.4

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Overjet3.6

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Dental6.8

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Md7.7

Skeletal−3.2

Fig. 3 Changes in patients treated with 2 4 appliance (millimeters). A. Changes during active treatment (T0-T1). B. Changes from post-treat-ment to 10-year follow-up (T1-T2). C. Changes from pretreatment to 10-year follow-up (T0-T2).

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B

C


Fig. 5 A. 10-year-old male patient from study, with deep overbite and reverse overjet before treatment. Note lack of space available for eruption of permanent canines. B. Placement of 2 4 appliance. C. Patient after eight months of treatment. D. Patient at five-year follow-up, with positive overjet maintained and dentition guided into stable Class I occlusion.

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D



Anderson, Rabie, and Wong

the mandibular plane angle decreased signifi-cantly more in the 2 × 4 appliance group than in the comprehensive group (p<.001).

Discussion

This study shows that early treatment of pseudo-Class III malocclusion with a 2 × 4 appli-ance can produce a stable positive overjet in the vast majority of patients, where stability is defined as a lack of reverse overjet 10 years post-treatment.28-31 Of the 18 patients in the follow-up group, 17 achieved a positive and often slightly overcorrected overjet during the active phase of treatment.

This effect was created by proclination of the upper incisors and slight retroclination of the lower incisors, with the corrected upper incisors kept in place by the normalized overjet and overbite. The interdigitation of the buccal occlusion promoted the growth of the maxillary complex while the mandible was outgrowing the maxilla. Thus, the dental corrections had secondary skeletal benefits that may also have contributed to the stability of the occlusion, as shown in a patient from the five-year follow-up study (Fig. 5). Because the patients were mature adults at the time of the 10-year fol-low-up (with an average age of 21.4), it is unlikely that unfavorable post-treatment changes would develop later.

Dentofacial changes in this study were as -sessed predominantly by linear measurements,24,25 which are reportedly more accurate than angular measurements.32,33 The Pancherz method of super-imposition24,25 is based on the occlusal plane, which is a more reliable reference than the planes used in other techniques.34

During the 10-year follow-up period, A point moved forward 4.5mm in the 2 × 4 appliance group—similar to the results shown by a previous study of longitudinal growth changes in the max-illa.35 This indicated that early treatment with a 2 × 4 appliance could provide a healthy environment for normal maxillary growth after active treatment to correct the reverse overjet. Forward mandibular growth was much greater than forward maxillary growth during the 10-year follow-up period, but the difference was less than the twofold difference that has been reported to occur after reverse head-gear treatment.28

One of the benefits of early treatment with a 2 × 4 appliance in patients with pseudo-Class III malocclusion is that space is created for eruption of the upper canines and premolars, allowing the erupting dentition to be guided into a Class I rela-tionship26 (Fig. 6). In the five-year follow up study, 23 (75%) of the patients treated with a 2 × 4 appli-ance did not need additional comprehensive treat-ment. Five patients had extended treatment, but

Fig. 6 A. 9-year-old patient from study, with reverse overjet before treatment (higher-resolution photographs not available). B. Treatment progress using upper .016" round stainless steel archwire with advancing loops. C. Patient after five months of treatment. D. Patient at two-year follow-up. E. Patient at 10-year fol-low-up.

A B C

D E



only one patient had extraction therapy. These results suggest that the majority of pseudo-Class III patients who receive early intervention with a 2 × 4 appliance will not need future orthodontic treatment. Various studies have reported self-correction of anterior crossbite during the transi-tion from the primary to the early mixed dentition,30,31 suggesting that treatment of anterior crossbite at such an early age should be approached cautiously.

ACKNOWLEDGMENTS: The authors express thanks to Shadow Yeung for his kind assistance with data analysis. The research was supported by a research grant from Hong Kong University.

REFERENCES

1. Gu, Y.: The characteristics of pseudo class III malocclusion in mixed dentition, Chinese J. Stomatol. 37:377-380, 2002.

2. Sharma, P.S. and Brown, R.V.: Pseudo mesiocclusion: Diagnosis and treatment, J. Dent. Child. 35:385-392, 1968.

3. Ngan, P.; Hu, A.M.; and Fields, H.W. Jr.: Treatment of Class III problems begins with differential diagnosis of anterior crossbites, Pediatr. Dent. 19:386-395, 1997.

4. Moyers, R.E.: Handbook of Orthodontics, 4th ed., Year Book Medical Publishers, Chicago, 1988, pp. 410-418.

5. Rabie, A.B. and Gu, Y.: Diagnostic criteria for pseudo-Class III malocclusion, Am. J. Orthod. 117:1-9, 2000.

6. McNamara, J.A.: Mixed dentition treatment, in Orthodontics: Current Principles and Techniques, 2nd ed., ed. T.M. Graber and R.L. Vanarsdall, Mosby, St. Louis, 1994, pp. 507-541.

7. Lin, J.J.: Prevalences of malocclusion in Chinese children age 9-15, Clin. Dent. 5:57-65, 1985.

8. Major, P.W. and Glover, K.: Treatment of anterior crossbite in early mixed dentition, J. Can. Dent. Assoc. 58:574-575; 578-579, 1992.

9. Rakosi, T. and Schilli, W.: Class III anomalies: A coordinated approach to skeletal, dental and soft tissue problems, J. Oral Surg. 39:860-870, 1981.

10. Kapur, A.; Chawla, H.S.; Utreja, A.; and Goyal, A.: Early class III occlusal tendency in children and its selective man-agement, J. Indian Soc. Pedod. Prev. Dent. 26:107-113, 2008.

11. Shaw, W.C.; Meek, S.C.; and Jones, D.S.: Nicknames, teasing, harassment and salience of dental features among school chil-dren, Br. J. Orthod. 7:75-80, 1980.

12. Shaw, W.C.: The influence of children’s dentofacial appear-ance on their social attractiveness judged by peers and lay adults, Am. J. Orthod. 79:399-415, 1981.

13. Campbell, P.M.: The dilemma of Class III treatment—early or late? Angle Orthod. 53:175-191, 1983.

14. Giancotti, A.; Maselli, A.; Mampieri, G.; and Spanò, E.: Pseudo-Class III malocclusion treatment with Balters' Bionator, J. Orthod. 30:203-215, 2003.

15. Bowman, S.J.: A quick fix for pseudo-Class III correction, J.

Clin. Orthod. 42:691-697, 2008.16. Vego, L.: Early orthopedic treatment for Class III skeletal pat-

tern, Am. J. Orthod. 70:59-69, 1976.17. McNamara, J.A.: An orthopedic approach to the treatment of

Class III malocclusion in young patients, J. Clin. Orthod. 22:598-608, 1987.

18. Turley, P.: Orthopedic correction of Class III malocclusion with palatal expansion and custom protraction headgear, J. Clin. Orthod. 22:314-325, 1988.

19. Santos-Pinto, A.; Paulin, R.F.; and Melo, A.C.: Pseudo-Class III treatment with reverse traction: Case report, J. Clin. Pediat. Dent. 25:267-274, 2001.

20. Postema, R.S.: Case report: Early adult pseudo Class III mal-occlusion, J. Gen. Orthod. 4:25-27, 1993.

21. Gu, Y.; Rabie, A.B.; and Hagg, U.: Treatment effects of simple fixed appliance and reverse headgear in correction of anterior crossbites, Am. J. Orthod. 117:691-699, 2000.

22. Rabie, A.B. and Gu, Y.: Management of pseudo Class III mal-occlusion in southern Chinese children, Br. Dent. J. 186:183-187, 1999.

23. Hägg, U.; Tse, A.; Bendeus, M.; and Rabie, A.B.: A follow-up study of early treatment of pseudo Class III malocclusion, Angle Orthod. 74:465-472, 2004.

24. Pancherz, H.: The mechanism of Class II correction in Herbst appliance treatment: A cephalometric investigation, Am. J. Orthod. 82:104-113, 1982.

25. Pancherz, H.: Vertical dentofacial changes during Herbst appliance treatment, Swed. Dent. J. 15(suppl):189-196, 1982.

26. Gu, Y. and Rabie, A.B.: Dental changes and space gained as a result of early treatment of pseudo-Class III malocclusion, Aust. Orthod. J. 16:40-52, 2001.

27. Hägg, U.; Tse, A.; Bendeus, M.; and Rabie, A.B.: A follow-up study of early treatment of pseudo Class III malocclusion, Angle Orthod. 74:465-472, 2004.

28. Hagg, U.; Tse, A.; Bendeus, M.; and Rabie, A.B.: Long-term follow-up of early treatment with reverse headgear, Eur. J. Orthod. 25:95-102, 2003.

29. Ngan, P.; Hagg, U.; Yiu, C.; and Wei, S.H.Y.: Treatment response and long term dentofacial adaptations to maxillary expansion and protraction, Semin. Orthod. 3:255-264, 1997.

30. Deguchi, T.; Kanomi, R.; Ashizawa, Y.; and Rosenstein, S.W.: Very early face mask therapy in Class III children, Angle Orthod. 69:349-355, 1999.

31. Lertpitayakun, P.; Miyajima, K.; Kanomi, R.; and Sinha, P.K.: Cephalometric changes after long-term early treatment with face mask and maxillary intraoral appliance therapy, Semin. Orthod. 7:169-179, 2001.

32. Bjork, A.: The face in profile: An anthropological x-ray inves-tigation of Swedish children and conscripts, Sven. Tandlak. Tidskr. 40:40-58, 1947.

33. Bookstein, F.L.: Landmark methods for forms without land-marks: Morphometrics of group differences in outline shape, Med. Image Anal. 1:225-243, 1997.

34. You, Q.L. and Hagg, U.: A comparison of three superimposi-tion methods, Eur. J. Orthod. 21:717-725, 1999.

35. Bendeus, M.; Hagg, U.; and Rabie, A.B.: Growth and treat-ment changes in patients treated with a headgear-activator appliance, Am. J. Orthod. 121:376-384, 2002.

The first article in this four-part series on the 2009 JCO Orthodontic Practice Study (JCO,

October 2009) covered trends in orthodontic economics and ad min istration since our first biennial survey in 1981. The questionnaire and meth odology were also described. JCO subscrib-ers may review the complete tables from the 2009 Practice Study by visiting the Online Archive at www.jco-online.com.

This month’s article discusses practice suc-cess in terms of factors that seem to be associated with increased net income and case starts. Annual data refer to the previous calendar year—in this case, 2008. It should be noted that the responding practices were all owned by solo practitioners; practices with multiple orthodontist-owners were excluded from the main results.

Although medians are reported in most of the Practice Study, many tables in this article use means to test the statistical significance of responses. The significance level (“p”) is set at .01 instead of the more conventional .05 because the large number of variables in this survey increases the likelihood that the data may be affected by chance.

Net Income Level

As in every Practice Study to date, respon-

dents were arbitrarily divided into three groups according to net in come. To highlight the differ-ences among the categories, about one-fourth of the respondents were placed in each group, and the remaining one-fourth were omitted from these particular tables. The net income levels were the same as in the 2007 Study: high ($600,000 or more), moderate ($325,000-525,000), and low ($25,000-250,000).

The disparity between high and low net income practices was not quite as wide as in previ-ous surveys in terms of patient numbers, but the high income respondents still treated more than twice the number of cases as the low income prac-tices while earning more than twice the net income per case (Table 9). Increased efficiency could be the reason, since the high net income practices reported significantly lower overhead rates with about twice the number of employees. There were no significant differences among the three groups in percentages of adult, third-party, or managed-care patients or in the number of annual hours worked.

When respondents were divided by years in practice, the orthodontists who had been in prac-tice for 16-20 or 6-10 years were most likely to fall into the high net income category (Table 10). Re spond ents who had practiced for 11-15 years

VOLUME XLIII NUMBER 11 © 2009 JCO, Inc. 699

2009 JCO Orthodontic Practice StudyPart 2 Practice SuccessROBERT G. KEIM, DDS, EDD, PHDEUGENE L. GOTTLIEB, DDSALLEN H. NELSON, PHDDAVID S. VOGELS III

Dr. Keim is Editor, Dr. Gottlieb is Senior Editor, and Mr. Vogels is Managing Editor of the Journal of Clinical Orthodontics, 1828 Pearl St., Boulder, CO 80302. Dr. Nel son is Director and Research Con-sultant, Nelson Associates, Ned er-land, CO.

Dr. GottliebDr. Keim Dr. Nelson Mr. Vogels



TABLE 9SELECTED VARIABLES (MEANS) BY NET INCOME LEVEL

High Moderate Low

Number of Satellite Offices 0.8 0.8 0.5*Full-Time Employees 7.7 5.4 3.6*Part-Time Employees 2.1 1.5 1.4Total Referrals 482.0 307.0 218.9*Case Starts 376.4 241.8 148.0*Adult Case Starts 27.1% 25.4% 24.9%Active Treatment Cases 763.8 530.6 337.3*Adult Active Cases 22.9% 20.5% 20.8%Patients Covered by Third Party 48.4% 46.4% 47.8%Patients Covered by Managed Care 6.5% 5.7% 5.6%Offer Third-Party Financing Plan 70.3% 70.5% 65.9%Total Chairs 6.8 6.0 5.5*Annual Hours 1,656.9 1,615.7 1,659.0Patients per Day 64.6 50.7 37.0*Emergencies per Day 4.6 3.0 2.6Broken Appointments per Day 4.2 3.5 2.3*Cancellations per Day 3.4 3.0 2.1*Gross Income $1,730,623 $1,014,387 $590,704*Overhead Rate 47.5 56.1 66.8*Net Income $892,719 $422,471 $168,473*Net Income per Case $1,457 $890 $670**Differences between these groups are statistically significant at or below the .01 probability level.

$0

$200,000

$400,000

$600,000

$800,000

$1,000,000

$1,200,000

$1,400,000

$1,600,000

$1,800,000

$2,000,000

High Moderate Low0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

Gross IncomeNet IncomeActive CasesCase Starts

NET INCOME LEVEL

No. of Cases


TABLE 10NET INCOME LEVEL BY YEARS IN PRACTICE

High Moderate Low

2-5 years 39.3% 25.0% 35.7%6-10 years 46.2 34.6 19.211-15 years 25.0 21.4 53.616-20 years 47.1 33.3 19.621-25 years 37.2 34.9 27.926 or more years 23.9 34.8 41.3

TABLE 11NET INCOME LEVEL BY GEOGRAPHIC REGION

High Moderate Low

New England 20.0% 40.0% 40.0%(CT,ME,MA,NH,RI,VT)

Middle Atlantic 50.0 21.9 28.1(NJ,NY,PA)

South Atlantic 40.5 21.4 38.1(DE,DC,FL,GA,MD,NC,SC,VA,WV)

East South Central 50.0 42.9 7.1(AL,KY,MS,TN)

East North Central 31.9 38.3 29.8(IL,IN,MI,OH,WI)

West North Central 11.8 41.2 47.1(IA,KS,MN,MO,NE,ND,SD)

Mountain 32.0 28.0 40.0(AZ,CO,ID,MT,NV,NM,UT,WY)

West South Central 35.3 32.4 32.4(AR,LA,OK,TX)

Pacific 26.7 37.8 35.6(AK,CA,HI,OR,WA)

TABLE 12MEAN FEES AND FINANCIAL POLICIES

BY NET INCOME LEVEL

High Moderate Low

Child Fee (Permanent Dentition) $5,312 $5,043 $5,009Adult Fee $5,727 $5,481 $5,4382007 Fee Increase (Reported) 4.4% 4.3% 3.8%2008 Fee Increase (Reported) 3.2% 2.8% 3.0%Initial Payment 23.1% 23.1% 25.4%Payment Period (months) 21.0 21.1 21.0

were most likely to be in the low net income group, followed by the oldest and newest practices.

As in the past two surveys, the highest per-centage of respondents in the high net income category was in the East South Central region—this time, tied with the Middle Atlantic region (Table 11). East South Central practices also reported the lowest percentage of low net income respondents. The highest percentage of low net income practices was in the West North Central region, followed by the New England and Mountain regions.

There were no significant differences among the three income groups in terms of fees or finan-cial policies, but the high net income practices did report the highest mean fees and two-year fee increases (Table 12).

Management Methods

Users of every management method listed on the questionnaire reported more mean case starts than non-users did (Table 13). The differences were statistically significant for written philosophy

TABLE 13MEAN CASE STARTS BY USE OF MANAGEMENT METHODS

Used Not Used

Written philosophy of practice 263.3 221.9*Written practice objectives 260.8 234.9Written practice plan 277.0 236.5Written practice budget 279.6 236.5Office policy manual 254.7 197.5*Office procedure manual 249.3 239.6Written job descriptions 257.8 223.7Written staff training program 267.1 233.3Staff meetings 259.5 175.5*Individual performance appraisals 271.5 190.9*Measurement of staff productivity 280.4 238.9In-depth analysis of practice activity 271.2 232.8*Practice promotion plan 263.1 232.8Dental management consultant 315.3 223.8*Patient satisfaction surveys 273.7 229.8*Employee with primary responsibility as communications supervisor 257.1 242.0Progress reports 263.7 234.5Post-treatment consultations 257.3 239.9Pretreatment flow control system 263.1 229.7Treatment flow control system 265.1 239.4Cases beyond estimate report 256.3 239.5Profit and loss statements 255.9 212.7*Delinquent account register 255.3 206.3*Monthly accounts-receivable reports 257.0 187.9*Monthly contracts-written reports 263.2 228.1Measurement of case acceptance 274.4 213.3**Differences between these groups are statistically significant at or below the .01 probability level.


2009 JCO Orthodontic Practice Study

of practice, office policy manual, staff meetings, individual performance appraisals, in-depth anal-ysis of practice activity, dental management con-sultant, patient satisfaction surveys, profit and loss statements, delinquent account register, monthly accounts-receivable reports, and measurement of case acceptance.

Differences in the use of management methods by net income level were somewhat more apparent in the 2009 Study than in 2007 (Table 14). High net income practices were sig-

nificantly more likely than the other two groups to use individual performance appraisals, in-depth analysis of practice activity, monthly accounts-receivable reports, and measurement of case acceptance. The only management meth-ods used as much or more by low net income practices than by high net income respondents were written staff training program, post-treat-ment consultations, treatment flow control sys-tem, cases beyond estimate report, and profit and loss statements.

TABLE 14USE OF MANAGEMENT METHODS BY NET INCOME LEVEL

High Moderate Low

Written philosophy of practice 58% 60% 57%Written practice objectives 43 46 41Written practice plan 29 21 24Written practice budget 28 26 21Office policy manual 90 83 83Office procedure manual 66 56 64Written job descriptions 68 61 62Written staff training program 39 38 40Staff meetings 89 80 78Individual performance appraisals 79 75 56*Measurement of staff productivity 19 13 17In-depth analysis of practice activity 43 38 22*Practice promotion plan 47 36 45Dental management consultant 33 24 17Patient satisfaction surveys 37 35 35Employee with primary responsibility as communications supervisor 27 17 20Progress reports 38 36 31Post-treatment consultations 26 40 33Pretreatment flow control system 56 48 47Treatment flow control system 27 23 27Cases beyond estimate report 38 42 38Profit and loss statements 72 83 78Delinquent account register 86 82 77Monthly accounts-receivable reports 91 88 76*Monthly contracts-written reports 63 48 44Measurement of case acceptance 59 58 38**Differences between these groups are statistically significant at or below the .01 probability level.


Keim, Gottlieb, Nelson, and Vogels

Delegation

As in previous Studies, routine delegation to staff members (as opposed to delegating occasionally or not at all) was associated with greater mean numbers of case starts for every task listed on the survey (Table 15). These dif-

ferences were statistically significant for every task except fabrication and adjustment of arch-wires, financial arrangements, progress reports, post-treatment conferences, and patient instruc-tion and education.

Delegation did not seem to make as sub-stantial a difference in terms of net income as

TABLE 15MEAN CASE STARTS BY DELEGATION

Routinely Not Routinely Delegated Delegated

Record-TakingImpressions for study models 252.0 158.7*X-rays 252.2 165.1*Cephalometric tracings 270.7 228.2*

ClinicalImpressions for appliances 257.7 182.8*Removal of residual adhesive 280.6 224.3*Fabrication of: Bands 272.5 200.0* Archwires 266.3 229.2 Removable appliances 276.1 223.8*Insertion of: Bands 281.4 225.1* Bonds 320.1 234.9* Archwires 269.0 201.6* Removable appliances 288.9 230.9*Adjustment of: Archwires 284.2 239.2 Removable appliances 312.1 237.1*Removal of: Bands 270.8 208.2* Bonds 276.6 204.3* Archwires 258.5 182.8*

AdministrativeCase presentation 292.4 228.9*Fee presentation 260.6 194.1*Financial arrangements 251.2 195.9Progress reports 273.7 234.7Post-treatment conferences 258.0 235.8Patient instruction and education 249.3 196.8

*Differences between these groups are statistically significant at or below the .01 probability level.


2009 JCO Orthodontic Practice Study

it did for case starts (Table 16). Differences among the three net income groups were sta-tistically significant only for insertion of removable appliances and removal of bands, bonds, and archwires. On the other hand, the high net income practices were more likely

than the other practices to delegate every task routinely except for impressions for appli-ances; insertion of bands, bonds, archwires, and removable appliances; financial arrange-ments; progress reports; and post-treatment conferences.

TABLE 16ROUTINE DELEGATION BY NET INCOME LEVEL

High Moderate Low

Record-TakingImpressions for study models 96% 95% 86%X-rays 97 96 87Cephalometric tracings 44 37 25

ClinicalImpressions for appliances 87 90 77Removal of residual adhesive 40 36 23Fabrication of: Bands 64 58 44

Archwires 35 28 33Removable appliances 45 43 37

Insertion of:Bands 33 38 25Bonds 14 20 9Archwires 65 72 51Removable appliances 27 40 16*

Adjustment of:Archwires 19 15 11Removable appliances 15 14 8

Removal of:Bands 71 60 35*Bonds 70 56 35*Archwires 90 88 68*

AdministrativeCase presentation 33 25 20Fee presentation 78 76 71Financial arrangements 91 91 86Progress reports 26 34 17Post-treatment conferences 15 23 16Patient instruction and education 93 91 86

*Differences between these groups are statistically significant at or below the .01 probability level.



TABLE 17PRACTICE-BUILDING METHODS BY NET INCOME LEVEL

High Moderate Low Used Rating† Used Rating† Used Rating†

Change practice location 38% 3.3 32% 3.3 32% 3.3Expand practice hours: Open one or more evenings/week 15 2.9 12 2.4 20 2.3 Open one or more Saturdays/month 14 2.8 12 2.6 11 2.1Open a satellite office 35 3.4 32 3.1 36 2.8Participate in community activities 72 2.6 59 2.8 65 2.6Participate in dental society activities 66 2.1 64 2.2 61 2.0Seek referrals from general dentists: Letters of appreciation 80 2.6 68 2.6 66 2.3 Entertainment 73 2.6 56 2.3 51 2.2 Gifts 81 2.4 73 2.5 78 2.3 Education of GPs 54 2.6 36 2.6 36 2.3 Reports to GPs 73 2.7 72 2.6 71 2.3Seek referrals from patients and parents: Letters of appreciation 70 2.8 68 2.8 55 2.7 Follow-up calls after difficult appointments 76 3.1 68 3.0 74 2.9 Entertainment 35 2.6 32 2.6 25 2.5 Gifts 51 2.7 50 2.8 46 2.6Seek referrals from staff members 63 1.9 63 1.9 57 1.9Seek referrals from other professionals (non-dentists) 35 2.0 21 2.0 24 1.9Treat adult patients 90 3.0 90 2.9 86 2.7Improve scheduling: On time for appointments 90 3.3 78 3.2 80 3.0 On-time case finishing 87 3.3 71 3.1 67 3.0Improve case presentation 56 3.2 53 3.2 47 3.0Improve staff management 54 2.9 42 3.2 45 2.8Improve patient education 53 2.9 49 2.9 47 2.7Expand services: TMJ 23 2.2 22 2.1 30 2.3 Functional appliances 30 2.3 28 2.5 26 2.7 Lingual orthodontics 20 2.0 18 1.8 22 1.7 Surgical orthodontics 52 2.1 38 2.2 38 2.4 Invisalign treatment 70 2.5 46 2.8 53 2.4 Cosmetic laser treatment 27 2.2 15 2.3 12 2.6Patient motivation techniques 47 2.7 44 2.6 42 2.5No-charge initial visit 87 3.0 82 3.1 82 2.9No-charge diagnostic records 32 2.9 27 3.3 26 3.0No initial payment 18 2.6 15 2.8 20 2.3Up-front payment discount 84 2.5 76 2.6 82 2.4Extended payment period 56 2.6 46 2.8 50 2.4Practice newsletter 30 2.5 13 2.0 20 2.1Personal publicity in local media 25 2.0 21 2.5 22 2.1Advertising: Yellow pages Boldface listing 62 1.4 63 1.9 64 1.5 Display advertising 34 1.6 29 2.3 30 1.7 Local newspapers 20 1.7 17 1.9 34 1.8 Local TV 9 NA 6 NA 4 NA Local radio 10 1.6 8 NA 8 NA Direct-mail promotion 19 1.7 21 2.0 20 1.7Managed care 10 2.8 13 2.7 9 NAManagement service affiliation 5 NA 1 NA 0 NA†4 = excellent; 3 = good; 2 = fair; 1 = poor; NA = too few responses to calculate accurately.


Practice-Building Methods

There was no significant relationship be tween the use of practice-building methods and net income level, as in every Study since the early 1990s (Table 17). Practice-building methods used by more than 70% of the high net income prac-tices were (in descending order of usage): treat adult patients, on time for appointments, on-time case finishing, no-charge initial visit, up-front payment discount, gifts and letters of appreciation to GPs, follow-up calls after difficult appoint-ments, entertainment of and reports to GPs, and participate in community activities.

The most effective methods might be con-sidered those rated good (3.0) or better by the high net income practices. These were (from

highest to lowest ratings): open a satellite office, change practice location, on time for appoint-ments, on-time case finishing, improve case presentation, follow-up calls after difficult ap -pointments, treat adult patients, and no-charge initial visit.

On the other hand, the practice-building methods rated fair (2.0) or worse by the high net income respondents were (from lowest to highest ratings): yellow-pages advertising, radio and news-paper advertising, direct-mail promotion, seek referrals from staff members and from other pro-fessionals, lingual orthodontics, and personal publicity in local media.

(TO BE CONTINUED)



0

1

2

3

4

Open asatellite office

Follow-up callsafter difficultappointments

On-time casefinishing

Cosmetic lasertreatment

No-chargeinitial visit

Direct-mailpromotion

High

Moderate

Low

MEAN EFFECTIVENESS RATINGS FOR SELECTED PRACTICE-BUILDING METHODS

(4 = excellent; 3 = good; 2 = fair; 1 = poor)

Net Income Level

708 JCO/NOVEMBER 2009© 2009 JCO, Inc.

We have designed a simple instrument for interproximal stripping. Fabrication is as

follows:1. Bend a helix with three and a half circles and a diameter of 6mm into the center section of a 6" length of .040" hard stainless steel wire.* The free legs should form an angle of about 130° (A).2. Make additional 30° bends at the center of each leg and double-back bends at the end of each leg (B).3. Insert an interproximal strip into one of the double-back bends, winding it through twice to secure it. After compressing the strip holder so that the ends are parallel to each other, insert the other end of the interproximal strip into the sec-ond double-back bend in the same way (C). The strip holder is now ready to use (D).

The spring design of this strip holder keeps the strip under tension. This tool is easily fabri-cated, and the interproximal strip can be changed quickly at chairside.

(Editor’s Note: If you have a clinical or practice management Pearl to share with your colleagues, send it to JCO, 1828 Pearl St., Boulder, CO 80302. Appropriate illustrations are welcome; a photograph of the author and a copyright transfer form are required prior to publication.)

D

C

A

B

A Spring-Loaded Stripping Tool

U.S. KRISHNA NAYAK, BDS, MDSDean of Academics and Head

Department of OrthodonticsA.B. Shetty Memorial Institute of

Dental SciencesDeralakatte, Mangalore, Karnataka, India

ANKUR AGGARWAL, BDS, MDSP-8 Green Park Extension

New Delhi 110016India

[email protected]

*LeoWire, Leone S.p.A., Via P. a Quaracchi, 50, 50019 Sesto Fiorentino, Italy; www.leone.it.


This article describes a biomechanical approach for treating an impacted, dilacerated maxillary

central incisor in the mixed dentition. A new fixed appliance promotes proper sagittal and vertical traction of the incisor into the dental arch, while maintaining the patient’s periodontal health and preserving root length.

The appliance is an .040" stainless steel fixed lingual arch, soldered to the lingual surfaces of the maxillary first molar bands (Fig. 1). A vertical arm of the same wire type, ending in a helix, is soldered to the arch at the center of the incisor space. Four metal occlusal rests are soldered to the lingual arch: two on either side of the impacted incisor and two at the first deciduous molars. These rests are bonded to the teeth with light-cured composite.

Case Report

Use of the appliance is demonstrated in a 9-year-old male in the early mixed dentition who presented with the complaint of an unerupted maxillary left central incisor (Fig. 2). The boy’s parents indicated that the patient had lost the deciduous central incisor in a traumatic incident

© 2009 JCO, Inc.

A New Device for Traction of Dilacerated Maxillary Central IncisorsALDO GIANCOTTI, DDSPAOLA MOZZICATO, DDSFRANCESCO GERMANO, DDS

Fig. 1 Fixed lingual arch for traction of unerupted, dilacerated maxillary central incisor.


Dr. GermanoDr. Mozzicato

Dr. Giancotti is an Assistant Professor and Drs. Mozzicato and Germano are post-graduate residents, Department of Ortho-dontics, University of Rome “Tor Vergata”. Contact Dr. Giancotti at Viale Gorizia 24/c, Rome 00198, Italy; [email protected].

Dr. Giancotti


Fig. 2 9-year-old male patient showing dilacerated maxillary left central incisor, horizontally positioned with tip of crown near apex of right central incisor.


A New Device for Traction of Dilacerated Maxillary Central Incisors

between age 2 and 3.Clinical examination showed a Class I molar

relationship, normal overjet and overbite, a midline deviation, and an unerupted maxillary left central incisor, which was not palpable either palatally or labially. Radiographs indicated a skeletal Class I malocclusion and a normal vertical growth pattern. A dilacerated maxillary left central incisor was positioned horizontally, with the tip of the crown near the apex of the right central incisor. The angle of dilaceration was about 60°; the incisor was rotated counterclockwise in relation to its long axis, with the crown in the usual apical area and the apex in the crown position.

The treatment plan involved extrusion of the dilacerated tooth with all its supporting tissue (alveolar bone and attached gingiva). A multidis-ciplinary approach involving both surgical and orthodontic treatment was implemented.

Procedure

Brackets were bonded to the three maxillary incisors, and space was opened for the misplaced left central incisor. After adequate space had been gained, a flap was raised to expose the surface of the dilacerated crown. A metal mesh attached to a specially fabricated metal chain (Fig. 3) was bonded directly to the exposed tooth surface. This thin metallic mesh can be easily adapted to the shape of the tooth, which minimizes irritation of the gingival tissues and promotes healing.

To simulate natural eruption, the orthodontic traction was first directed anteriorly, parallel to the occlusal plane, using an elastomeric ligature from the metal chain to the vertical arm of the lingual arch. A light force of about 50g was applied. This

anterior movement is designed to preserve the root length of the impacted incisor, avoiding undesir-able and potentially dangerous clockwise rotation of an already damaged root.

Tooth movement and soft-tissue status were monitored every three weeks (Fig. 4). Once the dilacerated tooth was visible clinically, a button was bonded to the facial surface of the crown, and orthodontic traction was redirected vertically by bending the vertical arm of the appliance down-ward (Fig. 5). At this point the anterior occlusal rests were removed from the traction appliance; space for the erupting central incisor was main-tained with an open-coil spring. Generally, the occlusal rests can be carefully removed from the lingual wire using a conventional handpiece, with-out removing the appliance.

The final alignment was completed with a standard twin bracket bonded to the dilacerated

Fig. 4 Position of dilacerated incisor after six weeks of anterior traction.


Giancotti, Mozzicato, and Germano

Fig. 3 Thin metal mesh and specially fabricated chain for bonding to unerupted incisor.

Fig. 5 Button bonded to incisor, replacing metal mesh and chain; traction changed to vertical direction by bending vertical arm downward.

tooth and an .014" nickel titanium overlay wire, while the anterior teeth were stabilized with an .016" × .022" stainless steel archwire (Fig. 6). After 12 months of treatment, fixed appliances were removed and replaced with an upper Essix* retainer (Fig. 7).

Treatment Results

This treatment was successful in achieving a natural position for the maxillary central incisor, despite the root dilaceration. No adverse effects on the maxillary central incisor, including pulp pathology, color change, and mobility, were ob -served at post-treatment examinations. Radiograph-ically, the incisor showed proper root alignment and no apparent soft-tissue disease. The root of the dilacerated incisor continued to mature during the post-treatment phase. Although the hooked apex prevented a thorough evaluation of the apical third of the root, its development appeared normal.

Ten months after debonding, a second phase of orthodontic treatment was started using Invisalign Teen** appliances (Fig. 8). The patient was considered a good candidate for this technique because the permanent dentition had almost com-pletely erupted, and the space for the eruption of the upper left canine was adequate. The damaged front tooth suggested a less invasive approach with

clear aligners rather than conventional fixed appli-ances. Moreover, the “virtual” treatment allows the clinician to plan and visualize the progression of tooth movement with extreme precision, so that any critical movement can be safely performed.

Although the final evaluation of the impact-ed incisor’s gingival tissue was delayed until the end of comprehensive treatment, positive changes can already be observed five months after starting the Invisalign Teen therapy. No periodontal treat-ment was carried out during the whole period, except for oral hygiene recommendations.

Discussion

The maxillary central incisors are the teeth most likely to be impacted, along with the third molars and maxillary canines.1,2 According to Andreasen, defective eruption of the upper central incisors can result from trauma to the primary incisor, presence of a supernumerary tooth, or obstruction of the eruption pathway.3 Other authors also believe dilaceration4 results from early trauma to the deciduous tooth5,6; Stewart attributes it in some cases to ectopic development of the tooth germ.6 Impaction is commonly associated with a severely dilacerated root, especially when the affected tooth is the maxillary incisor.

In adult patients, the most common therapeu-tic approach for a dilaceration is surgical extraction and replacement with a prosthetic implant. In the mixed dentition, the best solution is a multidisci-plinary treatment,6-8 including extraction when required by the severity of the tooth inversion. Some studies show that a dilacerated root with an obtuse angle, a lower position, and incomplete root formation has a better prognosis for treatment with orthodontic traction.5,9-13 Moreover, if a traumatic event occurred before root formation, and the dam-age did not involve the cementum and periodontal membrane, the root can be expected to mature normally.14

The ideal treatment for an impacted tooth directs eruption through the attached gingiva, rather than the alveolar mucosa.7,15,16 This general rule cannot be followed, however, when treating a deeply impacted tooth, because of the distance to



Fig. 6 Bracket bonded to incisor for final align-ment with overlay wire.

*Trademark of Raintree Essix, 6448 Parkland Drive, Sarasota, FL 34243; www.essix.com.

**Trademark of Align Technology, Inc., 881 Martin Ave., Santa Clara, CA 95050; www.aligntech.com.


Giancotti, Mozzicato, and Germano

Fig. 7 Patient after 12 months of treatment.



the crest of the alveolus. In such a case, two surgi-cal steps are needed: the first to expose the impact-ed tooth and the second, at the end of the comprehensive phase of orthodontic treatment, to provide an adequate gingival attachment. An addi-tional concern in cases involving a dilacerated incisor is unfavorable tooth rotation, which can inhibit vertical traction. In this case, the tooth movement should occur in two stages, and precau-tions should be taken to avoid any traction that could damage the already compromised root.

The patient shown here was treated in the mixed dentition, when his root development was incomplete, using a light orthodontic force to allow normal root maturation.14 The results dem-onstrate that open eruption and orthodontic trac-tion using a two-step anchorage device can be an effective treatment for an impacted, dilacerated maxillary incisor.

REFERENCES

1. Chaushu, S.; Zilberman, Y.; and Becker, A.: Maxillary incisor impaction and its relationship to canine displacement, Am. J. Orthod. 124:144-150, 2003.

2. Chaushu, S.; Sharabi, S.; and Becker, A.: Dental morphologic characteristic of normal versus delayed developing dentitions with palatally displaced canines, Am. J. Orthod. 121:339-346, 2002.

3. Andreasen, J.O.; Petersen, J.K.; and Laskin, D.M.: Textbook

and Color Atlas of Tooth Impactions, Munksgaard International Publishers, Copenhagen, 1997, pp. 114-123.

4. Crawford, L.B.: Impacted maxillary central incisor in mixed dentition treatment, Am. J. Orthod. 112:1-7, 1997.

5. Smith, D.M. and Winter, G.B.: Root dilacerations of maxillary incisors, Br. Dent. J. 150:125-127, 1981.

6. Stewart, D.J.: Dilacerate unerupted maxillary central incisors, Br. Dent. J. 145:229-233, 1978.

7. Vermette, M.E.; Kokich, V.G.; and Kennedy, D.B.: Uncovering labially impacted teeth: Apically positioned flap and closed-eruption techniques, Angle Orthod. 65:23-32, 1995.

8. Maspero, C.; Farronato, D.; Alicino, C.; Santoro, G.; and Farronato, G.: Orthodontic surgical treatment on an upper cen-tral dilacerated incisor in an adult patient, Prog. Orthod. 8:314-321, 2007.

9. Kuvvetli, S.S.; Seymen, F.; and Gecay, K.: Management of an unerupted dilacerated maxillary central incisor: A case report, Dent. Traumatol. 23:257-261, 2007.

10. Bishara, S.E.: Treatment of unerupted incisors, Am. J. Orthod. 59:443-447, 1971.

11. De Echave-Krutwig, M. and Sánchez-Fernandez, L.: Impacted incisors with dilacerated roots, J. Clin. Orthod. 36:641-645, 2002.

12. Saldarriaga, J.R. and Patino, M.C.: Ectopic eruption and severe root resorption, Am. J. Orthod. 123:259-265, 2003.

13. Singh, G.P. and Sharma, V.P.: Eruption of an impacted maxil-lary central incisor with an unusual dilaceration, J. Clin. Orthod. 40:353-356, 2006.

14. Korbendau, J.M. and Patti, A.: Clinical Success in Surgical and Orthodontic Treatment of Impacted Teeth, Quintessence, Chicago, 2006.

15. Vanarsdall, R.L. and Corn, H.: Soft-tissue management of labi-ally positioned unerupted teeth, Am. J. Orthod. 72:53-64, 1977.

16. Becker, A.; Brin, I.; Ben-Bassat, Y.; Zilberman, Y.; and Chaushu, S.: Periodontal status following surgical-orthodontic alignment of impacted maxillary incisors by closed-eruption technique, Am. J. Orthod. 122:9-14, 2002.

Fig. 8 Patient after five months of Invisalign Teen therapy.

A 14-year-old female presented with the chief complaint of

irregular upper front teeth and an unesthetic smile (Fig. 1).

Diagnosis

The patient had a pleasant facial profile with competent lips. Intraoral examination indicated a Class I molar relationship on the right side and a half-unit Class II on the left. Both arches showed moderate crowding, with a scissor bite in the right posterior region from first premolar to first molar. The mandibular left lateral inci-

sor was lingually displaced. The maxillary left canine was trans-posed with the lateral incisor, which was also in crossbite; on palpation of the mucobuccal fold of the left maxillary arch, the root of the canine appeared to be next to the root of the central incisor. The maxillary midline was shift-ed to the left. Oral hygiene was good, and the periodontium was healthy.

Radiographs revealed an incomplete transposition, with the root apices of the lateral incisor and canine in normal positions. The transposition extended above

the midroot level. All permanent teeth, including the developing third molars, were present.

Cephalometric analysis showed that the patient was an average grower with a skeletal Class I pattern (Table 1).

Treatment Plan

The following treatment objectives were developed:• Realignment of the transposed max illary canine and lateral incisor.• Correction of the crossbite and scissor bite.


CASE REPORTManagement of a Transposed Maxillary Canine and Lateral Incisor

VINAY K. CHUGH, BDS, MDS, MOrth RCS EDVIJAY P. SHARMA, BDS, MDS PRADEEP TANDON, BDS, MDS GYAN P. SINGH, BDS, MDS

© 2009 JCO, Inc.

Dr. SinghDr. TandonDr. SharmaDr. Chugh

Dr. Chugh is Senior Lecturer, Department of Orthodontics and Dentofacial Orthopedics, Mahatma Gandhi Dental College and Hospital, Jaipur, Rajasthan, India; e-mail: [email protected]. Dr. Sharma is Professor and Head, Dr. Tandon is Professor, and Dr. Singh is Assistant Professor, Faculty of Dental Sciences, CSM Medical University, Department of Orthodontics and Dentofacial Orthopedics, Lucknow, Uttar Pradesh, India.


Management of a Transposed Maxillary Canine and Lateral Incisor


Fig. 1 14-year-old female with transposed maxillary canine and lateral incisor before treatment.

• Achievement of a buccal Class I relationship.• Correction of the midline.• Attainment of a good static, functional occlusion.

Treatment Progress

Treatment was initiated in the maxillary arch using an .022" × .028" standard edgewise appli-ance with welded triple tubes on the molar bands. A transpalatal arch was placed, with a hook sol-dered onto the side opposite the transposition. The left lateral inci-sor was banded, and a lever arm1 made of .028" stainless steel wire was soldered to the band to apply a force passing through the center of resistance2 (Fig. 2).

The maxillary arch was ini-tially leveled with a light, round wire. Class I elastics with a force of 45g each were applied off-center to derotate and translate the maxillary left canine, accord-

ing to the “cue-ball concept” (a force applied on a body, but not through the center of that body, results in translation and rotation3).

Once the canine was slightly derotated, a T-loop fabricated from .017" × .025" TMA* wire was ligated to the canine bracket and inserted into the auxiliary molar tubes (Fig. 3A). The beta


Chugh, Sharma, Tandon, and Singh

TABLE 1CEPHALOMETRIC DATA

Variable Norm Pretreatment Post-Treatment

SNA 82° ± 3° 79.0° 80.0°SNB 79° ± 3° 78.0° 77.0°ANB 3° ± 1° 1.0° 3.0°Wits appraisal 0mm −2.0mm −1.0mmU1-maxillary plane angle 108° ± 5° 112.0° 111.0°L1-mandibular plane angle 92° ± 5° 85.0° 93.0°Interincisal angle 133° ± 10° 141.0° 134.0°Maxillomandibular plane angle 27° ± 5° 23.0° 23.0°Upper anterior facial height 51.0mm 51.0mmLower anterior facial height 67.0mm 68.0mmFacial height ratio 55% ± 2% 56.7% 57.1%L1-APo 0-2mm 2.0mm 2.5mmLower lip-Ricketts E plane −2mm 0.0mm 1.0mmUpper lip-Ricketts E plane −2 to −3mm −2.0mm −1.5mm

Fig. 2 With line of force passing through center of resistance, tooth will translate bodily, even though point of attachment is at bracket.

Fig. 3 A. T-loop ligated for canine retraction. B,C. .018" stainless steel wire with step-out bends and open-coil spring used to cre-ate space.

A

B

C

*Registered trademark of Ormco, 1717 W. Collins Ave., Orange, CA 92867; www.ormco.com.



angulation was increased near the canine to enhance posterior anchorage, and the T-loop was activated 4mm as recommended by Marcotte.4 Intermed iate-pull headgear was worn for 12 hours daily during canine retraction to maintain the Class I occlusion.

At the same time, an elastic chain** was attached from the hook of the lever arm to the hook on the transpalatal arch. About 50g of force was used to move the lateral incisor lingually, thus avoiding any root interference or loss of the canine’s already thin labial cortical plate during retrac-tion (Figs. 2,3C). The elastic chain was changed every three weeks.

Step-out bends were then added to an .018" stainless steel archwire to provide clearance in the canine region. An open-coil spring** was compressed to

simultaneously create space, align the transposed teeth, and correct the maxillary midline, saving treatment time (Fig. 3B,C). This archwire was later replaced with an .018" × .025" stainless steel

wire in the same configuration to maintain arch integrity.

The T-loop was activated every eight to 10 weeks, depend-ing on the root movement of the canine. After the canine had been retracted adjacent to the first pre-molar (Fig. 4), the T-loop was left in place to increase the moment-to-force ratio for effective root movement. Intraoral periapical radiographs were taken periodi-cally to monitor the root move-ment of the canine.

After 13 months of treat-ment, the headgear was discontin-ued. The lever arm was removed from the lateral incisor, and a bracket was bonded to the lingual surface. An .014" copper nickel titanium (CuNiTi*) auxiliary wire was ligated to the lingual bracket to track the lateral incisor labially, with toe-in and tipback bends incorporated into the .019" × .025" stainless steel main arch-wire (Fig. 5A). A mandibular posterior biteplate was added to provide clearance for the cross-bite correction. As the lateral incisor moved labially, a bracket was bonded to the labial surface, and an .016" CuNiTi* wire was ligated labially (Fig. 5B).

Once the maxillary lateral incisor was aligned, the mandibu-lar arch was bonded (Fig. 6). Increasing the intercanine width to resolve 6mm of lower crowding at this patient’s age would have jeopardized the stability of the

Fig. 5 A. Auxiliary wire used to move lateral incisor labially. B. Bracket bonded to labial surface of incisor for final alignment.

Fig. 4 Retraction of canine and lin-gual movement of lateral incisor.

*Registered trademark of Ormco, 1717 W. Collins Ave., Orange, CA 92867; www.ormco.com.

**Ortho Organizers, Inc., 1619 S. Rancho Santa Fe Road, San Mar cos, CA 92069; www.orthoorganizers.com.

A

B

archform.5,6 We therefore decided to extract the left lateral incisor, which had a mesiodistal width of 6mm. This would also simplify the mechanotherapy and minimize adverse effects on the profile.

Because the patient required significant root movement of the maxillary lateral incisor, the roots were torqued labially with an .019" × .025" stainless steel wire and individual torquing pliers. Thurow has advised against using archwires that completely fill the slots for torquing individual teeth.7 We used “incremental torque” to move the roots labially, generat-ing a more comfortable torsional force and reducing the risk of root resorption.

After the mandibular crowd-ing had been resolved (Fig. 7), coordinated maxillary and man-dibular archwires with artistic positioning bends were placed to

correct the mesiodistal angula-tions. Final settling was accom-plished on lighter wires with up-and-down elastics. Toward the end of treatment, the incisal edges of the upper right central and lat-eral incisors were slightly re -shaped to match their counterparts, and mild gingivectomies of the maxillary left and mandibular right lateral incisors were per-formed to normalize the gingival margins.

Fixed appliances were removed after 27 months of treat-ment, and bonded maxillary and mandibular lingual retainers were placed.

Treatment Results

Post-treatment records showed good functional and esthetic results (Fig. 8). Well-interdigitated Class I canine and first molar relationships were obtained, with proper overjet and overbite (Table 1). As expected, the left maxillary lateral incisor root showed mild resorption, but this was limited to the apical third. Both the canine and lateral incisor

maintained their original color and responded normally to vital-ity tests at the end of treatment.

Discussion

Considerable treatment time was spent in rotating, uprighting, and paralleling the roots of the canine and lateral incisor. Only light force was used, and special care was taken to avoid any dam-age to the teeth and supporting structures. The patient was moti-vated and cooperative throughout the treatment period. Although this kind of treatment requires considerably more time than usual, the esthetic and functional results justify the complex mech-anotherapy.

ACKNOWLEDGMENTS: The authors thank Dr. Ankita for assistance in preparation of the manuscript.

REFERENCES

1. Kucher, G.; Weiland, F.J.; and Bantleon, H.P.: Modified lingual lever arm tech-nique, J. Clin. Orthod. 27:18-22, 1993.

2. Smith, R.J. and Burstone, C.J.: Mech -anics of tooth movement, Am. J. Orthod. 85:294-307, 1984.

3. Mulligan, T.: Common Sense Mech-anics: Part 2, J. Clin. Orthod. 13:676-683, 1979.

4. Marcotte, M.R.: Biomechanics in Ortho dontics, B.C. Decker, Toronto, 1990, pp. 127-137.

5. Shapiro, P.A.: Mandibular dental arch form and dimensions, Am. J. Orthod. 66:58-69, 1974.

6. Little, R.M.; Riedel, R.A.; and Bui, T.D.: Mandib ular incisor extraction: Postretention evaluation of stability and relapse, Angle Orthod. 62:103-116, 1992.

7. Thurow, R.C.: Edgewise Orthodontics, C.V. Mosby Company, St. Louis, 1982, p. 171.


Chugh, Sharma, Tandon, and Singh

Fig. 6 Patient after 18 months of treatment.

Fig. 7 Mandibular arch aligned after 22 months of treatment.

(continued on next page)



Fig. 8 A. Patient after 27 months of treatment. B. Superimpositions of pre- and post-treatment cephalomet-ric tracings.

A B


DR. SINCLAIR Would you describe for our readers the source of the unique University of Washington post-retention sample?

DR. LITTLE My teacher, mentor, and good friend Dick Riedel had the idea of recalling his own ABO cases to see how they fared years later. He learned so much that he decided to expand the search to as many of his former patients as he could locate. While chair of the UW Department of Orthodontics, Dick broadened the search to cases treated by our graduate students. Faculty, alumni, and other ortho dontic colleagues contrib-

uted cases from their own practices. The result is about 900 sets of long-term post-retention records, about one-fourth of the cases having been treated by UW graduate students.

DR. SINCLAIR Are there clinical procedures that can improve stability?

DR. LITTLE As I mentioned in last month’s article, space maintenance during the mixed den-tition for cases with enough leeway space to coun-ter the degree of anterior crowding is an excellent way to improve stability for cases that qualify. It is necessary to do an arch-length assessment by measuring erupted and unerupted canines and premolars, using accurate radiographs and casts. If leeway space is favorable, space maintenance can shift a potential extraction case to a nonextrac-tion plan in the permanent dentition without arch development. The success rate is much higher, upwards of 70% success post-retention. For cases with inadequate leeway space for this approach, either extraction or arch enlargement would be considered.

Unfortunately, both extraction and nonex-traction enlargement strategies yield poor success post-retention, with extraction cases faring better than arch-development cases. For improved stabil-ity, routine mandibular arch treatment should focus on not enlarging and not changing the arch shape. Maintaining the original upper and lower incisor angulations or adjusting them to standard norms would be additional goals.

In almost all cases with generalized spacing,

© 2009 JCO, Inc.

JCO INTERVIEWS

Dr. Robert M. Little on the University of Washington Post-Retention Studies

Dr. Little retired as a Professor Emeritus, Department of Orthodontics, University of Washington, Seattle, and continues to teach and lec-ture. E-mail him at [email protected]. Dr. Sinclair is an Associate Editor of the Journal of Clinical Orthodontics and a Professor, Department of Craniofacial Science and Therapeutics, School of Dentistry, University of Southern California, Los Angeles; e-mail: [email protected]. A related article on the University of Washington studies appeared in the October 2009 issue of JCO.

Dr. LittleDr. Sinclair


JCO INTERVIEWS


discontinuing fixed retention after a few years would be fine. For crowded and extracted cases, we can’t predict which cases will fail, so lifetime retention seems prudent. For nonextraction treat-ment of crowded cases, lifetime retention is man-datory, since anything less will predictably fail.

Serial extraction of premolars typically im -proves alignment during the observation phase, with a simpler full-treatment phase to follow. Unfortunately, long-term alignment success is no better than the 30% success rate of premolar extraction cases treated in one phase.

Supracrestal fiberotomy (sulcus slice) is use-ful to reduce the percentage of rotational relapse, but does not eliminate all rotational relapse. Inter-proximal stripping to flatten contacts does not seem to aid stability, nor does reducing incisor width to meet Peck and Peck labiolingual vs. mesio distal dimension standards.1 Stripping eith-er or both arches to meet Bolton tooth-size norms can be warranted to meet overbite/overjet/occlu-sion goals, but this will not necessarily improve the stability of alignment.

Finally, fixed mandibular retention is much preferred over removable retainers to ensure that the retainer is faithfully utilized. Patients need to understand that they are at risk if the fixed retain-er becomes disconnected. The patient should be advised to have it reattached as soon as possible.

DR. SINCLAIR What other retention rules do you suggest clinicians should follow?

DR. LITTLE Always obtain and maintain pre-treatment and end-of-active-treatment records for future review. These will be quite helpful in guid-ing the retention and post-retention phase. Pre-treatment, perform a Bolton tooth-size analysis for every case and record this information in the chart. A patient with significant discrepancy requires a lab wax setup in order to visualize the problems and treatment needed. Obtain cephalometric and panoramic radiographs during treatment to assess progress, growth, and the need for treatment alteration toward the intended goal. Cephalometric superimposition is critical to fully understand treatment progress.

Employ supracrestal fiberotomy for incisor rotations noted before treatment.

Continue to see your patients following treat-ment. This may mean every three to six months for several years, and then yearly thereafter. The retainer status needs to be checked, as do signs of relapse. Be available to counsel your patients.

Facilitate interaction with the patient’s gen-eral dentist, so that the generalist and hygienist do not remove the fixed retainer. Encourage them to send the patient back for repairs. Dialogue with the patient’s dental team of professionals so that all are aware of your goals and concerns.

Advise the use of lower-arch fixed retention rather than removable retention to eliminate com-pliance as an issue. Utilize upper removable retain-ers full-time for a number of months after treat-ment—usually a year in my cases—followed by continued use on a declining scale until some minimum is established, such as once a week for an extended time.

Only proceed from active treatment to reten-tion when the very highest treatment standard attainable has been met. Assume that every case is a future ABO case, and treat to that standard.

DR. SINCLAIR How do you advise retaining deep-bite and open-bite cases?

DR. LITTLE Retention of the deep-overbite case can be a challenge, particularly for the growing patient. I overtreat to about 10% overbite and fol-low with a flat-biteplate removable upper retainer with a circumferential labial/buccal wire. The biteplate is trimmed so that canines and posteriors are in full occlusion, while the lower incisors just make even contact with the biteplate and lingual surfaces of the upper incisors. Six to 12 months of full-time upper retainer wear is recommended, followed by nightly wear.

Retention of open-bite cases in growing individuals is even more of a challenge. Certainly, overtreating to about a 30% or greater overbite is the goal, if it can be attained. Many practitioners, including myself, follow that plan with all sorts of gadgets or spurs added to resist tongue interfer-ence. I recall a number of growing open-bite

Dr. Robert M. Little


patients with a vertical growth direction who ben-efitted from posterior high-pull headgear during treatment and retention.

DR. SINCLAIR Should retention be different for adults vs. children?

DR. LITTLE In my view, the retention strategy should be the same. I am humbled by my inability to predict post-retention changes. I can’t reliably predict the post-retention successful cases or the ones that will fail, whether treated as an adult or a child. My best defense is the highest-quality treatment that I can achieve, followed by lifetime retention.

Adults seem to have a few unique problems, such as slight space reopening in extraction sites. This may be due to non-parallel roots of teeth adjacent to the extraction sites; it can also be due to excessively rapid space closure. Cases with inflamed gingivae seem to also have this problem. Improved oral hygiene, such as the use of a water-irrigation device during treatment, and other perio-dontal strategies should be considered. In some cases, the reason for space reopening may be unclear. My strategy for the case with parallel roots, but space tending to reopen during retention, is to reclose the space and bond a buccal wire to the teeth adjacent to the space, with that wire removed six months later.

DR. SINCLAIR Is there a relapse risk profile that might help us identify patients at the highest and lowest risk of relapse?

DR. LITTLE A patient who has adequate or excess arch length in the mixed or permanent dentition is in the low-risk category. Those with inadequate arch length and crowding before treatment are in the high-risk category, no matter what the treat-ment. Those crowded cases treated with arch enlargement in the mixed or permanent dentition are in the very high-risk category. Mixed dentition arch development routinely fails if the lower retain-er is removed. Permanent dentition arch develop-ment is also a very high-risk strategy. Lifetime fixed retention is mandatory for such cases.

When comparing our best and worst UW

post-retention cases treated in the permanent den-tition, several items stood out as risk factors: pre-treatment high PAR score, pretreatment crowding, active post-treatment growth, males, and Class II malocclusion.

DR. SINCLAIR When is extraction treatment a more stable choice than nonextraction therapy?

DR. LITTLE Nonextraction arch development in crowded cases almost guarantees instability. Ex -traction of first premolars in crowded cases gives variable results, about 30% having success 10 years post-retention. Second premolar extraction yields similar results. Serial extraction can make the case easier to treat, but stability is no better than in cases that are extracted and treated in the full permanent dentition.

For the unique, very crowded case where tooth size permits extraction of either one or two lower incisors rather than premolars, the post-retention scores are much improved (Figs. 1,2). In fact, incisor extraction cases as a group were far better than crowded and premolar-extracted cases and approached the long-term quality level of spaced or adequate-arch-length cases.

DR. SINCLAIR What about the Damon approach to treatment?

DR. LITTLE Dwight Damon and I were class-mates in the University of Washington orthodontic class of 1970. Nonextraction enlargement of arch-es for crowded cases was as far from the philoso-phy of that time as one could imagine, our school being a Tweed-influenced faculty. If a case was crowded, extraction of premolars was the standard plan. Enlargement of the crowded arch was reluc-tantly used for the occasional case where there was a concern about facial profile.

We have looked at the degree of arch-width and arch-length enlargement shown on plaster casts in Damon-philosophy-treated crowded cases, as well as cephalometric changes during treatment, such as flaring of anteriors to achieve alignment. The amount of arch-width and -length enlargement and flaring of anteriors was impressive in many cases, but what about stability? All of the cases

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had permanent retention in both arches, so we were unable to test for stability vs. relapse. Hopefully, we can eventually accumulate cases with post-retention records. My prediction would be severe relapse if the lower retainer is removed or lost.

I’d also like to study long-term records for those Damon cases with long retention times, searching for iatrogenic effects. I noted a few Damon cases anecdotally over the years that had labial and/or buccal gingival dehiscence of some anterior and posterior teeth, a particular concern that needs more study. We have not seen nearly as many problems of this type in cases where there was not arch enlargement.

DR. SINCLAIR Some say, “Little shows that all orthodontic treatment fails.” So why bother trying to achieve high-quality results?

DR. LITTLE Our work shows how cases post-retention are susceptible to the ravages of normal physiology and aging. My message is that we

should strive for the highest-quality result for every patient in order to achieve the best in health, func-tion, and esthetics. And once achieved, we need to freeze the correction with lifetime retention. What could be better than that?

One of our studies pointed out that the high-est-quality treated cases, as measured by ABO standards, showed varying degrees of deterioration once retainers were removed. To me, this does not justify a lesser-quality result. Rather, it shows that even the best treatment needs the crutch of fixed retention to preserve the superior result. I advise to aim high and maintain that correction. Our patients expect and deserve our best efforts not just for a few years, but for their lifetime.

In addition to our studies, I’ve gained much from my orthodontic colleagues during casual conversations at meetings and conferences on the topic of stability and relapse. We need to be con-stant students of this topic. I’d recommend that we all maintain pretreatment and end-of-treatment records of every patient and then strive to get every

Fig. 1 A. 29-year-old patient before treatment. B. After 28 months of active treatment, with one incisor extracted. C. Good alignment 10 years after retention (age 42).

A B C

Dr. Robert M. Little


one of them back for their benefit and our contin-ued learning.

DR. SINCLAIR Now that you are “retired”, are you still busy in professional orthodontics?

DR. LITTLE I continue to enjoy the occasional orthodontic lecture trip. Particularly noteworthy were invitations to New Zealand, Switzerland, Germany, and Sweden, each an outstanding adven-ture inside and outside the lecture hall. I’ve gained much from interactions with colleagues while pre-senting at about 130 lecture trips all over the world. Combined with vacations to explore the local areas, these trips have been truly wonderful.

I continue to enjoy developing teaching mod-ules. My friend and colleague Mike Fey and I did a CD on cephalometric superimposition for ABO applicants. This module has also been incorpo-rated into several graduate orthodontic programs. I’ve also done a series of modules on cephalomet-rics for Rebecca Poling’s outstanding educational

program, the International Training Institute.*One recent offbeat teaching book plus CD

plus web format was quite a challenge, but fun. For a local firm called American Tug that made my own pleasure boat, I spent a year developing 12 chapters called “Tug Training and Tactics”. New boat owners get a copy before their first voyage from the dock. I must say that teaching has always been and continues to be my hobby.

DR. SINCLAIR Thank you for sharing your insights on the stability of orthodontic treatment with our readers.

REFERENCES

1. Peck, S. and Peck, H.: An index for assessing tooth shape deviations as applied to the mandibular incisors, Am. J. Orthod. 61:384-401, 1972.

Fig. 2 A. 14-year-old patient with one missing incisor before treatment. B. After 23 months of active treat-ment, with second incisor extracted. C. Good alignment 10 years after retention (age 30).

A B C

*International Training Institute, 1000 O’Malley Road, Suite 104, Anchorage, AK 99515; www.intltraining.com.

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